| 'use strict'; |
| |
| // (C) 1995-2013 Jean-loup Gailly and Mark Adler |
| // (C) 2014-2017 Vitaly Puzrin and Andrey Tupitsin |
| // |
| // This software is provided 'as-is', without any express or implied |
| // warranty. In no event will the authors be held liable for any damages |
| // arising from the use of this software. |
| // |
| // Permission is granted to anyone to use this software for any purpose, |
| // including commercial applications, and to alter it and redistribute it |
| // freely, subject to the following restrictions: |
| // |
| // 1. The origin of this software must not be misrepresented; you must not |
| // claim that you wrote the original software. If you use this software |
| // in a product, an acknowledgment in the product documentation would be |
| // appreciated but is not required. |
| // 2. Altered source versions must be plainly marked as such, and must not be |
| // misrepresented as being the original software. |
| // 3. This notice may not be removed or altered from any source distribution. |
| |
| var utils = require('../utils/common'); |
| var trees = require('./trees'); |
| var adler32 = require('./adler32'); |
| var crc32 = require('./crc32'); |
| var msg = require('./messages'); |
| |
| /* Public constants ==========================================================*/ |
| /* ===========================================================================*/ |
| |
| |
| /* Allowed flush values; see deflate() and inflate() below for details */ |
| var Z_NO_FLUSH = 0; |
| var Z_PARTIAL_FLUSH = 1; |
| //var Z_SYNC_FLUSH = 2; |
| var Z_FULL_FLUSH = 3; |
| var Z_FINISH = 4; |
| var Z_BLOCK = 5; |
| //var Z_TREES = 6; |
| |
| |
| /* Return codes for the compression/decompression functions. Negative values |
| * are errors, positive values are used for special but normal events. |
| */ |
| var Z_OK = 0; |
| var Z_STREAM_END = 1; |
| //var Z_NEED_DICT = 2; |
| //var Z_ERRNO = -1; |
| var Z_STREAM_ERROR = -2; |
| var Z_DATA_ERROR = -3; |
| //var Z_MEM_ERROR = -4; |
| var Z_BUF_ERROR = -5; |
| //var Z_VERSION_ERROR = -6; |
| |
| |
| /* compression levels */ |
| //var Z_NO_COMPRESSION = 0; |
| //var Z_BEST_SPEED = 1; |
| //var Z_BEST_COMPRESSION = 9; |
| var Z_DEFAULT_COMPRESSION = -1; |
| |
| |
| var Z_FILTERED = 1; |
| var Z_HUFFMAN_ONLY = 2; |
| var Z_RLE = 3; |
| var Z_FIXED = 4; |
| var Z_DEFAULT_STRATEGY = 0; |
| |
| /* Possible values of the data_type field (though see inflate()) */ |
| //var Z_BINARY = 0; |
| //var Z_TEXT = 1; |
| //var Z_ASCII = 1; // = Z_TEXT |
| var Z_UNKNOWN = 2; |
| |
| |
| /* The deflate compression method */ |
| var Z_DEFLATED = 8; |
| |
| /*============================================================================*/ |
| |
| |
| var MAX_MEM_LEVEL = 9; |
| /* Maximum value for memLevel in deflateInit2 */ |
| var MAX_WBITS = 15; |
| /* 32K LZ77 window */ |
| var DEF_MEM_LEVEL = 8; |
| |
| |
| var LENGTH_CODES = 29; |
| /* number of length codes, not counting the special END_BLOCK code */ |
| var LITERALS = 256; |
| /* number of literal bytes 0..255 */ |
| var L_CODES = LITERALS + 1 + LENGTH_CODES; |
| /* number of Literal or Length codes, including the END_BLOCK code */ |
| var D_CODES = 30; |
| /* number of distance codes */ |
| var BL_CODES = 19; |
| /* number of codes used to transfer the bit lengths */ |
| var HEAP_SIZE = 2 * L_CODES + 1; |
| /* maximum heap size */ |
| var MAX_BITS = 15; |
| /* All codes must not exceed MAX_BITS bits */ |
| |
| var MIN_MATCH = 3; |
| var MAX_MATCH = 258; |
| var MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1); |
| |
| var PRESET_DICT = 0x20; |
| |
| var INIT_STATE = 42; |
| var EXTRA_STATE = 69; |
| var NAME_STATE = 73; |
| var COMMENT_STATE = 91; |
| var HCRC_STATE = 103; |
| var BUSY_STATE = 113; |
| var FINISH_STATE = 666; |
| |
| var BS_NEED_MORE = 1; /* block not completed, need more input or more output */ |
| var BS_BLOCK_DONE = 2; /* block flush performed */ |
