1 files changed, 94 insertions, 0 deletions
diff --git a/src/runtime/java/jni_utils.c b/src/runtime/java/jni_utils.c
new file mode 100644
index 000000000..64352e157
--- /dev/null
+++ b/src/runtime/java/jni_utils.c
@@ -0,0 +1,94 @@
+#include <jni.h>
+#include <gu/utf8.h>
+#include <gu/string.h>
+#include "jni_utils.h"
+#ifndef __MINGW32__
+#include <alloca.h>
+#else
+#include <malloc.h>
+#endif
+
+#define l2p(x) ((void*) (intptr_t) (x))
+#define p2l(x) ((jlong) (intptr_t) (x))
+
+jstring
+gu2j_string(JNIEnv *env, GuString s) {
+	const char* utf8 = s;
+	size_t len = strlen(s);
+
+	jchar* utf16 = alloca(len*sizeof(jchar));
+	jchar* dst   = utf16;
+	while (s-utf8 < len) {
+		GuUCS ucs = gu_utf8_decode((const uint8_t**) &s);
+
+		if (ucs <= 0xFFFF) {
+			*dst++ = ucs;
+		} else {
+			ucs -= 0x10000;
+			*dst++ = 0xD800+((ucs >> 10) & 0x3FF);
+			*dst++ = 0xDC00+(ucs & 0x3FF);
+		}
+	}
+
+	return (*env)->NewString(env, utf16, dst-utf16);
+}
+
+GuString
+j2gu_string(JNIEnv *env, jstring s, GuPool* pool) {
+	GuString str = (*env)->GetStringUTFChars(env, s, 0);
+	GuString copy = gu_string_copy(str, pool);
+	(*env)->ReleaseStringUTFChars(env, s, str);
+	return copy;
+}
+
+size_t
+gu2j_string_offset(GuString s, size_t offset) {
+	const char* utf8 = s;
+	size_t joffset = 0;
+	while (utf8-s < offset) {
+		gu_utf8_decode((const uint8_t**) &utf8);
+		joffset++;
+	}
+	return joffset;
+}
+
+size_t
+j2gu_string_offset(GuString s, size_t joffset) {
+	const char* utf8 = s;
+	while (joffset > 0) {
+		gu_utf8_decode((const uint8_t**) &utf8);
+		joffset--;
+	}
+	return utf8-s;
+}
+
+void*
+get_ref(JNIEnv *env, jobject self) {
+	jfieldID refId = (*env)->GetFieldID(env, (*env)->GetObjectClass(env, self), "ref", "J");
+	return l2p((*env)->GetLongField(env, self, refId));
+}
+
+void
+throw_jstring_exception(JNIEnv *env, const char* class_name, jstring msg)
+{
+	jclass exception_class = (*env)->FindClass(env, class_name);
+	if (!exception_class)
+		return;
+	jmethodID constrId = (*env)->GetMethodID(env, exception_class, "<init>", "(Ljava/lang/String;)V");
+	if (!constrId)
+		return;
+	jobject exception = (*env)->NewObject(env, exception_class, constrId, msg);
+	if (!exception)
+		return;
+	(*env)->Throw(env, exception);
+}
+
+void
+throw_string_exception(JNIEnv *env, const char* class_name, const char* msg)
+{
+	jstring jmsg = (*env)->NewStringUTF(env, msg);
+	if (!jmsg)
+		return;
+	throw_jstring_exception(env, class_name, jmsg);
+}
+