Deflate.java
/*
* Copyright (c) 2000-2011 ymnk, JCraft,Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions
* and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other materials provided with
* the distribution.
*
* 3. The names of the authors may not be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL JCRAFT, INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This program is based on zlib-1.1.3, so all credit should go authors Jean-loup
* Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu) and contributors of zlib.
*/
package com.jcraft.jsch.jzlib;
final class Deflate implements Cloneable {
private static final int MAX_MEM_LEVEL = 9;
private static final int Z_DEFAULT_COMPRESSION = -1;
private static final int MAX_WBITS = 15; // 32K LZ77 window
private static final int DEF_MEM_LEVEL = 8;
static class Config {
int good_length; // reduce lazy search above this match length
int max_lazy; // do not perform lazy search above this match length
int nice_length; // quit search above this match length
int max_chain;
int func;
Config(int good_length, int max_lazy, int nice_length, int max_chain, int func) {
this.good_length = good_length;
this.max_lazy = max_lazy;
this.nice_length = nice_length;
this.max_chain = max_chain;
this.func = func;
}
}
private static final int STORED = 0;
private static final int FAST = 1;
private static final int SLOW = 2;
private static final Config[] config_table;
static {
config_table = new Config[10];
// good lazy nice chain
config_table[0] = new Config(0, 0, 0, 0, STORED);
config_table[1] = new Config(4, 4, 8, 4, FAST);
config_table[2] = new Config(4, 5, 16, 8, FAST);
config_table[3] = new Config(4, 6, 32, 32, FAST);
config_table[4] = new Config(4, 4, 16, 16, SLOW);
config_table[5] = new Config(8, 16, 32, 32, SLOW);
config_table[6] = new Config(8, 16, 128, 128, SLOW);
config_table[7] = new Config(8, 32, 128, 256, SLOW);
config_table[8] = new Config(32, 128, 258, 1024, SLOW);
config_table[9] = new Config(32, 258, 258, 4096, SLOW);
}
private static final String[] z_errmsg = {"need dictionary", // Z_NEED_DICT 2
"stream end", // Z_STREAM_END 1
"", // Z_OK 0
"file error", // Z_ERRNO (-1)
"stream error", // Z_STREAM_ERROR (-2)
"data error", // Z_DATA_ERROR (-3)
"insufficient memory", // Z_MEM_ERROR (-4)
"buffer error", // Z_BUF_ERROR (-5)
"incompatible version", // Z_VERSION_ERROR (-6)
""};
// block not completed, need more input or more output
private static final int NeedMore = 0;
// block flush performed
private static final int BlockDone = 1;
// finish started, need only more output at next deflate
private static final int FinishStarted = 2;
// finish done, accept no more input or output
private static final int FinishDone = 3;
// preset dictionary flag in zlib header
private static final int PRESET_DICT = 0x20;
private static final int Z_FILTERED = 1;
private static final int Z_HUFFMAN_ONLY = 2;
private static final int Z_DEFAULT_STRATEGY = 0;
private static final int Z_NO_FLUSH = 0;
private static final int Z_PARTIAL_FLUSH = 1;
private static final int Z_SYNC_FLUSH = 2;
private static final int Z_FULL_FLUSH = 3;
private static final int Z_FINISH = 4;
private static final int Z_OK = 0;
private static final int Z_STREAM_END = 1;
private static final int Z_NEED_DICT = 2;
private static final int Z_ERRNO = -1;
private static final int Z_STREAM_ERROR = -2;
private static final int Z_DATA_ERROR = -3;
private static final int Z_MEM_ERROR = -4;
private static final int Z_BUF_ERROR = -5;
private static final int Z_VERSION_ERROR = -6;
private static final int INIT_STATE = 42;
private static final int BUSY_STATE = 113;
private static final int FINISH_STATE = 666;
// The deflate compression method
private static final int Z_DEFLATED = 8;
private static final int STORED_BLOCK = 0;
private static final int STATIC_TREES = 1;
private static final int DYN_TREES = 2;
// The three kinds of block type
private static final int Z_BINARY = 0;
private static final int Z_ASCII = 1;
private static final int Z_UNKNOWN = 2;
private static final int Buf_size = 8 * 2;
// repeat previous bit length 3-6 times (2 bits of repeat count)
private static final int REP_3_6 = 16;
// repeat a zero length 3-10 times (3 bits of repeat count)
private static final int REPZ_3_10 = 17;
// repeat a zero length 11-138 times (7 bits of repeat count)
private static final int REPZ_11_138 = 18;
private static final int MIN_MATCH = 3;
private static final int MAX_MATCH = 258;
private static final int MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1);
private static final int MAX_BITS = 15;
private static final int D_CODES = 30;
private static final int BL_CODES = 19;
private static final int LENGTH_CODES = 29;
private static final int LITERALS = 256;
private static final int L_CODES = (LITERALS + 1 + LENGTH_CODES);
private static final int HEAP_SIZE = (2 * L_CODES + 1);
private static final int END_BLOCK = 256;
ZStream strm; // pointer back to this zlib stream
int status; // as the name implies
byte[] pending_buf; // output still pending
int pending_buf_size; // size of pending_buf
int pending_out; // next pending byte to output to the stream
int pending; // nb of bytes in the pending buffer
int wrap = 1;
byte data_type; // UNKNOWN, BINARY or ASCII
byte method; // STORED (for zip only) or DEFLATED
int last_flush; // value of flush param for previous deflate call
int w_size; // LZ77 window size (32K by default)
int w_bits; // log2(w_size) (8..16)
int w_mask; // w_size - 1
byte[] window;
// Sliding window. Input bytes are read into the second half of the window,
// and move to the first half later to keep a dictionary of at least wSize
// bytes. With this organization, matches are limited to a distance of
// wSize-MAX_MATCH bytes, but this ensures that IO is always
// performed with a length multiple of the block size. Also, it limits
// the window size to 64K, which is quite useful on MSDOS.
// To do: use the user input buffer as sliding window.
int window_size;
// Actual size of window: 2*wSize, except when the user input buffer
// is directly used as sliding window.
short[] prev;
// Link to older string with same hash index. To limit the size of this
// array to 64K, this link is maintained only for the last 32K strings.
