Use AutoCloseable for structs named Locked*
[ldk-java] / genbindings.py
index be317e8f455d3eca87b728134ac0b0f0b26dd99e..f4086f56adc1aad997c9d02b8673efe2aba90717 100755 (executable)
@@ -2,12 +2,12 @@
 import sys, re
 
 if len(sys.argv) != 6:
-    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/enums/ /path/to/bindings/output.c debug")
+    print("USAGE: /path/to/lightning.h /path/to/bindings/output.java /path/to/bindings/ /path/to/bindings/output.c debug")
     print("debug should be true or false and indicates whether to track allocations and ensure we don't leak")
     sys.exit(1)
 
 class TypeInfo:
-    def __init__(self, rust_obj, java_ty, java_fn_ty_arg, c_ty, passed_as_ptr, is_ptr, var_name, arr_len):
+    def __init__(self, rust_obj, java_ty, java_fn_ty_arg, c_ty, passed_as_ptr, is_ptr, var_name, arr_len, arr_access):
         self.rust_obj = rust_obj
         self.java_ty = java_ty
         self.java_fn_ty_arg = java_fn_ty_arg
@@ -16,18 +16,22 @@ class TypeInfo:
         self.is_ptr = is_ptr
         self.var_name = var_name
         self.arr_len = arr_len
+        self.arr_access = arr_access
 
 class ConvInfo:
-    def __init__(self, ty_info, arg_name, arg_conv, arg_conv_name, ret_conv, ret_conv_name):
+    def __init__(self, ty_info, arg_name, arg_conv, arg_conv_name, arg_conv_cleanup, ret_conv, ret_conv_name):
         assert(ty_info.c_ty is not None)
         assert(ty_info.java_ty is not None)
         assert(arg_name is not None)
+        self.passed_as_ptr = ty_info.passed_as_ptr
+        self.rust_obj = ty_info.rust_obj
         self.c_ty = ty_info.c_ty
         self.java_ty = ty_info.java_ty
         self.java_fn_ty_arg = ty_info.java_fn_ty_arg
         self.arg_name = arg_name
         self.arg_conv = arg_conv
         self.arg_conv_name = arg_conv_name
+        self.arg_conv_cleanup = arg_conv_cleanup
         self.ret_conv = ret_conv
         self.ret_conv_name = ret_conv_name
 
@@ -43,124 +47,184 @@ class ConvInfo:
             out_java.write(" arg")
             out_c.write(" arg")
 
-with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[4], "w") as out_c:
-    opaque_structs = set()
-    trait_structs = set()
-    unitary_enums = set()
-
-    def camel_to_snake(s):
-        # Convert camel case to snake case, in a way that appears to match cbindgen
-        con = "_"
-        ret = ""
-        lastchar = ""
-        lastund = False
-        for char in s:
-            if lastchar.isupper():
-                if not char.isupper() and not lastund:
-                    ret = ret + "_"
-                    lastund = True
-                else:
-                    lastund = False
-                ret = ret + lastchar.lower()
+def camel_to_snake(s):
+    # Convert camel case to snake case, in a way that appears to match cbindgen
+    con = "_"
+    ret = ""
+    lastchar = ""
+    lastund = False
+    for char in s:
+        if lastchar.isupper():
+            if not char.isupper() and not lastund:
+                ret = ret + "_"
+                lastund = True
             else:
-                ret = ret + lastchar
-                if char.isupper() and not lastund:
-                    ret = ret + "_"
-                    lastund = True
-                else:
-                    lastund = False
-            lastchar = char
-            if char.isnumeric():
+                lastund = False
+            ret = ret + lastchar.lower()
+        else:
+            ret = ret + lastchar
+            if char.isupper() and not lastund:
+                ret = ret + "_"
                 lastund = True
-        return (ret + lastchar.lower()).strip("_")
-
-    var_is_arr_regex = re.compile("\(\*([A-za-z_]*)\)\[([0-9]*)\]")
-    var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
-    def java_c_types(fn_arg, ret_arr_len):
-        fn_arg = fn_arg.strip()
-        if fn_arg.startswith("MUST_USE_RES "):
-            fn_arg = fn_arg[13:]
-        is_const = False
-        if fn_arg.startswith("const "):
-            fn_arg = fn_arg[6:]
-            is_const = True
-
-        is_ptr = False
-        take_by_ptr = False
-        rust_obj = None
-        if fn_arg.startswith("void"):
-            java_ty = "void"
-            c_ty = "void"
-            fn_ty_arg = "V"
-            fn_arg = fn_arg[4:].strip()
-        elif fn_arg.startswith("bool"):
-            java_ty = "boolean"
-            c_ty = "jboolean"
-            fn_ty_arg = "Z"
-            fn_arg = fn_arg[4:].strip()
-        elif fn_arg.startswith("uint8_t"):
-            java_ty = "byte"
-            c_ty = "jbyte"
-            fn_ty_arg = "B"
-            fn_arg = fn_arg[7:].strip()
-        elif fn_arg.startswith("uint16_t"):
-            java_ty = "short"
-            c_ty = "jshort"
-            fn_ty_arg = "S"
-            fn_arg = fn_arg[8:].strip()
-        elif fn_arg.startswith("uint32_t"):
-            java_ty = "int"
-            c_ty = "jint"
-            fn_ty_arg = "I"
+            else:
+                lastund = False
+        lastchar = char
+        if char.isnumeric():
+            lastund = True
+    return (ret + lastchar.lower()).strip("_")
+
+unitary_enums = set()
+var_is_arr_regex = re.compile("\(\*([A-za-z0-9_]*)\)\[([a-z0-9]*)\]")
+var_ty_regex = re.compile("([A-za-z_0-9]*)(.*)")
+def java_c_types(fn_arg, ret_arr_len):
+    fn_arg = fn_arg.strip()
+    if fn_arg.startswith("MUST_USE_RES "):
+        fn_arg = fn_arg[13:]
+    is_const = False
+    if fn_arg.startswith("const "):
+        fn_arg = fn_arg[6:]
+        is_const = True
+
+    is_ptr = False
+    take_by_ptr = False
+    rust_obj = None
+    arr_access = None
+    if fn_arg.startswith("LDKThirtyTwoBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[18:] + ")[32]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKThirtyTwoBytes"
+        arr_access = "data"
+    if fn_arg.startswith("LDKPublicKey"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[33]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKPublicKey"
+        arr_access = "compressed_form"
+    if fn_arg.startswith("LDKSecretKey"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[32]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKSecretKey"
+        arr_access = "bytes"
+    if fn_arg.startswith("LDKSignature"):
+        fn_arg = "uint8_t (*" + fn_arg[13:] + ")[64]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKSignature"
+        arr_access = "compact_form"
+    if fn_arg.startswith("LDKThreeBytes"):
+        fn_arg = "uint8_t (*" + fn_arg[14:] + ")[3]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKThreeBytes"
+        arr_access = "data"
+    if fn_arg.startswith("LDKu8slice"):
+        fn_arg = "uint8_t (*" + fn_arg[11:] + ")[datalen]"
+        assert var_is_arr_regex.match(fn_arg[8:])
+        rust_obj = "LDKu8slice"
+        arr_access = "data"
+
+    if fn_arg.startswith("void"):
+        java_ty = "void"
+        c_ty = "void"
+        fn_ty_arg = "V"
+        fn_arg = fn_arg[4:].strip()
+    elif fn_arg.startswith("bool"):
+        java_ty = "boolean"
+        c_ty = "jboolean"
+        fn_ty_arg = "Z"
+        fn_arg = fn_arg[4:].strip()
+    elif fn_arg.startswith("uint8_t"):
+        java_ty = "byte"
+        c_ty = "jbyte"
+        fn_ty_arg = "B"
+        fn_arg = fn_arg[7:].strip()
+    elif fn_arg.startswith("uint16_t"):
+        java_ty = "short"
+        c_ty = "jshort"
+        fn_ty_arg = "S"
+        fn_arg = fn_arg[8:].strip()
+    elif fn_arg.startswith("uint32_t"):
+        java_ty = "int"
+        c_ty = "jint"
+        fn_ty_arg = "I"
+        fn_arg = fn_arg[8:].strip()
+    elif fn_arg.startswith("uint64_t") or fn_arg.startswith("uintptr_t"):
+        java_ty = "long"
+        c_ty = "jlong"
+        fn_ty_arg = "J"
+        if fn_arg.startswith("uint64_t"):
             fn_arg = fn_arg[8:].strip()
-        elif fn_arg.startswith("uint64_t") or fn_arg.startswith("uintptr_t"):
+        else:
+            fn_arg = fn_arg[9:].strip()
+    elif is_const and fn_arg.startswith("char *"):
+        java_ty = "String"
+        c_ty = "const char*"
+        fn_ty_arg = "Ljava/lang/String;"
+        fn_arg = fn_arg[6:].strip()
+    else:
+        ma = var_ty_regex.match(fn_arg)
+        if ma.group(1).strip() in unitary_enums:
+            java_ty = ma.group(1).strip()
+            c_ty = "jclass"
+            fn_ty_arg = "Lorg/ldk/enums/" + ma.group(1).strip() + ";"
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+        else:
             java_ty = "long"
             c_ty = "jlong"
             fn_ty_arg = "J"
-            if fn_arg.startswith("uint64_t"):
-                fn_arg = fn_arg[8:].strip()
-            else:
-                fn_arg = fn_arg[9:].strip()
-        elif is_const and fn_arg.startswith("char *"):
-            java_ty = "String"
-            c_ty = "const char*"
-            fn_ty_arg = "Ljava/lang/String;"
-            fn_arg = fn_arg[6:].strip()
-        else:
-            ma = var_ty_regex.match(fn_arg)
-            if ma.group(1).strip() in unitary_enums:
-                java_ty = ma.group(1).strip()
-                c_ty = "jclass"
-                fn_ty_arg = "Lorg/ldk/enums/" + ma.group(1).strip() + ";"
-                fn_arg = ma.group(2).strip()
-                rust_obj = ma.group(1).strip()
-                take_by_ptr = True
+            fn_arg = ma.group(2).strip()
+            rust_obj = ma.group(1).strip()
+            take_by_ptr = True
+
+    if fn_arg.startswith(" *") or fn_arg.startswith("*"):
+        fn_arg = fn_arg.replace("*", "").strip()
+        is_ptr = True
+        c_ty = "jlong"
+        java_ty = "long"
+        fn_ty_arg = "J"
+
+    var_is_arr = var_is_arr_regex.match(fn_arg)
+    if var_is_arr is not None or ret_arr_len is not None:
+        assert(not take_by_ptr)
+        assert(not is_ptr)
+        java_ty = java_ty + "[]"
+        c_ty = c_ty + "Array"
+        if var_is_arr is not None:
+            if var_is_arr.group(1) == "":
+                return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                    passed_as_ptr=False, is_ptr=False, var_name="arg", arr_len=var_is_arr.group(2), arr_access=arr_access)
+            return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
+                passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2), arr_access=arr_access)
+    return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
+        is_ptr=is_ptr, var_name=fn_arg, arr_len=None, arr_access=None)
+
+
+
+fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
+fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
+reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
+clone_fns = set()
+constructor_fns = {}
+with open(sys.argv[1]) as in_h:
+    for line in in_h:
+        reg_fn = reg_fn_regex.match(line)
+        if reg_fn is not None:
+            if reg_fn.group(2).endswith("_clone"):
+                clone_fns.add(reg_fn.group(2))
             else:
-                java_ty = "long"
-                c_ty = "jlong"
-                fn_ty_arg = "J"
-                fn_arg = ma.group(2).strip()
-                rust_obj = ma.group(1).strip()
-                take_by_ptr = True
-
-        if fn_arg.startswith(" *") or fn_arg.startswith("*"):
-            fn_arg = fn_arg.replace("*", "").strip()
-            is_ptr = True
-            c_ty = "jlong"
-            java_ty = "long"
-            fn_ty_arg = "J"
+                rty = java_c_types(reg_fn.group(1), None)
+                if rty.rust_obj is not None and reg_fn.group(2) == rty.rust_obj.replace("LDK", "") + "_new":
+                    constructor_fns[rty.rust_obj] = reg_fn.group(3)
+            continue
+        arr_fn = fn_ret_arr_regex.match(line)
+        if arr_fn is not None:
+            if arr_fn.group(2).endswith("_clone"):
+                clone_fns.add(arr_fn.group(2))
+            # No object constructors return arrays, as then they wouldn't be an object constructor
+            continue
 
