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1 /* -*-mode:java; c-basic-offset:2; -*- */
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2 /*
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3 Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved.
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4
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5 Redistribution and use in source and binary forms, with or without
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6 modification, are permitted provided that the following conditions are met:
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7
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8 1. Redistributions of source code must retain the above copyright notice,
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9 this list of conditions and the following disclaimer.
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10
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11 2. Redistributions in binary form must reproduce the above copyright
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12 notice, this list of conditions and the following disclaimer in
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13 the documentation and/or other materials provided with the distribution.
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14
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15 3. The names of the authors may not be used to endorse or promote products
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16 derived from this software without specific prior written permission.
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17
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18 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
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19 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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20 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
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21 INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
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22 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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23 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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24 OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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25 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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26 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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27 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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28 */
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29 /*
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30 * This program is based on zlib-1.1.3, so all credit should go authors
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31 * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
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32 * and contributors of zlib.
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33 */
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34
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35 package com.jcraft.jzlib;
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36
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37 public
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38 final class Deflate {
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39
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40 static final private int MAX_MEM_LEVEL = 9;
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41
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42 static final private int Z_DEFAULT_COMPRESSION = -1;
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43
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44 static final private int MAX_WBITS = 15; // 32K LZ77 window
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45 static final private int DEF_MEM_LEVEL = 8;
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46
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47 static class Config {
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48 int good_length; // reduce lazy search above this match length
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49 int max_lazy; // do not perform lazy search above this match length
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50 int nice_length; // quit search above this match length
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51 int max_chain;
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52 int func;
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53 Config(int good_length, int max_lazy,
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54 int nice_length, int max_chain, int func) {
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55 this.good_length = good_length;
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56 this.max_lazy = max_lazy;
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57 this.nice_length = nice_length;
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58 this.max_chain = max_chain;
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59 this.func = func;
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60 }
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61 }
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62
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63 static final private int STORED = 0;
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64 static final private int FAST = 1;
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65 static final private int SLOW = 2;
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66 static final private Config[] config_table;
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67 static {
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68 config_table = new Config[10];
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69 // good lazy nice chain
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70 config_table[0] = new Config(0, 0, 0, 0, STORED);
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71 config_table[1] = new Config(4, 4, 8, 4, FAST);
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72 config_table[2] = new Config(4, 5, 16, 8, FAST);
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73 config_table[3] = new Config(4, 6, 32, 32, FAST);
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74 config_table[4] = new Config(4, 4, 16, 16, SLOW);
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75 config_table[5] = new Config(8, 16, 32, 32, SLOW);
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76 config_table[6] = new Config(8, 16, 128, 128, SLOW);
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77 config_table[7] = new Config(8, 32, 128, 256, SLOW);
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78 config_table[8] = new Config(32, 128, 258, 1024, SLOW);
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79 config_table[9] = new Config(32, 258, 258, 4096, SLOW);
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80 }
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81
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82 static final private String[] z_errmsg = {
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83 "need dictionary", // Z_NEED_DICT 2
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84 "stream end", // Z_STREAM_END 1
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85 "", // Z_OK 0
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86 "file error", // Z_ERRNO (-1)
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87 "stream error", // Z_STREAM_ERROR (-2)
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88 "data error", // Z_DATA_ERROR (-3)
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89 "insufficient memory", // Z_MEM_ERROR (-4)
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90 "buffer error", // Z_BUF_ERROR (-5)
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91 "incompatible version",// Z_VERSION_ERROR (-6)
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92 ""
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93 };
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94
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95 // block not completed, need more input or more output
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96 static final private int NeedMore = 0;
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97
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98 // block flush performed
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99 static final private int BlockDone = 1;
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100
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101 // finish started, need only more output at next deflate
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102 static final private int FinishStarted = 2;
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103
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104 // finish done, accept no more input or output
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105 static final private int FinishDone = 3;
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106
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107 // preset dictionary flag in zlib header
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108 static final private int PRESET_DICT = 0x20;
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109
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110 static final private int Z_FILTERED = 1;
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111 static final private int Z_HUFFMAN_ONLY = 2;
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112 static final private int Z_DEFAULT_STRATEGY = 0;
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113
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114 static final private int Z_NO_FLUSH = 0;
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115 static final private int Z_PARTIAL_FLUSH = 1;
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116 static final private int Z_SYNC_FLUSH = 2;
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117 static final private int Z_FULL_FLUSH = 3;
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118 static final private int Z_FINISH = 4;
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119
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120 static final private int Z_OK = 0;
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121 static final private int Z_STREAM_END = 1;
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122 static final private int Z_NEED_DICT = 2;
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123 static final private int Z_ERRNO = -1;
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124 static final private int Z_STREAM_ERROR = -2;
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125 static final private int Z_DATA_ERROR = -3;
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126 static final private int Z_MEM_ERROR = -4;
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127 static final private int Z_BUF_ERROR = -5;
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128 static final private int Z_VERSION_ERROR = -6;
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129
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130 static final private int INIT_STATE = 42;
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131 static final private int BUSY_STATE = 113;
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132 static final private int FINISH_STATE = 666;
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133
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134 // The deflate compression method
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135 static final private int Z_DEFLATED = 8;
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136
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137 static final private int STORED_BLOCK = 0;
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138 static final private int STATIC_TREES = 1;
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139 static final private int DYN_TREES = 2;
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140
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141 // The three kinds of block type
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142 static final private int Z_BINARY = 0;
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143 static final private int Z_ASCII = 1;
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144 static final private int Z_UNKNOWN = 2;
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145
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146 static final private int Buf_size = 8 * 2;
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147
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148 // repeat previous bit length 3-6 times (2 bits of repeat count)
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149 static final private int REP_3_6 = 16;
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150
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151 // repeat a zero length 3-10 times (3 bits of repeat count)
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152 static final private int REPZ_3_10 = 17;
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153
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154 // repeat a zero length 11-138 times (7 bits of repeat count)
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155 static final private int REPZ_11_138 = 18;
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156
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157 static final private int MIN_MATCH = 3;
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158 static final private int MAX_MATCH = 258;
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159 static final private int MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1);
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160
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161 static final private int MAX_BITS = 15;
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162 static final private int D_CODES = 30;
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163 static final private int BL_CODES = 19;
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164 static final private int LENGTH_CODES = 29;
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165 static final private int LITERALS = 256;
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166 static final private int L_CODES = (LITERALS + 1 + LENGTH_CODES);
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167 static final private int HEAP_SIZE = (2 * L_CODES + 1);
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168
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169 static final private int END_BLOCK = 256;
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170
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171 ZStream strm; // pointer back to this zlib stream
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172 int status; // as the name implies
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173 byte[] pending_buf; // output still pending
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174 int pending_buf_size; // size of pending_buf
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175 int pending_out; // next pending byte to output to the stream
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176 int pending; // nb of bytes in the pending buffer
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177 int noheader; // suppress zlib header and adler32
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178 byte data_type; // UNKNOWN, BINARY or ASCII
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179 byte method; // STORED (for zip only) or DEFLATED
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180 int last_flush; // value of flush param for previous deflate call
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181
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182 int w_size; // LZ77 window size (32K by default)
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183 int w_bits; // log2(w_size) (8..16)
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184 int w_mask; // w_size - 1
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185
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186 byte[] window;
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187 // Sliding window. Input bytes are read into the second half of the window,
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188 // and move to the first half later to keep a dictionary of at least wSize
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189 // bytes. With this organization, matches are limited to a distance of
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190 // wSize-MAX_MATCH bytes, but this ensures that IO is always
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191 // performed with a length multiple of the block size. Also, it limits
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192 // the window size to 64K, which is quite useful on MSDOS.
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193 // To do: use the user input buffer as sliding window.
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194
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195 int window_size;
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196 // Actual size of window: 2*wSize, except when the user input buffer
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197 // is directly used as sliding window.
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198
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199 short[] prev;
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200 // Link to older string with same hash index. To limit the size of this
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201 // array to 64K, this link is maintained only for the last 32K strings.
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202 // An index in this array is thus a window index modulo 32K.
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203
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204 short[] head; // Heads of the hash chains or NIL.
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205
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206 int ins_h; // hash index of string to be inserted
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207 int hash_size; // number of elements in hash table
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208 int hash_bits; // log2(hash_size)
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209 int hash_mask; // hash_size-1
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210
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211 // Number of bits by which ins_h must be shifted at each input
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212 // step. It must be such that after MIN_MATCH steps, the oldest
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213 // byte no longer takes part in the hash key, that is:
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214 // hash_shift * MIN_MATCH >= hash_bits
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215 int hash_shift;
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216
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217 // Window position at the beginning of the current output block. Gets
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218 // negative when the window is moved backwards.
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219
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220 int block_start;
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221
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222 int match_length; // length of best match
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223 int prev_match; // previous match
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224 int match_available; // set if previous match exists
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225 int strstart; // start of string to insert
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226 int match_start; // start of matching string
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227 int lookahead; // number of valid bytes ahead in window
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228
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229 // Length of the best match at previous step. Matches not greater than this
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230 // are discarded. This is used in the lazy match evaluation.
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231 int prev_length;
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232
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233 // To speed up deflation, hash chains are never searched beyond this
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234 // length. A higher limit improves compression ratio but degrades the speed.
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235 int max_chain_length;
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236
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237 // Attempt to find a better match only when the current match is strictly
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238 // smaller than this value. This mechanism is used only for compression
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239 // levels >= 4.
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240 int max_lazy_match;
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241
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242 // Insert new strings in the hash table only if the match length is not
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243 // greater than this length. This saves time but degrades compression.
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244 // max_insert_length is used only for compression levels <= 3.