// An index in this array is thus a window index modulo 32K.
short[] head; // Heads of the hash chains or NIL.
int ins_h; // hash index of string to be inserted
int hash_size; // number of elements in hash table
int hash_bits; // log2(hash_size)
int hash_mask; // hash_size-1
// Number of bits by which ins_h must be shifted at each input
// step. It must be such that after MIN_MATCH steps, the oldest
// byte no longer takes part in the hash key, that is:
// hash_shift * MIN_MATCH >= hash_bits
int hash_shift;
// Window position at the beginning of the current output block. Gets
// negative when the window is moved backwards.
int block_start;
int match_length; // length of best match
int prev_match; // previous match
int match_available; // set if previous match exists
int strstart; // start of string to insert
int match_start; // start of matching string
int lookahead; // number of valid bytes ahead in window
// Length of the best match at previous step. Matches not greater than this
// are discarded. This is used in the lazy match evaluation.
int prev_length;
// To speed up deflation, hash chains are never searched beyond this
// length. A higher limit improves compression ratio but degrades the speed.
int max_chain_length;
// Attempt to find a better match only when the current match is strictly
// smaller than this value. This mechanism is used only for compression
// levels >= 4.
int max_lazy_match;
// Insert new strings in the hash table only if the match length is not
// greater than this length. This saves time but degrades compression.
// max_insert_length is used only for compression levels <= 3.
int level; // compression level (1..9)
int strategy; // favor or force Huffman coding
// Use a faster search when the previous match is longer than this
int good_match;
// Stop searching when current match exceeds this
int nice_match;
short[] dyn_ltree; // literal and length tree
short[] dyn_dtree; // distance tree
short[] bl_tree; // Huffman tree for bit lengths
Tree l_desc = new Tree(); // desc for literal tree
Tree d_desc = new Tree(); // desc for distance tree
Tree bl_desc = new Tree(); // desc for bit length tree
// number of codes at each bit length for an optimal tree
short[] bl_count = new short[MAX_BITS + 1];
// working area to be used in Tree#gen_codes()
short[] next_code = new short[MAX_BITS + 1];
// heap used to build the Huffman trees
int[] heap = new int[2 * L_CODES + 1];
int heap_len; // number of elements in the heap
int heap_max; // element of largest frequency
// The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
// The same heap array is used to build all trees.
// Depth of each subtree used as tie breaker for trees of equal frequency
byte[] depth = new byte[2 * L_CODES + 1];
byte[] l_buf; // index for literals or lengths */
// Size of match buffer for literals/lengths. There are 4 reasons for
// limiting lit_bufsize to 64K:
// - frequencies can be kept in 16 bit counters
// - if compression is not successful for the first block, all input
// data is still in the window so we can still emit a stored block even
// when input comes from standard input. (This can also be done for
// all blocks if lit_bufsize is not greater than 32K.)
// - if compression is not successful for a file smaller than 64K, we can
// even emit a stored file instead of a stored block (saving 5 bytes).
// This is applicable only for zip (not gzip or zlib).
// - creating new Huffman trees less frequently may not provide fast
// adaptation to changes in the input data statistics. (Take for
// example a binary file with poorly compressible code followed by
// a highly compressible string table.) Smaller buffer sizes give
// fast adaptation but have of course the overhead of transmitting
// trees more frequently.
// - I can't count above 4
int lit_bufsize;
int last_lit; // running index in l_buf
// Buffer for distances. To simplify the code, d_buf and l_buf have
// the same number of elements. To use different lengths, an extra flag
// array would be necessary.
int d_buf; // index of pendig_buf
int opt_len; // bit length of current block with optimal trees
int static_len; // bit length of current block with static trees
int matches; // number of string matches in current block
int last_eob_len; // bit length of EOB code for last block
// Output buffer. bits are inserted starting at the bottom (least
// significant bits).
short bi_buf;
// Number of valid bits in bi_buf. All bits above the last valid bit
// are always zero.
int bi_valid;
GZIPHeader gheader = null;
Deflate(ZStream strm) {
this.strm = strm;
dyn_ltree = new short[HEAP_SIZE * 2];
dyn_dtree = new short[(2 * D_CODES + 1) * 2]; // distance tree
bl_tree = new short[(2 * BL_CODES + 1) * 2]; // Huffman tree for bit lengths
}
void lm_init() {
window_size = 2 * w_size;
head[hash_size - 1] = 0;
for (int i = 0; i < hash_size - 1; i++) {
head[i] = 0;
}
// Set the default configuration parameters:
max_lazy_match = Deflate.config_table[level].max_lazy;
good_match = Deflate.config_table[level].good_length;
nice_match = Deflate.config_table[level].nice_length;
max_chain_length = Deflate.config_table[level].max_chain;
strstart = 0;
block_start = 0;
lookahead = 0;
match_length = prev_length = MIN_MATCH - 1;
match_available = 0;
ins_h = 0;
}
// Initialize the tree data structures for a new zlib stream.
void tr_init() {
l_desc.dyn_tree = dyn_ltree;
l_desc.stat_desc = StaticTree.static_l_desc;
d_desc.dyn_tree = dyn_dtree;
d_desc.stat_desc = StaticTree.static_d_desc;
bl_desc.dyn_tree = bl_tree;
bl_desc.stat_desc = StaticTree.static_bl_desc;
bi_buf = 0;
bi_valid = 0;
last_eob_len = 8; // enough lookahead for inflate
// Initialize the first block of the first file:
init_block();
}
void init_block() {
// Initialize the trees.
for (int i = 0; i < L_CODES; i++)
dyn_ltree[i * 2] = 0;
for (int i = 0; i < D_CODES; i++)
dyn_dtree[i * 2] = 0;
for (int i = 0; i < BL_CODES; i++)
bl_tree[i * 2] = 0;
dyn_ltree[END_BLOCK * 2] = 1;
opt_len = static_len = 0;
last_lit = matches = 0;
}
// Restore the heap property by moving down the tree starting at node k,
// exchanging a node with the smallest of its two sons if necessary, stopping
// when the heap property is re-established (each father smaller than its
// two sons).
void pqdownheap(short[] tree, // the tree to restore
int k // node to move down
) {
int v = heap[k];
int j = k << 1; // left son of k
while (j <= heap_len) {
// Set j to the smallest of the two sons:
if (j < heap_len && smaller(tree, heap[j + 1], heap[j], depth)) {
j++;
}
// Exit if v is smaller than both sons
if (smaller(tree, v, heap[j], depth))
break;
// Exchange v with the smallest son
heap[k] = heap[j];
k = j;
// And continue down the tree, setting j to the left son of k
j <<= 1;
}
heap[k] = v;
}
static boolean smaller(short[] tree, int n, int m, byte[] depth) {
short tn2 = tree[n * 2];
short tm2 = tree[m * 2];
return (tn2 < tm2 || (tn2 == tm2 && depth[n] <= depth[m]));
}
// Scan a literal or distance tree to determine the frequencies of the codes
// in the bit length tree.