-        var_is_arr = var_is_arr_regex.match(fn_arg)
-        if var_is_arr is not None or ret_arr_len is not None:
-            assert(not take_by_ptr)
-            assert(not is_ptr)
-            java_ty = java_ty + "[]"
-            c_ty = c_ty + "Array"
-            if var_is_arr is not None:
-                return TypeInfo(rust_obj=None, java_ty=java_ty, java_fn_ty_arg="[" + fn_ty_arg, c_ty=c_ty,
-                    passed_as_ptr=False, is_ptr=False, var_name=var_is_arr.group(1), arr_len=var_is_arr.group(2))
-        return TypeInfo(rust_obj=rust_obj, java_ty=java_ty, java_fn_ty_arg=fn_ty_arg, c_ty=c_ty, passed_as_ptr=is_ptr or take_by_ptr,
-            is_ptr=is_ptr, var_name=fn_arg, arr_len=None)
+with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.argv[4], "w") as out_c:
+    opaque_structs = set()
+    trait_structs = set()
 
     def map_type(fn_arg, print_void, ret_arr_len, is_free):
         ty_info = java_c_types(fn_arg, ret_arr_len)
@@ -168,7 +232,8 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         if ty_info.c_ty == "void":
             if not print_void:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = None, ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
+                    ret_conv = None, ret_conv_name = None)
 
         if ty_info.c_ty.endswith("Array"):
             arr_len = ty_info.arr_len
@@ -178,26 +243,65 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                 arr_name = "ret"
                 arr_len = ret_arr_len
             assert(ty_info.c_ty == "jbyteArray")
+            ret_conv = ("jbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" + "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", ", "")
+            arg_conv_cleanup = None
+            if not arr_len.isdigit():
+                arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
+                arg_conv = arg_conv + arr_name + "_ref." + ty_info.arr_access + " = (*_env)->GetByteArrayElements (_env, " + arr_name + ", NULL);\n"
+                arg_conv = arg_conv + arr_name + "_ref." + arr_len + " = (*_env)->GetArrayLength (_env, " + arr_name + ");"
+                arg_conv_cleanup = "(*_env)->ReleaseByteArrayElements(_env, " + arr_name + ", (int8_t*)" + arr_name + "_ref." + ty_info.arr_access + ", 0);"
+                arr_access = "." + ty_info.arr_access
+                ret_conv = (ty_info.rust_obj + " " + arr_name + "_var = ", "")
+                ret_conv = (ret_conv[0], ";\njbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_name + "_var." + arr_len + ");\n")
+                ret_conv = (ret_conv[0], ret_conv[1] + "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_name + "_var." + arr_len + ", " + arr_name + "_var." + ty_info.arr_access + ");")
+            elif ty_info.rust_obj is not None:
+                arg_conv = ty_info.rust_obj + " " + arr_name + "_ref;\n"
+                arg_conv = arg_conv + "CHECK((*_env)->GetArrayLength (_env, " + arr_name + ") == " + arr_len + ");\n"
+                arg_conv = arg_conv + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_ref." + ty_info.arr_access + ");"
+                ret_conv = (ret_conv[0], "." + ty_info.arr_access + ");")
+            else:
+                arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n"
+                arg_conv = arg_conv + "CHECK((*_env)->GetArrayLength (_env, " + arr_name + ") == " + arr_len + ");\n"
+                arg_conv = arg_conv + "(*_env)->GetByteArrayRegion (_env, " + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" + "unsigned char (*" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;"
+                ret_conv = (ret_conv[0] + "*", ");")
             return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                arg_conv = "unsigned char " + arr_name + "_arr[" + arr_len + "];\n" +
-                    "(*_env)->GetByteArrayRegion (_env, """ + arr_name + ", 0, " + arr_len + ", " + arr_name + "_arr);\n" +
-                    "unsigned char (*""" + arr_name + "_ref)[" + arr_len + "] = &" + arr_name + "_arr;",
-                arg_conv_name = arr_name + "_ref",
-                ret_conv = ("jbyteArray " + arr_name + "_arr = (*_env)->NewByteArray(_env, " + arr_len + ");\n" +
-                    "(*_env)->SetByteArrayRegion(_env, " + arr_name + "_arr, 0, " + arr_len + ", *",
-                    ");"),
-                ret_conv_name = arr_name + "_arr")
+                arg_conv = arg_conv, arg_conv_name = arr_name + "_ref", arg_conv_cleanup = arg_conv_cleanup,
+                ret_conv = ret_conv, ret_conv_name = arr_name + "_arr")
         elif ty_info.var_name != "":
             # If we have a parameter name, print it (noting that it may indicate its a pointer)
             if ty_info.rust_obj is not None:
                 assert(ty_info.passed_as_ptr)
+                opaque_arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv;\n"
+                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.inner = (void*)(" + ty_info.var_name + " & (~1));\n"
+                opaque_arg_conv = opaque_arg_conv + ty_info.var_name + "_conv.is_owned = (" + ty_info.var_name + " & 1) || (" + ty_info.var_name + " == 0);"
+                if not ty_info.is_ptr and not is_free:
+                    if (ty_info.rust_obj.replace("LDK", "") + "_clone") in clone_fns:
+                        # TODO: This is a bit too naive, even with the checks above, we really need to know if rust wants a ref or not, not just if its pass as a ptr.
+                        opaque_arg_conv = opaque_arg_conv + "\nif (" + ty_info.var_name + "_conv.inner != NULL)\n"
+                        opaque_arg_conv = opaque_arg_conv + "\t" + ty_info.var_name + "_conv = " + ty_info.rust_obj.replace("LDK", "") + "_clone(&" + ty_info.var_name + "_conv);"
+                    elif ty_info.passed_as_ptr:
+                        opaque_arg_conv = opaque_arg_conv + "\n// Warning: we may need a move here but can't clone!"
                 if not ty_info.is_ptr:
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
                             arg_conv_name = ty_info.var_name + "_conv",
+                            arg_conv_cleanup = None,
                             ret_conv = ("jclass " + ty_info.var_name + "_conv = " + ty_info.rust_obj + "_to_java(_env, ", ");"),
                             ret_conv_name = ty_info.var_name + "_conv")
+                    if ty_info.rust_obj in opaque_structs:
+                        ret_conv_suf = ";\nCHECK((((long)" + ty_info.var_name + "_var.inner) & 1) == 0); // We rely on a free low bit, malloc guarantees this.\n"
+                        ret_conv_suf = ret_conv_suf + "CHECK((((long)&" + ty_info.var_name + "_var) & 1) == 0); // We rely on a free low bit, pointer alignment guarantees this.\n"
+                        ret_conv_suf = ret_conv_suf + "long " + ty_info.var_name + "_ref;\n"
+                        ret_conv_suf = ret_conv_suf + "if (" + ty_info.var_name + "_var.is_owned) {\n"
+                        ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)" + ty_info.var_name + "_var.inner | 1;\n"
+                        ret_conv_suf = ret_conv_suf + "} else {\n"
+                        ret_conv_suf = ret_conv_suf + "\t" + ty_info.var_name + "_ref = (long)&" + ty_info.var_name + "_var;\n"
+                        ret_conv_suf = ret_conv_suf + "}"
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = opaque_arg_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = (ty_info.rust_obj + " " + ty_info.var_name + "_var = ", ret_conv_suf),
+                            ret_conv_name = ty_info.var_name + "_ref")
                     base_conv = ty_info.rust_obj + " " + ty_info.var_name + "_conv = *(" + ty_info.rust_obj + "*)" + ty_info.var_name + ";";
                     if ty_info.rust_obj in trait_structs:
                         if not is_free:
@@ -207,49 +311,47 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         else:
                             base_conv = base_conv + "\n" + "FREE((void*)" + ty_info.var_name + ");"
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                            arg_conv = base_conv,
-                            arg_conv_name = ty_info.var_name + "_conv",
+                            arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                             ret_conv = ("CANT PASS TRAIT TO Java?", ""), ret_conv_name = "NO CONV POSSIBLE")
                     if ty_info.rust_obj != "LDKu8slice":
-                        # Don't bother free'ing slices passed in - we often pass them Rust -> Rust
+                        # Don't bother free'ing slices passed in - Rust doesn't auto-free the
+                        # underlying unlike Vecs, and it gives Java more freedom.
                         base_conv = base_conv + "\nFREE((void*)" + ty_info.var_name + ");";
-                    if ty_info.rust_obj in opaque_structs:
-                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                            arg_conv = base_conv + "\n" + ty_info.var_name + "_conv.is_owned = true;",
-                            arg_conv_name = ty_info.var_name + "_conv",
-                            ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref")
-
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                        arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv",
+                        arg_conv = base_conv, arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = ("long " + ty_info.var_name + "_ref = (long)&", ";"), ret_conv_name = ty_info.var_name + "_ref")
                 else:
                     assert(not is_free)
+                    if ty_info.rust_obj in opaque_structs:
+                        return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
+                            arg_conv = opaque_arg_conv, arg_conv_name = "&" + ty_info.var_name + "_conv", arg_conv_cleanup = None,
+                            ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         arg_conv = ty_info.rust_obj + "* " + ty_info.var_name + "_conv = (" + ty_info.rust_obj + "*)" + ty_info.var_name + ";",
-                        arg_conv_name = ty_info.var_name + "_conv",
+                        arg_conv_name = ty_info.var_name + "_conv", arg_conv_cleanup = None,
                         ret_conv = None, ret_conv_name = None) # its a pointer, no conv needed
             elif ty_info.is_ptr:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = ty_info.var_name, ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None, ret_conv = None, ret_conv_name = None)
             elif ty_info.java_ty == "String":
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = None,
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None,
                     ret_conv = ("jstring " + ty_info.var_name + "_conv = (*_env)->NewStringUTF(_env, ", ");"), ret_conv_name = ty_info.var_name + "_conv")
             else:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = ty_info.var_name, ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = ty_info.var_name, arg_conv_cleanup = None, ret_conv = None, ret_conv_name = None)
         elif not print_void:
             # We don't have a parameter name, and want one, just call it arg
             if ty_info.rust_obj is not None:
                 assert(not is_free or ty_info.rust_obj not in opaque_structs);
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                     arg_conv = ty_info.rust_obj + " arg_conv = *(" + ty_info.rust_obj + "*)arg;\nFREE((void*)arg);",
-                    arg_conv_name = "arg_conv",
+                    arg_conv_name = "arg_conv", arg_conv_cleanup = None,
                     ret_conv = None, ret_conv_name = None)
             else:
                 assert(not is_free)
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = "arg", ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = "arg", arg_conv_cleanup = None, ret_conv = None, ret_conv_name = None)
         else:
             # We don't have a parameter name, and don't want one (cause we're returning)
             if ty_info.rust_obj is not None:
@@ -257,7 +359,7 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                     if ty_info.rust_obj in unitary_enums:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             arg_conv = ty_info.rust_obj + " ret = " + ty_info.rust_obj + "_from_java(_env, " + ty_info.var_name + ");",
-                            arg_conv_name = "ret",
+                            arg_conv_name = "ret", arg_conv_cleanup = None,
                             ret_conv = ("jclass ret = " + ty_info.rust_obj + "_to_java(_env, ", ");"), ret_conv_name = "ret")
                     if ty_info.rust_obj in opaque_structs:
                         # If we're returning a newly-allocated struct, we don't want Rust to ever
@@ -265,29 +367,33 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
                         # any _free function.
                         # To avoid any issues, we first assert that the incoming object is non-ref.
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                            ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";\nDO_ASSERT(ret->is_owned);\nret->is_owned = false;"),
-                            ret_conv_name = "(long)ret",
-                            arg_conv = None, arg_conv_name = None)
+                            ret_conv = (ty_info.rust_obj + " ret = ", ";"),
+                            ret_conv_name = "((long)ret.inner) | (ret.is_owned ? 1 : 0)",
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None)
                     else:
                         return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                             ret_conv = (ty_info.rust_obj + "* ret = MALLOC(sizeof(" + ty_info.rust_obj + "), \"" + ty_info.rust_obj + "\");\n*ret = ", ";"),
                             ret_conv_name = "(long)ret",
-                            arg_conv = None, arg_conv_name = None)
+                            arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None)
                 else:
                     return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
                         ret_conv = ("long ret = (long)", ";"), ret_conv_name = "ret",
-                        arg_conv = None, arg_conv_name = None)
+                        arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None)
             else:
                 return ConvInfo(ty_info = ty_info, arg_name = ty_info.var_name,
-                    arg_conv = None, arg_conv_name = None, ret_conv = None, ret_conv_name = None)
+                    arg_conv = None, arg_conv_name = None, arg_conv_cleanup = None, ret_conv = None, ret_conv_name = None)
 
