Support converting Option<&[]> to C

[ldk-c-bindings] / lightning-c-bindings / src / c_types / mod.rs

diff --git a/lightning-c-bindings/src/c_types/mod.rs b/lightning-c-bindings/src/c_types/mod.rs
index 95dae8da8762437db4dbd53f456def6ac122dcab..69319563b72a8c2fd284fda2de9f7a9de460731f 100644 (file)
--- a/lightning-c-bindings/src/c_types/mod.rs
+++ b/lightning-c-bindings/src/c_types/mod.rs
@@ -15,6 +15,18 @@ use bitcoin::bech32;
 
 use std::convert::TryInto; // Bindings need at least rustc 1.34
 
+use std::io::{Cursor, Read}; // TODO: We should use core2 here when we support no_std
+
+#[repr(C)]
+/// A dummy struct of which an instance must never exist.
+/// This corresponds to the Rust type `Infallible`, or, in unstable rust, `!`
+pub struct NotConstructable {
+       _priv_thing: core::convert::Infallible,
+}
+impl From<core::convert::Infallible> for NotConstructable {
+       fn from(_: core::convert::Infallible) -> Self { unreachable!(); }
+}
+
 /// Integer in the range `0..32`
 #[derive(PartialEq, Eq, Copy, Clone)]
 #[allow(non_camel_case_types)]
@@ -289,6 +301,13 @@ pub extern "C" fn Transaction_free(_res: Transaction) { }
 pub(crate) fn bitcoin_to_C_outpoint(outpoint: ::bitcoin::blockdata::transaction::OutPoint) -> crate::lightning::chain::transaction::OutPoint {
        crate::lightning::chain::transaction::OutPoint_new(ThirtyTwoBytes { data: outpoint.txid.into_inner() }, outpoint.vout.try_into().unwrap())
 }
+pub(crate) fn C_to_bitcoin_outpoint(outpoint: crate::lightning::chain::transaction::OutPoint) -> ::bitcoin::blockdata::transaction::OutPoint {
+       unsafe {
+               ::bitcoin::blockdata::transaction::OutPoint {
+                       txid: (*outpoint.inner).txid, vout: (*outpoint.inner).index as u32
+               }
+       }
+}
 
 #[repr(C)]
 #[derive(Clone)]
@@ -348,6 +367,18 @@ impl u8slice {
                if self.datalen == 0 { return &[]; }
                unsafe { std::slice::from_raw_parts(self.data, self.datalen) }
        }
+       pub(crate) fn to_reader<'a>(&'a self) -> Cursor<&'a [u8]> {
+               let sl = self.to_slice();
+               Cursor::new(sl)
+       }
+       pub(crate) fn from_vec(v: &derived::CVec_u8Z) -> u8slice {
+               Self::from_slice(v.as_slice())
+       }
+}
+pub(crate) fn reader_to_vec<R: Read>(r: &mut R) -> derived::CVec_u8Z {
+       let mut res = Vec::new();
+       r.read_to_end(&mut res).unwrap();
+       derived::CVec_u8Z::from(res)
 }
 
 #[repr(C)]
@@ -404,7 +435,6 @@ pub(crate) fn deserialize_obj_arg<A, I: lightning::util::ser::ReadableArgs<A>>(s
 }
 
 #[repr(C)]
-#[derive(Clone)]
 /// A Rust str object, ie a reference to a UTF8-valid string.
 /// This is *not* null-terminated so cannot be used directly as a C string!
 pub struct Str {
@@ -448,6 +478,11 @@ impl Into<Str> for String {
                Str { chars: s.as_ptr(), len: s.len(), chars_is_owned: true }
        }
 }
+impl Clone for Str {
+       fn clone(&self) -> Self {
+               self.into_str().clone().into()
+       }
+}
 
 impl Drop for Str {
        fn drop(&mut self) {
@@ -572,3 +607,28 @@ pub(crate) mod ObjOps {
                }
        }
 }
+
+pub(crate) struct SmartPtr<T> {
+       ptr: *mut T,
+}
+impl<T> SmartPtr<T> {
+       pub(crate) fn from_obj(o: T) -> Self {
+               Self { ptr: Box::into_raw(Box::new(o)) }
+       }
+       pub(crate) fn null() -> Self {
+               Self { ptr: std::ptr::null_mut() }
+       }
+}
+impl<T> Drop for SmartPtr<T> {
+       fn drop(&mut self) {
+               if self.ptr != std::ptr::null_mut() {
+                       unsafe { Box::from_raw(self.ptr); }
+               }
+       }
+}
+impl<T> std::ops::Deref for SmartPtr<T> {
+       type Target = *mut T;
+       fn deref(&self) -> &*mut T {
+               &self.ptr
+       }
+}