void scan_tree(short[] tree, // the tree to be scanned
int max_code // and its largest code of non zero frequency
) {
int n; // iterates over all tree elements
int prevlen = -1; // last emitted length
int curlen; // length of current code
int nextlen = tree[0 * 2 + 1]; // length of next code
int count = 0; // repeat count of the current code
int max_count = 7; // max repeat count
int min_count = 4; // min repeat count
if (nextlen == 0) {
max_count = 138;
min_count = 3;
}
tree[(max_code + 1) * 2 + 1] = (short) 0xffff; // guard
for (n = 0; n <= max_code; n++) {
curlen = nextlen;
nextlen = tree[(n + 1) * 2 + 1];
if (++count < max_count && curlen == nextlen) {
continue;
} else if (count < min_count) {
bl_tree[curlen * 2] += (short) count;
} else if (curlen != 0) {
if (curlen != prevlen)
bl_tree[curlen * 2]++;
bl_tree[REP_3_6 * 2]++;
} else if (count <= 10) {
bl_tree[REPZ_3_10 * 2]++;
} else {
bl_tree[REPZ_11_138 * 2]++;
}
count = 0;
prevlen = curlen;
if (nextlen == 0) {
max_count = 138;
min_count = 3;
} else if (curlen == nextlen) {
max_count = 6;
min_count = 3;
} else {
max_count = 7;
min_count = 4;
}
}
}
// Construct the Huffman tree for the bit lengths and return the index in
// bl_order of the last bit length code to send.
int build_bl_tree() {
int max_blindex; // index of last bit length code of non zero freq
// Determine the bit length frequencies for literal and distance trees
scan_tree(dyn_ltree, l_desc.max_code);
scan_tree(dyn_dtree, d_desc.max_code);
// Build the bit length tree:
bl_desc.build_tree(this);
// opt_len now includes the length of the tree representations, except
// the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
// Determine the number of bit length codes to send. The pkzip format
// requires that at least 4 bit length codes be sent. (appnote.txt says
// 3 but the actual value used is 4.)
for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
if (bl_tree[Tree.bl_order[max_blindex] * 2 + 1] != 0)
break;
}
// Update opt_len to include the bit length tree and counts
opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
return max_blindex;
}
// Send the header for a block using dynamic Huffman trees: the counts, the
// lengths of the bit length codes, the literal tree and the distance tree.
// IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
void send_all_trees(int lcodes, int dcodes, int blcodes) {
int rank; // index in bl_order
send_bits(lcodes - 257, 5); // not +255 as stated in appnote.txt
send_bits(dcodes - 1, 5);
send_bits(blcodes - 4, 4); // not -3 as stated in appnote.txt
for (rank = 0; rank < blcodes; rank++) {
send_bits(bl_tree[Tree.bl_order[rank] * 2 + 1], 3);
}
send_tree(dyn_ltree, lcodes - 1); // literal tree
send_tree(dyn_dtree, dcodes - 1); // distance tree
}
// Send a literal or distance tree in compressed form, using the codes in
// bl_tree.
void send_tree(short[] tree, // the tree to be sent
int max_code // and its largest code of non zero frequency
) {
int n; // iterates over all tree elements
int prevlen = -1; // last emitted length
int curlen; // length of current code
int nextlen = tree[0 * 2 + 1]; // length of next code
int count = 0; // repeat count of the current code
int max_count = 7; // max repeat count
int min_count = 4; // min repeat count
if (nextlen == 0) {
max_count = 138;
min_count = 3;
}
for (n = 0; n <= max_code; n++) {
curlen = nextlen;
nextlen = tree[(n + 1) * 2 + 1];
if (++count < max_count && curlen == nextlen) {
continue;
} else if (count < min_count) {
do {
send_code(curlen, bl_tree);
} while (--count != 0);
} else if (curlen != 0) {
if (curlen != prevlen) {
send_code(curlen, bl_tree);
count--;
}
send_code(REP_3_6, bl_tree);
send_bits(count - 3, 2);
} else if (count <= 10) {
send_code(REPZ_3_10, bl_tree);
send_bits(count - 3, 3);
} else {
send_code(REPZ_11_138, bl_tree);
send_bits(count - 11, 7);
}
count = 0;
prevlen = curlen;
if (nextlen == 0) {
max_count = 138;
min_count = 3;
} else if (curlen == nextlen) {
max_count = 6;
min_count = 3;
} else {
max_count = 7;
min_count = 4;
}
}
}
// Output a byte on the stream.
// IN assertion: there is enough room in pending_buf.
final void put_byte(byte[] p, int start, int len) {
System.arraycopy(p, start, pending_buf, pending, len);
pending += len;
}
final void put_byte(byte c) {
pending_buf[pending++] = c;
}
final void put_short(int w) {
put_byte((byte) (w /* &0xff */));
put_byte((byte) (w >>> 8));
}
final void putShortMSB(int b) {
put_byte((byte) (b >> 8));
put_byte((byte) (b /* &0xff */));
}
final void send_code(int c, short[] tree) {
int c2 = c * 2;
send_bits((tree[c2] & 0xffff), (tree[c2 + 1] & 0xffff));
}
void send_bits(int value, int length) {
int len = length;
if (bi_valid > Buf_size - len) {
int val = value;
// bi_buf |= (val << bi_valid);
bi_buf |= (short) ((val << bi_valid) & 0xffff);
put_short(bi_buf);
bi_buf = (short) (val >>> (Buf_size - bi_valid));
bi_valid += len - Buf_size;
} else {
// bi_buf |= (value) << bi_valid;
bi_buf |= (short) (((value) << bi_valid) & 0xffff);
bi_valid += len;
}
}
// Send one empty static block to give enough lookahead for inflate.
// This takes 10 bits, of which 7 may remain in the bit buffer.
// The current inflate code requires 9 bits of lookahead. If the
// last two codes for the previous block (real code plus EOB) were coded
// on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
// the last real code. In this case we send two empty static blocks instead
// of one. (There are no problems if the previous block is stored or fixed.)