| var BS_FINISH_STARTED = 3; /* finish started, need only more output at next deflate */ |
| var BS_FINISH_DONE = 4; /* finish done, accept no more input or output */ |
| |
| var OS_CODE = 0x03; // Unix :) . Don't detect, use this default. |
| |
| function err(strm, errorCode) { |
| strm.msg = msg[errorCode]; |
| return errorCode; |
| } |
| |
| function rank(f) { |
| return ((f) << 1) - ((f) > 4 ? 9 : 0); |
| } |
| |
| function zero(buf) { var len = buf.length; while (--len >= 0) { buf[len] = 0; } } |
| |
| |
| /* ========================================================================= |
| * Flush as much pending output as possible. All deflate() output goes |
| * through this function so some applications may wish to modify it |
| * to avoid allocating a large strm->output buffer and copying into it. |
| * (See also read_buf()). |
| */ |
| function flush_pending(strm) { |
| var s = strm.state; |
| |
| //_tr_flush_bits(s); |
| var len = s.pending; |
| if (len > strm.avail_out) { |
| len = strm.avail_out; |
| } |
| if (len === 0) { return; } |
| |
| utils.arraySet(strm.output, s.pending_buf, s.pending_out, len, strm.next_out); |
| strm.next_out += len; |
| s.pending_out += len; |
| strm.total_out += len; |
| strm.avail_out -= len; |
| s.pending -= len; |
| if (s.pending === 0) { |
| s.pending_out = 0; |
| } |
| } |
| |
| |
| function flush_block_only(s, last) { |
| trees._tr_flush_block(s, (s.block_start >= 0 ? s.block_start : -1), s.strstart - s.block_start, last); |
| s.block_start = s.strstart; |
| flush_pending(s.strm); |
| } |
| |
| |
| function put_byte(s, b) { |
| s.pending_buf[s.pending++] = b; |
| } |
| |
| |
| /* ========================================================================= |
| * Put a short in the pending buffer. The 16-bit value is put in MSB order. |
| * IN assertion: the stream state is correct and there is enough room in |
| * pending_buf. |
| */ |
| function putShortMSB(s, b) { |
| // put_byte(s, (Byte)(b >> 8)); |
| // put_byte(s, (Byte)(b & 0xff)); |
| s.pending_buf[s.pending++] = (b >>> 8) & 0xff; |
| s.pending_buf[s.pending++] = b & 0xff; |
| } |
| |
| |
| /* =========================================================================== |
| * Read a new buffer from the current input stream, update the adler32 |
| * and total number of bytes read. All deflate() input goes through |
| * this function so some applications may wish to modify it to avoid |
| * allocating a large strm->input buffer and copying from it. |
| * (See also flush_pending()). |
| */ |
| function read_buf(strm, buf, start, size) { |
| var len = strm.avail_in; |
| |
| if (len > size) { len = size; } |
| if (len === 0) { return 0; } |
| |
| strm.avail_in -= len; |
| |
| // zmemcpy(buf, strm->next_in, len); |
| utils.arraySet(buf, strm.input, strm.next_in, len, start); |
| if (strm.state.wrap === 1) { |
| strm.adler = adler32(strm.adler, buf, len, start); |
| } |
| |
| else if (strm.state.wrap === 2) { |
| strm.adler = crc32(strm.adler, buf, len, start); |
| } |
| |
| strm.next_in += len; |
| strm.total_in += len; |
| |
| return len; |
| } |
| |
| |
| /* =========================================================================== |
| * Set match_start to the longest match starting at the given string and |
| * return its length. Matches shorter or equal to prev_length are discarded, |
| * in which case the result is equal to prev_length and match_start is |
| * garbage. |
| * IN assertions: cur_match is the head of the hash chain for the current |
| * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 |
| * OUT assertion: the match length is not greater than s->lookahead. |
| */ |
| function longest_match(s, cur_match) { |
| var chain_length = s.max_chain_length; /* max hash chain length */ |
| var scan = s.strstart; /* current string */ |
| var match; /* matched string */ |
| var len; /* length of current match */ |
| var best_len = s.prev_length; /* best match length so far */ |
