--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/platform/java/jni/buffer.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,370 @@
+// Copyright (C) 2004-2025 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+/* Buffer interface */
+
+JNIEXPORT void JNICALL
+FUN(Buffer_finalize)(JNIEnv *env, jobject self)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer_safe(env, self);
+	if (!ctx || !buf) return;
+	(*env)->SetLongField(env, self, fid_Buffer_pointer, 0);
+	fz_drop_buffer(ctx, buf);
+}
+
+JNIEXPORT jlong JNICALL
+FUN(Buffer_newNativeBuffer)(JNIEnv *env, jobject self, jint n)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = NULL;
+
+	if (!ctx) return 0;
+	if (n < 0) jni_throw_arg(env, "n cannot be negative");
+
+	fz_try(ctx)
+		buf = fz_new_buffer(ctx, n);
+	fz_catch(ctx)
+		jni_rethrow(env, ctx);
+
+	return jlong_cast(buf);
+}
+
+JNIEXPORT jint JNICALL
+FUN(Buffer_getLength)(JNIEnv *env, jobject self)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+
+	if (!ctx || !buf) return -1;
+
+	return (jint)fz_buffer_storage(ctx, buf, NULL);
+}
+
+JNIEXPORT jint JNICALL
+FUN(Buffer_readByte)(JNIEnv *env, jobject self, jint jat)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	size_t at = (size_t) jat;
+	size_t len;
+	unsigned char *data;
+
+	if (!ctx || !buf) return -1;
+	if (jat < 0) jni_throw_oob(env, "at is negative");
+
+	len = fz_buffer_storage(ctx, buf, &data);
+	if (at >= len)
+		return -1;
+
+	return data[at];
+}
+
+JNIEXPORT jint JNICALL
+FUN(Buffer_readBytes)(JNIEnv *env, jobject self, jint jat, jobject jbs)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	size_t at = (size_t) jat;
+	jbyte *bs = NULL;
+	size_t len;
+	size_t remaining_input = 0;
+	size_t remaining_output = 0;
+	unsigned char *data;
+
+	if (!ctx || !buf) return -1;
+	if (jat < 0) jni_throw_oob(env, "at is negative");
+	if (!jbs) jni_throw_arg(env, "buffer must not be null");
+
+	len = fz_buffer_storage(ctx, buf, &data);
+	if (at >= len)
+		return -1;
+
+	remaining_input = len - at;
+	remaining_output = (*env)->GetArrayLength(env, jbs);
+	len = fz_minz(remaining_output, remaining_input);
+
+	bs = (*env)->GetByteArrayElements(env, jbs, NULL);
+	if (!bs) jni_throw_io(env, "cannot get bytes to read");
+
+	memcpy(bs, &data[at], len);
+	(*env)->ReleaseByteArrayElements(env, jbs, bs, 0);
+
+	return (jint)len;
+}
+
+JNIEXPORT jint JNICALL
+FUN(Buffer_readBytesInto)(JNIEnv *env, jobject self, jint jat, jobject jbs, jint joff, jint jlen)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	size_t at = (size_t) jat;
+	jbyte *bs = NULL;
+	size_t off = (size_t) joff;
+	size_t len = (size_t) jlen;
+	size_t bslen = 0;
+	size_t blen;
+	unsigned char *data;
+
+	if (!ctx || !buf) return -1;
+	if (jat < 0) jni_throw_oob(env, "at is negative");
+	if (!jbs) jni_throw_arg(env, "buffer must not be null");
+	if (joff < 0) jni_throw_oob(env, "offset is negative");
+	if (jlen < 0) jni_throw_oob(env, "length is negative");
+
+	bslen = (*env)->GetArrayLength(env, jbs);
+	if (len > bslen - off) jni_throw_oob(env, "offset + length is outside of buffer");
+
+	blen = fz_buffer_storage(ctx, buf, &data);
+	if (at >= blen)
+		return -1;
+
+	len = fz_minz(len, blen - at);
+
+	bs = (*env)->GetByteArrayElements(env, jbs, NULL);
+	if (!bs) jni_throw_io(env, "cannot get bytes to read");
+
+	memcpy(&bs[off], &data[at], len);
+	(*env)->ReleaseByteArrayElements(env, jbs, bs, 0);
+
+	return (jint)len;
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeByte)(JNIEnv *env, jobject self, jbyte b)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+
+	if (!ctx || !buf) return;
+
+	fz_try(ctx)
+		fz_append_byte(ctx, buf, b);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeBytes)(JNIEnv *env, jobject self, jobject jbs)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	jsize len = 0;
+	jbyte *bs = NULL;
+
+	if (!ctx || !buf) return;
+	if (!jbs) jni_throw_arg_void(env, "buffer must not be null");
+
+	len = (*env)->GetArrayLength(env, jbs);
+	bs = (*env)->GetByteArrayElements(env, jbs, NULL);
+	if (!bs) jni_throw_io_void(env, "cannot get bytes to write");
+
+	fz_try(ctx)
+		fz_append_data(ctx, buf, bs, len);
+	fz_always(ctx)