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245
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246 int level; // compression level (1..9)
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247 int strategy; // favor or force Huffman coding
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248
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249 // Use a faster search when the previous match is longer than this
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250 int good_match;
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251
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252 // Stop searching when current match exceeds this
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253 int nice_match;
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254
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255 short[] dyn_ltree; // literal and length tree
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256 short[] dyn_dtree; // distance tree
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257 short[] bl_tree; // Huffman tree for bit lengths
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258
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259 Tree l_desc = new Tree(); // desc for literal tree
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260 Tree d_desc = new Tree(); // desc for distance tree
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261 Tree bl_desc = new Tree(); // desc for bit length tree
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262
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263 // number of codes at each bit length for an optimal tree
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264 short[] bl_count = new short[MAX_BITS + 1];
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265
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266 // heap used to build the Huffman trees
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267 int[] heap = new int[2 * L_CODES + 1];
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268
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269 int heap_len; // number of elements in the heap
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270 int heap_max; // element of largest frequency
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271 // The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
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272 // The same heap array is used to build all trees.
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273
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274 // Depth of each subtree used as tie breaker for trees of equal frequency
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275 byte[] depth = new byte[2 * L_CODES + 1];
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276
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277 int l_buf; // index for literals or lengths */
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278
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279 // Size of match buffer for literals/lengths. There are 4 reasons for
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280 // limiting lit_bufsize to 64K:
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281 // - frequencies can be kept in 16 bit counters
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282 // - if compression is not successful for the first block, all input
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283 // data is still in the window so we can still emit a stored block even
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284 // when input comes from standard input. (This can also be done for
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285 // all blocks if lit_bufsize is not greater than 32K.)
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286 // - if compression is not successful for a file smaller than 64K, we can
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287 // even emit a stored file instead of a stored block (saving 5 bytes).
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288 // This is applicable only for zip (not gzip or zlib).
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289 // - creating new Huffman trees less frequently may not provide fast
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290 // adaptation to changes in the input data statistics. (Take for
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291 // example a binary file with poorly compressible code followed by
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292 // a highly compressible string table.) Smaller buffer sizes give
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293 // fast adaptation but have of course the overhead of transmitting
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294 // trees more frequently.
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295 // - I can't count above 4
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296 int lit_bufsize;
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297
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298 int last_lit; // running index in l_buf
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299
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300 // Buffer for distances. To simplify the code, d_buf and l_buf have
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301 // the same number of elements. To use different lengths, an extra flag
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302 // array would be necessary.
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303
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304 int d_buf; // index of pendig_buf
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305
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306 int opt_len; // bit length of current block with optimal trees
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307 int static_len; // bit length of current block with static trees
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308 int matches; // number of string matches in current block
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309 int last_eob_len; // bit length of EOB code for last block
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310
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311 // Output buffer. bits are inserted starting at the bottom (least
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312 // significant bits).
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313 short bi_buf;
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314
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315 // Number of valid bits in bi_buf. All bits above the last valid bit
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316 // are always zero.
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317 int bi_valid;
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318
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319 Deflate() {
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320 dyn_ltree = new short[HEAP_SIZE * 2];
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321 dyn_dtree = new short[(2 * D_CODES + 1) * 2]; // distance tree
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322 bl_tree = new short[(2 * BL_CODES + 1) * 2]; // Huffman tree for bit lengths
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323 }
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324
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325 void lm_init() {
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326 window_size = 2 * w_size;
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327 head[hash_size - 1] = 0;
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328
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329 for (int i = 0; i < hash_size - 1; i++) {
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330 head[i] = 0;
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331 }
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332
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333 // Set the default configuration parameters:
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334 max_lazy_match = Deflate.config_table[level].max_lazy;
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335 good_match = Deflate.config_table[level].good_length;
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336 nice_match = Deflate.config_table[level].nice_length;
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337 max_chain_length = Deflate.config_table[level].max_chain;
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338 strstart = 0;
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339 block_start = 0;
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340 lookahead = 0;
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341 match_length = prev_length = MIN_MATCH - 1;
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342 match_available = 0;
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343 ins_h = 0;
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344 }
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345
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346 // Initialize the tree data structures for a new zlib stream.
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347 void tr_init() {
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348 l_desc.dyn_tree = dyn_ltree;
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349 l_desc.stat_desc = StaticTree.static_l_desc;
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350 d_desc.dyn_tree = dyn_dtree;
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351 d_desc.stat_desc = StaticTree.static_d_desc;
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352 bl_desc.dyn_tree = bl_tree;
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353 bl_desc.stat_desc = StaticTree.static_bl_desc;
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354 bi_buf = 0;
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355 bi_valid = 0;
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356 last_eob_len = 8; // enough lookahead for inflate
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357 // Initialize the first block of the first file:
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358 init_block();
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359 }
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360
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361 void init_block() {
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362 // Initialize the trees.
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363 for (int i = 0; i < L_CODES; i++) dyn_ltree[i * 2] = 0;
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364
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365 for (int i = 0; i < D_CODES; i++) dyn_dtree[i * 2] = 0;
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366
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367 for (int i = 0; i < BL_CODES; i++) bl_tree[i * 2] = 0;
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368
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369 dyn_ltree[END_BLOCK * 2] = 1;
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370 opt_len = static_len = 0;
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371 last_lit = matches = 0;
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372 }
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373
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374 // Restore the heap property by moving down the tree starting at node k,
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375 // exchanging a node with the smallest of its two sons if necessary, stopping
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376 // when the heap property is re-established (each father smaller than its
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377 // two sons).
|
|
|
378 void pqdownheap(short[] tree, // the tree to restore
|
|
|
379 int k // node to move down
|
|
|
380 ) {
|
|
|
381 int v = heap[k];
|
|
|
382 int j = k << 1; // left son of k
|
|
|
383
|
|
|
384 while (j <= heap_len) {
|
|
|
385 // Set j to the smallest of the two sons:
|
|
|
386 if (j < heap_len &&
|
|
|
387 smaller(tree, heap[j + 1], heap[j], depth)) {
|
|
|
388 j++;
|
|
|
389 }
|
|
|
390
|
|
|
391 // Exit if v is smaller than both sons
|
|
|
392 if (smaller(tree, v, heap[j], depth)) break;
|
|
|
393
|
|
|
394 // Exchange v with the smallest son
|
|
|
395 heap[k] = heap[j]; k = j;
|
|
|
396 // And continue down the tree, setting j to the left son of k
|
|
|
397 j <<= 1;
|
|
|
398 }
|
|
|
399
|
|
|
400 heap[k] = v;
|
|
|
401 }
|
|
|
402
|
|
|
403 static boolean smaller(short[] tree, int n, int m, byte[] depth) {
|
|
|
404 short tn2 = tree[n * 2];
|
|
|
405 short tm2 = tree[m * 2];
|
|
|
406 return (tn2 < tm2 ||
|
|
|
407 (tn2 == tm2 && depth[n] <= depth[m]));
|
|
|
408 }
|
|
|
409
|
|
|
410 // Scan a literal or distance tree to determine the frequencies of the codes
|
|
|
411 // in the bit length tree.
|
|
|
412 void scan_tree(short[] tree, // the tree to be scanned
|
|
|
413 int max_code // and its largest code of non zero frequency
|
|
|
414 ) {
|
|
|
415 int n; // iterates over all tree elements
|
|
|
416 int prevlen = -1; // last emitted length
|
|
|
417 int curlen; // length of current code
|
|
|
418 int nextlen = tree[0 * 2 + 1]; // length of next code
|
|
|
419 int count = 0; // repeat count of the current code
|
|
|
420 int max_count = 7; // max repeat count
|
|
|
421 int min_count = 4; // min repeat count
|
|
|
422
|
|
|
423 if (nextlen == 0) { max_count = 138; min_count = 3; }
|
|
|
424
|
|
|
425 tree[(max_code + 1) * 2 + 1] = (short)0xffff; // guard
|
|
|
426
|
|
|
427 for (n = 0; n <= max_code; n++) {
|
|
|
428 curlen = nextlen; nextlen = tree[(n + 1) * 2 + 1];
|
|
|
429
|
|
|
430 if (++count < max_count && curlen == nextlen) {
|
|
|
431 continue;
|
|
|
432 }
|
|
|
433 else if (count < min_count) {
|
|
|
434 bl_tree[curlen * 2] += count;
|
|
|
435 }
|
|
|
436 else if (curlen != 0) {
|
|
|
437 if (curlen != prevlen) bl_tree[curlen * 2]++;
|
|
|
438
|
|
|
439 bl_tree[REP_3_6 * 2]++;
|
|
|
440 }
|
|
|
441 else if (count <= 10) {
|
|
|
442 bl_tree[REPZ_3_10 * 2]++;
|
|
|
443 }
|
|
|
444 else {
|
|
|
445 bl_tree[REPZ_11_138 * 2]++;
|
|
|
446 }
|
|
|
447
|
|
|
448 count = 0; prevlen = curlen;
|
|
|
449
|
|
|
450 if (nextlen == 0) {
|
|
|
451 max_count = 138; min_count = 3;
|
|
|
452 }
|
|
|
453 else if (curlen == nextlen) {
|
|
|
454 max_count = 6; min_count = 3;
|
|
|
455 }
|
|
|
456 else {
|
|
|
457 max_count = 7; min_count = 4;
|
|
|
458 }
|
|
|
459 }
|
|
|
460 }
|
|
|
461
|
|
|
462 // Construct the Huffman tree for the bit lengths and return the index in
|
|
|
463 // bl_order of the last bit length code to send.
|
|
|
464 int build_bl_tree() {
|
|
|
465 int max_blindex; // index of last bit length code of non zero freq
|
|
|
466 // Determine the bit length frequencies for literal and distance trees
|
|
|
467 scan_tree(dyn_ltree, l_desc.max_code);
|
|
|
468 scan_tree(dyn_dtree, d_desc.max_code);
|
|
|
469 // Build the bit length tree:
|
|
|
470 bl_desc.build_tree(this);
|
|
|
471
|
|
|
472 // opt_len now includes the length of the tree representations, except
|
|
|
473 // the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
|
|
|
474 // Determine the number of bit length codes to send. The pkzip format
|
|
|
475 // requires that at least 4 bit length codes be sent. (appnote.txt says
|
|
|
476 // 3 but the actual value used is 4.)