| var nice_match = s.nice_match; /* stop if match long enough */ |
| var limit = (s.strstart > (s.w_size - MIN_LOOKAHEAD)) ? |
| s.strstart - (s.w_size - MIN_LOOKAHEAD) : 0/*NIL*/; |
| |
| var _win = s.window; // shortcut |
| |
| var wmask = s.w_mask; |
| var prev = s.prev; |
| |
| /* Stop when cur_match becomes <= limit. To simplify the code, |
| * we prevent matches with the string of window index 0. |
| */ |
| |
| var strend = s.strstart + MAX_MATCH; |
| var scan_end1 = _win[scan + best_len - 1]; |
| var scan_end = _win[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. |
| */ |
| // Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); |
| |
| /* Do not waste too much time if we already have a good match: */ |
| if (s.prev_length >= s.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 > s.lookahead) { nice_match = s.lookahead; } |
| |
| // Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); |
| |
| do { |
| // Assert(cur_match < s->strstart, "no future"); |
| match = cur_match; |
| |
| /* Skip to next match if the match length cannot increase |
| * or if the match length is less than 2. Note that the checks below |
| * for insufficient lookahead only occur occasionally for performance |
| * reasons. Therefore uninitialized memory will be accessed, and |
| * conditional jumps will be made that depend on those values. |
| * However the length of the match is limited to the lookahead, so |
| * the output of deflate is not affected by the uninitialized values. |
| */ |
| |
| if (_win[match + best_len] !== scan_end || |
| _win[match + best_len - 1] !== scan_end1 || |
| _win[match] !== _win[scan] || |
| _win[++match] !== _win[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++; |
| // Assert(*scan == *match, "match[2]?"); |
| |
| /* We check for insufficient lookahead only every 8th comparison; |
| * the 256th check will be made at strstart+258. |
| */ |
| do { |
| /*jshint noempty:false*/ |
| } while (_win[++scan] === _win[++match] && _win[++scan] === _win[++match] && |
| _win[++scan] === _win[++match] && _win[++scan] === _win[++match] && |
| _win[++scan] === _win[++match] && _win[++scan] === _win[++match] && |
| _win[++scan] === _win[++match] && _win[++scan] === _win[++match] && |
| scan < strend); |
| |
| // Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
| |
| len = MAX_MATCH - (strend - scan); |
| scan = strend - MAX_MATCH; |
| |
| if (len > best_len) { |
| s.match_start = cur_match; |
| best_len = len; |
| if (len >= nice_match) { |
| break; |
| } |
| scan_end1 = _win[scan + best_len - 1]; |
| scan_end = _win[scan + best_len]; |
| } |
| } while ((cur_match = prev[cur_match & wmask]) > limit && --chain_length !== 0); |
| |
| if (best_len <= s.lookahead) { |
| return best_len; |
| } |
| return s.lookahead; |
| } |
| |
| |
| /* =========================================================================== |
| * 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). |
| */ |
| function fill_window(s) { |
| var _w_size = s.w_size; |
| var p, n, m, more, str; |
| |
| //Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead"); |
| |
| do { |
| more = s.window_size - s.lookahead - s.strstart; |
| |
| // JS ints have 32 bit, block below not needed |
| /* Deal with !@#$% 64K limit: */ |
| //if (sizeof(int) <= 2) { |
| // if (more == 0 && s->strstart == 0 && s->lookahead == 0) { |
| // more = wsize; |
| // |
| // } else if (more == (unsigned)(-1)) { |
| // /* Very unlikely, but possible on 16 bit machine if |
| // * strstart == 0 && lookahead == 1 (input done a 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. |
| */ |
| if (s.strstart >= _w_size + (_w_size - MIN_LOOKAHEAD)) { |
| |
| utils.arraySet(s.window, s.window, _w_size, _w_size, 0); |
| s.match_start -= _w_size; |
| s.strstart -= _w_size; |
| /* we now have strstart >= MAX_DIST */ |
| s.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 = s.hash_size; |
| p = n; |
| do { |
| m = s.head[--p]; |
| s.head[p] = (m >= _w_size ? m - _w_size : 0); |
