typedef jbyteArray int8_tArray;
typedef jshortArray int16_tArray;
-static inline jstring str_ref_to_java(JNIEnv *env, const char* chars, size_t len) {
- // Sadly we need to create a temporary because Java can't accept a char* without a 0-terminator
- char* conv_buf = MALLOC(len + 1, "str conv buf");
- memcpy(conv_buf, chars, len);
- conv_buf[len] = 0;
- jstring ret = (*env)->NewStringUTF(env, conv_buf);
- FREE(conv_buf);
+static inline jstring str_ref_to_java(JNIEnv *env, const unsigned char* chars, size_t len) {
+ // Java uses "Modified UTF-8" rather than UTF-8. This requires special
+ // handling for codepoints above 0xFFFF, which get converted from four
+ // bytes to six. We don't know upfront how many codepoints in the string
+ // are above 0xFFFF, so we just allocate an extra 33% up front and waste a
+ // bit of space.
+ unsigned char* java_chars = MALLOC(len * 3 / 2 + 1, "str conv buf");
+ unsigned char* next_java_char = java_chars;
+ const unsigned char* next_in_char = chars;
+ const unsigned char* end = chars + len;
+ #define COPY_CHAR_TO_JAVA do { *next_java_char = *next_in_char; next_java_char++; next_in_char++; } while (0)
+
+ while (next_in_char < end) {
+ if (!*next_in_char) break;
+ if (!(*next_in_char & 0b10000000)) {
+ COPY_CHAR_TO_JAVA;
+ } else if ((*next_in_char & 0b11100000) == 0b11000000) {
+ if (next_in_char + 2 > end) { CHECK(false); break; } // bad string
+ COPY_CHAR_TO_JAVA;
+ COPY_CHAR_TO_JAVA;
+ } else if ((*next_in_char & 0b11110000) == 0b11100000) {
+ if (next_in_char + 3 > end) { CHECK(false); break; } // bad string
+ COPY_CHAR_TO_JAVA;
+ COPY_CHAR_TO_JAVA;
+ COPY_CHAR_TO_JAVA;
+ } else if ((*next_in_char & 0b11111000) == 0b11110000) {
+ if (next_in_char + 4 > end) { CHECK(false); break; } // bad string
+ uint32_t codepoint = 0;
+ codepoint |= (((uint32_t)*(next_in_char )) & 0b00000111) << 18;
+ codepoint |= (((uint32_t)*(next_in_char + 1)) & 0b00111111) << 12;
+ codepoint |= (((uint32_t)*(next_in_char + 2)) & 0b00111111) << 6;
+ codepoint |= (((uint32_t)*(next_in_char + 3)) & 0b00111111) << 0;
+ codepoint -= 0x10000;
+ *next_java_char = 0b11101101;
+ next_java_char++;
+ *next_java_char = 0b10100000 | ((codepoint >> 16) & 0b00001111);
+ next_java_char++;
+ *next_java_char = 0b10000000 | ((codepoint >> 10) & 0b00111111);
+ next_java_char++;
+ *next_java_char = 0b11101101;
+ next_java_char++;
+ *next_java_char = 0b10110000 | ((codepoint >> 6) & 0b00001111);
+ next_java_char++;
+ *next_java_char = 0b10000000 | ((codepoint >> 0) & 0b00111111);
+ next_java_char++;
+ next_in_char += 4;
+ } else {
+ // Bad string
+ CHECK(false);
+ break;
+ }
+ }
+ *next_java_char = 0;
+ jstring ret = (*env)->NewStringUTF(env, java_chars);
+ FREE(java_chars);
return ret;
}
static inline LDKStr java_to_owned_str(JNIEnv *env, jstring str) {
uint64_t str_len = (*env)->GetStringUTFLength(env, str);
- char* newchars = MALLOC(str_len + 1, "String chars");
- const char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
- memcpy(newchars, jchars, str_len);
- newchars[str_len] = 0;
+ // Java uses "Modified UTF-8" rather than UTF-8. This requires special
+ // handling for codepoints above 0xFFFF, which we implement below.
+ unsigned char* newchars = MALLOC(str_len, "String chars");
+ unsigned char* next_newchar = newchars;
+ uint64_t utf8_len = 0;
+
+ const unsigned char* jchars = (*env)->GetStringUTFChars(env, str, NULL);
+ const unsigned char* next_char = jchars;
+ const unsigned char* end = jchars + str_len;
+
+ #define COPY_CHAR_FROM_JAVA do { *next_newchar = *next_char; next_newchar++; next_char++; utf8_len++; } while (0)
+
+ while (next_char < end) {
+ if (!(*next_char & 0b10000000)) {
+ CHECK(*next_char != 0); // Bad Modified UTF-8 string, but we'll just cut here
+ COPY_CHAR_FROM_JAVA;
+ } else if ((*next_char & 0b11100000) == 0b11000000) {
+ if (next_char + 2 > end) { CHECK(false); break; } // bad string
+ uint16_t codepoint = 0;
+ codepoint |= (((uint16_t)(*next_char & 0x1f)) << 6);
+ codepoint |= *(next_char + 1) & 0x3f;
+ if (codepoint == 0) {
+ // We should really never get null codepoints, but java allows them.
+ // Just skip it.
+ next_char += 2;
+ } else {
+ COPY_CHAR_FROM_JAVA;
+ COPY_CHAR_FROM_JAVA;
+ }
+ } else if ((*next_char & 0b11110000) == 0b11100000) {
+ if (next_char + 3 > end) { CHECK(false); break; } // bad string
+ if (*next_char == 0b11101101 && (*(next_char + 1) & 0b11110000) == 0b10100000) {
+ // Surrogate code unit shoul indicate we have a codepoint above
+ // 0xFFFF, which is where Modified UTF-8 and UTF-8 diverge.
+ if (next_char + 6 > end) { CHECK(false); break; } // bad string
+ CHECK(*(next_char + 3) == 0b11101101);
+ CHECK((*(next_char + 4) & 0b11110000) == 0b10110000);
+ // Calculate the codepoint per https://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/types.html#wp16542
+ uint32_t codepoint = 0x10000;
+ codepoint += ((((uint32_t)*(next_char + 1)) & 0x0f) << 16);
+ codepoint += ((((uint32_t)*(next_char + 2)) & 0x3f) << 10);
+ codepoint += ((((uint32_t)*(next_char + 4)) & 0x0f) << 6);
+ codepoint += (((uint32_t)*(next_char + 5)) & 0x3f);
+ *next_newchar = 0b11110000 | ((codepoint >> 18) & 0b111);
+ next_newchar++;
+ *next_newchar = 0b10000000 | ((codepoint >> 12) & 0b111111);
+ next_newchar++;
+ *next_newchar = 0b10000000 | ((codepoint >> 6) & 0b111111);
+ next_newchar++;
+ *next_newchar = 0b10000000 | ( codepoint & 0b111111);
+ next_newchar++;
+ next_char += 6;
+ utf8_len += 4;
+ } else {
+ COPY_CHAR_FROM_JAVA;
+ COPY_CHAR_FROM_JAVA;
+ COPY_CHAR_FROM_JAVA;
+ }
+ } else {
+ // Bad string
+ CHECK(false);
+ break;
+ }
+ }
(*env)->ReleaseStringUTFChars(env, str, jchars);
LDKStr res = {
.chars = newchars,
- .len = str_len,
+ .len = utf8_len,
.chars_is_owned = true
};
return res;
projects / ldk-java / commitdiff