com.itextpdf.io.codec.brotli.dec.State Maven / Gradle / Ivy
/* Copyright 2015 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
package com.itextpdf.io.codec.brotli.dec;
import java.io.IOException;
import java.io.InputStream;
final class State {
int runningState = RunningState.UNINITIALIZED;
int nextRunningState;
final BitReader br = new BitReader();
byte[] ringBuffer;
final int[] blockTypeTrees = new int[3 * Huffman.HUFFMAN_MAX_TABLE_SIZE];
final int[] blockLenTrees = new int[3 * Huffman.HUFFMAN_MAX_TABLE_SIZE];
// Current meta-block header information.
int metaBlockLength;
boolean inputEnd;
boolean isUncompressed;
boolean isMetadata;
final HuffmanTreeGroup hGroup0 = new HuffmanTreeGroup();
final HuffmanTreeGroup hGroup1 = new HuffmanTreeGroup();
final HuffmanTreeGroup hGroup2 = new HuffmanTreeGroup();
final int[] blockLength = new int[3];
final int[] numBlockTypes = new int[3];
final int[] blockTypeRb = new int[6];
final int[] distRb = {16, 15, 11, 4};
int pos = 0;
int maxDistance = 0;
int distRbIdx = 0;
boolean trivialLiteralContext = false;
int literalTreeIndex = 0;
int literalTree;
int j;
int insertLength;
byte[] contextModes;
byte[] contextMap;
int contextMapSlice;
int distContextMapSlice;
int contextLookupOffset1;
int contextLookupOffset2;
int treeCommandOffset;
int distanceCode;
byte[] distContextMap;
int numDirectDistanceCodes;
int distancePostfixMask;
int distancePostfixBits;
int distance;
int copyLength;
int copyDst;
int maxBackwardDistance;
int maxRingBufferSize;
int ringBufferSize = 0;
long expectedTotalSize = 0;
byte[] customDictionary = new byte[0];
int bytesToIgnore = 0;
int outputOffset;
int outputLength;
int outputUsed;
int bytesWritten;
int bytesToWrite;
byte[] output;
// TODO: Update to current spec.
private static int decodeWindowBits(BitReader br) {
if (BitReader.readBits(br, 1) == 0) {
return 16;
}
int n = BitReader.readBits(br, 3);
if (n != 0) {
return 17 + n;
}
n = BitReader.readBits(br, 3);
if (n != 0) {
return 8 + n;
}
return 17;
}
/**
* Associate input with decoder state.
*
* @param state uninitialized state without associated input
* @param input compressed data source
*/
static void setInput(State state, InputStream input) {
if (state.runningState != RunningState.UNINITIALIZED) {
throw new IllegalStateException("State MUST be uninitialized");
}
BitReader.init(state.br, input);
int windowBits = decodeWindowBits(state.br);
if (windowBits == 9) { /* Reserved case for future expansion. */
throw new BrotliRuntimeException("Invalid 'windowBits' code");
}
state.maxRingBufferSize = 1 << windowBits;
state.maxBackwardDistance = state.maxRingBufferSize - 16;
state.runningState = RunningState.BLOCK_START;
}
static void close(State state) throws IOException {
if (state.runningState == RunningState.UNINITIALIZED) {
throw new IllegalStateException("State MUST be initialized");
}
if (state.runningState == RunningState.CLOSED) {
return;
}
state.runningState = RunningState.CLOSED;
BitReader.close(state.br);
}
}