| } while (--n); |
| |
| n = _w_size; |
| p = n; |
| do { |
| m = s.prev[--p]; |
| s.prev[p] = (m >= _w_size ? 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); |
| |
| more += _w_size; |
| } |
| if (s.strm.avail_in === 0) { |
| break; |
| } |
| |
| /* 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. |
| */ |
| //Assert(more >= 2, "more < 2"); |
| n = read_buf(s.strm, s.window, s.strstart + s.lookahead, more); |
| s.lookahead += n; |
| |
| /* Initialize the hash value now that we have some input: */ |
| if (s.lookahead + s.insert >= MIN_MATCH) { |
| str = s.strstart - s.insert; |
| s.ins_h = s.window[str]; |
| |
| /* UPDATE_HASH(s, s->ins_h, s->window[str + 1]); */ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[str + 1]) & s.hash_mask; |
| //#if MIN_MATCH != 3 |
| // Call update_hash() MIN_MATCH-3 more times |
| //#endif |
| while (s.insert) { |
| /* UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); */ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[str + MIN_MATCH - 1]) & s.hash_mask; |
| |
| s.prev[str & s.w_mask] = s.head[s.ins_h]; |
| s.head[s.ins_h] = str; |
| str++; |
| s.insert--; |
| if (s.lookahead + s.insert < MIN_MATCH) { |
| break; |
| } |
| } |
| } |
| /* 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 (s.lookahead < MIN_LOOKAHEAD && s.strm.avail_in !== 0); |
| |
| /* If the WIN_INIT bytes after the end of the current data have never been |
| * written, then zero those bytes in order to avoid memory check reports of |
| * the use of uninitialized (or uninitialised as Julian writes) bytes by |
| * the longest match routines. Update the high water mark for the next |
| * time through here. WIN_INIT is set to MAX_MATCH since the longest match |
| * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. |
| */ |
| // if (s.high_water < s.window_size) { |
| // var curr = s.strstart + s.lookahead; |
| // var init = 0; |
| // |
| // if (s.high_water < curr) { |
| // /* Previous high water mark below current data -- zero WIN_INIT |
| // * bytes or up to end of window, whichever is less. |
| // */ |
| // init = s.window_size - curr; |
| // if (init > WIN_INIT) |
| // init = WIN_INIT; |
| // zmemzero(s->window + curr, (unsigned)init); |
| // s->high_water = curr + init; |
| // } |
| // else if (s->high_water < (ulg)curr + WIN_INIT) { |
| // /* High water mark at or above current data, but below current data |
| // * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up |
| // * to end of window, whichever is less. |
| // */ |
| // init = (ulg)curr + WIN_INIT - s->high_water; |
| // if (init > s->window_size - s->high_water) |
| // init = s->window_size - s->high_water; |
| // zmemzero(s->window + s->high_water, (unsigned)init); |
| // s->high_water += init; |
| // } |
| // } |
| // |
| // Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD, |
| // "not enough room for search"); |
| } |
| |
| /* =========================================================================== |
| * 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. |
| */ |
| function deflate_stored(s, 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: |
| */ |
| var max_block_size = 0xffff; |
| |
| if (max_block_size > s.pending_buf_size - 5) { |
| max_block_size = s.pending_buf_size - 5; |
| } |
| |
| /* Copy as much as possible from input to output: */ |
| for (;;) { |
| /* Fill the window as much as possible: */ |
| if (s.lookahead <= 1) { |
| |
| //Assert(s->strstart < s->w_size+MAX_DIST(s) || |
| // s->block_start >= (long)s->w_size, "slide too late"); |
| // if (!(s.strstart < s.w_size + (s.w_size - MIN_LOOKAHEAD) || |
| // s.block_start >= s.w_size)) { |
| // throw new Error("slide too late"); |
| // } |
| |
| fill_window(s); |
| if (s.lookahead === 0 && flush === Z_NO_FLUSH) { |
| return BS_NEED_MORE; |
| } |
| |
| if (s.lookahead === 0) { |
| break; |
| } |
| /* flush the current block */ |
| } |
| //Assert(s->block_start >= 0L, "block gone"); |