     def map_fn(line, re_match, ret_arr_len, c_call_string):
         out_java.write("\t// " + line)
         out_java.write("\tpublic static native ")
         out_c.write("JNIEXPORT ")
 
+        is_free = re_match.group(2).endswith("_free")
+        struct_meth = re_match.group(2).split("_")[0]
+
         ret_info = map_type(re_match.group(1), True, ret_arr_len, False)
         ret_info.print_ty()
+
         if ret_info.ret_conv is not None:
             ret_conv_pfx, ret_conv_sfx = ret_info.ret_conv
 
@@ -295,28 +401,93 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write(" JNICALL Java_org_ldk_impl_bindings_" + re_match.group(2).replace('_', '_1') + "(JNIEnv * _env, jclass _b")
 
         arg_names = []
+        default_constructor_args = {}
+        takes_self = False
+        args_known = not ret_info.passed_as_ptr or ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs
         for idx, arg in enumerate(re_match.group(3).split(',')):
             if idx != 0:
                 out_java.write(", ")
             if arg != "void":
                 out_c.write(", ")
-            arg_conv_info = map_type(arg, False, None, re_match.group(2).endswith("_free"))
+            arg_conv_info = map_type(arg, False, None, is_free)
             if arg_conv_info.c_ty != "void":
                 arg_conv_info.print_ty()
                 arg_conv_info.print_name()
+            if arg_conv_info.arg_name == "this_arg":
+                takes_self = True
+            if arg_conv_info.passed_as_ptr and not arg_conv_info.rust_obj in opaque_structs:
+                if not arg_conv_info.rust_obj in trait_structs and not arg_conv_info.rust_obj in unitary_enums:
+                    args_known = False
+            if arg_conv_info.arg_conv is not None and "Warning" in arg_conv_info.arg_conv:
+                if arg_conv_info.rust_obj in constructor_fns:
+                    assert not is_free
+                    for explode_arg in constructor_fns[arg_conv_info.rust_obj].split(','):
+                        explode_arg_conv = map_type(explode_arg, False, None, False)
+                        if explode_arg_conv.c_ty == "void":
+                            # We actually want to handle this case, but for now its only used in NetGraphMsgHandler::new()
+                            # which ends up resulting in a redundant constructor - both without arguments for the NetworkGraph.
+                            args_known = False
+                        assert explode_arg_conv.arg_name != "this_arg"
+                        if explode_arg_conv.passed_as_ptr and not explode_arg_conv.rust_obj in trait_structs:
+                            args_known = False
+                        if not arg_conv_info.arg_name in default_constructor_args:
+                            default_constructor_args[arg_conv_info.arg_name] = []
+                        default_constructor_args[arg_conv_info.arg_name].append(explode_arg_conv)
+                else:
+                    args_known = False
             arg_names.append(arg_conv_info)
 
+        out_java_struct = None
+        if ("LDK" + struct_meth in opaque_structs or "LDK" + struct_meth in trait_structs) and not is_free:
+            out_java_struct = open(sys.argv[3] + "/structs/" + struct_meth + ".java", "a")
+            if not args_known:
+                out_java_struct.write("\t// Skipped " + re_match.group(2) + "\n")
+                out_java_struct.close()
+                out_java_struct = None
+            else:
+                out_java_struct.write("\tpublic ")
+                meth_n = re_match.group(2)[len(struct_meth) + 1:]
+                if ret_info.rust_obj == "LDK" + struct_meth:
+                    out_java_struct.write(struct_meth + "(")
+                elif ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs:
+                    out_java_struct.write(ret_info.rust_obj.replace("LDK", "") + " " + meth_n + "(")
+                else:
+                    out_java_struct.write(ret_info.java_ty + " " + meth_n + "(")
+                for idx, arg in enumerate(arg_names):
+                    if idx != 0:
+                        if not takes_self or idx > 1:
+                            out_java_struct.write(", ")
+                    if arg.java_ty != "void" and arg.arg_name != "this_arg":
+                        if arg.arg_name in default_constructor_args:
+                            for explode_idx, explode_arg in enumerate(default_constructor_args[arg.arg_name]):
+                                if explode_idx != 0:
+                                    out_java_struct.write(", ")
+                                assert explode_arg.rust_obj in opaque_structs or explode_arg.rust_obj in trait_structs
+                                out_java_struct.write(explode_arg.rust_obj.replace("LDK", "") + " " + arg.arg_name + "_" + explode_arg.arg_name)
+                        elif arg.passed_as_ptr:
+                            if arg.rust_obj in opaque_structs or arg.rust_obj in trait_structs:
+                                out_java_struct.write(arg.rust_obj.replace("LDK", "") + " " + arg.arg_name)
+                            else:
+                                out_java_struct.write(arg.rust_obj + " " + arg.arg_name)
+                        else:
+                            out_java_struct.write(arg.java_ty + " " + arg.arg_name)
+
+
         out_java.write(");\n")
         out_c.write(") {\n")
+        if out_java_struct is not None:
+            out_java_struct.write(") {\n")
 
         for info in arg_names:
             if info.arg_conv is not None:
-                out_c.write("\t" + info.arg_conv.replace('\n', "\n\t") + "\n");
+                out_c.write("\t" + info.arg_conv.replace('\n', "\n\t") + "\n")
 
         if ret_info.ret_conv is not None:
-            out_c.write("\t" + ret_conv_pfx.replace('\n', '\n\t'));
+            out_c.write("\t" + ret_conv_pfx.replace('\n', '\n\t'))
+        elif ret_info.c_ty != "void":
+            out_c.write("\t" + ret_info.c_ty + " ret_val = ")
         else:
-            out_c.write("\treturn ");
+            out_c.write("\t")
 