|
|
|
477 for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
|
|
|
478 if (bl_tree[Tree.bl_order[max_blindex] * 2 + 1] != 0) break;
|
|
|
479 }
|
|
|
480
|
|
|
481 // Update opt_len to include the bit length tree and counts
|
|
|
482 opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
|
|
|
483 return max_blindex;
|
|
|
484 }
|
|
|
485
|
|
|
486
|
|
|
487 // Send the header for a block using dynamic Huffman trees: the counts, the
|
|
|
488 // lengths of the bit length codes, the literal tree and the distance tree.
|
|
|
489 // IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
|
|
|
490 void send_all_trees(int lcodes, int dcodes, int blcodes) {
|
|
|
491 int rank; // index in bl_order
|
|
|
492 send_bits(lcodes - 257, 5); // not +255 as stated in appnote.txt
|
|
|
493 send_bits(dcodes - 1, 5);
|
|
|
494 send_bits(blcodes - 4, 4); // not -3 as stated in appnote.txt
|
|
|
495
|
|
|
496 for (rank = 0; rank < blcodes; rank++) {
|
|
|
497 send_bits(bl_tree[Tree.bl_order[rank] * 2 + 1], 3);
|
|
|
498 }
|
|
|
499
|
|
|
500 send_tree(dyn_ltree, lcodes - 1); // literal tree
|
|
|
501 send_tree(dyn_dtree, dcodes - 1); // distance tree
|
|
|
502 }
|
|
|
503
|
|
|
504 // Send a literal or distance tree in compressed form, using the codes in
|
|
|
505 // bl_tree.
|
|
|
506 void send_tree(short[] tree, // the tree to be sent
|
|
|
507 int max_code // and its largest code of non zero frequency
|
|
|
508 ) {
|
|
|
509 int n; // iterates over all tree elements
|
|
|
510 int prevlen = -1; // last emitted length
|
|
|
511 int curlen; // length of current code
|
|
|
512 int nextlen = tree[0 * 2 + 1]; // length of next code
|
|
|
513 int count = 0; // repeat count of the current code
|
|
|
514 int max_count = 7; // max repeat count
|
|
|
515 int min_count = 4; // min repeat count
|
|
|
516
|
|
|
517 if (nextlen == 0) { max_count = 138; min_count = 3; }
|
|
|
518
|
|
|
519 for (n = 0; n <= max_code; n++) {
|
|
|
520 curlen = nextlen; nextlen = tree[(n + 1) * 2 + 1];
|
|
|
521
|
|
|
522 if (++count < max_count && curlen == nextlen) {
|
|
|
523 continue;
|
|
|
524 }
|
|
|
525 else if (count < min_count) {
|
|
|
526 do { send_code(curlen, bl_tree); }
|
|
|
527 while (--count != 0);
|
|
|
528 }
|
|
|
529 else if (curlen != 0) {
|
|
|
530 if (curlen != prevlen) {
|
|
|
531 send_code(curlen, bl_tree); count--;
|
|
|
532 }
|
|
|
533
|
|
|
534 send_code(REP_3_6, bl_tree);
|
|
|
535 send_bits(count - 3, 2);
|
|
|
536 }
|
|
|
537 else if (count <= 10) {
|
|
|
538 send_code(REPZ_3_10, bl_tree);
|
|
|
539 send_bits(count - 3, 3);
|
|
|
540 }
|
|
|
541 else {
|
|
|
542 send_code(REPZ_11_138, bl_tree);
|
|
|
543 send_bits(count - 11, 7);
|
|
|
544 }
|
|
|
545
|
|
|
546 count = 0; prevlen = curlen;
|
|
|
547
|
|
|
548 if (nextlen == 0) {
|
|
|
549 max_count = 138; min_count = 3;
|
|
|
550 }
|
|
|
551 else if (curlen == nextlen) {
|
|
|
552 max_count = 6; min_count = 3;
|
|
|
553 }
|
|
|
554 else {
|
|
|
555 max_count = 7; min_count = 4;
|
|
|
556 }
|
|
|
557 }
|
|
|
558 }
|
|
|
559
|
|
|
560 // Output a byte on the stream.
|
|
|
561 // IN assertion: there is enough room in pending_buf.
|
|
|
562 final void put_byte(byte[] p, int start, int len) {
|
|
|
563 System.arraycopy(p, start, pending_buf, pending, len);
|
|
|
564 pending += len;
|
|
|
565 }
|
|
|
566
|
|
|
567 final void put_byte(byte c) {
|
|
|
568 pending_buf[pending++] = c;
|
|
|
569 }
|
|
|
570 final void put_short(int w) {
|
|
|
571 put_byte((byte)(w/*&0xff*/));
|
|
|
572 put_byte((byte)(w >>> 8));
|
|
|
573 }
|
|
|
574 final void putShortMSB(int b) {
|
|
|
575 put_byte((byte)(b >> 8));
|
|
|
576 put_byte((byte)(b/*&0xff*/));
|
|
|
577 }
|
|
|
578
|
|
|
579 final void send_code(int c, short[] tree) {
|
|
|
580 int c2 = c * 2;
|
|
|
581 send_bits((tree[c2] & 0xffff), (tree[c2 + 1] & 0xffff));
|
|
|
582 }
|
|
|
583
|
|
|
584 void send_bits(int value, int length) {
|
|
|
585 int len = length;
|
|
|
586
|
|
|
587 if (bi_valid > (int)Buf_size - len) {
|
|
|
588 int val = value;
|
|
|
589 // bi_buf |= (val << bi_valid);
|
|
|
590 bi_buf |= ((val << bi_valid) & 0xffff);
|
|
|
591 put_short(bi_buf);
|
|
|
592 bi_buf = (short)(val >>> (Buf_size - bi_valid));
|
|
|
593 bi_valid += len - Buf_size;
|
|
|
594 }
|
|
|
595 else {
|
|
|
596 // bi_buf |= (value) << bi_valid;
|
|
|
597 bi_buf |= (((value) << bi_valid) & 0xffff);
|
|
|
598 bi_valid += len;
|
|
|
599 }
|
|
|
600 }
|
|
|
601
|
|
|
602 // Send one empty static block to give enough lookahead for inflate.
|
|
|
603 // This takes 10 bits, of which 7 may remain in the bit buffer.
|
|
|
604 // The current inflate code requires 9 bits of lookahead. If the
|
|
|
605 // last two codes for the previous block (real code plus EOB) were coded
|
|
|
606 // on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
|
|
|
607 // the last real code. In this case we send two empty static blocks instead
|
|
|
608 // of one. (There are no problems if the previous block is stored or fixed.)
|
|
|
609 // To simplify the code, we assume the worst case of last real code encoded
|
|
|
610 // on one bit only.
|
|
|
611 void _tr_align() {
|
|
|
612 send_bits(STATIC_TREES << 1, 3);
|
|
|
613 send_code(END_BLOCK, StaticTree.static_ltree);
|
|
|
614 bi_flush();
|
|
|
615
|
|
|
616 // Of the 10 bits for the empty block, we have already sent
|
|
|
617 // (10 - bi_valid) bits. The lookahead for the last real code (before
|
|
|
618 // the EOB of the previous block) was thus at least one plus the length
|
|
|
619 // of the EOB plus what we have just sent of the empty static block.
|
|
|
620 if (1 + last_eob_len + 10 - bi_valid < 9) {
|
|
|
621 send_bits(STATIC_TREES << 1, 3);
|
|
|
622 send_code(END_BLOCK, StaticTree.static_ltree);
|
|
|
623 bi_flush();
|
|
|
624 }
|
|
|
625
|
|
|
626 last_eob_len = 7;
|
|
|
627 }
|
|
|
628
|
|
|
629
|
|
|
630 // Save the match info and tally the frequency counts. Return true if
|
|
|
631 // the current block must be flushed.
|
|
|
632 boolean _tr_tally(int dist, // distance of matched string
|
|
|
633 int lc // match length-MIN_MATCH or unmatched char (if dist==0)
|
|
|
634 ) {
|
|
|
635 pending_buf[d_buf + last_lit * 2] = (byte)(dist >>> 8);
|
|
|
636 pending_buf[d_buf + last_lit * 2 + 1] = (byte)dist;
|
|
|
637 pending_buf[l_buf + last_lit] = (byte)lc; last_lit++;
|
|
|
638
|
|
|
639 if (dist == 0) {
|
|
|
640 // lc is the unmatched char
|
|
|
641 dyn_ltree[lc * 2]++;
|
|
|
642 }
|
|
|
643 else {
|
|
|
644 matches++;
|
|
|
645 // Here, lc is the match length - MIN_MATCH
|
|
|
646 dist--; // dist = match distance - 1
|
|
|
647 dyn_ltree[(Tree._length_code[lc] + LITERALS + 1) * 2]++;
|
|
|
648 dyn_dtree[Tree.d_code(dist) * 2]++;
|
|
|
649 }
|
|
|
650
|
|
|
651 if ((last_lit & 0x1fff) == 0 && level > 2) {
|
|
|
652 // Compute an upper bound for the compressed length
|
|
|
653 int out_length = last_lit * 8;
|
|
|
654 int in_length = strstart - block_start;
|
|
|
655 int dcode;
|
|
|
656
|
|
|
657 for (dcode = 0; dcode < D_CODES; dcode++) {
|
|
|
658 out_length += (int)dyn_dtree[dcode * 2] *
|
|
|
659 (5L + Tree.extra_dbits[dcode]);
|
|
|
660 }
|
|
|
661
|
|
|
662 out_length >>>= 3;
|
|
|
663
|
|
|
664 if ((matches < (last_lit / 2)) && out_length < in_length / 2) return true;
|
|
|
665 }
|
|
|
666
|
|
|
667 return (last_lit == lit_bufsize - 1);
|
|
|
668 // We avoid equality with lit_bufsize because of wraparound at 64K
|
|
|
669 // on 16 bit machines and because stored blocks are restricted to
|
|
|
670 // 64K-1 bytes.