| // if (s.block_start < 0) throw new Error("block gone"); |
| |
| s.strstart += s.lookahead; |
| s.lookahead = 0; |
| |
| /* Emit a stored block if pending_buf will be full: */ |
| var max_start = s.block_start + max_block_size; |
| |
| if (s.strstart === 0 || s.strstart >= max_start) { |
| /* strstart == 0 is possible when wraparound on 16-bit machine */ |
| s.lookahead = s.strstart - max_start; |
| s.strstart = max_start; |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| |
| |
| } |
| /* Flush if we may have to slide, otherwise block_start may become |
| * negative and the data will be gone: |
| */ |
| if (s.strstart - s.block_start >= (s.w_size - MIN_LOOKAHEAD)) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| } |
| |
| s.insert = 0; |
| |
| if (flush === Z_FINISH) { |
| /*** FLUSH_BLOCK(s, 1); ***/ |
| flush_block_only(s, true); |
| if (s.strm.avail_out === 0) { |
| return BS_FINISH_STARTED; |
| } |
| /***/ |
| return BS_FINISH_DONE; |
| } |
| |
| if (s.strstart > s.block_start) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| |
| return BS_NEED_MORE; |
| } |
| |
| /* =========================================================================== |
| * 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. |
| */ |
| function deflate_fast(s, flush) { |
| var hash_head; /* head of the hash chain */ |
| var bflush; /* set if current block must be flushed */ |
| |
| for (;;) { |
| /* 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 (s.lookahead < MIN_LOOKAHEAD) { |
| fill_window(s); |
| if (s.lookahead < MIN_LOOKAHEAD && flush === Z_NO_FLUSH) { |
| return BS_NEED_MORE; |
| } |
| if (s.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: |
| */ |
| hash_head = 0/*NIL*/; |
| if (s.lookahead >= MIN_MATCH) { |
| /*** INSERT_STRING(s, s.strstart, hash_head); ***/ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask; |
| hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h]; |
| s.head[s.ins_h] = s.strstart; |
| /***/ |
| } |
| |
| /* Find the longest match, discarding those <= prev_length. |
| * At this point we have always match_length < MIN_MATCH |
| */ |
| if (hash_head !== 0/*NIL*/ && ((s.strstart - hash_head) <= (s.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). |
| */ |
| s.match_length = longest_match(s, hash_head); |
| /* longest_match() sets match_start */ |
| } |
| if (s.match_length >= MIN_MATCH) { |
| // check_match(s, s.strstart, s.match_start, s.match_length); // for debug only |
| |
| /*** _tr_tally_dist(s, s.strstart - s.match_start, |
| s.match_length - MIN_MATCH, bflush); ***/ |
| bflush = trees._tr_tally(s, s.strstart - s.match_start, s.match_length - MIN_MATCH); |
| |
| s.lookahead -= s.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 (s.match_length <= s.max_lazy_match/*max_insert_length*/ && s.lookahead >= MIN_MATCH) { |
| s.match_length--; /* string at strstart already in table */ |
| do { |
| s.strstart++; |
| /*** INSERT_STRING(s, s.strstart, hash_head); ***/ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask; |
| hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h]; |
| s.head[s.ins_h] = s.strstart; |
| /***/ |
| /* strstart never exceeds WSIZE-MAX_MATCH, so there are |
| * always MIN_MATCH bytes ahead. |
| */ |
| } while (--s.match_length !== 0); |
| s.strstart++; |
| } else |
| { |
| s.strstart += s.match_length; |
| s.match_length = 0; |
| s.ins_h = s.window[s.strstart]; |
| /* UPDATE_HASH(s, s.ins_h, s.window[s.strstart+1]); */ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + 1]) & s.hash_mask; |
| |
| //#if MIN_MATCH != 3 |
| // Call UPDATE_HASH() MIN_MATCH-3 more times |
| //#endif |
| /* 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 */ |
| //Tracevv((stderr,"%c", s.window[s.strstart])); |
| /*** _tr_tally_lit(s, s.window[s.strstart], bflush); ***/ |
| bflush = trees._tr_tally(s, 0, s.window[s.strstart]); |
| |
| s.lookahead--; |
| s.strstart++; |
| } |
| if (bflush) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| } |