// To simplify the code, we assume the worst case of last real code encoded
// on one bit only.
void _tr_align() {
send_bits(STATIC_TREES << 1, 3);
send_code(END_BLOCK, StaticTree.static_ltree);
bi_flush();
// Of the 10 bits for the empty block, we have already sent
// (10 - bi_valid) bits. The lookahead for the last real code (before
// the EOB of the previous block) was thus at least one plus the length
// of the EOB plus what we have just sent of the empty static block.
if (1 + last_eob_len + 10 - bi_valid < 9) {
send_bits(STATIC_TREES << 1, 3);
send_code(END_BLOCK, StaticTree.static_ltree);
bi_flush();
}
last_eob_len = 7;
}
// Save the match info and tally the frequency counts. Return true if
// the current block must be flushed.
boolean _tr_tally(int dist, // distance of matched string
int lc // match length-MIN_MATCH or unmatched char (if dist==0)
) {
pending_buf[d_buf + last_lit * 2] = (byte) (dist >>> 8);
pending_buf[d_buf + last_lit * 2 + 1] = (byte) dist;
l_buf[last_lit] = (byte) lc;
last_lit++;
if (dist == 0) {
// lc is the unmatched char
dyn_ltree[lc * 2]++;
} else {
matches++;
// Here, lc is the match length - MIN_MATCH
dist--; // dist = match distance - 1
dyn_ltree[(Tree._length_code[lc] + LITERALS + 1) * 2]++;
dyn_dtree[Tree.d_code(dist) * 2]++;
}
if ((last_lit & 0x1fff) == 0 && level > 2) {
// Compute an upper bound for the compressed length
int out_length = last_lit * 8;
int in_length = strstart - block_start;
int dcode;
for (dcode = 0; dcode < D_CODES; dcode++) {
out_length += (int) dyn_dtree[dcode * 2] * (5 + Tree.extra_dbits[dcode]);
}
out_length >>>= 3;
if ((matches < (last_lit / 2)) && out_length < in_length / 2)
return true;
}
return (last_lit == lit_bufsize - 1);
// We avoid equality with lit_bufsize because of wraparound at 64K
// on 16 bit machines and because stored blocks are restricted to
// 64K-1 bytes.
}
// Send the block data compressed using the given Huffman trees
void compress_block(short[] ltree, short[] dtree) {
int dist; // distance of matched string
int lc; // match length or unmatched char (if dist == 0)
int lx = 0; // running index in l_buf
int code; // the code to send
int extra; // number of extra bits to send
if (last_lit != 0) {
do {
dist = ((pending_buf[d_buf + lx * 2] << 8) & 0xff00)
| (pending_buf[d_buf + lx * 2 + 1] & 0xff);
lc = (l_buf[lx]) & 0xff;
lx++;
if (dist == 0) {
send_code(lc, ltree); // send a literal byte
} else {
// Here, lc is the match length - MIN_MATCH
code = Tree._length_code[lc];
send_code(code + LITERALS + 1, ltree); // send the length code
extra = Tree.extra_lbits[code];
if (extra != 0) {
lc -= Tree.base_length[code];
send_bits(lc, extra); // send the extra length bits
}
dist--; // dist is now the match distance - 1
code = Tree.d_code(dist);
send_code(code, dtree); // send the distance code
extra = Tree.extra_dbits[code];
if (extra != 0) {
dist -= Tree.base_dist[code];
send_bits(dist, extra); // send the extra distance bits
}
} // literal or match pair ?
// Check that the overlay between pending_buf and d_buf+l_buf is ok:
} while (lx < last_lit);
}
send_code(END_BLOCK, ltree);
last_eob_len = ltree[END_BLOCK * 2 + 1];
}
// Set the data type to ASCII or BINARY, using a crude approximation:
// binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
// IN assertion: the fields freq of dyn_ltree are set and the total of all
// frequencies does not exceed 64K (to fit in an int on 16 bit machines).
void set_data_type() {
int n = 0;
int ascii_freq = 0;
int bin_freq = 0;
while (n < 7) {
bin_freq += dyn_ltree[n * 2];
n++;
}
while (n < 128) {
ascii_freq += dyn_ltree[n * 2];
n++;
}
while (n < LITERALS) {
bin_freq += dyn_ltree[n * 2];
n++;
}
data_type = (byte) (bin_freq > (ascii_freq >>> 2) ? Z_BINARY : Z_ASCII);
}
// Flush the bit buffer, keeping at most 7 bits in it.
void bi_flush() {
if (bi_valid == 16) {
put_short(bi_buf);
bi_buf = 0;
bi_valid = 0;
} else if (bi_valid >= 8) {
put_byte((byte) bi_buf);
bi_buf >>>= 8;
bi_valid -= 8;
}
}
// Flush the bit buffer and align the output on a byte boundary
void bi_windup() {
if (bi_valid > 8) {
put_short(bi_buf);
} else if (bi_valid > 0) {
put_byte((byte) bi_buf);
}
bi_buf = 0;
bi_valid = 0;
}
// Copy a stored block, storing first the length and its
// one's complement if requested.
void copy_block(int buf, // the input data
int len, // its length
boolean header // true if block header must be written
) {
int index = 0;
bi_windup(); // align on byte boundary
last_eob_len = 8; // enough lookahead for inflate
if (header) {
put_short((short) len);
put_short((short) ~len);
}
// while(len--!=0) {
// put_byte(window[buf+index]);
// index++;
// }
put_byte(window, buf, len);
}
void flush_block_only(boolean eof) {
_tr_flush_block(block_start >= 0 ? block_start : -1, strstart - block_start, eof);
block_start = strstart;
strm.flush_pending();
}
// Copy without compression as much as possible from the input stream, return
// the current block state.
// This function does not insert new strings in the dictionary since
// uncompressible data is probably not useful. This function is used
// only for the level=0 compression option.
// NOTE: this function should be optimized to avoid extra copying from
// window to pending_buf.
int deflate_stored(int flush) {
// Stored blocks are limited to 0xffff bytes, pending_buf is limited
// to pending_buf_size, and each stored block has a 5 byte header:
int max_block_size = 0xffff;
int max_start;
if (max_block_size > pending_buf_size - 5) {
max_block_size = pending_buf_size - 5;
}
// Copy as much as possible from input to output:
while (true) {
// Fill the window as much as possible:
if (lookahead <= 1) {
fill_window();
if (lookahead == 0 && flush == Z_NO_FLUSH)
return NeedMore;
if (lookahead == 0)
break; // flush the current block
}
strstart += lookahead;
lookahead = 0;
// Emit a stored block if pending_buf will be full:
max_start = block_start + max_block_size;
if (strstart == 0 || strstart >= max_start) {
// strstart == 0 is possible when wraparound on 16-bit machine
lookahead = strstart - max_start;
strstart = max_start;
flush_block_only(false);
if (strm.avail_out == 0)
return NeedMore;
}
// Flush if we may have to slide, otherwise block_start may become
// negative and the data will be gone:
if (strstart - block_start >= w_size - MIN_LOOKAHEAD) {
flush_block_only(false);
if (strm.avail_out == 0)
return NeedMore;
}
}
flush_block_only(flush == Z_FINISH);
if (strm.avail_out == 0)
return (flush == Z_FINISH) ? FinishStarted : NeedMore;
return flush == Z_FINISH ? FinishDone : BlockDone;
}
// Send a stored block
void _tr_stored_block(int buf, // input block
int stored_len, // length of input block
boolean eof // true if this is the last block for a file
) {
send_bits((STORED_BLOCK << 1) + (eof ? 1 : 0), 3); // send block type
copy_block(buf, stored_len, true); // with header
}
// Determine the best encoding for the current block: dynamic trees, static
// trees or store, and output the encoded block to the zip file.
void _tr_flush_block(int buf, // input block, or NULL if too old
int stored_len, // length of input block
boolean eof // true if this is the last block for a file
) {
int opt_lenb, static_lenb; // opt_len and static_len in bytes
int max_blindex = 0; // index of last bit length code of non zero freq
// Build the Huffman trees unless a stored block is forced
if (level > 0) {
// Check if the file is ascii or binary
if (data_type == Z_UNKNOWN)
set_data_type();
// Construct the literal and distance trees
l_desc.build_tree(this);
d_desc.build_tree(this);
// At this point, opt_len and static_len are the total bit lengths of
// the compressed block data, excluding the tree representations.
