| /* Copyright 2017 Google Inc. All Rights Reserved. |
| |
| Distributed under MIT license. |
| See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
| */ |
| |
| package org.brotli.wrapper.dec; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| |
| /** |
| * JNI wrapper for brotli decoder. |
| */ |
| class DecoderJNI { |
| private static native ByteBuffer nativeCreate(long[] context); |
| private static native void nativePush(long[] context, int length); |
| private static native ByteBuffer nativePull(long[] context); |
| private static native void nativeDestroy(long[] context); |
| |
| enum Status { |
| ERROR, |
| DONE, |
| NEEDS_MORE_INPUT, |
| NEEDS_MORE_OUTPUT, |
| OK |
| }; |
| |
| static class Wrapper { |
| private final long[] context = new long[2]; |
| private final ByteBuffer inputBuffer; |
| private Status lastStatus = Status.NEEDS_MORE_INPUT; |
| |
| Wrapper(int inputBufferSize) throws IOException { |
| this.context[1] = inputBufferSize; |
| this.inputBuffer = nativeCreate(this.context); |
| if (this.context[0] == 0) { |
| throw new IOException("failed to initialize native brotli decoder"); |
| } |
| } |
| |
| void push(int length) { |
| if (length < 0) { |
| throw new IllegalArgumentException("negative block length"); |
| } |
| if (context[0] == 0) { |
| throw new IllegalStateException("brotli decoder is already destroyed"); |
| } |
| if (lastStatus != Status.NEEDS_MORE_INPUT && lastStatus != Status.OK) { |
| throw new IllegalStateException("pushing input to decoder in " + lastStatus + " state"); |
| } |
| if (lastStatus == Status.OK && length != 0) { |
| throw new IllegalStateException("pushing input to decoder in OK state"); |
| } |
| nativePush(context, length); |
| parseStatus(); |
| } |
| |
| private void parseStatus() { |
| long status = context[1]; |
| if (status == 1) { |
| lastStatus = Status.DONE; |
| } else if (status == 2) { |
| lastStatus = Status.NEEDS_MORE_INPUT; |
| } else if (status == 3) { |
| lastStatus = Status.NEEDS_MORE_OUTPUT; |
| } else if (status == 4) { |
| lastStatus = Status.OK; |
| } else { |
| lastStatus = Status.ERROR; |
| } |
| } |
| |
| Status getStatus() { |
| return lastStatus; |
| } |
| |
| ByteBuffer getInputBuffer() { |
| return inputBuffer; |
| } |
| |
| ByteBuffer pull() { |
| if (context[0] == 0) { |
| throw new IllegalStateException("brotli decoder is already destroyed"); |
| } |
| if (lastStatus != Status.NEEDS_MORE_OUTPUT) { |
| throw new IllegalStateException("pulling output from decoder in " + lastStatus + " state"); |
| } |
| ByteBuffer result = nativePull(context); |
| parseStatus(); |
| return result; |
| } |
| |
| /** |
| * Releases native resources. |
| */ |
| void destroy() { |
| if (context[0] == 0) { |
| throw new IllegalStateException("brotli decoder is already destroyed"); |
| } |
| nativeDestroy(context); |
| context[0] = 0; |
| } |
| |
| @Override |
| protected void finalize() throws Throwable { |
| if (context[0] != 0) { |
| /* TODO: log resource leak? */ |
| destroy(); |
| } |
| super.finalize(); |
| } |
| } |
| } |