| s.insert = ((s.strstart < (MIN_MATCH - 1)) ? s.strstart : MIN_MATCH - 1); |
| if (flush === Z_FINISH) { |
| /*** FLUSH_BLOCK(s, 1); ***/ |
| flush_block_only(s, true); |
| if (s.strm.avail_out === 0) { |
| return BS_FINISH_STARTED; |
| } |
| /***/ |
| return BS_FINISH_DONE; |
| } |
| if (s.last_lit) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| return BS_BLOCK_DONE; |
| } |
| |
| /* =========================================================================== |
| * 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. |
| */ |
| function deflate_slow(s, flush) { |
| var hash_head; /* head of hash chain */ |
| var bflush; /* set if current block must be flushed */ |
| |
| var max_insert; |
| |
| /* Process the input block. */ |
| for (;;) { |
| /* 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 (s.lookahead < MIN_LOOKAHEAD) { |
| fill_window(s); |
| if (s.lookahead < MIN_LOOKAHEAD && flush === Z_NO_FLUSH) { |
| return BS_NEED_MORE; |
| } |
| if (s.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: |
| */ |
| hash_head = 0/*NIL*/; |
| if (s.lookahead >= MIN_MATCH) { |
| /*** INSERT_STRING(s, s.strstart, hash_head); ***/ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask; |
| hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h]; |
| s.head[s.ins_h] = s.strstart; |
| /***/ |
| } |
| |
| /* Find the longest match, discarding those <= prev_length. |
| */ |
| s.prev_length = s.match_length; |
| s.prev_match = s.match_start; |
| s.match_length = MIN_MATCH - 1; |
| |
| if (hash_head !== 0/*NIL*/ && s.prev_length < s.max_lazy_match && |
| s.strstart - hash_head <= (s.w_size - MIN_LOOKAHEAD)/*MAX_DIST(s)*/) { |
| /* 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). |
| */ |
| s.match_length = longest_match(s, hash_head); |
| /* longest_match() sets match_start */ |
| |
| if (s.match_length <= 5 && |
| (s.strategy === Z_FILTERED || (s.match_length === MIN_MATCH && s.strstart - s.match_start > 4096/*TOO_FAR*/))) { |
| |
| /* If prev_match is also MIN_MATCH, match_start is garbage |
| * but we will ignore the current match anyway. |
| */ |
| s.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 (s.prev_length >= MIN_MATCH && s.match_length <= s.prev_length) { |
| max_insert = s.strstart + s.lookahead - MIN_MATCH; |
| /* Do not insert strings in hash table beyond this. */ |
| |
| //check_match(s, s.strstart-1, s.prev_match, s.prev_length); |
| |
| /***_tr_tally_dist(s, s.strstart - 1 - s.prev_match, |
| s.prev_length - MIN_MATCH, bflush);***/ |
| bflush = trees._tr_tally(s, s.strstart - 1 - s.prev_match, s.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. |
| */ |
| s.lookahead -= s.prev_length - 1; |
| s.prev_length -= 2; |
| do { |
| if (++s.strstart <= max_insert) { |
| /*** INSERT_STRING(s, s.strstart, hash_head); ***/ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask; |
| hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h]; |
| s.head[s.ins_h] = s.strstart; |
| /***/ |
| } |
| } while (--s.prev_length !== 0); |
| s.match_available = 0; |
| s.match_length = MIN_MATCH - 1; |
| s.strstart++; |
| |
| if (bflush) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| |
| } else if (s.match_available) { |
| /* 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. |
| */ |
| //Tracevv((stderr,"%c", s->window[s->strstart-1])); |
| /*** _tr_tally_lit(s, s.window[s.strstart-1], bflush); ***/ |
| bflush = trees._tr_tally(s, 0, s.window[s.strstart - 1]); |
| |
| if (bflush) { |
| /*** FLUSH_BLOCK_ONLY(s, 0) ***/ |
| flush_block_only(s, false); |
| /***/ |
| } |
| s.strstart++; |
| s.lookahead--; |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| } else { |
| /* There is no previous match to compare with, wait for |
| * the next step to decide. |
| */ |
| s.match_available = 1; |
| s.strstart++; |
| s.lookahead--; |
| } |
| } |
| //Assert (flush != Z_NO_FLUSH, "no flush?"); |
| if (s.match_available) { |