|
|
|
671 }
|
|
|
672
|
|
|
673 // Send the block data compressed using the given Huffman trees
|
|
|
674 void compress_block(short[] ltree, short[] dtree) {
|
|
|
675 int dist; // distance of matched string
|
|
|
676 int lc; // match length or unmatched char (if dist == 0)
|
|
|
677 int lx = 0; // running index in l_buf
|
|
|
678 int code; // the code to send
|
|
|
679 int extra; // number of extra bits to send
|
|
|
680
|
|
|
681 if (last_lit != 0) {
|
|
|
682 do {
|
|
|
683 dist = ((pending_buf[d_buf + lx * 2] << 8) & 0xff00) |
|
|
|
684 (pending_buf[d_buf + lx * 2 + 1] & 0xff);
|
|
|
685 lc = (pending_buf[l_buf + lx]) & 0xff; lx++;
|
|
|
686
|
|
|
687 if (dist == 0) {
|
|
|
688 send_code(lc, ltree); // send a literal byte
|
|
|
689 }
|
|
|
690 else {
|
|
|
691 // Here, lc is the match length - MIN_MATCH
|
|
|
692 code = Tree._length_code[lc];
|
|
|
693 send_code(code + LITERALS + 1, ltree); // send the length code
|
|
|
694 extra = Tree.extra_lbits[code];
|
|
|
695
|
|
|
696 if (extra != 0) {
|
|
|
697 lc -= Tree.base_length[code];
|
|
|
698 send_bits(lc, extra); // send the extra length bits
|
|
|
699 }
|
|
|
700
|
|
|
701 dist--; // dist is now the match distance - 1
|
|
|
702 code = Tree.d_code(dist);
|
|
|
703 send_code(code, dtree); // send the distance code
|
|
|
704 extra = Tree.extra_dbits[code];
|
|
|
705
|
|
|
706 if (extra != 0) {
|
|
|
707 dist -= Tree.base_dist[code];
|
|
|
708 send_bits(dist, extra); // send the extra distance bits
|
|
|
709 }
|
|
|
710 } // literal or match pair ?
|
|
|
711
|
|
|
712 // Check that the overlay between pending_buf and d_buf+l_buf is ok:
|
|
|
713 }
|
|
|
714 while (lx < last_lit);
|
|
|
715 }
|
|
|
716
|
|
|
717 send_code(END_BLOCK, ltree);
|
|
|
718 last_eob_len = ltree[END_BLOCK * 2 + 1];
|
|
|
719 }
|
|
|
720
|
|
|
721 // Set the data type to ASCII or BINARY, using a crude approximation:
|
|
|
722 // binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
|
|
|
723 // IN assertion: the fields freq of dyn_ltree are set and the total of all
|
|
|
724 // frequencies does not exceed 64K (to fit in an int on 16 bit machines).
|
|
|
725 void set_data_type() {
|
|
|
726 int n = 0;
|
|
|
727 int ascii_freq = 0;
|
|
|
728 int bin_freq = 0;
|
|
|
729
|
|
|
730 while (n < 7) { bin_freq += dyn_ltree[n * 2]; n++;}
|
|
|
731
|
|
|
732 while (n < 128) { ascii_freq += dyn_ltree[n * 2]; n++;}
|
|
|
733
|
|
|
734 while (n < LITERALS) { bin_freq += dyn_ltree[n * 2]; n++;}
|
|
|
735
|
|
|
736 data_type = (byte)(bin_freq > (ascii_freq >>> 2) ? Z_BINARY : Z_ASCII);
|
|
|
737 }
|
|
|
738
|
|
|
739 // Flush the bit buffer, keeping at most 7 bits in it.
|
|
|
740 void bi_flush() {
|
|
|
741 if (bi_valid == 16) {
|
|
|
742 put_short(bi_buf);
|
|
|
743 bi_buf = 0;
|
|
|
744 bi_valid = 0;
|
|
|
745 }
|
|
|
746 else if (bi_valid >= 8) {
|
|
|
747 put_byte((byte)bi_buf);
|
|
|
748 bi_buf >>>= 8;
|
|
|
749 bi_valid -= 8;
|
|
|
750 }
|
|
|
751 }
|
|
|
752
|
|
|
753 // Flush the bit buffer and align the output on a byte boundary
|
|
|
754 void bi_windup() {
|
|
|
755 if (bi_valid > 8) {
|
|
|
756 put_short(bi_buf);
|
|
|
757 }
|
|
|
758 else if (bi_valid > 0) {
|
|
|
759 put_byte((byte)bi_buf);
|
|
|
760 }
|
|
|
761
|
|
|
762 bi_buf = 0;
|
|
|
763 bi_valid = 0;
|
|
|
764 }
|
|
|
765
|
|
|
766 // Copy a stored block, storing first the length and its
|
|
|
767 // one's complement if requested.
|
|
|
768 void copy_block(int buf, // the input data
|
|
|
769 int len, // its length
|
|
|
770 boolean header // true if block header must be written
|
|
|
771 ) {
|
|
|
772 int index = 0;
|
|
|
773 bi_windup(); // align on byte boundary
|
|
|
774 last_eob_len = 8; // enough lookahead for inflate
|
|
|
775
|
|
|
776 if (header) {
|
|
|
777 put_short((short)len);
|
|
|
778 put_short((short)~len);
|
|
|
779 }
|
|
|
780
|
|
|
781 // while(len--!=0) {
|
|
|
782 // put_byte(window[buf+index]);
|
|
|
783 // index++;
|
|
|
784 // }
|
|
|
785 put_byte(window, buf, len);
|
|
|
786 }
|
|
|
787
|
|
|
788 void flush_block_only(boolean eof) {
|
|
|
789 _tr_flush_block(block_start >= 0 ? block_start : -1,
|
|
|
790 strstart - block_start,
|
|
|
791 eof);
|
|
|
792 block_start = strstart;
|
|
|
793 strm.flush_pending();
|
|
|
794 }
|
|
|
795
|
|
|
796 // Copy without compression as much as possible from the input stream, return
|
|
|
797 // the current block state.
|
|
|
798 // This function does not insert new strings in the dictionary since
|
|
|
799 // uncompressible data is probably not useful. This function is used
|
|
|
800 // only for the level=0 compression option.
|
|
|
801 // NOTE: this function should be optimized to avoid extra copying from
|
|
|
802 // window to pending_buf.
|
|
|
803 int deflate_stored(int flush) {
|
|
|
804 // Stored blocks are limited to 0xffff bytes, pending_buf is limited
|
|
|
805 // to pending_buf_size, and each stored block has a 5 byte header:
|
|
|
806 int max_block_size = 0xffff;
|
|
|
807 int max_start;
|
|
|
808
|
|
|
809 if (max_block_size > pending_buf_size - 5) {
|
|
|
810 max_block_size = pending_buf_size - 5;
|
|
|
811 }
|
|
|
812
|
|
|
813 // Copy as much as possible from input to output:
|
|
|
814 while (true) {
|
|
|
815 // Fill the window as much as possible:
|
|
|
816 if (lookahead <= 1) {
|
|
|
817 fill_window();
|
|
|
818
|
|
|
819 if (lookahead == 0 && flush == Z_NO_FLUSH) return NeedMore;
|
|
|
820
|
|
|
821 if (lookahead == 0) break; // flush the current block
|
|
|
822 }
|
|
|
823
|
|
|
824 strstart += lookahead;
|
|
|
825 lookahead = 0;
|
|
|
826 // Emit a stored block if pending_buf will be full:
|
|
|
827 max_start = block_start + max_block_size;
|
|
|
828
|
|
|
829 if (strstart == 0 || strstart >= max_start) {
|
|
|
830 // strstart == 0 is possible when wraparound on 16-bit machine
|
|
|
831 lookahead = (int)(strstart - max_start);
|
|
|
832 strstart = (int)max_start;
|
|
|
833 flush_block_only(false);
|
|
|
834
|
|
|
835 if (strm.avail_out == 0) return NeedMore;
|
|
|
836 }
|
|
|
837
|
|
|
838 // Flush if we may have to slide, otherwise block_start may become
|
|
|
839 // negative and the data will be gone:
|
|
|
840 if (strstart - block_start >= w_size - MIN_LOOKAHEAD) {
|
|
|
841 flush_block_only(false);
|
|
|
842
|
|
|
843 if (strm.avail_out == 0) return NeedMore;
|
|
|
844 }
|
|
|
845 }
|
|
|
846
|
|
|
847 flush_block_only(flush == Z_FINISH);
|
|
|
848
|
|
|
849 if (strm.avail_out == 0)
|
|
|
850 return (flush == Z_FINISH) ? FinishStarted : NeedMore;
|
|
|
851
|
|
|
852 return flush == Z_FINISH ? FinishDone : BlockDone;
|
|
|
853 }
|
|
|
854
|
|
|
855 // Send a stored block
|
|
|
856 void _tr_stored_block(int buf, // input block
|
|
|
857 int stored_len, // length of input block
|
|
|
858 boolean eof // true if this is the last block for a file
|
|
|
859 ) {
|
|
|
860 send_bits((STORED_BLOCK << 1) + (eof ? 1 : 0), 3); // send block type
|
|
|
861 copy_block(buf, stored_len, true); // with header
|
|
|
862 }
|
|
|
863
|
|
|
864 // Determine the best encoding for the current block: dynamic trees, static
|
|
|
865 // trees or store, and output the encoded block to the zip file.