         if c_call_string is None:
             out_c.write(re_match.group(2) + "(")
@@ -332,168 +503,393 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write(")")
         if ret_info.ret_conv is not None:
             out_c.write(ret_conv_sfx.replace('\n', '\n\t'))
-            out_c.write("\n\treturn " + ret_info.ret_conv_name + ";")
         else:
             out_c.write(";")
+        for info in arg_names:
+            if info.arg_conv_cleanup is not None:
+                out_c.write("\n\t" + info.arg_conv_cleanup.replace("\n", "\n\t"))
+        if ret_info.ret_conv is not None:
+            out_c.write("\n\treturn " + ret_info.ret_conv_name + ";")
+        elif ret_info.c_ty != "void":
+            out_c.write("\n\treturn ret_val;")
         out_c.write("\n}\n\n")
-
-    def map_trait(struct_name, field_var_lines, trait_fn_lines):
-        out_c.write("typedef struct " + struct_name + "_JCalls {\n")
-        out_c.write("\tatomic_size_t refcnt;\n")
-        out_c.write("\tJavaVM *vm;\n")
-        out_c.write("\tjobject o;\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\t" + var_line.group(1) + "_JCalls* " + var_line.group(2) + ";\n")
-        for fn_line in trait_fn_lines:
-            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
-        out_c.write("} " + struct_name + "_JCalls;\n")
-
-        out_java.write("\tpublic interface " + struct_name + " {\n")
-        java_meths = []
-        for fn_line in trait_fn_lines:
-            java_meth_descr = "("
-            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                ret_ty_info = java_c_types(fn_line.group(1), None)
-
-                out_java.write("\t\t " + ret_ty_info.java_ty + " " + fn_line.group(2) + "(")
-                is_const = fn_line.group(3) is not None
-                out_c.write(fn_line.group(1) + fn_line.group(2) + "_jcall(")
-                if is_const:
-                    out_c.write("const void* this_arg")
+        if out_java_struct is not None:
+            out_java_struct.write("\t\t")
+            if ret_info.rust_obj == "LDK" + struct_meth:
+                out_java_struct.write("super(")
+            elif ret_info.java_ty != "void" and not ret_info.passed_as_ptr:
+                out_java_struct.write(ret_info.java_ty + " ret = ")
+            elif ret_info.java_ty != "void":
+                out_java_struct.write(ret_info.rust_obj.replace("LDK", "") + " ret = ")
+                if ret_info.rust_obj in opaque_structs or ret_info.rust_obj in trait_structs:
+                    out_java_struct.write("new " + ret_info.rust_obj.replace("LDK", "") + "(null, ")
+            out_java_struct.write("bindings." + re_match.group(2) + "(")
+            for idx, info in enumerate(arg_names):
+                if idx != 0:
+                    out_java_struct.write(", ")
+                if info.arg_name == "this_arg":
+                    out_java_struct.write("this.ptr")
+                elif info.arg_name in default_constructor_args:
+                    out_java_struct.write("bindings." + info.rust_obj.replace("LDK", "") + "_new(")
+                    for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
+                        if explode_idx != 0:
+                            out_java_struct.write(", ")
+                        assert explode_arg.passed_as_ptr and explode_arg.rust_obj in trait_structs
+                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
+                        out_java_struct.write(expl_arg_name + " == null ? 0 : " + expl_arg_name + ".ptr")
+                    out_java_struct.write(")")
+                elif info.passed_as_ptr and info.rust_obj in opaque_structs:
+                    out_java_struct.write(info.arg_name + " == null ? 0 : " + info.arg_name + ".ptr & ~1")
+                elif info.passed_as_ptr and info.rust_obj in trait_structs:
+                    out_java_struct.write(info.arg_name + " == null ? 0 : " + info.arg_name + ".ptr")
                 else:
-                    out_c.write("void* this_arg")
-
-                arg_names = []
-                for idx, arg in enumerate(fn_line.group(4).split(',')):
-                    if arg == "":
-                        continue
-                    if idx >= 2:
-                        out_java.write(", ")
-                    out_c.write(", ")
-                    arg_conv_info = map_type(arg, True, None, False)
-                    out_c.write(arg.strip())
-                    out_java.write(arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
-                    arg_names.append(arg_conv_info)
-                    java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
-                java_meth_descr = java_meth_descr + ")" + ret_ty_info.java_fn_ty_arg
-                java_meths.append(java_meth_descr)
-
-                out_java.write(");\n")
-                out_c.write(") {\n")
-                out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
-                out_c.write("\tJNIEnv *env;\n")
-                out_c.write("\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
-
-                for arg_info in arg_names:
-                    if arg_info.ret_conv is not None:
-                        out_c.write("\t" + arg_info.ret_conv[0].replace('\n', '\n\t').replace("_env", "env"));
-                        out_c.write(arg_info.arg_name)
-                        out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
-
-                if not ret_ty_info.passed_as_ptr:
-                    out_c.write("\treturn (*env)->Call" + ret_ty_info.java_ty.title() + "Method(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth")
+                    out_java_struct.write(info.arg_name)
+            out_java_struct.write(")")
+            if ret_info.rust_obj == "LDK" + struct_meth:
+                out_java_struct.write(");\n")
+            elif ret_info.rust_obj in opaque_structs:
+                out_java_struct.write(");\n")
+            elif ret_info.rust_obj in trait_structs:
+                out_java_struct.write(");\n\t\tret.ptrs_to.add(this);\n")
+            else:
+                out_java_struct.write(";\n")
+
+            for info in arg_names:
+                if info.arg_name == "this_arg":
+                    pass
+                elif info.arg_name in default_constructor_args:
+                    for explode_arg in default_constructor_args[info.arg_name]:
+                        out_java_struct.write("\t\tthis.ptrs_to.add(" + info.arg_name + "_" + explode_arg.arg_name + ");\n")
+                elif info.passed_as_ptr and (info.rust_obj in opaque_structs or info.rust_obj in trait_structs):
+                    out_java_struct.write("\t\tthis.ptrs_to.add(" + info.arg_name + ");\n")
+
+            if ret_info.java_ty != "void" and ret_info.rust_obj != "LDK" + struct_meth:
+                out_java_struct.write("\t\treturn ret;\n")
+            out_java_struct.write("\t}\n\n")
+            out_java_struct.close()
+
+    def map_unitary_enum(struct_name, field_lines):
+        with open(sys.argv[3] + "/enums/" + struct_name + ".java", "w") as out_java_enum:
+            out_java_enum.write("package org.ldk.enums;\n\n")
+            unitary_enums.add(struct_name)
+            out_c.write("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
+            out_c.write("\tswitch ((*env)->CallIntMethod(env, val, ordinal_meth)) {\n")
+            ord_v = 0
+            for idx, struct_line in enumerate(field_lines):
+                if idx == 0:
+                    out_java_enum.write("public enum " + struct_name + " {\n")
+                elif idx == len(field_lines) - 3:
+                    assert(struct_line.endswith("_Sentinel,"))
+                elif idx == len(field_lines) - 2:
+                    out_java_enum.write("\t; static native void init();\n")
+                    out_java_enum.write("\tstatic { init(); }\n")
+                    out_java_enum.write("}")
+                    out_java.write("\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n")
+                elif idx == len(field_lines) - 1:
+                    assert(struct_line == "")
                 else:
-                    out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*env)->CallLongMethod(env, j_calls->o, j_calls->" + fn_line.group(2) + "_meth");
-
-                for arg_info in arg_names:
-                    if arg_info.ret_conv is not None:
-                        out_c.write(", " + arg_info.ret_conv_name)
-                    else:
-                        out_c.write(", " + arg_info.arg_name)
-                out_c.write(");\n");
-
-                if ret_ty_info.passed_as_ptr:
-                    out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
-                    out_c.write("\tFREE(ret);\n")
-                    out_c.write("\treturn res;\n")
-                out_c.write("}\n")
-            elif fn_line.group(2) == "free":
-                out_c.write("static void " + struct_name + "_JCalls_free(void* this_arg) {\n")
-                out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
-                out_c.write("\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n")
-                out_c.write("\t\tJNIEnv *env;\n")
-                out_c.write("\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
-                out_c.write("\t\t(*env)->DeleteGlobalRef(env, j_calls->o);\n")
-                out_c.write("\t\tFREE(j_calls);\n")
-                out_c.write("\t}\n}\n")
-
-        # Write out a clone function whether we need one or not, as we use them in moving to rust
-        out_c.write("static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")
-        out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
-        out_c.write("\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\tatomic_fetch_add_explicit(&j_calls->" + var_line.group(2) + "->refcnt, 1, memory_order_release);\n")
-        out_c.write("\treturn (void*) this_arg;\n")
-        out_c.write("}\n")
-
-        out_java.write("\t}\n")
-
-        out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl")
-        out_c.write("static inline " + struct_name + " " + struct_name + "_init (JNIEnv * env, jclass _a, jobject o")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_java.write(", " + var_line.group(1) + " " + var_line.group(2))
-                out_c.write(", jobject " + var_line.group(2))
-        out_java.write(");\n")
-        out_c.write(") {\n")
-
-        out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
-        out_c.write("\tDO_ASSERT(c != NULL);\n")
-        out_c.write("\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n")
-        out_c.write("\tatomic_init(&calls->refcnt, 1);\n")
-        out_c.write("\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n")
-        out_c.write("\tcalls->o = (*env)->NewGlobalRef(env, o);\n")
-        for (fn_line, java_meth_descr) in zip(trait_fn_lines, java_meths):
-            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                out_c.write("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + java_meth_descr + "\");\n")
-                out_c.write("\tDO_ASSERT(calls->" + fn_line.group(2) + "_meth != NULL);\n")
-        out_c.write("\n\t" + struct_name + " ret = {\n")
-        out_c.write("\t\t.this_arg = (void*) calls,\n")
-        for fn_line in trait_fn_lines:
-            if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
-                out_c.write("\t\t." + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall,\n")
-            elif fn_line.group(2) == "free":
-                out_c.write("\t\t.free = " + struct_name + "_JCalls_free,\n")
+                    out_java_enum.write(struct_line + "\n")
+                    out_c.write("\t\tcase %d: return %s;\n" % (ord_v, struct_line.strip().strip(",")))
+                    ord_v = ord_v + 1
+            out_c.write("\t}\n")
+            out_c.write("\tabort();\n")
+            out_c.write("}\n")
+
+            ord_v = 0
+            out_c.write("static jclass " + struct_name + "_class = NULL;\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    out_c.write("static jfieldID " + struct_name + "_" + variant + " = NULL;\n")
+            out_c.write("JNIEXPORT void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass clz) {\n")
+            out_c.write("\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n")
+            out_c.write("\tCHECK(" + struct_name + "_class != NULL);\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    out_c.write("\t" + struct_name + "_" + variant + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + variant + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n")
+                    out_c.write("\tCHECK(" + struct_name + "_" + variant + " != NULL);\n")
+            out_c.write("}\n")
+            out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
+            out_c.write("\tswitch (val) {\n")
+            for idx, struct_line in enumerate(field_lines):
+                if idx > 0 and idx < len(field_lines) - 3:
+                    variant = struct_line.strip().strip(",")
+                    out_c.write("\t\tcase " + variant + ":\n")
+                    out_c.write("\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + variant + ");\n")
+                    ord_v = ord_v + 1
+            out_c.write("\t\tdefault: abort();\n")
+            out_c.write("\t}\n")
+            out_c.write("}\n\n")
+
+    def map_complex_enum(struct_name, union_enum_items):
+        tag_field_lines = union_enum_items["field_lines"]
+        init_meth_jty_strs = {}
+        for idx, struct_line in enumerate(tag_field_lines):
+            if idx == 0:
+                out_java.write("\tpublic static class " + struct_name + " {\n")
+                out_java.write("\t\tprivate " + struct_name + "() {}\n")
+            elif idx == len(tag_field_lines) - 3:
+                assert(struct_line.endswith("_Sentinel,"))
+            elif idx == len(tag_field_lines) - 2:
+                out_java.write("\t\tstatic native void init();\n")
+                out_java.write("\t}\n")
+            elif idx == len(tag_field_lines) - 1:
+                assert(struct_line == "")
             else:
-                out_c.write("\t\t.clone = " + struct_name + "_JCalls_clone,\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\t\t." + var_line.group(2) + " = " + var_line.group(1) + "_init(env, _a, " + var_line.group(2) + "),\n")
-        out_c.write("\t};\n")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write("\tcalls->" + var_line.group(2) + " = ret." + var_line.group(2) + ".this_arg;\n")
-        out_c.write("\treturn ret;\n")
+                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                out_java.write("\t\tpublic final static class " + var_name + " extends " + struct_name + " {\n")
+                out_c.write("static jclass " + struct_name + "_" + var_name + "_class = NULL;\n")
+                out_c.write("static jmethodID " + struct_name + "_" + var_name + "_meth = NULL;\n")
+                init_meth_jty_str = ""
+                init_meth_params = ""
+                init_meth_body = ""
+                if "LDK" + var_name in union_enum_items:
+                    enum_var_lines = union_enum_items["LDK" + var_name]
+                    for idx, field in enumerate(enum_var_lines):
+                        if idx != 0 and idx < len(enum_var_lines) - 2:
+                            field_ty = java_c_types(field.strip(' ;'), None)
+                            out_java.write("\t\t\tpublic " + field_ty.java_ty + " " + field_ty.var_name + ";\n")
+                            init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
+                            if idx > 1:
+                                init_meth_params = init_meth_params + ", "
+                            init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.var_name
+                            init_meth_body = init_meth_body + "this." + field_ty.var_name + " = " + field_ty.var_name + "; "
+                    out_java.write("\t\t\t" + var_name + "(" + init_meth_params + ") { ")
+                    out_java.write(init_meth_body)
+                    out_java.write("}\n")
+                out_java.write("\t\t}\n")
+                init_meth_jty_strs[var_name] = init_meth_jty_str
+        out_java.write("\tstatic { " + struct_name + ".init(); }\n")
+        out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
+
+        out_c.write("JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass _a) {\n")
+        for idx, struct_line in enumerate(tag_field_lines):
+            if idx != 0 and idx < len(tag_field_lines) - 3:
+                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                out_c.write("\t" + struct_name + "_" + var_name + "_class =\n")
+                out_c.write("\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n")
+                out_c.write("\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n")
+                out_c.write("\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n")
+                out_c.write("\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n")
         out_c.write("}\n")
+        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (JNIEnv * env, jclass _c, jlong ptr) {\n")
+        out_c.write("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
+        out_c.write("\tswitch(obj->tag) {\n")
+        for idx, struct_line in enumerate(tag_field_lines):
+            if idx != 0 and idx < len(tag_field_lines) - 3:
+                var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
+                out_c.write("\t\tcase " + struct_name + "_" + var_name + ": {\n")
+                c_params_text = ""
+                if "LDK" + var_name in union_enum_items:
+                    enum_var_lines = union_enum_items["LDK" + var_name]
+                    for idx, field in enumerate(enum_var_lines):
+                        if idx != 0 and idx < len(enum_var_lines) - 2:
+                            field_map = map_type(field.strip(' ;'), False, None, False)
+                            if field_map.ret_conv is not None:
+                                out_c.write("\t\t\t" + field_map.ret_conv[0].replace("\n", "\n\t\t\t").replace("_env", "env"))
+                                out_c.write("obj->" + camel_to_snake(var_name) + "." + field_map.arg_name)
+                                out_c.write(field_map.ret_conv[1].replace("\n", "\n\t\t\t") + "\n")
+                                c_params_text = c_params_text + ", " + field_map.ret_conv_name
+                            else:
+                                c_params_text = c_params_text + ", obj->" + camel_to_snake(var_name) + "." + field_map.arg_name
+                out_c.write("\t\t\treturn (*env)->NewObject(env, " + struct_name + "_" + var_name + "_class, " + struct_name + "_" + var_name + "_meth" + c_params_text + ");\n")
+                out_c.write("\t\t}\n")
+        out_c.write("\t\tdefault: abort();\n")
+        out_c.write("\t}\n}\n")
 