// Build the bit length tree for the above two trees, and get the index
// in bl_order of the last bit length code to send.
max_blindex = build_bl_tree();
// Determine the best encoding. Compute first the block length in bytes
opt_lenb = (opt_len + 3 + 7) >>> 3;
static_lenb = (static_len + 3 + 7) >>> 3;
if (static_lenb <= opt_lenb)
opt_lenb = static_lenb;
} else {
opt_lenb = static_lenb = stored_len + 5; // force a stored block
}
if (stored_len + 4 <= opt_lenb && buf != -1) {
// 4: two words for the lengths
// The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
// Otherwise we can't have processed more than WSIZE input bytes since
// the last block flush, because compression would have been
// successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
// transform a block into a stored block.
_tr_stored_block(buf, stored_len, eof);
} else if (static_lenb == opt_lenb) {
send_bits((STATIC_TREES << 1) + (eof ? 1 : 0), 3);
compress_block(StaticTree.static_ltree, StaticTree.static_dtree);
} else {
send_bits((DYN_TREES << 1) + (eof ? 1 : 0), 3);
send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, max_blindex + 1);
compress_block(dyn_ltree, dyn_dtree);
}
// The above check is made mod 2^32, for files larger than 512 MB
// and uLong implemented on 32 bits.
init_block();
if (eof) {
bi_windup();
}
}
// Fill the window when the lookahead becomes insufficient.
// Updates strstart and lookahead.
//
// IN assertion: lookahead < MIN_LOOKAHEAD
// OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
// At least one byte has been read, or avail_in == 0; reads are
// performed for at least two bytes (required for the zip translate_eol
// option -- not supported here).
void fill_window() {
int n, m;
int p;
int more; // Amount of free space at the end of the window.
do {
more = (window_size - lookahead - strstart);
// Deal with !@#$% 64K limit:
if (more == 0 && strstart == 0 && lookahead == 0) {
more = w_size;
} else if (more == -1) {
// Very unlikely, but possible on 16 bit machine if strstart == 0
// and lookahead == 1 (input done one byte at time)
more--;
// If the window is almost full and there is insufficient lookahead,
// move the upper half to the lower one to make room in the upper half.
} else if (strstart >= w_size + w_size - MIN_LOOKAHEAD) {
System.arraycopy(window, w_size, window, 0, w_size);
match_start -= w_size;
strstart -= w_size; // we now have strstart >= MAX_DIST
block_start -= w_size;
// Slide the hash table (could be avoided with 32 bit values
// at the expense of memory usage). We slide even when level == 0
// to keep the hash table consistent if we switch back to level > 0
// later. (Using level 0 permanently is not an optimal usage of
// zlib, so we don't care about this pathological case.)
n = hash_size;
p = n;
do {
m = (head[--p] & 0xffff);
head[p] = (m >= w_size ? (short) (m - w_size) : 0);
} while (--n != 0);
n = w_size;
p = n;
do {
m = (prev[--p] & 0xffff);
prev[p] = (m >= w_size ? (short) (m - w_size) : 0);
// If n is not on any hash chain, prev[n] is garbage but
// its value will never be used.
} while (--n != 0);
more += w_size;
}
if (strm.avail_in == 0)
return;
// If there was no sliding:
// strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
// more == window_size - lookahead - strstart
// => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
// => more >= window_size - 2*WSIZE + 2
// In the BIG_MEM or MMAP case (not yet supported),
// window_size == input_size + MIN_LOOKAHEAD &&
// strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
// Otherwise, window_size == 2*WSIZE so more >= 2.
// If there was sliding, more >= WSIZE. So in all cases, more >= 2.
n = strm.read_buf(window, strstart + lookahead, more);
lookahead += n;
// Initialize the hash value now that we have some input:
if (lookahead >= MIN_MATCH) {
ins_h = window[strstart] & 0xff;
ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
}
// If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
// but this is not important since only literal bytes will be emitted.
} while (lookahead < MIN_LOOKAHEAD && strm.avail_in != 0);
}
// Compress as much as possible from the input stream, return the current
// block state.
// This function does not perform lazy evaluation of matches and inserts
// new strings in the dictionary only for unmatched strings or for short
// matches. It is used only for the fast compression options.
int deflate_fast(int flush) {
// short hash_head = 0; // head of the hash chain
int hash_head = 0; // head of the hash chain
boolean bflush; // set if current block must be flushed
while (true) {
// Make sure that we always have enough lookahead, except
// at the end of the input file. We need MAX_MATCH bytes
// for the next match, plus MIN_MATCH bytes to insert the
// string following the next match.
if (lookahead < MIN_LOOKAHEAD) {
fill_window();
if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
return NeedMore;
}
if (lookahead == 0)
break; // flush the current block
}
// Insert the string window[strstart .. strstart+2] in the
// dictionary, and set hash_head to the head of the hash chain:
if (lookahead >= MIN_MATCH) {
ins_h =
(((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
// prev[strstart&w_mask]=hash_head=head[ins_h];
hash_head = (head[ins_h] & 0xffff);
prev[strstart & w_mask] = head[ins_h];
head[ins_h] = (short) strstart;
}
// Find the longest match, discarding those <= prev_length.