|
|
|
866 void _tr_flush_block(int buf, // input block, or NULL if too old
|
|
|
867 int stored_len, // length of input block
|
|
|
868 boolean eof // true if this is the last block for a file
|
|
|
869 ) {
|
|
|
870 int opt_lenb, static_lenb;// opt_len and static_len in bytes
|
|
|
871 int max_blindex = 0; // index of last bit length code of non zero freq
|
|
|
872
|
|
|
873 // Build the Huffman trees unless a stored block is forced
|
|
|
874 if (level > 0) {
|
|
|
875 // Check if the file is ascii or binary
|
|
|
876 if (data_type == Z_UNKNOWN) set_data_type();
|
|
|
877
|
|
|
878 // Construct the literal and distance trees
|
|
|
879 l_desc.build_tree(this);
|
|
|
880 d_desc.build_tree(this);
|
|
|
881 // At this point, opt_len and static_len are the total bit lengths of
|
|
|
882 // the compressed block data, excluding the tree representations.
|
|
|
883 // Build the bit length tree for the above two trees, and get the index
|
|
|
884 // in bl_order of the last bit length code to send.
|
|
|
885 max_blindex = build_bl_tree();
|
|
|
886 // Determine the best encoding. Compute first the block length in bytes
|
|
|
887 opt_lenb = (opt_len + 3 + 7) >>> 3;
|
|
|
888 static_lenb = (static_len + 3 + 7) >>> 3;
|
|
|
889
|
|
|
890 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
|
|
|
891 }
|
|
|
892 else {
|
|
|
893 opt_lenb = static_lenb = stored_len + 5; // force a stored block
|
|
|
894 }
|
|
|
895
|
|
|
896 if (stored_len + 4 <= opt_lenb && buf != -1) {
|
|
|
897 // 4: two words for the lengths
|
|
|
898 // The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
|
|
|
899 // Otherwise we can't have processed more than WSIZE input bytes since
|
|
|
900 // the last block flush, because compression would have been
|
|
|
901 // successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
|
|
|
902 // transform a block into a stored block.
|
|
|
903 _tr_stored_block(buf, stored_len, eof);
|
|
|
904 }
|
|
|
905 else if (static_lenb == opt_lenb) {
|
|
|
906 send_bits((STATIC_TREES << 1) + (eof ? 1 : 0), 3);
|
|
|
907 compress_block(StaticTree.static_ltree, StaticTree.static_dtree);
|
|
|
908 }
|
|
|
909 else {
|
|
|
910 send_bits((DYN_TREES << 1) + (eof ? 1 : 0), 3);
|
|
|
911 send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, max_blindex + 1);
|
|
|
912 compress_block(dyn_ltree, dyn_dtree);
|
|
|
913 }
|
|
|
914
|
|
|
915 // The above check is made mod 2^32, for files larger than 512 MB
|
|
|
916 // and uLong implemented on 32 bits.
|
|
|
917 init_block();
|
|
|
918
|
|
|
919 if (eof) {
|
|
|
920 bi_windup();
|
|
|
921 }
|
|
|
922 }
|
|
|
923
|
|
|
924 // Fill the window when the lookahead becomes insufficient.
|
|
|
925 // Updates strstart and lookahead.
|
|
|
926 //
|
|
|
927 // IN assertion: lookahead < MIN_LOOKAHEAD
|
|
|
928 // OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
|
|
|
929 // At least one byte has been read, or avail_in == 0; reads are
|
|
|
930 // performed for at least two bytes (required for the zip translate_eol
|
|
|
931 // option -- not supported here).
|
|
|
932 void fill_window() {
|
|
|
933 int n, m;
|
|
|
934 int p;
|
|
|
935 int more; // Amount of free space at the end of the window.
|
|
|
936
|
|
|
937 do {
|
|
|
938 more = (window_size - lookahead - strstart);
|
|
|
939
|
|
|
940 // Deal with !@#$% 64K limit:
|
|
|
941 if (more == 0 && strstart == 0 && lookahead == 0) {
|
|
|
942 more = w_size;
|
|
|
943 }
|
|
|
944 else if (more == -1) {
|
|
|
945 // Very unlikely, but possible on 16 bit machine if strstart == 0
|
|
|
946 // and lookahead == 1 (input done one byte at time)
|
|
|
947 more--;
|
|
|
948 // If the window is almost full and there is insufficient lookahead,
|
|
|
949 // move the upper half to the lower one to make room in the upper half.
|
|
|
950 }
|
|
|
951 else if (strstart >= w_size + w_size - MIN_LOOKAHEAD) {
|
|
|
952 System.arraycopy(window, w_size, window, 0, w_size);
|
|
|
953 match_start -= w_size;
|
|
|
954 strstart -= w_size; // we now have strstart >= MAX_DIST
|
|
|
955 block_start -= w_size;
|
|
|
956 // Slide the hash table (could be avoided with 32 bit values
|
|
|
957 // at the expense of memory usage). We slide even when level == 0
|
|
|
958 // to keep the hash table consistent if we switch back to level > 0
|
|
|
959 // later. (Using level 0 permanently is not an optimal usage of
|
|
|
960 // zlib, so we don't care about this pathological case.)
|
|
|
961 n = hash_size;
|
|
|
962 p = n;
|
|
|
963
|
|
|
964 do {
|
|
|
965 m = (head[--p] & 0xffff);
|
|
|
966 head[p] = (m >= w_size ? (short)(m - w_size) : 0);
|
|
|
967 }
|
|
|
968 while (--n != 0);
|
|
|
969
|
|
|
970 n = w_size;
|
|
|
971 p = n;
|
|
|
972
|
|
|
973 do {
|
|
|
974 m = (prev[--p] & 0xffff);
|
|
|
975 prev[p] = (m >= w_size ? (short)(m - w_size) : 0);
|
|
|
976 // If n is not on any hash chain, prev[n] is garbage but
|
|
|
977 // its value will never be used.
|
|
|
978 }
|
|
|
979 while (--n != 0);
|
|
|
980
|
|
|
981 more += w_size;
|
|
|
982 }
|
|
|
983
|
|
|
984 if (strm.avail_in == 0) return;
|
|
|
985
|
|
|
986 // If there was no sliding:
|
|
|
987 // strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
|
|
|
988 // more == window_size - lookahead - strstart
|
|
|
989 // => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
|
|
|
990 // => more >= window_size - 2*WSIZE + 2
|
|
|
991 // In the BIG_MEM or MMAP case (not yet supported),
|
|
|
992 // window_size == input_size + MIN_LOOKAHEAD &&
|
|
|
993 // strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
|
|
|
994 // Otherwise, window_size == 2*WSIZE so more >= 2.
|
|
|
995 // If there was sliding, more >= WSIZE. So in all cases, more >= 2.
|
|
|
996 n = strm.read_buf(window, strstart + lookahead, more);
|
|
|
997 lookahead += n;
|
|
|
998
|
|
|
999 // Initialize the hash value now that we have some input:
|
|
|
1000 if (lookahead >= MIN_MATCH) {
|
|
|
1001 ins_h = window[strstart] & 0xff;
|
|
|
1002 ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
|
|
|
1003 }
|
|
|
1004
|
|
|
1005 // If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
|
|
|
1006 // but this is not important since only literal bytes will be emitted.
|
|
|
1007 }
|
|
|
1008 while (lookahead < MIN_LOOKAHEAD && strm.avail_in != 0);
|
|
|
1009 }
|
|
|
1010
|
|
|
1011 // Compress as much as possible from the input stream, return the current
|
|
|
1012 // block state.
|
|
|
1013 // This function does not perform lazy evaluation of matches and inserts
|
|
|
1014 // new strings in the dictionary only for unmatched strings or for short
|
|
|
1015 // matches. It is used only for the fast compression options.
|
|
|
1016 int deflate_fast(int flush) {
|
|
|
1017 // short hash_head = 0; // head of the hash chain
|
|
|
1018 int hash_head = 0; // head of the hash chain
|
|
|
1019 boolean bflush; // set if current block must be flushed
|
|
|
1020
|
|
|
1021 while (true) {
|
|
|
1022 // Make sure that we always have enough lookahead, except
|
|
|
1023 // at the end of the input file. We need MAX_MATCH bytes
|
|
|
1024 // for the next match, plus MIN_MATCH bytes to insert the
|
|
|
1025 // string following the next match.
|
|
|
1026 if (lookahead < MIN_LOOKAHEAD) {
|
|
|
1027 fill_window();
|
|
|
1028
|
|
|
1029 if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
|
|
|
1030 return NeedMore;
|
|
|
1031 }
|
|
|
1032
|
|
|
1033 if (lookahead == 0) break; // flush the current block
|
|
|
1034 }
|
|
|
1035
|
|
|
1036 // Insert the string window[strstart .. strstart+2] in the
|
|
|
1037 // dictionary, and set hash_head to the head of the hash chain:
|
|
|
1038 if (lookahead >= MIN_MATCH) {
|
|
|
1039 ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
|
|
1040 // prev[strstart&w_mask]=hash_head=head[ins_h];
|
|
|
1041 hash_head = (head[ins_h] & 0xffff);
|
|
|
1042 prev[strstart & w_mask] = head[ins_h];
|
|
|
1043 head[ins_h] = (short)strstart;
|
|
|
1044 }
|
|
|
1045
|
|
|
1046 // Find the longest match, discarding those <= prev_length.
|
|
|
1047 // At this point we have always match_length < MIN_MATCH
|
|
|
1048 if (hash_head != 0L &&
|
|
|
1049 ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD
|
|
|
1050 ) {
|
|
|
1051 // To simplify the code, we prevent matches with the string
|
|
|
1052 // of window index 0 (in particular we have to avoid a match
|
|
|
1053 // of the string with itself at the start of the input file).