-        out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write(", jobject " + var_line.group(2))
-        out_c.write(") {\n")
-        out_c.write("\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
-        out_c.write("\t*res_ptr = " + struct_name + "_init(env, _a, o")
-        for var_line in field_var_lines:
-            if var_line.group(1) in trait_structs:
-                out_c.write(", " + var_line.group(2))
-        out_c.write(");\n")
-        out_c.write("\treturn (long)res_ptr;\n")
-        out_c.write("}\n")
+    def map_trait(struct_name, field_var_lines, trait_fn_lines):
+        with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_trait:
+            out_c.write("typedef struct " + struct_name + "_JCalls {\n")
+            out_c.write("\tatomic_size_t refcnt;\n")
+            out_c.write("\tJavaVM *vm;\n")
+            out_c.write("\tjweak o;\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\t" + var_line.group(1) + "_JCalls* " + var_line.group(2) + ";\n")
+            for fn_line in trait_fn_lines:
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    out_c.write("\tjmethodID " + fn_line.group(2) + "_meth;\n")
+            out_c.write("} " + struct_name + "_JCalls;\n")
+
+            out_java_trait.write("package org.ldk.structs;\n\n")
+            out_java_trait.write("import org.ldk.impl.bindings;\n\n")
+            out_java_trait.write("import org.ldk.enums.*;\n\n")
+            out_java_trait.write("public class " + struct_name.replace("LDK","") + " extends CommonBase {\n")
+            out_java_trait.write("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
+            out_java_trait.write("\tpublic " + struct_name.replace("LDK", "") + "(bindings." + struct_name + " arg")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_java_trait.write(", bindings." + var_line.group(1) + " " + var_line.group(2))
+            out_java_trait.write(") {\n")
+            out_java_trait.write("\t\tsuper(bindings." + struct_name + "_new(arg")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_java_trait.write(", " + var_line.group(2))
+            out_java_trait.write("));\n")
+            out_java_trait.write("\t\tthis.ptrs_to.add(arg);\n")
+            out_java_trait.write("\t}\n")
+            out_java_trait.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
+            out_java_trait.write("\tprotected void finalize() throws Throwable {\n")
+            out_java_trait.write("\t\tbindings." + struct_name.replace("LDK","") + "_free(ptr); super.finalize();\n")
+            out_java_trait.write("\t}\n\n")
+
+            out_java.write("\tpublic interface " + struct_name + " {\n")
+            java_meths = []
+            for fn_line in trait_fn_lines:
+                java_meth_descr = "("
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    ret_ty_info = java_c_types(fn_line.group(1), None)
+
+                    out_java.write("\t\t " + ret_ty_info.java_ty + " " + fn_line.group(2) + "(")
+                    is_const = fn_line.group(3) is not None
+                    out_c.write(fn_line.group(1) + fn_line.group(2) + "_jcall(")
+                    if is_const:
+                        out_c.write("const void* this_arg")
+                    else:
+                        out_c.write("void* this_arg")
+
+                    arg_names = []
+                    for idx, arg in enumerate(fn_line.group(4).split(',')):
+                        if arg == "":
+                            continue
+                        if idx >= 2:
+                            out_java.write(", ")
+                        out_c.write(", ")
+                        arg_conv_info = map_type(arg, True, None, False)
+                        out_c.write(arg.strip())
+                        out_java.write(arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
+                        arg_names.append(arg_conv_info)
+                        java_meth_descr = java_meth_descr + arg_conv_info.java_fn_ty_arg
+                    java_meth_descr = java_meth_descr + ")" + ret_ty_info.java_fn_ty_arg
+                    java_meths.append(java_meth_descr)
+
+                    out_java.write(");\n")
+                    out_c.write(") {\n")
+                    out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+                    out_c.write("\tJNIEnv *env;\n")
+                    out_c.write("\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
+
+                    for arg_info in arg_names:
+                        if arg_info.ret_conv is not None:
+                            out_c.write("\t" + arg_info.ret_conv[0].replace('\n', '\n\t').replace("_env", "env"));
+                            out_c.write(arg_info.arg_name)
+                            out_c.write(arg_info.ret_conv[1].replace('\n', '\n\t').replace("_env", "env") + "\n")
+
+                    out_c.write("\tjobject obj = (*env)->NewLocalRef(env, j_calls->o);\n\tCHECK(obj != NULL);\n")
+                    if ret_ty_info.c_ty.endswith("Array"):
+                        assert(ret_ty_info.c_ty == "jbyteArray")
+                        out_c.write("\tjbyteArray jret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                    elif not ret_ty_info.passed_as_ptr:
+                        out_c.write("\treturn (*env)->Call" + ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.group(2) + "_meth")
+                    else:
+                        out_c.write("\t" + fn_line.group(1).strip() + "* ret = (" + fn_line.group(1).strip() + "*)(*env)->CallLongMethod(env, obj, j_calls->" + fn_line.group(2) + "_meth");
 
-        out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n")
-        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (JNIEnv * env, jclass _a, jlong val) {\n")
-        out_c.write("\treturn ((" + struct_name + "_JCalls*)val)->o;\n")
-        out_c.write("}\n")
+                    for arg_info in arg_names:
+                        if arg_info.ret_conv is not None:
+                            out_c.write(", " + arg_info.ret_conv_name)
+                        else:
+                            out_c.write(", " + arg_info.arg_name)
+                    out_c.write(");\n");
+                    if ret_ty_info.c_ty.endswith("Array"):
+                        out_c.write("\t" + ret_ty_info.rust_obj + " ret;\n")
+                        out_c.write("\tCHECK((*env)->GetArrayLength(env, jret) == " + ret_ty_info.arr_len + ");\n")
+                        out_c.write("\t(*env)->GetByteArrayRegion(env, jret, 0, " + ret_ty_info.arr_len + ", ret." + ret_ty_info.arr_access + ");\n")
+                        out_c.write("\treturn ret;\n")
+
+                    if ret_ty_info.passed_as_ptr:
+                        out_c.write("\t" + fn_line.group(1).strip() + " res = *ret;\n")
+                        out_c.write("\tFREE(ret);\n")
+                        out_c.write("\treturn res;\n")
+                    out_c.write("}\n")
+                elif fn_line.group(2) == "free":
+                    out_c.write("static void " + struct_name + "_JCalls_free(void* this_arg) {\n")
+                    out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+                    out_c.write("\tif (atomic_fetch_sub_explicit(&j_calls->refcnt, 1, memory_order_acquire) == 1) {\n")
+                    out_c.write("\t\tJNIEnv *env;\n")
+                    out_c.write("\t\tDO_ASSERT((*j_calls->vm)->GetEnv(j_calls->vm, (void**)&env, JNI_VERSION_1_8) == JNI_OK);\n")
+                    out_c.write("\t\t(*env)->DeleteWeakGlobalRef(env, j_calls->o);\n")
+                    out_c.write("\t\tFREE(j_calls);\n")
+                    out_c.write("\t}\n}\n")
+
+            # Write out a clone function whether we need one or not, as we use them in moving to rust
+            out_c.write("static void* " + struct_name + "_JCalls_clone(const void* this_arg) {\n")
+            out_c.write("\t" + struct_name + "_JCalls *j_calls = (" + struct_name + "_JCalls*) this_arg;\n")
+            out_c.write("\tatomic_fetch_add_explicit(&j_calls->refcnt, 1, memory_order_release);\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\tatomic_fetch_add_explicit(&j_calls->" + var_line.group(2) + "->refcnt, 1, memory_order_release);\n")
+            out_c.write("\treturn (void*) this_arg;\n")
+            out_c.write("}\n")
+
+            out_java.write("\t}\n")
+
+            out_java.write("\tpublic static native long " + struct_name + "_new(" + struct_name + " impl")
+            out_c.write("static inline " + struct_name + " " + struct_name + "_init (JNIEnv * env, jclass _a, jobject o")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_java.write(", " + var_line.group(1) + " " + var_line.group(2))
+                    out_c.write(", jobject " + var_line.group(2))
+            out_java.write(");\n")
+            out_c.write(") {\n")
+
+            out_c.write("\tjclass c = (*env)->GetObjectClass(env, o);\n")
+            out_c.write("\tCHECK(c != NULL);\n")
+            out_c.write("\t" + struct_name + "_JCalls *calls = MALLOC(sizeof(" + struct_name + "_JCalls), \"" + struct_name + "_JCalls\");\n")
+            out_c.write("\tatomic_init(&calls->refcnt, 1);\n")
+            out_c.write("\tDO_ASSERT((*env)->GetJavaVM(env, &calls->vm) == 0);\n")
+            out_c.write("\tcalls->o = (*env)->NewWeakGlobalRef(env, o);\n")
+            for (fn_line, java_meth_descr) in zip(trait_fn_lines, java_meths):
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    out_c.write("\tcalls->" + fn_line.group(2) + "_meth = (*env)->GetMethodID(env, c, \"" + fn_line.group(2) + "\", \"" + java_meth_descr + "\");\n")
+                    out_c.write("\tCHECK(calls->" + fn_line.group(2) + "_meth != NULL);\n")
+            out_c.write("\n\t" + struct_name + " ret = {\n")
+            out_c.write("\t\t.this_arg = (void*) calls,\n")
+            for fn_line in trait_fn_lines:
+                if fn_line.group(2) != "free" and fn_line.group(2) != "clone":
+                    out_c.write("\t\t." + fn_line.group(2) + " = " + fn_line.group(2) + "_jcall,\n")
+                elif fn_line.group(2) == "free":
+                    out_c.write("\t\t.free = " + struct_name + "_JCalls_free,\n")
+                else:
+                    clone_fns.add(struct_name + "_clone")
+                    out_c.write("\t\t.clone = " + struct_name + "_JCalls_clone,\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\t\t." + var_line.group(2) + " = " + var_line.group(1) + "_init(env, _a, " + var_line.group(2) + "),\n")
+            out_c.write("\t};\n")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write("\tcalls->" + var_line.group(2) + " = ret." + var_line.group(2) + ".this_arg;\n")
+            out_c.write("\treturn ret;\n")
+            out_c.write("}\n")
+
+            out_c.write("JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new (JNIEnv * env, jclass _a, jobject o")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write(", jobject " + var_line.group(2))
+            out_c.write(") {\n")
+            out_c.write("\t" + struct_name + " *res_ptr = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+            out_c.write("\t*res_ptr = " + struct_name + "_init(env, _a, o")
+            for var_line in field_var_lines:
+                if var_line.group(1) in trait_structs:
+                    out_c.write(", " + var_line.group(2))
+            out_c.write(");\n")
+            out_c.write("\treturn (long)res_ptr;\n")
+            out_c.write("}\n")
+
+            out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_get_obj_from_jcalls(long val);\n")
+            out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1get_1obj_1from_1jcalls (JNIEnv * env, jclass _a, jlong val) {\n")
+            out_c.write("\tjobject ret = (*env)->NewLocalRef(env, ((" + struct_name + "_JCalls*)val)->o);\n")
+            out_c.write("\tCHECK(ret != NULL);\n")
+            out_c.write("\treturn ret;\n")
+            out_c.write("}\n")
 