// At this point we have always match_length < MIN_MATCH
if (hash_head != 0L && ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD) {
// To simplify the code, we prevent matches with the string
// of window index 0 (in particular we have to avoid a match
// of the string with itself at the start of the input file).
if (strategy != Z_HUFFMAN_ONLY) {
match_length = longest_match(hash_head);
}
// longest_match() sets match_start
}
if (match_length >= MIN_MATCH) {
// check_match(strstart, match_start, match_length);
bflush = _tr_tally(strstart - match_start, match_length - MIN_MATCH);
lookahead -= match_length;
// Insert new strings in the hash table only if the match length
// is not too large. This saves time but degrades compression.
if (match_length <= max_lazy_match && lookahead >= MIN_MATCH) {
match_length--; // string at strstart already in hash table
do {
strstart++;
ins_h =
((ins_h << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
// prev[strstart&w_mask]=hash_head=head[ins_h];
hash_head = (head[ins_h] & 0xffff);
prev[strstart & w_mask] = head[ins_h];
head[ins_h] = (short) strstart;
// strstart never exceeds WSIZE-MAX_MATCH, so there are
// always MIN_MATCH bytes ahead.
} while (--match_length != 0);
strstart++;
} else {
strstart += match_length;
match_length = 0;
ins_h = window[strstart] & 0xff;
ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
// If lookahead < MIN_MATCH, ins_h is garbage, but it does not
// matter since it will be recomputed at next deflate call.
}
} else {
// No match, output a literal byte
bflush = _tr_tally(0, window[strstart] & 0xff);
lookahead--;
strstart++;
}
if (bflush) {
flush_block_only(false);
if (strm.avail_out == 0)
return NeedMore;
}
}
flush_block_only(flush == Z_FINISH);
if (strm.avail_out == 0) {
if (flush == Z_FINISH)
return FinishStarted;
else
return NeedMore;
}
return flush == Z_FINISH ? FinishDone : BlockDone;
}
// Same as above, but achieves better compression. We use a lazy
// evaluation for matches: a match is finally adopted only if there is
// no better match at the next window position.
int deflate_slow(int flush) {
// short hash_head = 0; // head of hash chain
int hash_head = 0; // head of hash chain
boolean bflush; // set if current block must be flushed
// Process the input block.
while (true) {
// Make sure that we always have enough lookahead, except
// at the end of the input file. We need MAX_MATCH bytes
// for the next match, plus MIN_MATCH bytes to insert the
// string following the next match.
if (lookahead < MIN_LOOKAHEAD) {
fill_window();
if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
return NeedMore;
}
if (lookahead == 0)
break; // flush the current block
}
// Insert the string window[strstart .. strstart+2] in the
// dictionary, and set hash_head to the head of the hash chain:
if (lookahead >= MIN_MATCH) {
ins_h =
(((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
// prev[strstart&w_mask]=hash_head=head[ins_h];
hash_head = (head[ins_h] & 0xffff);
prev[strstart & w_mask] = head[ins_h];
head[ins_h] = (short) strstart;
}
// Find the longest match, discarding those <= prev_length.
prev_length = match_length;
prev_match = match_start;
match_length = MIN_MATCH - 1;
if (hash_head != 0 && prev_length < max_lazy_match
&& ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD) {
// To simplify the code, we prevent matches with the string
// of window index 0 (in particular we have to avoid a match
// of the string with itself at the start of the input file).
if (strategy != Z_HUFFMAN_ONLY) {
match_length = longest_match(hash_head);
}
// longest_match() sets match_start
if (match_length <= 5 && (strategy == Z_FILTERED
|| (match_length == MIN_MATCH && strstart - match_start > 4096))) {
// If prev_match is also MIN_MATCH, match_start is garbage
// but we will ignore the current match anyway.
match_length = MIN_MATCH - 1;
}
}
// If there was a match at the previous step and the current
// match is not better, output the previous match:
if (prev_length >= MIN_MATCH && match_length <= prev_length) {
int max_insert = strstart + lookahead - MIN_MATCH;
// Do not insert strings in hash table beyond this.
// check_match(strstart-1, prev_match, prev_length);
bflush = _tr_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
// Insert in hash table all strings up to the end of the match.
// strstart-1 and strstart are already inserted. If there is not
// enough lookahead, the last two strings are not inserted in
// the hash table.
lookahead -= prev_length - 1;
prev_length -= 2;
do {
if (++strstart <= max_insert) {
ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff))
& hash_mask;
// prev[strstart&w_mask]=hash_head=head[ins_h];
hash_head = (head[ins_h] & 0xffff);
prev[strstart & w_mask] = head[ins_h];
head[ins_h] = (short) strstart;
}
} while (--prev_length != 0);
match_available = 0;
match_length = MIN_MATCH - 1;
strstart++;
if (bflush) {
flush_block_only(false);
if (strm.avail_out == 0)
return NeedMore;
}
} else if (match_available != 0) {
// If there was no match at the previous position, output a
// single literal. If there was a match but the current match
// is longer, truncate the previous match to a single literal.
bflush = _tr_tally(0, window[strstart - 1] & 0xff);
if (bflush) {
flush_block_only(false);
}
strstart++;
lookahead--;
if (strm.avail_out == 0)
return NeedMore;
} else {
// There is no previous match to compare with, wait for
// the next step to decide.
match_available = 1;
strstart++;
lookahead--;
}
}
if (match_available != 0) {
bflush = _tr_tally(0, window[strstart - 1] & 0xff);
match_available = 0;
}
flush_block_only(flush == Z_FINISH);
if (strm.avail_out == 0) {
if (flush == Z_FINISH)
return FinishStarted;
else
return NeedMore;
}
return flush == Z_FINISH ? FinishDone : BlockDone;
}
int longest_match(int cur_match) {
int chain_length = max_chain_length; // max hash chain length
int scan = strstart; // current string
int match; // matched string
int len; // length of current match
int best_len = prev_length; // best match length so far
int limit = strstart > (w_size - MIN_LOOKAHEAD) ? strstart - (w_size - MIN_LOOKAHEAD) : 0;
int nice_match = this.nice_match;
// Stop when cur_match becomes <= limit. To simplify the code,
// we prevent matches with the string of window index 0.
int wmask = w_mask;
int strend = strstart + MAX_MATCH;
byte scan_end1 = window[scan + best_len - 1];
byte scan_end = window[scan + best_len];
// The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
// It is easy to get rid of this optimization if necessary.
// Do not waste too much time if we already have a good match:
if (prev_length >= good_match) {
chain_length >>= 2;
}
// Do not look for matches beyond the end of the input. This is necessary
// to make deflate deterministic.
if (nice_match > lookahead)
nice_match = lookahead;
do {
match = cur_match;
// Skip to next match if the match length cannot increase
// or if the match length is less than 2:
if (window[match + best_len] != scan_end || window[match + best_len - 1] != scan_end1
|| window[match] != window[scan] || window[++match] != window[scan + 1])
continue;
// The check at best_len-1 can be removed because it will be made
// again later. (This heuristic is not always a win.)