+		(*env)->ReleaseByteArrayElements(env, jbs, bs, JNI_ABORT);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeBytesFrom)(JNIEnv *env, jobject self, jobject jbs, jint joff, jint jlen)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	jbyte *bs = NULL;
+	jsize off = (jsize) joff;
+	jsize len = (jsize) jlen;
+	jsize bslen = 0;
+
+	if (!ctx || !buf) return;
+	if (!jbs) jni_throw_arg_void(env, "buffer must not be null");
+
+	bslen = (*env)->GetArrayLength(env, jbs);
+	if (joff < 0) jni_throw_oob_void(env, "offset is negative");
+	if (jlen < 0) jni_throw_oob_void(env, "length is negative");
+	if (off + len > bslen) jni_throw_oob_void(env, "offset + length is outside of buffer");
+
+	bs = (*env)->GetByteArrayElements(env, jbs, NULL);
+	if (!bs) jni_throw_io_void(env, "cannot get bytes to write");
+
+	fz_try(ctx)
+		fz_append_data(ctx, buf, &bs[off], len);
+	fz_always(ctx)
+		(*env)->ReleaseByteArrayElements(env, jbs, bs, JNI_ABORT);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeBuffer)(JNIEnv *env, jobject self, jobject jbuf)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	fz_buffer *cat = from_Buffer(env, jbuf);
+
+	if (!ctx || !buf) return;
+	if (!cat) jni_throw_arg_void(env, "buffer must not be null");
+
+	fz_try(ctx)
+		fz_append_buffer(ctx, buf, cat);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeRune)(JNIEnv *env, jobject self, jint rune)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+
+	if (!ctx || !buf) return;
+
+	fz_try(ctx)
+		fz_append_rune(ctx, buf, rune);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeLine)(JNIEnv *env, jobject self, jstring jline)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	const char *line = NULL;
+
+	if (!ctx || !buf) return;
+	if (!jline) jni_throw_arg_void(env, "line must not be null");
+
+	line = (*env)->GetStringUTFChars(env, jline, NULL);
+	if (!line) return;
+
+	fz_try(ctx)
+	{
+		fz_append_string(ctx, buf, line);
+		fz_append_byte(ctx, buf, '\n');
+	}
+	fz_always(ctx)
+		(*env)->ReleaseStringUTFChars(env, jline, line);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_writeLines)(JNIEnv *env, jobject self, jobject jlines)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	int i = 0;
+	jsize len = 0;
+
+	if (!ctx || !buf) return;
+	if (!jlines) jni_throw_arg_void(env, "lines must not be null");
+
+	len = (*env)->GetArrayLength(env, jlines);
+
+	for (i = 0; i < len; ++i)
+	{
+		const char *line;
+		jobject jline;
+
+		jline = (*env)->GetObjectArrayElement(env, jlines, i);
+		if ((*env)->ExceptionCheck(env)) return;
+
+		if (!jline)
+			continue;
+		line = (*env)->GetStringUTFChars(env, jline, NULL);
+		if (!line) return;
+
+		fz_try(ctx)
+		{
+			fz_append_string(ctx, buf, line);
+			fz_append_byte(ctx, buf, '\n');
+		}
+		fz_always(ctx)
+			(*env)->ReleaseStringUTFChars(env, jline, line);
+		fz_catch(ctx)
+			jni_rethrow_void(env, ctx);
+	}
+}
+
+JNIEXPORT void JNICALL
+FUN(Buffer_save)(JNIEnv *env, jobject self, jstring jfilename)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	const char *filename = NULL;
+
+	if (!ctx || !buf) return;
+	if (jfilename)
+	{
+		filename = (*env)->GetStringUTFChars(env, jfilename, NULL);
+		if (!filename) return;
+	}
+
+	fz_try(ctx)
+		fz_save_buffer(ctx, buf, filename);
+	fz_always(ctx)
+		if (filename)
+			(*env)->ReleaseStringUTFChars(env, jfilename, filename);
+	fz_catch(ctx)
+		jni_rethrow_void(env, ctx);
+}
+
+JNIEXPORT jobject JNICALL
+FUN(Buffer_slice)(JNIEnv *env, jobject self, jint start, jint end)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	fz_buffer *copy = NULL;
+	jobject jcopy = NULL;
+
+	if (!ctx || !buf) return NULL;
+
+	fz_try(ctx)
+		copy = fz_slice_buffer(ctx, buf, start, end);
+	fz_catch(ctx)
+		jni_rethrow(env, ctx);
+
+	jcopy = (*env)->NewObject(env, cls_Buffer, mid_Buffer_init, copy);
+	if (!jcopy || (*env)->ExceptionCheck(env))
+		return NULL;
+
+	return jcopy;
+}
+
+JNIEXPORT jstring JNICALL
+FUN(Buffer_asString)(JNIEnv *env, jobject self)
+{
+	fz_context *ctx = get_context(env);
+	fz_buffer *buf = from_Buffer(env, self);
+	const char *s = NULL;
+
+	if (!ctx || !buf) return NULL;
+
+	fz_try(ctx)
+		s = fz_string_from_buffer(ctx, buf);
+	fz_catch(ctx)
+		jni_rethrow(env, ctx);
+
+	return to_String_safe(ctx, env, s);
+}