         for fn_line in trait_fn_lines:
             # For now, just disable enabling the _call_log - we don't know how to inverse-map String
             is_log = fn_line.group(2) == "log" and struct_name == "LDKLogger"
             if fn_line.group(2) != "free" and fn_line.group(2) != "clone" and fn_line.group(2) != "eq" and not is_log:
-                dummy_line = fn_line.group(1) + struct_name + "_call_" + fn_line.group(2) + " " + struct_name + "* arg" + fn_line.group(4) + "\n"
-                map_fn(dummy_line, re.compile("([A-Za-z_0-9]*) *([A-Za-z_0-9]*) *(.*)").match(dummy_line), None, "(arg_conv->" + fn_line.group(2) + ")(arg_conv->this_arg")
+                dummy_line = fn_line.group(1) + struct_name.replace("LDK", "") + "_" + fn_line.group(2) + " " + struct_name + "* this_arg" + fn_line.group(4) + "\n"
+                map_fn(dummy_line, re.compile("([A-Za-z_0-9]*) *([A-Za-z_0-9]*) *(.*)").match(dummy_line), None, "(this_arg_conv->" + fn_line.group(2) + ")(this_arg_conv->this_arg")
 
     out_c.write("""#include \"org_ldk_impl_bindings.h\"
 #include <rust_types.h>
@@ -506,37 +902,56 @@ with open(sys.argv[1]) as in_h, open(sys.argv[2], "w") as out_java, open(sys.arg
         out_c.write("#define MALLOC(a, _) malloc(a)\n")
         out_c.write("#define FREE free\n")
         out_c.write("#define DO_ASSERT(a) (void)(a)\n")
+        out_c.write("#define CHECK(a)\n")
     else:
         out_c.write("""#include <assert.h>
+// Always run a, then assert it is true:
 #define DO_ASSERT(a) do { bool _assert_val = (a); assert(_assert_val); } while(0)
+// Assert a is true or do nothing
+#define CHECK(a) DO_ASSERT(a)
 
+// Running a leak check across all the allocations and frees of the JDK is a mess,
+// so instead we implement our own naive leak checker here, relying on the -wrap
+// linker option to wrap malloc/calloc/realloc/free, tracking everyhing allocated
+// and free'd in Rust or C across the generated bindings shared library.
 #include <threads.h>
+#include <execinfo.h>
+#include <unistd.h>
 static mtx_t allocation_mtx;
 
 void __attribute__((constructor)) init_mtx() {
        DO_ASSERT(mtx_init(&allocation_mtx, mtx_plain) == thrd_success);
 }
 
+#define BT_MAX 128
 typedef struct allocation {
        struct allocation* next;
        void* ptr;
        const char* struct_name;
+       void* bt[BT_MAX];
+       int bt_len;
 } allocation;
 static allocation* allocation_ll = NULL;
 
-void* MALLOC(size_t len, const char* struct_name) {
-       void* res = malloc(len);
-       allocation* new_alloc = malloc(sizeof(allocation));
+void* __real_malloc(size_t len);
+void* __real_calloc(size_t nmemb, size_t len);
+static void new_allocation(void* res, const char* struct_name) {
+       allocation* new_alloc = __real_malloc(sizeof(allocation));
        new_alloc->ptr = res;
        new_alloc->struct_name = struct_name;
+       new_alloc->bt_len = backtrace(new_alloc->bt, BT_MAX);
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        new_alloc->next = allocation_ll;
        allocation_ll = new_alloc;
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
+}
+static void* MALLOC(size_t len, const char* struct_name) {
+       void* res = __real_malloc(len);
+       new_allocation(res, struct_name);
        return res;
 }
-
-void FREE(void* ptr) {
+void __real_free(void* ptr);
+static void alloc_freed(void* ptr) {
        allocation* p = NULL;
        DO_ASSERT(mtx_lock(&allocation_mtx) == thrd_success);
        allocation* it = allocation_ll;
@@ -544,12 +959,46 @@ void FREE(void* ptr) {
        if (p) { p->next = it->next; } else { allocation_ll = it->next; }
        DO_ASSERT(mtx_unlock(&allocation_mtx) == thrd_success);
        DO_ASSERT(it->ptr == ptr);
-       free(it);
-       free(ptr);
+       __real_free(it);
+}
+static void FREE(void* ptr) {
+       alloc_freed(ptr);
+       __real_free(ptr);
+}
+
+void* __wrap_malloc(size_t len) {
+       void* res = __real_malloc(len);
+       new_allocation(res, "malloc call");
+       return res;
+}
+void* __wrap_calloc(size_t nmemb, size_t len) {
+       void* res = __real_calloc(nmemb, len);
+       new_allocation(res, "calloc call");
+       return res;
+}
+void __wrap_free(void* ptr) {
+       alloc_freed(ptr);
+       __real_free(ptr);
+}
+
+void* __real_realloc(void* ptr, size_t newlen);
+void* __wrap_realloc(void* ptr, size_t len) {
+       alloc_freed(ptr);
+       void* res = __real_realloc(ptr, len);
+       new_allocation(res, "realloc call");
+       return res;
+}
+void __wrap_reallocarray(void* ptr, size_t new_sz) {
+       // Rust doesn't seem to use reallocarray currently
+       assert(false);
 }
 
 void __attribute__((destructor)) check_leaks() {
-       for (allocation* a = allocation_ll; a != NULL; a = a->next) { fprintf(stderr, "%s %p remains\\n", a->struct_name, a->ptr); }
+       for (allocation* a = allocation_ll; a != NULL; a = a->next) {
+               fprintf(stderr, "%s %p remains:\\n", a->struct_name, a->ptr);
+               backtrace_symbols_fd(a->bt, a->bt_len, STDERR_FILENO);
+               fprintf(stderr, "\\n\\n");
+       }
        DO_ASSERT(allocation_ll == NULL);
 }
 """)
@@ -577,21 +1026,22 @@ public class bindings {
        public static native byte[] read_bytes(long ptr, long len);
        public static native byte[] get_u8_slice_bytes(long slice_ptr);
        public static native long bytes_to_u8_vec(byte[] bytes);
+       public static native long new_txpointer_copy_data(byte[] txdata);
        public static native long vec_slice_len(long vec);
        public static native long new_empty_slice_vec();
 
 """)
     out_c.write("""
-jmethodID ordinal_meth = NULL;
-jmethodID slicedef_meth = NULL;
-jclass slicedef_cls = NULL;
+static jmethodID ordinal_meth = NULL;
+static jmethodID slicedef_meth = NULL;
+static jclass slicedef_cls = NULL;
 JNIEXPORT void Java_org_ldk_impl_bindings_init(JNIEnv * env, jclass _b, jclass enum_class, jclass slicedef_class) {
        ordinal_meth = (*env)->GetMethodID(env, enum_class, "ordinal", "()I");
-       DO_ASSERT(ordinal_meth != NULL);
+       CHECK(ordinal_meth != NULL);
        slicedef_meth = (*env)->GetMethodID(env, slicedef_class, "<init>", "(JJJ)V");
-       DO_ASSERT(slicedef_meth != NULL);
+       CHECK(slicedef_meth != NULL);
        slicedef_cls = (*env)->NewGlobalRef(env, slicedef_class);
-       DO_ASSERT(slicedef_cls != NULL);
+       CHECK(slicedef_cls != NULL);
 }
 
 JNIEXPORT jboolean JNICALL Java_org_ldk_impl_bindings_deref_1bool (JNIEnv * env, jclass _a, jlong ptr) {
@@ -617,10 +1067,18 @@ JNIEXPORT jbyteArray JNICALL Java_org_ldk_impl_bindings_get_1u8_1slice_1bytes (J
 JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_bytes_1to_1u8_1vec (JNIEnv * _env, jclass _b, jbyteArray bytes) {
        LDKCVec_u8Z *vec = (LDKCVec_u8Z*)MALLOC(sizeof(LDKCVec_u8Z), "LDKCVec_u8");
        vec->datalen = (*_env)->GetArrayLength(_env, bytes);
-       vec->data = (uint8_t*)malloc(vec->datalen); // May be freed by rust, so don't track allocation
+       vec->data = (uint8_t*)MALLOC(vec->datalen, "LDKCVec_u8Z Bytes");
        (*_env)->GetByteArrayRegion (_env, bytes, 0, vec->datalen, vec->data);
        return (long)vec;
 }
+JNIEXPORT long JNICALL Java_org_ldk_impl_bindings_new_1txpointer_1copy_1data (JNIEnv * env, jclass _b, jbyteArray bytes) {
+       LDKTransaction *txdata = (LDKTransaction*)MALLOC(sizeof(LDKTransaction), "LDKTransaction");
+       txdata->datalen = (*env)->GetArrayLength(env, bytes);
+       txdata->data = (uint8_t*)MALLOC(txdata->datalen, "Tx Data Bytes");
+       txdata->data_is_owned = true;
+       (*env)->GetByteArrayRegion (env, bytes, 0, txdata->datalen, txdata->data);
+       return (long)txdata;
+}
 JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_vec_1slice_1len (JNIEnv * env, jclass _a, jlong ptr) {
         // Check offsets of a few Vec types are all consistent as we're meant to be generic across types
        _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKCVec_SignatureZ, datalen), "Vec<*> needs to be mapped identically");
@@ -649,22 +1107,23 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
 
 """)
 
-    # XXX: Temporarily write out a manual SecretKey_new() for testing, we should auto-gen this kind of thing
-    out_java.write("\tpublic static native long LDKSecretKey_new();\n\n") # TODO: rm me
-    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_LDKSecretKey_1new(JNIEnv * _env, jclass _b) {\n") # TODO: rm me
-    out_c.write("\tLDKSecretKey* key = (LDKSecretKey*)MALLOC(sizeof(LDKSecretKey), \"LDKSecretKey\");\n") # TODO: rm me
-    out_c.write("\treturn (long)key;\n") # TODO: rm me
-    out_c.write("}\n") # TODO: rm me
+    with open(sys.argv[3] + "/structs/CommonBase.java", "a") as out_java_struct:
+        out_java_struct.write("""package org.ldk.structs;
+import java.util.LinkedList;
+class CommonBase {
+       final long ptr;
+       LinkedList<Object> ptrs_to = new LinkedList();
+       protected CommonBase(long ptr) { this.ptr = ptr; }
+       public long _test_only_get_ptr() { return this.ptr; }
+}
+""")
 
     in_block_comment = False
     cur_block_obj = None
 
-    fn_ptr_regex = re.compile("^extern const ([A-Za-z_0-9\* ]*) \(\*(.*)\)\((.*)\);$")
-    fn_ret_arr_regex = re.compile("(.*) \(\*(.*)\((.*)\)\)\[([0-9]*)\];$")
-    reg_fn_regex = re.compile("([A-Za-z_0-9\* ]* \*?)([a-zA-Z_0-9]*)\((.*)\);$")
     const_val_regex = re.compile("^extern const ([A-Za-z_0-9]*) ([A-Za-z_0-9]*);$")
 