// It is not necessary to compare scan[2] and match[2] since they
// are always equal when the other bytes match, given that
// the hash keys are equal and that HASH_BITS >= 8.
scan += 2;
match++;
// We check for insufficient lookahead only every 8th comparison;
// the 256th check will be made at strstart+258.
do {
} while (window[++scan] == window[++match] && window[++scan] == window[++match]
&& window[++scan] == window[++match] && window[++scan] == window[++match]
&& window[++scan] == window[++match] && window[++scan] == window[++match]
&& window[++scan] == window[++match] && window[++scan] == window[++match]
&& scan < strend);
len = MAX_MATCH - strend - scan;
scan = strend - MAX_MATCH;
if (len > best_len) {
match_start = cur_match;
best_len = len;
if (len >= nice_match)
break;
scan_end1 = window[scan + best_len - 1];
scan_end = window[scan + best_len];
}
} while ((cur_match = (prev[cur_match & wmask] & 0xffff)) > limit && --chain_length != 0);
if (best_len <= lookahead)
return best_len;
return lookahead;
}
int deflateInit(int level, int bits, int memlevel) {
return deflateInit(level, Z_DEFLATED, bits, memlevel, Z_DEFAULT_STRATEGY);
}
int deflateInit(int level, int bits) {
return deflateInit(level, Z_DEFLATED, bits, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
}
int deflateInit(int level) {
return deflateInit(level, MAX_WBITS);
}
private int deflateInit(int level, int method, int windowBits, int memLevel, int strategy) {
int wrap = 1;
// byte[] my_version=ZLIB_VERSION;
//
// if (version == null || version[0] != my_version[0]
// || stream_size != sizeof(z_stream)) {
// return Z_VERSION_ERROR;
// }
strm.msg = null;
if (level == Z_DEFAULT_COMPRESSION)
level = 6;
if (windowBits < 0) { // undocumented feature: suppress zlib header
wrap = 0;
windowBits = -windowBits;
} else if (windowBits > 15) {
wrap = 2;
windowBits -= 16;
strm.adler = new CRC32();
}
if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || windowBits < 9
|| windowBits > 15 || level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
return Z_STREAM_ERROR;
}
strm.dstate = this;
this.wrap = wrap;
w_bits = windowBits;
w_size = 1 << w_bits;
w_mask = w_size - 1;
hash_bits = memLevel + 7;
hash_size = 1 << hash_bits;
hash_mask = hash_size - 1;
hash_shift = ((hash_bits + MIN_MATCH - 1) / MIN_MATCH);
window = new byte[w_size * 2];
prev = new short[w_size];
head = new short[hash_size];
lit_bufsize = 1 << (memLevel + 6); // 16K elements by default
// We overlay pending_buf and d_buf+l_buf. This works since the average
// output size for (length,distance) codes is <= 24 bits.
pending_buf = new byte[lit_bufsize * 3];
pending_buf_size = lit_bufsize * 3;
d_buf = lit_bufsize;
l_buf = new byte[lit_bufsize];
this.level = level;
this.strategy = strategy;
this.method = (byte) method;
return deflateReset();
}
int deflateReset() {
strm.total_in = strm.total_out = 0;
strm.msg = null; //
strm.data_type = Z_UNKNOWN;
pending = 0;
pending_out = 0;
if (wrap < 0) {
wrap = -wrap;
}
status = (wrap == 0) ? BUSY_STATE : INIT_STATE;
strm.adler.reset();
last_flush = Z_NO_FLUSH;
tr_init();
lm_init();
return Z_OK;
}
int deflateEnd() {
if (status != INIT_STATE && status != BUSY_STATE && status != FINISH_STATE) {
return Z_STREAM_ERROR;
}
// Deallocate in reverse order of allocations:
pending_buf = null;
l_buf = null;
head = null;
prev = null;
window = null;
// free
// dstate=null;
return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
}
int deflateParams(int _level, int _strategy) {
int err = Z_OK;
if (_level == Z_DEFAULT_COMPRESSION) {
_level = 6;
}
if (_level < 0 || _level > 9 || _strategy < 0 || _strategy > Z_HUFFMAN_ONLY) {
return Z_STREAM_ERROR;
}
if (config_table[level].func != config_table[_level].func && strm.total_in != 0) {
// Flush the last buffer:
err = strm.deflate(Z_PARTIAL_FLUSH);
}
if (level != _level) {
level = _level;
max_lazy_match = config_table[level].max_lazy;
good_match = config_table[level].good_length;
nice_match = config_table[level].nice_length;
max_chain_length = config_table[level].max_chain;
}
strategy = _strategy;
return err;
}
int deflateSetDictionary(byte[] dictionary, int dictLength) {
int length = dictLength;
int index = 0;
if (dictionary == null || status != INIT_STATE)
return Z_STREAM_ERROR;
strm.adler.update(dictionary, 0, dictLength);
if (length < MIN_MATCH)
return Z_OK;
if (length > w_size - MIN_LOOKAHEAD) {
length = w_size - MIN_LOOKAHEAD;
index = dictLength - length; // use the tail of the dictionary
}
System.arraycopy(dictionary, index, window, 0, length);
strstart = length;
block_start = length;
// Insert all strings in the hash table (except for the last two bytes).
// s->lookahead stays null, so s->ins_h will be recomputed at the next
// call of fill_window.
ins_h = window[0] & 0xff;
ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;
for (int n = 0; n <= length - MIN_MATCH; n++) {
ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
prev[n & w_mask] = head[ins_h];
head[ins_h] = (short) n;
}
return Z_OK;
}
int deflate(int flush) {
int old_flush;
if (flush > Z_FINISH || flush < 0) {
return Z_STREAM_ERROR;
}
if (strm.next_out == null || (strm.next_in == null && strm.avail_in != 0)
|| (status == FINISH_STATE && flush != Z_FINISH)) {
strm.msg = z_errmsg[Z_NEED_DICT - (Z_STREAM_ERROR)];
return Z_STREAM_ERROR;
}
if (strm.avail_out == 0) {
strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
return Z_BUF_ERROR;
}
old_flush = last_flush;
last_flush = flush;
// Write the zlib header
if (status == INIT_STATE) {
if (wrap == 2) {
getGZIPHeader().put(this);
status = BUSY_STATE;
strm.adler.reset();
} else {
int header = (Z_DEFLATED + ((w_bits - 8) << 4)) << 8;
int level_flags = ((level - 1) & 0xff) >> 1;
if (level_flags > 3)
level_flags = 3;
header |= (level_flags << 6);
if (strstart != 0)
header |= PRESET_DICT;
header += 31 - (header % 31);
status = BUSY_STATE;
putShortMSB(header);
// Save the adler32 of the preset dictionary:
if (strstart != 0) {
long adler = strm.adler.getValue();
putShortMSB((int) (adler >>> 16));
putShortMSB((int) (adler & 0xffff));
}
strm.adler.reset();
}
}
// Flush as much pending output as possible
if (pending != 0) {
strm.flush_pending();
if (strm.avail_out == 0) {
// Since avail_out is 0, deflate will be called again with
// more output space, but possibly with both pending and
// avail_in equal to zero. There won't be anything to do,
// but this is not an error situation so make sure we
// return OK instead of BUF_ERROR at next call of deflate:
last_flush = -1;
return Z_OK;
}
// Make sure there is something to do and avoid duplicate consecutive
// flushes. For repeated and useless calls with Z_FINISH, we keep
// returning Z_STREAM_END instead of Z_BUFF_ERROR.