|
|
|
1054 if (strategy != Z_HUFFMAN_ONLY) {
|
|
|
1055 match_length = longest_match(hash_head);
|
|
|
1056 }
|
|
|
1057
|
|
|
1058 // longest_match() sets match_start
|
|
|
1059 }
|
|
|
1060
|
|
|
1061 if (match_length >= MIN_MATCH) {
|
|
|
1062 // check_match(strstart, match_start, match_length);
|
|
|
1063 bflush = _tr_tally(strstart - match_start, match_length - MIN_MATCH);
|
|
|
1064 lookahead -= match_length;
|
|
|
1065
|
|
|
1066 // Insert new strings in the hash table only if the match length
|
|
|
1067 // is not too large. This saves time but degrades compression.
|
|
|
1068 if (match_length <= max_lazy_match &&
|
|
|
1069 lookahead >= MIN_MATCH) {
|
|
|
1070 match_length--; // string at strstart already in hash table
|
|
|
1071
|
|
|
1072 do {
|
|
|
1073 strstart++;
|
|
|
1074 ins_h = ((ins_h << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
|
|
1075 // prev[strstart&w_mask]=hash_head=head[ins_h];
|
|
|
1076 hash_head = (head[ins_h] & 0xffff);
|
|
|
1077 prev[strstart & w_mask] = head[ins_h];
|
|
|
1078 head[ins_h] = (short)strstart;
|
|
|
1079 // strstart never exceeds WSIZE-MAX_MATCH, so there are
|
|
|
1080 // always MIN_MATCH bytes ahead.
|
|
|
1081 }
|
|
|
1082 while (--match_length != 0);
|
|
|
1083
|
|
|
1084 strstart++;
|
|
|
1085 }
|
|
|
1086 else {
|
|
|
1087 strstart += match_length;
|
|
|
1088 match_length = 0;
|
|
|
1089 ins_h = window[strstart] & 0xff;
|
|
|
1090 ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
|
|
|
1091 // If lookahead < MIN_MATCH, ins_h is garbage, but it does not
|
|
|
1092 // matter since it will be recomputed at next deflate call.
|
|
|
1093 }
|
|
|
1094 }
|
|
|
1095 else {
|
|
|
1096 // No match, output a literal byte
|
|
|
1097 bflush = _tr_tally(0, window[strstart] & 0xff);
|
|
|
1098 lookahead--;
|
|
|
1099 strstart++;
|
|
|
1100 }
|
|
|
1101
|
|
|
1102 if (bflush) {
|
|
|
1103 flush_block_only(false);
|
|
|
1104
|
|
|
1105 if (strm.avail_out == 0) return NeedMore;
|
|
|
1106 }
|
|
|
1107 }
|
|
|
1108
|
|
|
1109 flush_block_only(flush == Z_FINISH);
|
|
|
1110
|
|
|
1111 if (strm.avail_out == 0) {
|
|
|
1112 if (flush == Z_FINISH) return FinishStarted;
|
|
|
1113 else return NeedMore;
|
|
|
1114 }
|
|
|
1115
|
|
|
1116 return flush == Z_FINISH ? FinishDone : BlockDone;
|
|
|
1117 }
|
|
|
1118
|
|
|
1119 // Same as above, but achieves better compression. We use a lazy
|
|
|
1120 // evaluation for matches: a match is finally adopted only if there is
|
|
|
1121 // no better match at the next window position.
|
|
|
1122 int deflate_slow(int flush) {
|
|
|
1123 // short hash_head = 0; // head of hash chain
|
|
|
1124 int hash_head = 0; // head of hash chain
|
|
|
1125 boolean bflush; // set if current block must be flushed
|
|
|
1126
|
|
|
1127 // Process the input block.
|
|
|
1128 while (true) {
|
|
|
1129 // Make sure that we always have enough lookahead, except
|
|
|
1130 // at the end of the input file. We need MAX_MATCH bytes
|
|
|
1131 // for the next match, plus MIN_MATCH bytes to insert the
|
|
|
1132 // string following the next match.
|
|
|
1133 if (lookahead < MIN_LOOKAHEAD) {
|
|
|
1134 fill_window();
|
|
|
1135
|
|
|
1136 if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
|
|
|
1137 return NeedMore;
|
|
|
1138 }
|
|
|
1139
|
|
|
1140 if (lookahead == 0) break; // flush the current block
|
|
|
1141 }
|
|
|
1142
|
|
|
1143 // Insert the string window[strstart .. strstart+2] in the
|
|
|
1144 // dictionary, and set hash_head to the head of the hash chain:
|
|
|
1145 if (lookahead >= MIN_MATCH) {
|
|
|
1146 ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
|
|
1147 // prev[strstart&w_mask]=hash_head=head[ins_h];
|
|
|
1148 hash_head = (head[ins_h] & 0xffff);
|
|
|
1149 prev[strstart & w_mask] = head[ins_h];
|
|
|
1150 head[ins_h] = (short)strstart;
|
|
|
1151 }
|
|
|
1152
|
|
|
1153 // Find the longest match, discarding those <= prev_length.
|
|
|
1154 prev_length = match_length; prev_match = match_start;
|
|
|
1155 match_length = MIN_MATCH - 1;
|
|
|
1156
|
|
|
1157 if (hash_head != 0 && prev_length < max_lazy_match &&
|
|
|
1158 ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD
|
|
|
1159 ) {
|
|
|
1160 // To simplify the code, we prevent matches with the string
|
|
|
1161 // of window index 0 (in particular we have to avoid a match
|
|
|
1162 // of the string with itself at the start of the input file).
|
|
|
1163 if (strategy != Z_HUFFMAN_ONLY) {
|
|
|
1164 match_length = longest_match(hash_head);
|
|
|
1165 }
|
|
|
1166
|
|
|
1167 // longest_match() sets match_start
|
|
|
1168 if (match_length <= 5 && (strategy == Z_FILTERED ||
|
|
|
1169 (match_length == MIN_MATCH &&
|
|
|
1170 strstart - match_start > 4096))) {
|
|
|
1171 // If prev_match is also MIN_MATCH, match_start is garbage
|
|
|
1172 // but we will ignore the current match anyway.
|
|
|
1173 match_length = MIN_MATCH - 1;
|
|
|
1174 }
|
|
|
1175 }
|
|
|
1176
|
|
|
1177 // If there was a match at the previous step and the current
|
|
|
1178 // match is not better, output the previous match:
|
|
|
1179 if (prev_length >= MIN_MATCH && match_length <= prev_length) {
|
|
|
1180 int max_insert = strstart + lookahead - MIN_MATCH;
|
|
|
1181 // Do not insert strings in hash table beyond this.
|
|
|
1182 // check_match(strstart-1, prev_match, prev_length);
|
|
|
1183 bflush = _tr_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
|
|
|
1184 // Insert in hash table all strings up to the end of the match.
|
|
|
1185 // strstart-1 and strstart are already inserted. If there is not
|
|
|
1186 // enough lookahead, the last two strings are not inserted in
|
|
|
1187 // the hash table.
|
|
|
1188 lookahead -= prev_length - 1;
|
|
|
1189 prev_length -= 2;
|
|
|
1190
|
|
|
1191 do {
|
|
|
1192 if (++strstart <= max_insert) {
|
|
|
1193 ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
|
|
1194 //prev[strstart&w_mask]=hash_head=head[ins_h];
|
|
|
1195 hash_head = (head[ins_h] & 0xffff);
|
|
|
1196 prev[strstart & w_mask] = head[ins_h];
|
|
|
1197 head[ins_h] = (short)strstart;
|
|
|
1198 }
|
|
|
1199 }
|
|
|
1200 while (--prev_length != 0);
|
|
|
1201
|
|
|
1202 match_available = 0;
|
|
|
1203 match_length = MIN_MATCH - 1;
|
|
|
1204 strstart++;
|
|
|
1205
|
|
|
1206 if (bflush) {
|
|
|
1207 flush_block_only(false);
|
|
|
1208
|
|
|
1209 if (strm.avail_out == 0) return NeedMore;
|
|
|
1210 }
|
|
|
1211 }
|
|
|
1212 else if (match_available != 0) {
|
|
|
1213 // If there was no match at the previous position, output a
|
|
|
1214 // single literal. If there was a match but the current match
|
|
|
1215 // is longer, truncate the previous match to a single literal.
|
|
|
1216 bflush = _tr_tally(0, window[strstart - 1] & 0xff);
|
|
|
1217
|
|
|
1218 if (bflush) {
|
|
|
1219 flush_block_only(false);
|
|
|
1220 }
|
|
|
1221
|
|
|
1222 strstart++;
|
|
|
1223 lookahead--;
|
|
|
1224
|
|
|
1225 if (strm.avail_out == 0) return NeedMore;
|
|
|
1226 }
|
|
|
1227 else {
|
|
|
1228 // There is no previous match to compare with, wait for
|
|
|
1229 // the next step to decide.
|
|
|
1230 match_available = 1;
|
|
|
1231 strstart++;
|
|
|
1232 lookahead--;
|
|
|
1233 }
|
|
|
1234 }
|
|
|
1235
|
|
|
1236 if (match_available != 0) {
|
|
|
1237 bflush = _tr_tally(0, window[strstart - 1] & 0xff);
|
|
|
1238 match_available = 0;
|
|
|
1239 }
|
|
|
1240
|
|
|
1241 flush_block_only(flush == Z_FINISH);
|
|
|
1242
|
|
|
1243 if (strm.avail_out == 0) {
|
|
|
1244 if (flush == Z_FINISH) return FinishStarted;
|
|
|
1245 else return NeedMore;
|
|
|
1246 }
|
|
|
1247
|
|
|
1248 return flush == Z_FINISH ? FinishDone : BlockDone;
|
|
|
1249 }
|
|
|
1250
|
|
|
1251 int longest_match(int cur_match) {
|
|
|
1252 int chain_length = max_chain_length; // max hash chain length
|
|
|
1253 int scan = strstart; // current string
|
|
|
1254 int match; // matched string
|
|
|
1255 int len; // length of current match
|
|
|
1256 int best_len = prev_length; // best match length so far
|
|
|
1257 int limit = strstart > (w_size - MIN_LOOKAHEAD) ?