-    line_indicates_result_regex = re.compile("^   bool result_ok;$")
+    line_indicates_result_regex = re.compile("^   (LDKCResultPtr_[A-Za-z_0-9]*) contents;$")
     line_indicates_vec_regex = re.compile("^   ([A-Za-z_0-9]*) \*data;$")
     line_indicates_opaque_regex = re.compile("^   bool is_owned;$")
     line_indicates_trait_regex = re.compile("^   ([A-Za-z_0-9]* \*?)\(\*([A-Za-z_0-9]*)\)\((const )?void \*this_arg(.*)\);$")
@@ -681,9 +1140,9 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
 
     result_templ_structs = set()
     union_enum_items = {}
+    result_ptr_struct_items = {}
     for line in in_h:
         if in_block_comment:
-            #out_java.write("\t" + line)
             if line.endswith("*/\n"):
                 in_block_comment = False
         elif cur_block_obj is not None:
@@ -694,10 +1153,11 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                 vec_ty = None
                 obj_lines = cur_block_obj.split("\n")
                 is_opaque = False
-                is_result = False
+                result_contents = None
                 is_unitary_enum = False
                 is_union_enum = False
                 is_union = False
+                is_tuple = False
                 trait_fn_lines = []
                 field_var_lines = []
 
@@ -709,7 +1169,6 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                             in_block_comment = False
                     else:
                         struct_name_match = struct_name_regex.match(struct_line)
-                        vec_ty_match = line_indicates_vec_regex.match(struct_line)
                         if struct_name_match is not None:
                             struct_name = struct_name_match.group(3)
                             if struct_name_match.group(1) == "enum":
@@ -721,10 +1180,14 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                                 is_union = True
                         if line_indicates_opaque_regex.match(struct_line):
                             is_opaque = True
-                        elif line_indicates_result_regex.match(struct_line):
-                            is_result = True
-                        elif vec_ty_match is not None and struct_name.startswith("LDKCVecTempl_"):
+                        result_match = line_indicates_result_regex.match(struct_line)
+                        if result_match is not None:
+                            result_contents = result_match.group(1)
+                        vec_ty_match = line_indicates_vec_regex.match(struct_line)
+                        if vec_ty_match is not None and struct_name.startswith("LDKCVecTempl_"):
                             vec_ty = vec_ty_match.group(1)
+                        elif struct_name.startswith("LDKC2TupleTempl_") or struct_name.startswith("LDKC3TupleTempl_"):
+                            is_tuple = True
                         trait_fn_match = line_indicates_trait_regex.match(struct_line)
                         if trait_fn_match is not None:
                             trait_fn_lines.append(trait_fn_match)
@@ -734,30 +1197,114 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                         field_lines.append(struct_line)
 
                 assert(struct_name is not None)
-                assert(len(trait_fn_lines) == 0 or not (is_opaque or is_unitary_enum or is_union_enum or is_union or is_result or vec_ty is not None))
-                assert(not is_opaque or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_union or is_result or vec_ty is not None))
-                assert(not is_unitary_enum or not (len(trait_fn_lines) != 0 or is_opaque or is_union_enum or is_union or is_result or vec_ty is not None))
-                assert(not is_union_enum or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_opaque or is_union or is_result or vec_ty is not None))
-                assert(not is_union or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_result or vec_ty is not None))
-                assert(not is_result or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or vec_ty is not None))
-                assert(vec_ty is None or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or is_result))
+                assert(len(trait_fn_lines) == 0 or not (is_opaque or is_unitary_enum or is_union_enum or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_opaque or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_unitary_enum or not (len(trait_fn_lines) != 0 or is_opaque or is_union_enum or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_union_enum or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_opaque or is_union or result_contents is not None or vec_ty is not None))
+                assert(not is_union or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or result_contents is not None or vec_ty is not None))
+                assert(result_contents is None or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or vec_ty is not None))
+                assert(vec_ty is None or not (len(trait_fn_lines) != 0 or is_unitary_enum or is_union_enum or is_opaque or is_union or result_contents is not None))
 