} else if (strm.avail_in == 0 && flush <= old_flush && flush != Z_FINISH) {
strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
return Z_BUF_ERROR;
}
// User must not provide more input after the first FINISH:
if (status == FINISH_STATE && strm.avail_in != 0) {
strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
return Z_BUF_ERROR;
}
// Start a new block or continue the current one.
if (strm.avail_in != 0 || lookahead != 0 || (flush != Z_NO_FLUSH && status != FINISH_STATE)) {
int bstate = -1;
switch (config_table[level].func) {
case STORED:
bstate = deflate_stored(flush);
break;
case FAST:
bstate = deflate_fast(flush);
break;
case SLOW:
bstate = deflate_slow(flush);
break;
default:
}
if (bstate == FinishStarted || bstate == FinishDone) {
status = FINISH_STATE;
}
if (bstate == NeedMore || bstate == FinishStarted) {
if (strm.avail_out == 0) {
last_flush = -1; // avoid BUF_ERROR next call, see above
}
return Z_OK;
// If flush != Z_NO_FLUSH && avail_out == 0, the next call
// of deflate should use the same flush parameter to make sure
// that the flush is complete. So we don't have to output an
// empty block here, this will be done at next call. This also
// ensures that for a very small output buffer, we emit at most
// one empty block.
}
if (bstate == BlockDone) {
if (flush == Z_PARTIAL_FLUSH) {
_tr_align();
} else { // FULL_FLUSH or SYNC_FLUSH
_tr_stored_block(0, 0, false);
// For a full flush, this empty block will be recognized
// as a special marker by inflate_sync().
if (flush == Z_FULL_FLUSH) {
// state.head[s.hash_size-1]=0;
for (int i = 0; i < hash_size /*-1*/; i++) // forget history
head[i] = 0;
}
}
strm.flush_pending();
if (strm.avail_out == 0) {
last_flush = -1; // avoid BUF_ERROR at next call, see above
return Z_OK;
}
}
}
if (flush != Z_FINISH)
return Z_OK;
if (wrap <= 0)
return Z_STREAM_END;
if (wrap == 2) {
long adler = strm.adler.getValue();
put_byte((byte) (adler & 0xff));
put_byte((byte) ((adler >> 8) & 0xff));
put_byte((byte) ((adler >> 16) & 0xff));
put_byte((byte) ((adler >> 24) & 0xff));
put_byte((byte) (strm.total_in & 0xff));
put_byte((byte) ((strm.total_in >> 8) & 0xff));
put_byte((byte) ((strm.total_in >> 16) & 0xff));
put_byte((byte) ((strm.total_in >> 24) & 0xff));
getGZIPHeader().setCRC(adler);
} else {
// Write the zlib trailer (adler32)
long adler = strm.adler.getValue();
putShortMSB((int) (adler >>> 16));
putShortMSB((int) (adler & 0xffff));
}
strm.flush_pending();
// If avail_out is zero, the application will call deflate again
// to flush the rest.
if (wrap > 0)
wrap = -wrap; // write the trailer only once!
return pending != 0 ? Z_OK : Z_STREAM_END;
}
static int deflateCopy(ZStream dest, ZStream src) {
if (src.dstate == null) {
return Z_STREAM_ERROR;
}
if (src.next_in != null) {
dest.next_in = new byte[src.next_in.length];
System.arraycopy(src.next_in, 0, dest.next_in, 0, src.next_in.length);
}
dest.next_in_index = src.next_in_index;
dest.avail_in = src.avail_in;
dest.total_in = src.total_in;
if (src.next_out != null) {
dest.next_out = new byte[src.next_out.length];
System.arraycopy(src.next_out, 0, dest.next_out, 0, src.next_out.length);
}
dest.next_out_index = src.next_out_index;
dest.avail_out = src.avail_out;
dest.total_out = src.total_out;
dest.msg = src.msg;
dest.data_type = src.data_type;
dest.adler = src.adler.copy();
try {
dest.dstate = (Deflate) src.dstate.clone();
dest.dstate.strm = dest;
} catch (CloneNotSupportedException e) {
//
}
return Z_OK;
}
@Override
public Object clone() throws CloneNotSupportedException {
Deflate dest = (Deflate) super.clone();
dest.pending_buf = dup(dest.pending_buf);
dest.l_buf = dup(dest.l_buf);
dest.window = dup(dest.window);
dest.prev = dup(dest.prev);
dest.head = dup(dest.head);
dest.dyn_ltree = dup(dest.dyn_ltree);
dest.dyn_dtree = dup(dest.dyn_dtree);
dest.bl_tree = dup(dest.bl_tree);
dest.bl_count = dup(dest.bl_count);
dest.next_code = dup(dest.next_code);
dest.heap = dup(dest.heap);
dest.depth = dup(dest.depth);
dest.l_desc.dyn_tree = dest.dyn_ltree;
dest.d_desc.dyn_tree = dest.dyn_dtree;
dest.bl_desc.dyn_tree = dest.bl_tree;
/*
* dest.l_desc.stat_desc = StaticTree.static_l_desc; dest.d_desc.stat_desc =
* StaticTree.static_d_desc; dest.bl_desc.stat_desc = StaticTree.static_bl_desc;
*/
if (dest.gheader != null) {
dest.gheader = (GZIPHeader) dest.gheader.clone();
}
return dest;
}
private byte[] dup(byte[] buf) {
byte[] foo = new byte[buf.length];
System.arraycopy(buf, 0, foo, 0, foo.length);
return foo;
}
private short[] dup(short[] buf) {
short[] foo = new short[buf.length];
System.arraycopy(buf, 0, foo, 0, foo.length);
return foo;
}
private int[] dup(int[] buf) {
int[] foo = new int[buf.length];
System.arraycopy(buf, 0, foo, 0, foo.length);
return foo;
}
synchronized GZIPHeader getGZIPHeader() {
if (gheader == null) {
gheader = new GZIPHeader();
}
return gheader;
}
}