| //Tracevv((stderr,"%c", s->window[s->strstart-1])); |
| /*** _tr_tally_lit(s, s.window[s.strstart-1], bflush); ***/ |
| bflush = trees._tr_tally(s, 0, s.window[s.strstart - 1]); |
| |
| s.match_available = 0; |
| } |
| s.insert = s.strstart < MIN_MATCH - 1 ? s.strstart : MIN_MATCH - 1; |
| if (flush === Z_FINISH) { |
| /*** FLUSH_BLOCK(s, 1); ***/ |
| flush_block_only(s, true); |
| if (s.strm.avail_out === 0) { |
| return BS_FINISH_STARTED; |
| } |
| /***/ |
| return BS_FINISH_DONE; |
| } |
| if (s.last_lit) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| |
| return BS_BLOCK_DONE; |
| } |
| |
| |
| /* =========================================================================== |
| * For Z_RLE, simply look for runs of bytes, generate matches only of distance |
| * one. Do not maintain a hash table. (It will be regenerated if this run of |
| * deflate switches away from Z_RLE.) |
| */ |
| function deflate_rle(s, flush) { |
| var bflush; /* set if current block must be flushed */ |
| var prev; /* byte at distance one to match */ |
| var scan, strend; /* scan goes up to strend for length of run */ |
| |
| var _win = s.window; |
| |
| for (;;) { |
| /* Make sure that we always have enough lookahead, except |
| * at the end of the input file. We need MAX_MATCH bytes |
| * for the longest run, plus one for the unrolled loop. |
| */ |
| if (s.lookahead <= MAX_MATCH) { |
| fill_window(s); |
| if (s.lookahead <= MAX_MATCH && flush === Z_NO_FLUSH) { |
| return BS_NEED_MORE; |
| } |
| if (s.lookahead === 0) { break; } /* flush the current block */ |
| } |
| |
| /* See how many times the previous byte repeats */ |
| s.match_length = 0; |
| if (s.lookahead >= MIN_MATCH && s.strstart > 0) { |
| scan = s.strstart - 1; |
| prev = _win[scan]; |
| if (prev === _win[++scan] && prev === _win[++scan] && prev === _win[++scan]) { |
| strend = s.strstart + MAX_MATCH; |
| do { |
| /*jshint noempty:false*/ |
| } while (prev === _win[++scan] && prev === _win[++scan] && |
| prev === _win[++scan] && prev === _win[++scan] && |
| prev === _win[++scan] && prev === _win[++scan] && |
| prev === _win[++scan] && prev === _win[++scan] && |
| scan < strend); |
| s.match_length = MAX_MATCH - (strend - scan); |
| if (s.match_length > s.lookahead) { |
| s.match_length = s.lookahead; |
| } |
| } |
| //Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan"); |
| } |
| |
| /* Emit match if have run of MIN_MATCH or longer, else emit literal */ |
| if (s.match_length >= MIN_MATCH) { |
| //check_match(s, s.strstart, s.strstart - 1, s.match_length); |
| |
| /*** _tr_tally_dist(s, 1, s.match_length - MIN_MATCH, bflush); ***/ |
| bflush = trees._tr_tally(s, 1, s.match_length - MIN_MATCH); |
| |
| s.lookahead -= s.match_length; |
| s.strstart += s.match_length; |
| s.match_length = 0; |
| } else { |
| /* No match, output a literal byte */ |
| //Tracevv((stderr,"%c", s->window[s->strstart])); |
| /*** _tr_tally_lit(s, s.window[s.strstart], bflush); ***/ |
| bflush = trees._tr_tally(s, 0, s.window[s.strstart]); |
| |
| s.lookahead--; |
| s.strstart++; |
| } |
| if (bflush) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| } |
| s.insert = 0; |
| if (flush === Z_FINISH) { |
| /*** FLUSH_BLOCK(s, 1); ***/ |
| flush_block_only(s, true); |
| if (s.strm.avail_out === 0) { |
| return BS_FINISH_STARTED; |
| } |
| /***/ |
| return BS_FINISH_DONE; |
| } |
| if (s.last_lit) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| return BS_BLOCK_DONE; |
| } |
| |
| /* =========================================================================== |
| * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. |
| * (It will be regenerated if this run of deflate switches away from Huffman.) |
| */ |
| function deflate_huff(s, flush) { |
| var bflush; /* set if current block must be flushed */ |
| |
| for (;;) { |
| /* Make sure that we have a literal to write. */ |
| if (s.lookahead === 0) { |
| fill_window(s); |
| if (s.lookahead === 0) { |
| if (flush === Z_NO_FLUSH) { |