|
|
|
1258 strstart - (w_size - MIN_LOOKAHEAD) : 0;
|
|
|
1259 int nice_match = this.nice_match;
|
|
|
1260 // Stop when cur_match becomes <= limit. To simplify the code,
|
|
|
1261 // we prevent matches with the string of window index 0.
|
|
|
1262 int wmask = w_mask;
|
|
|
1263 int strend = strstart + MAX_MATCH;
|
|
|
1264 byte scan_end1 = window[scan + best_len - 1];
|
|
|
1265 byte scan_end = window[scan + best_len];
|
|
|
1266
|
|
|
1267 // The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
|
|
|
1268 // It is easy to get rid of this optimization if necessary.
|
|
|
1269 // Do not waste too much time if we already have a good match:
|
|
|
1270 if (prev_length >= good_match) {
|
|
|
1271 chain_length >>= 2;
|
|
|
1272 }
|
|
|
1273
|
|
|
1274 // Do not look for matches beyond the end of the input. This is necessary
|
|
|
1275 // to make deflate deterministic.
|
|
|
1276 if (nice_match > lookahead) nice_match = lookahead;
|
|
|
1277
|
|
|
1278 do {
|
|
|
1279 match = cur_match;
|
|
|
1280
|
|
|
1281 // Skip to next match if the match length cannot increase
|
|
|
1282 // or if the match length is less than 2:
|
|
|
1283 if (window[match + best_len] != scan_end ||
|
|
|
1284 window[match + best_len - 1] != scan_end1 ||
|
|
|
1285 window[match] != window[scan] ||
|
|
|
1286 window[++match] != window[scan + 1]) continue;
|
|
|
1287
|
|
|
1288 // The check at best_len-1 can be removed because it will be made
|
|
|
1289 // again later. (This heuristic is not always a win.)
|
|
|
1290 // It is not necessary to compare scan[2] and match[2] since they
|
|
|
1291 // are always equal when the other bytes match, given that
|
|
|
1292 // the hash keys are equal and that HASH_BITS >= 8.
|
|
|
1293 scan += 2; match++;
|
|
|
1294
|
|
|
1295 // We check for insufficient lookahead only every 8th comparison;
|
|
|
1296 // the 256th check will be made at strstart+258.
|
|
|
1297 do {
|
|
|
1298 }
|
|
|
1299 while (window[++scan] == window[++match] &&
|
|
|
1300 window[++scan] == window[++match] &&
|
|
|
1301 window[++scan] == window[++match] &&
|
|
|
1302 window[++scan] == window[++match] &&
|
|
|
1303 window[++scan] == window[++match] &&
|
|
|
1304 window[++scan] == window[++match] &&
|
|
|
1305 window[++scan] == window[++match] &&
|
|
|
1306 window[++scan] == window[++match] &&
|
|
|
1307 scan < strend);
|
|
|
1308
|
|
|
1309 len = MAX_MATCH - (int)(strend - scan);
|
|
|
1310 scan = strend - MAX_MATCH;
|
|
|
1311
|
|
|
1312 if (len > best_len) {
|
|
|
1313 match_start = cur_match;
|
|
|
1314 best_len = len;
|
|
|
1315
|
|
|
1316 if (len >= nice_match) break;
|
|
|
1317
|
|
|
1318 scan_end1 = window[scan + best_len - 1];
|
|
|
1319 scan_end = window[scan + best_len];
|
|
|
1320 }
|
|
|
1321 }
|
|
|
1322 while ((cur_match = (prev[cur_match & wmask] & 0xffff)) > limit
|
|
|
1323 && --chain_length != 0);
|
|
|
1324
|
|
|
1325 if (best_len <= lookahead) return best_len;
|
|
|
1326
|
|
|
1327 return lookahead;
|
|
|
1328 }
|
|
|
1329
|
|
|
1330 int deflateInit(ZStream strm, int level, int bits) {
|
|
|
1331 return deflateInit2(strm, level, Z_DEFLATED, bits, DEF_MEM_LEVEL,
|
|
|
1332 Z_DEFAULT_STRATEGY);
|
|
|
1333 }
|
|
|
1334 int deflateInit(ZStream strm, int level) {
|
|
|
1335 return deflateInit(strm, level, MAX_WBITS);
|
|
|
1336 }
|
|
|
1337 int deflateInit2(ZStream strm, int level, int method, int windowBits,
|
|
|
1338 int memLevel, int strategy) {
|
|
|
1339 int noheader = 0;
|
|
|
1340 // byte[] my_version=ZLIB_VERSION;
|
|
|
1341 //
|
|
|
1342 // if (version == null || version[0] != my_version[0]
|
|
|
1343 // || stream_size != sizeof(z_stream)) {
|
|
|
1344 // return Z_VERSION_ERROR;
|
|
|
1345 // }
|
|
|
1346 strm.msg = null;
|
|
|
1347
|
|
|
1348 if (level == Z_DEFAULT_COMPRESSION) level = 6;
|
|
|
1349
|
|
|
1350 if (windowBits < 0) { // undocumented feature: suppress zlib header
|
|
|
1351 noheader = 1;
|
|
|
1352 windowBits = -windowBits;
|
|
|
1353 }
|
|
|
1354
|
|
|
1355 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL ||
|
|
|
1356 method != Z_DEFLATED ||
|
|
|
1357 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
|
|
|
1358 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
|
|
|
1359 return Z_STREAM_ERROR;
|
|
|
1360 }
|
|
|
1361
|
|
|
1362 strm.dstate = (Deflate)this;
|
|
|
1363 this.noheader = noheader;
|
|
|
1364 w_bits = windowBits;
|
|
|
1365 w_size = 1 << w_bits;
|
|
|
1366 w_mask = w_size - 1;
|
|
|
1367 hash_bits = memLevel + 7;
|
|
|
1368 hash_size = 1 << hash_bits;
|
|
|
1369 hash_mask = hash_size - 1;
|
|
|
1370 hash_shift = ((hash_bits + MIN_MATCH - 1) / MIN_MATCH);
|
|
|
1371 window = new byte[w_size * 2];
|
|
|
1372 prev = new short[w_size];
|
|
|
1373 head = new short[hash_size];
|
|
|
1374 lit_bufsize = 1 << (memLevel + 6); // 16K elements by default
|
|
|
1375 // We overlay pending_buf and d_buf+l_buf. This works since the average
|
|
|
1376 // output size for (length,distance) codes is <= 24 bits.
|
|
|
1377 pending_buf = new byte[lit_bufsize * 4];
|
|
|
1378 pending_buf_size = lit_bufsize * 4;
|
|
|
1379 d_buf = lit_bufsize / 2;
|
|
|
1380 l_buf = (1 + 2) * lit_bufsize;
|
|
|
1381 this.level = level;
|
|
|
1382 //System.out.println("level="+level);
|
|
|
1383 this.strategy = strategy;
|
|
|
1384 this.method = (byte)method;
|
|
|
1385 return deflateReset(strm);
|
|
|
1386 }
|
|
|
1387
|
|
|
1388 int deflateReset(ZStream strm) {
|
|
|
1389 strm.total_in = strm.total_out = 0;
|
|
|
1390 strm.msg = null; //
|
|
|
1391 strm.data_type = Z_UNKNOWN;
|
|
|
1392 pending = 0;
|
|
|
1393 pending_out = 0;
|
|
|
1394
|
|
|
1395 if (noheader < 0) {
|
|
|
1396 noheader = 0; // was set to -1 by deflate(..., Z_FINISH);
|
|
|
1397 }
|
|
|
1398
|
|
|
1399 status = (noheader != 0) ? BUSY_STATE : INIT_STATE;
|
|
|
1400 strm.adler = strm._adler.adler32(0, null, 0, 0);
|
|
|
1401 last_flush = Z_NO_FLUSH;
|
|
|
1402 tr_init();
|
|
|
1403 lm_init();
|
|
|
1404 return Z_OK;
|
|
|
1405 }
|
|
|
1406
|
|
|
1407 int deflateEnd() {
|
|
|
1408 if (status != INIT_STATE && status != BUSY_STATE && status != FINISH_STATE) {
|
|
|
1409 return Z_STREAM_ERROR;
|
|
|
1410 }
|
|
|
1411
|
|
|
1412 // Deallocate in reverse order of allocations:
|
|
|
1413 pending_buf = null;
|
|
|
1414 head = null;
|
|
|
1415 prev = null;
|
|
|
1416 window = null;
|
|
|
1417 // free
|
|
|
1418 // dstate=null;
|
|
|
1419 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
|
|
|
1420 }
|
|
|
1421
|
|
|
1422 int deflateParams(ZStream strm, int _level, int _strategy) {
|
|
|
1423 int err = Z_OK;
|
|
|
1424
|
|
|
1425 if (_level == Z_DEFAULT_COMPRESSION) {
|
|
|
1426 _level = 6;
|
|
|
1427 }
|
|
|
1428
|
|
|
1429 if (_level < 0 || _level > 9 ||
|
|
|
1430 _strategy < 0 || _strategy > Z_HUFFMAN_ONLY) {
|
|
|
1431 return Z_STREAM_ERROR;
|
|
|
1432 }
|
|
|
1433
|
|
|
1434 if (config_table[level].func != config_table[_level].func &&
|
|
|
1435 strm.total_in != 0) {
|
|
|
1436 // Flush the last buffer:
|
|
|
1437 err = strm.deflate(Z_PARTIAL_FLUSH);
|
|
|
1438 }
|
|
|
1439
|
|
|
1440 if (level != _level) {
|
|
|
1441 level = _level;
|
|
|
1442 max_lazy_match = config_table[level].max_lazy;
|
|
|
1443 good_match = config_table[level].good_length;
|
|
|
1444 nice_match = config_table[level].nice_length;
|
|
|
1445 max_chain_length = config_table[level].max_chain;
|
|
|
1446 }
|
|
|
1447
|
|
|
1448 strategy = _strategy;
|
|
|
1449 return err;
|
|
|
1450 }
|
|
|
1451
|
|
|
1452 int deflateSetDictionary(ZStream strm, byte[] dictionary, int dictLength) {
|
|
|
1453 int length = dictLength;
|
|
|
1454 int index = 0;
|
|
|
1455
|
|
|
1456 if (dictionary == null || status != INIT_STATE)
|
|
|
1457 return Z_STREAM_ERROR;
|
|
|
1458
|
|
|
1459 strm.adler = strm._adler.adler32(strm.adler, dictionary, 0, dictLength);
|
|
|
1460
|
|
|
1461 if (length < MIN_MATCH) return Z_OK;
|
|
|
1462
|
|
|
1463 if (length > w_size - MIN_LOOKAHEAD) {
|
|
|
1464 length = w_size - MIN_LOOKAHEAD;
|
|
|
1465 index = dictLength - length; // use the tail of the dictionary
|
|
|
1466 }
|
|
|
1467
|
|
|
1468 System.arraycopy(dictionary, index, window, 0, length);
|
|
|
1469 strstart = length;
|
|
|
1470 block_start = length;
|
|
|
1471 // Insert all strings in the hash table (except for the last two bytes).