                 if is_opaque:
                     opaque_structs.add(struct_name)
-                    out_java.write("\tpublic static native long " + struct_name + "_optional_none();\n")
-                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1optional_1none (JNIEnv * env, jclass _a) {\n")
-                    out_c.write("\t" + struct_name + " *ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
-                    out_c.write("\tret->inner = NULL;\n")
+                    with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "w") as out_java_struct:
+                        out_java_struct.write("package org.ldk.structs;\n\n")
+                        out_java_struct.write("import org.ldk.impl.bindings;\n")
+                        out_java_struct.write("import org.ldk.enums.*;\n\n")
+                        out_java_struct.write("public class " + struct_name.replace("LDK","") + " extends CommonBase")
+                        if struct_name.startswith("LDKLocked"):
+                            out_java_struct.write(" implements AutoCloseable")
+                        out_java_struct.write(" {\n")
+                        out_java_struct.write("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
+                        if struct_name.startswith("LDKLocked"):
+                            out_java_struct.write("\t@Override public void close() {\n")
+                        else:
+                            out_java_struct.write("\t@Override @SuppressWarnings(\"deprecation\")\n")
+                            out_java_struct.write("\tprotected void finalize() throws Throwable {\n")
+                            out_java_struct.write("\t\tsuper.finalize();\n")
+                        out_java_struct.write("\t\tbindings." + struct_name.replace("LDK","") + "_free(ptr);\n")
+                        out_java_struct.write("\t}\n\n")
+                elif result_contents is not None:
+                    result_templ_structs.add(struct_name)
+                    assert result_contents in result_ptr_struct_items
+                elif struct_name.startswith("LDKCResultPtr_"):
+                    for line in field_lines:
+                        if line.endswith("*result;"):
+                            res_ty = line[:-8].strip()
+                        elif line.endswith("*err;"):
+                            err_ty = line[:-5].strip()
+                    result_ptr_struct_items[struct_name] = (res_ty, err_ty)
+                elif is_tuple:
+                    out_java.write("\tpublic static native long " + struct_name + "_new(")
+                    out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *_env, jclass _b")
+                    for idx, line in enumerate(field_lines):
+                        if idx != 0 and idx < len(field_lines) - 2:
+                            ty_info = java_c_types(line.strip(';'), None)
+                            if idx != 1:
+                                out_java.write(", ")
+                            e = chr(ord('a') + idx - 1)
+                            out_java.write(ty_info.java_ty + " " + e)
+                            out_c.write(", " + ty_info.c_ty + " " + e)
+                    out_java.write(");\n")
+                    out_c.write(") {\n")
+                    out_c.write("\t" + struct_name + "* ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+                    for idx, line in enumerate(field_lines):
+                        if idx != 0 and idx < len(field_lines) - 2:
+                            ty_info = map_type(line.strip(';'), False, None, False)
+                            e = chr(ord('a') + idx - 1)
+                            if ty_info.arg_conv is not None:
+                                out_c.write("\t" + ty_info.arg_conv.replace("\n", "\n\t"))
+                                out_c.write("\n\tret->" + e + " = " + ty_info.arg_conv_name + ";\n")
+                            else:
+                                out_c.write("\tret->" + e + " = " + e + ";\n")
+                            assert ty_info.arg_conv_cleanup is None
                     out_c.write("\treturn (long)ret;\n")
                     out_c.write("}\n")
-                elif is_result:
-                    result_templ_structs.add(struct_name)
                 elif vec_ty is not None:
-                    out_java.write("\tpublic static native VecOrSliceDef " + struct_name + "_arr_info(long vec_ptr);\n")
-                    out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
+                    if vec_ty in opaque_structs:
+                        out_java.write("\tpublic static native long[] " + struct_name + "_arr_info(long vec_ptr);\n")
+                        out_c.write("JNIEXPORT jlongArray JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
+                    else:
+                        out_java.write("\tpublic static native VecOrSliceDef " + struct_name + "_arr_info(long vec_ptr);\n")
+                        out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1arr_1info(JNIEnv *env, jclass _b, jlong ptr) {\n")
                     out_c.write("\t" + struct_name + " *vec = (" + struct_name + "*)ptr;\n")
-                    out_c.write("\treturn (*env)->NewObject(env, slicedef_cls, slicedef_meth, (long)vec->data, (long)vec->datalen, sizeof(" + vec_ty + "));\n")
+                    if vec_ty in opaque_structs:
+                        out_c.write("\tjlongArray ret = (*env)->NewLongArray(env, vec->datalen);\n")
+                        out_c.write("\tjlong *ret_elems = (*env)->GetPrimitiveArrayCritical(env, ret, NULL);\n")
+                        out_c.write("\tfor (size_t i = 0; i < vec->datalen; i++) {\n")
+                        out_c.write("\t\tCHECK((((long)vec->data[i].inner) & 1) == 0);\n")
+                        out_c.write("\t\tret_elems[i] = (long)vec->data[i].inner | (vec->data[i].is_owned ? 1 : 0);\n")
+                        out_c.write("\t}\n")
+                        out_c.write("\t(*env)->ReleasePrimitiveArrayCritical(env, ret, ret_elems, 0);\n")
+                        out_c.write("\treturn ret;\n")
+                    else:
+                        out_c.write("\treturn (*env)->NewObject(env, slicedef_cls, slicedef_meth, (long)vec->data, (long)vec->datalen, sizeof(" + vec_ty + "));\n")
                     out_c.write("}\n")
+
+                    ty_info = map_type(vec_ty + " arr_elem", False, None, False)
+                    if len(ty_info.java_fn_ty_arg) == 1: # ie we're a primitive of some form
+                        out_java.write("\tpublic static native long " + struct_name + "_new(" + ty_info.java_ty + "[] elems);\n")
+                        out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1new(JNIEnv *env, jclass _b, j" + ty_info.java_ty + "Array elems){\n")
+                        out_c.write("\t" + struct_name + " *ret = MALLOC(sizeof(" + struct_name + "), \"" + struct_name + "\");\n")
+                        out_c.write("\tret->datalen = (*env)->GetArrayLength(env, elems);\n")
+                        out_c.write("\tif (ret->datalen == 0) {\n")
+                        out_c.write("\t\tret->data = NULL;\n")
+                        out_c.write("\t} else {\n")
+                        out_c.write("\t\tret->data = MALLOC(sizeof(" + vec_ty + ") * ret->datalen, \"" + struct_name + " Data\");\n")
+                        out_c.write("\t\t" + ty_info.c_ty + " *java_elems = (*env)->GetPrimitiveArrayCritical(env, elems, NULL);\n")
+                        out_c.write("\t\tfor (size_t i = 0; i < ret->datalen; i++) {\n")
+                        if ty_info.arg_conv is not None:
+                            out_c.write("\t\t\t" + ty_info.c_ty + " arr_elem = java_elems[i];\n")
+                            out_c.write("\t\t\t" + ty_info.arg_conv.replace("\n", "\n\t\t\t") + "\n")
+                            out_c.write("\t\t\tret->data[i] = " + ty_info.arg_conv_name + ";\n")
+                            assert ty_info.arg_conv_cleanup is None
+                        else:
+                            out_c.write("\t\t\tret->data[i] = java_elems[i];\n")
+                        out_c.write("\t\t}\n")
+                        out_c.write("\t\t(*env)->ReleasePrimitiveArrayCritical(env, elems, java_elems, 0);\n")
+                        out_c.write("\t}\n")
+                        out_c.write("\treturn (long)ret;\n")
+                        out_c.write("}\n")
                 elif is_union_enum:
                     assert(struct_name.endswith("_Tag"))
                     struct_name = struct_name[:-4]
@@ -766,134 +1313,9 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                     enum_var_name = struct_name.split("_")
                     union_enum_items[enum_var_name[0]][enum_var_name[1]] = field_lines
                 elif struct_name in union_enum_items:
-                    tag_field_lines = union_enum_items[struct_name]["field_lines"]
-                    init_meth_jty_strs = {}
-                    for idx, struct_line in enumerate(tag_field_lines):
-                        if idx == 0:
-                            out_java.write("\tpublic static class " + struct_name + " {\n")
-                            out_java.write("\t\tprivate " + struct_name + "() {}\n")
-                        elif idx == len(tag_field_lines) - 3:
-                            assert(struct_line.endswith("_Sentinel,"))
-                        elif idx == len(tag_field_lines) - 2:
-                            out_java.write("\t\tstatic native void init();\n")
-                            out_java.write("\t}\n")
-                        elif idx == len(tag_field_lines) - 1:
-                            assert(struct_line == "")
-                        else:
-                            var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
-                            out_java.write("\t\tpublic final static class " + var_name + " extends " + struct_name + " {\n")
-                            out_c.write("jclass " + struct_name + "_" + var_name + "_class = NULL;\n")
-                            out_c.write("jmethodID " + struct_name + "_" + var_name + "_meth = NULL;\n")
-                            init_meth_jty_str = ""
-                            init_meth_params = ""
-                            init_meth_body = ""
-                            if "LDK" + var_name in union_enum_items[struct_name]:
-                                enum_var_lines = union_enum_items[struct_name]["LDK" + var_name]
-                                for idx, field in enumerate(enum_var_lines):
-                                    if idx != 0 and idx < len(enum_var_lines) - 2:
-                                        field_ty = java_c_types(field.strip(' ;'), None)
-                                        out_java.write("\t\t\tpublic " + field_ty.java_ty + " " + field_ty.var_name + ";\n")
-                                        init_meth_jty_str = init_meth_jty_str + field_ty.java_fn_ty_arg
-                                        if idx > 1:
-                                            init_meth_params = init_meth_params + ", "
-                                        init_meth_params = init_meth_params + field_ty.java_ty + " " + field_ty.var_name
-                                        init_meth_body = init_meth_body + "this." + field_ty.var_name + " = " + field_ty.var_name + "; "
-                                out_java.write("\t\t\t" + var_name + "(" + init_meth_params + ") { ")
-                                out_java.write(init_meth_body)
-                                out_java.write("}\n")
-                            out_java.write("\t\t}\n")
-                            init_meth_jty_strs[var_name] = init_meth_jty_str
-                    out_java.write("\tstatic { " + struct_name + ".init(); }\n")
-                    out_java.write("\tpublic static native " + struct_name + " " + struct_name + "_ref_from_ptr(long ptr);\n");
-
-                    out_c.write("JNIEXPORT void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass _a) {\n")
-                    for idx, struct_line in enumerate(tag_field_lines):
-                        if idx != 0 and idx < len(tag_field_lines) - 3:
-                            var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
-                            out_c.write("\t" + struct_name + "_" + var_name + "_class =\n")
-                            out_c.write("\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n")
-                            out_c.write("\tDO_ASSERT(" + struct_name + "_" + var_name + "_class != NULL);\n")
-                            out_c.write("\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n")
-                            out_c.write("\tDO_ASSERT(" + struct_name + "_" + var_name + "_meth != NULL);\n")
-                    out_c.write("}\n")
-                    out_c.write("JNIEXPORT jobject JNICALL Java_org_ldk_impl_bindings_" + struct_name.replace("_", "_1") + "_1ref_1from_1ptr (JNIEnv * env, jclass _c, jlong ptr) {\n")
-                    out_c.write("\t" + struct_name + " *obj = (" + struct_name + "*)ptr;\n")
-                    out_c.write("\tswitch(obj->tag) {\n")
-                    for idx, struct_line in enumerate(tag_field_lines):
-                        if idx != 0 and idx < len(tag_field_lines) - 3:
-                            var_name = struct_line.strip(' ,')[len(struct_name) + 1:]
-                            out_c.write("\t\tcase " + struct_name + "_" + var_name + ":\n")
-                            out_c.write("\t\t\treturn (*env)->NewObject(env, " + struct_name + "_" + var_name + "_class, " + struct_name + "_" + var_name + "_meth")
-                            if "LDK" + var_name in union_enum_items[struct_name]:
-                                enum_var_lines = union_enum_items[struct_name]["LDK" + var_name]
-                                out_c.write(",\n\t\t\t\t")
-                                for idx, field in enumerate(enum_var_lines):
-                                    if idx != 0 and idx < len(enum_var_lines) - 2:
-                                        field_ty = java_c_types(field.strip(' ;'), None)
-                                        if idx >= 2:
-                                            out_c.write(", ")
-                                        if field_ty.is_ptr:
-                                            out_c.write("(long)")
-                                        elif field_ty.passed_as_ptr or field_ty.arr_len is not None:
-                                            out_c.write("(long)&")
-                                        out_c.write("obj->" + camel_to_snake(var_name) + "." + field_ty.var_name)
-                                out_c.write("\n\t\t\t")
-                            out_c.write(");\n")
-                    out_c.write("\t\tdefault: abort();\n")
-                    out_c.write("\t}\n}\n")
+                    map_complex_enum(struct_name, union_enum_items[struct_name])
                 elif is_unitary_enum:
-                    with open(sys.argv[3] + "/" + struct_name + ".java", "w") as out_java_enum:
-                        out_java_enum.write("package org.ldk.enums;\n\n")
-                        unitary_enums.add(struct_name)
-                        out_c.write("static inline " + struct_name + " " + struct_name + "_from_java(JNIEnv *env, jclass val) {\n")
-                        out_c.write("\tswitch ((*env)->CallIntMethod(env, val, ordinal_meth)) {\n")
-                        ord_v = 0
-                        for idx, struct_line in enumerate(field_lines):
-                            if idx == 0:
-                                out_java_enum.write("public enum " + struct_name + " {\n")
-                            elif idx == len(field_lines) - 3:
-                                assert(struct_line.endswith("_Sentinel,"))
-                            elif idx == len(field_lines) - 2:
-                                out_java_enum.write("\t; static native void init();\n")
-                                out_java_enum.write("\tstatic { init(); }\n")
-                                out_java_enum.write("}")
-                                out_java.write("\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n")
-                            elif idx == len(field_lines) - 1:
-                                assert(struct_line == "")
-                            else:
-                                out_java_enum.write(struct_line + "\n")
-                                out_c.write("\t\tcase %d: return %s;\n" % (ord_v, struct_line.strip().strip(",")))
-                                ord_v = ord_v + 1
-                        out_c.write("\t}\n")
-                        out_c.write("\tabort();\n")
-                        out_c.write("}\n")
-
-                        ord_v = 0
-                        out_c.write("static jclass " + struct_name + "_class = NULL;\n")
-                        for idx, struct_line in enumerate(field_lines):
-                            if idx > 0 and idx < len(field_lines) - 3:
-                                variant = struct_line.strip().strip(",")
-                                out_c.write("static jfieldID " + struct_name + "_" + variant + " = NULL;\n")
-                        out_c.write("JNIEXPORT void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (JNIEnv * env, jclass clz) {\n")
-                        out_c.write("\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n")
-                        out_c.write("\tDO_ASSERT(" + struct_name + "_class != NULL);\n")
-                        for idx, struct_line in enumerate(field_lines):
-                            if idx > 0 and idx < len(field_lines) - 3:
-                                variant = struct_line.strip().strip(",")
-                                out_c.write("\t" + struct_name + "_" + variant + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + variant + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n")
-                                out_c.write("\tDO_ASSERT(" + struct_name + "_" + variant + " != NULL);\n")
-                        out_c.write("}\n")
-                        out_c.write("static inline jclass " + struct_name + "_to_java(JNIEnv *env, " + struct_name + " val) {\n")
-                        out_c.write("\tswitch (val) {\n")
-                        for idx, struct_line in enumerate(field_lines):
-                            if idx > 0 and idx < len(field_lines) - 3:
-                                variant = struct_line.strip().strip(",")
-                                out_c.write("\t\tcase " + variant + ":\n")
-                                out_c.write("\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + variant + ");\n")
-                                ord_v = ord_v + 1
-                        out_c.write("\t\tdefault: abort();\n")
-                        out_c.write("\t}\n")
-                        out_c.write("}\n\n")
+                    map_unitary_enum(struct_name, field_lines)
                 elif len(trait_fn_lines) > 0:
                     trait_structs.add(struct_name)
                     map_trait(struct_name, field_var_lines, trait_fn_lines)
@@ -925,10 +1347,19 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                     out_c.write("\treturn ((" + alias_match.group(2) + "*)arg)->result_ok;\n")
                     out_c.write("}\n")
                     out_c.write("JNIEXPORT jlong JNICALL Java_org_ldk_impl_bindings_" + alias_match.group(2).replace("_", "_1") + "_1get_1inner (JNIEnv * env, jclass _a, jlong arg) {\n")
-                    out_c.write("\tif (((" + alias_match.group(2) + "*)arg)->result_ok) {\n")
-                    out_c.write("\t\treturn (long)((" + alias_match.group(2) + "*)arg)->contents.result;\n")
+                    contents_ty = alias_match.group(1).replace("LDKCResultTempl", "LDKCResultPtr")
+                    res_ty, err_ty = result_ptr_struct_items[contents_ty]
+                    out_c.write("\t" + alias_match.group(2) + " *val = (" + alias_match.group(2) + "*)arg;\n")
+                    out_c.write("\tif (val->result_ok) {\n")
+                    if res_ty not in opaque_structs:
+                        out_c.write("\t\treturn (long)val->contents.result;\n")
+                    else:
+                        out_c.write("\t\treturn (long)(val->contents.result->inner) | (val->contents.result->is_owned ? 1 : 0);\n")
                     out_c.write("\t} else {\n")
-                    out_c.write("\t\treturn (long)((" + alias_match.group(2) + "*)arg)->contents.err;\n")
+                    if err_ty not in opaque_structs:
+                        out_c.write("\t\treturn (long)val->contents.err;\n")
+                    else:
+                        out_c.write("\t\treturn (long)(val->contents.err->inner) | (val->contents.err->is_owned ? 1 : 0);\n")
                     out_c.write("\t}\n}\n")
                 pass
             elif fn_ptr is not None:
@@ -944,3 +1375,9 @@ _Static_assert(offsetof(LDKCVec_u8Z, datalen) == offsetof(LDKu8slice, datalen),
                 assert(line == "\n")
 
     out_java.write("}\n")
+    for struct_name in opaque_structs:
+        with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "a") as out_java_struct:
+            out_java_struct.write("}\n")
+    for struct_name in trait_structs:
+        with open(sys.argv[3] + "/structs/" + struct_name.replace("LDK","") + ".java", "a") as out_java_struct:
+            out_java_struct.write("}\n")