|
|
|
1472 // s->lookahead stays null, so s->ins_h will be recomputed at the next
|
|
|
1473 // call of fill_window.
|
|
|
1474 ins_h = window[0] & 0xff;
|
|
|
1475 ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;
|
|
|
1476
|
|
|
1477 for (int n = 0; n <= length - MIN_MATCH; n++) {
|
|
|
1478 ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
|
|
1479 prev[n & w_mask] = head[ins_h];
|
|
|
1480 head[ins_h] = (short)n;
|
|
|
1481 }
|
|
|
1482
|
|
|
1483 return Z_OK;
|
|
|
1484 }
|
|
|
1485
|
|
|
1486 int deflate(ZStream strm, int flush) {
|
|
|
1487 int old_flush;
|
|
|
1488
|
|
|
1489 if (flush > Z_FINISH || flush < 0) {
|
|
|
1490 return Z_STREAM_ERROR;
|
|
|
1491 }
|
|
|
1492
|
|
|
1493 if (strm.next_out == null ||
|
|
|
1494 (strm.next_in == null && strm.avail_in != 0) ||
|
|
|
1495 (status == FINISH_STATE && flush != Z_FINISH)) {
|
|
|
1496 strm.msg = z_errmsg[Z_NEED_DICT - (Z_STREAM_ERROR)];
|
|
|
1497 return Z_STREAM_ERROR;
|
|
|
1498 }
|
|
|
1499
|
|
|
1500 if (strm.avail_out == 0) {
|
|
|
1501 strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
|
|
|
1502 return Z_BUF_ERROR;
|
|
|
1503 }
|
|
|
1504
|
|
|
1505 this.strm = strm; // just in case
|
|
|
1506 old_flush = last_flush;
|
|
|
1507 last_flush = flush;
|
|
|
1508
|
|
|
1509 // Write the zlib header
|
|
|
1510 if (status == INIT_STATE) {
|
|
|
1511 int header = (Z_DEFLATED + ((w_bits - 8) << 4)) << 8;
|
|
|
1512 int level_flags = ((level - 1) & 0xff) >> 1;
|
|
|
1513
|
|
|
1514 if (level_flags > 3) level_flags = 3;
|
|
|
1515
|
|
|
1516 header |= (level_flags << 6);
|
|
|
1517
|
|
|
1518 if (strstart != 0) header |= PRESET_DICT;
|
|
|
1519
|
|
|
1520 header += 31 - (header % 31);
|
|
|
1521 status = BUSY_STATE;
|
|
|
1522 putShortMSB(header);
|
|
|
1523
|
|
|
1524 // Save the adler32 of the preset dictionary:
|
|
|
1525 if (strstart != 0) {
|
|
|
1526 putShortMSB((int)(strm.adler >>> 16));
|
|
|
1527 putShortMSB((int)(strm.adler & 0xffff));
|
|
|
1528 }
|
|
|
1529
|
|
|
1530 strm.adler = strm._adler.adler32(0, null, 0, 0);
|
|
|
1531 }
|
|
|
1532
|
|
|
1533 // Flush as much pending output as possible
|
|
|
1534 if (pending != 0) {
|
|
|
1535 strm.flush_pending();
|
|
|
1536
|
|
|
1537 if (strm.avail_out == 0) {
|
|
|
1538 //System.out.println(" avail_out==0");
|
|
|
1539 // Since avail_out is 0, deflate will be called again with
|
|
|
1540 // more output space, but possibly with both pending and
|
|
|
1541 // avail_in equal to zero. There won't be anything to do,
|
|
|
1542 // but this is not an error situation so make sure we
|
|
|
1543 // return OK instead of BUF_ERROR at next call of deflate:
|
|
|
1544 last_flush = -1;
|
|
|
1545 return Z_OK;
|
|
|
1546 }
|
|
|
1547
|
|
|
1548 // Make sure there is something to do and avoid duplicate consecutive
|
|
|
1549 // flushes. For repeated and useless calls with Z_FINISH, we keep
|
|
|
1550 // returning Z_STREAM_END instead of Z_BUFF_ERROR.
|
|
|
1551 }
|
|
|
1552 else if (strm.avail_in == 0 && flush <= old_flush &&
|
|
|
1553 flush != Z_FINISH) {
|
|
|
1554 strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
|
|
|
1555 return Z_BUF_ERROR;
|
|
|
1556 }
|
|
|
1557
|
|
|
1558 // User must not provide more input after the first FINISH:
|
|
|
1559 if (status == FINISH_STATE && strm.avail_in != 0) {
|
|
|
1560 strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
|
|
|
1561 return Z_BUF_ERROR;
|
|
|
1562 }
|
|
|
1563
|
|
|
1564 // Start a new block or continue the current one.
|
|
|
1565 if (strm.avail_in != 0 || lookahead != 0 ||
|
|
|
1566 (flush != Z_NO_FLUSH && status != FINISH_STATE)) {
|
|
|
1567 int bstate = -1;
|
|
|
1568
|
|
|
1569 switch (config_table[level].func) {
|
|
|
1570 case STORED:
|
|
|
1571 bstate = deflate_stored(flush);
|
|
|
1572 break;
|
|
|
1573
|
|
|
1574 case FAST:
|
|
|
1575 bstate = deflate_fast(flush);
|
|
|
1576 break;
|
|
|
1577
|
|
|
1578 case SLOW:
|
|
|
1579 bstate = deflate_slow(flush);
|
|
|
1580 break;
|
|
|
1581
|
|
|
1582 default:
|
|
|
1583 }
|
|
|
1584
|
|
|
1585 if (bstate == FinishStarted || bstate == FinishDone) {
|
|
|
1586 status = FINISH_STATE;
|
|
|
1587 }
|
|
|
1588
|
|
|
1589 if (bstate == NeedMore || bstate == FinishStarted) {
|
|
|
1590 if (strm.avail_out == 0) {
|
|
|
1591 last_flush = -1; // avoid BUF_ERROR next call, see above
|
|
|
1592 }
|
|
|
1593
|
|
|
1594 return Z_OK;
|
|
|
1595 // If flush != Z_NO_FLUSH && avail_out == 0, the next call
|
|
|
1596 // of deflate should use the same flush parameter to make sure
|
|
|
1597 // that the flush is complete. So we don't have to output an
|
|
|
1598 // empty block here, this will be done at next call. This also
|
|
|
1599 // ensures that for a very small output buffer, we emit at most
|
|
|
1600 // one empty block.
|
|
|
1601 }
|
|
|
1602
|
|
|
1603 if (bstate == BlockDone) {
|
|
|
1604 if (flush == Z_PARTIAL_FLUSH) {
|
|
|
1605 _tr_align();
|
|
|
1606 }
|
|
|
1607 else { // FULL_FLUSH or SYNC_FLUSH
|
|
|
1608 _tr_stored_block(0, 0, false);
|
|
|
1609
|
|
|
1610 // For a full flush, this empty block will be recognized
|
|
|
1611 // as a special marker by inflate_sync().
|
|
|
1612 if (flush == Z_FULL_FLUSH) {
|
|
|
1613 //state.head[s.hash_size-1]=0;
|
|
|
1614 for (int i = 0; i < hash_size/*-1*/; i++) // forget history
|
|
|
1615 head[i] = 0;
|
|
|
1616 }
|
|
|
1617 }
|
|
|
1618
|
|
|
1619 strm.flush_pending();
|
|
|
1620
|
|
|
1621 if (strm.avail_out == 0) {
|
|
|
1622 last_flush = -1; // avoid BUF_ERROR at next call, see above
|
|
|
1623 return Z_OK;
|
|
|
1624 }
|
|
|
1625 }
|
|
|
1626 }
|
|
|
1627
|
|
|
1628 if (flush != Z_FINISH) return Z_OK;
|
|
|
1629
|
|
|
1630 if (noheader != 0) return Z_STREAM_END;
|
|
|
1631
|
|
|
1632 // Write the zlib trailer (adler32)
|
|
|
1633 putShortMSB((int)(strm.adler >>> 16));
|
|
|
1634 putShortMSB((int)(strm.adler & 0xffff));
|
|
|
1635 strm.flush_pending();
|
|
|
1636 // If avail_out is zero, the application will call deflate again
|
|
|
1637 // to flush the rest.
|
|
|
1638 noheader = -1; // write the trailer only once!
|
|
|
1639 return pending != 0 ? Z_OK : Z_STREAM_END;
|
|
|
1640 }
|
|
|
1641 }
|