| return BS_NEED_MORE; |
| } |
| break; /* flush the current block */ |
| } |
| } |
| |
| /* Output a literal byte */ |
| s.match_length = 0; |
| //Tracevv((stderr,"%c", s->window[s->strstart])); |
| /*** _tr_tally_lit(s, s.window[s.strstart], bflush); ***/ |
| bflush = trees._tr_tally(s, 0, s.window[s.strstart]); |
| s.lookahead--; |
| s.strstart++; |
| if (bflush) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| } |
| s.insert = 0; |
| if (flush === Z_FINISH) { |
| /*** FLUSH_BLOCK(s, 1); ***/ |
| flush_block_only(s, true); |
| if (s.strm.avail_out === 0) { |
| return BS_FINISH_STARTED; |
| } |
| /***/ |
| return BS_FINISH_DONE; |
| } |
| if (s.last_lit) { |
| /*** FLUSH_BLOCK(s, 0); ***/ |
| flush_block_only(s, false); |
| if (s.strm.avail_out === 0) { |
| return BS_NEED_MORE; |
| } |
| /***/ |
| } |
| return BS_BLOCK_DONE; |
| } |
| |
| /* Values for max_lazy_match, good_match and max_chain_length, depending on |
| * the desired pack level (0..9). The values given below have been tuned to |
| * exclude worst case performance for pathological files. Better values may be |
| * found for specific files. |
| */ |
| function Config(good_length, max_lazy, nice_length, max_chain, func) { |
| this.good_length = good_length; |
| this.max_lazy = max_lazy; |
| this.nice_length = nice_length; |
| this.max_chain = max_chain; |
| this.func = func; |
| } |
| |
| var configuration_table; |
| |
| configuration_table = [ |
| /* good lazy nice chain */ |
| new Config(0, 0, 0, 0, deflate_stored), /* 0 store only */ |
| new Config(4, 4, 8, 4, deflate_fast), /* 1 max speed, no lazy matches */ |
| new Config(4, 5, 16, 8, deflate_fast), /* 2 */ |
| new Config(4, 6, 32, 32, deflate_fast), /* 3 */ |
| |
| new Config(4, 4, 16, 16, deflate_slow), /* 4 lazy matches */ |
| new Config(8, 16, 32, 32, deflate_slow), /* 5 */ |
| new Config(8, 16, 128, 128, deflate_slow), /* 6 */ |
| new Config(8, 32, 128, 256, deflate_slow), /* 7 */ |
| new Config(32, 128, 258, 1024, deflate_slow), /* 8 */ |
| new Config(32, 258, 258, 4096, deflate_slow) /* 9 max compression */ |
| ]; |
| |
| |
| /* =========================================================================== |
| * Initialize the "longest match" routines for a new zlib stream |
| */ |
| function lm_init(s) { |
| s.window_size = 2 * s.w_size; |
| |
| /*** CLEAR_HASH(s); ***/ |
| zero(s.head); // Fill with NIL (= 0); |
| |
| /* Set the default configuration parameters: |
| */ |
| s.max_lazy_match = configuration_table[s.level].max_lazy; |
| s.good_match = configuration_table[s.level].good_length; |
| s.nice_match = configuration_table[s.level].nice_length; |
| s.max_chain_length = configuration_table[s.level].max_chain; |
| |
| s.strstart = 0; |
| s.block_start = 0; |
| s.lookahead = 0; |
| s.insert = 0; |
| s.match_length = s.prev_length = MIN_MATCH - 1; |
| s.match_available = 0; |
| s.ins_h = 0; |
| } |
| |
| |
| function DeflateState() { |
| this.strm = null; /* pointer back to this zlib stream */ |
| this.status = 0; /* as the name implies */ |
| this.pending_buf = null; /* output still pending */ |
| this.pending_buf_size = 0; /* size of pending_buf */ |
| this.pending_out = 0; /* next pending byte to output to the stream */ |
| this.pending = 0; /* nb of bytes in the pending buffer */ |
| this.wrap = 0; /* bit 0 true for zlib, bit 1 true for gzip */ |
| this.gzhead = null; /* gzip header information to write */ |
| this.gzindex = 0; /* where in extra, name, or comment */ |
| this.method = Z_DEFLATED; /* can only be DEFLATED */ |
| this.last_flush = -1; /* value of flush param for previous deflate call */ |
| |
| this.w_size = 0; /* LZ77 window size (32K by default) */ |
| this.w_bits = 0; /* log2(w_size) (8..16) */ |
| this.w_mask = 0; /* w_size - 1 */ |
| |
| this.window = null; |
| /* 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. |
| */ |
| |
| this.window_size = 0; |
| /* Actual size of window: 2*wSize, except when the user input buffer |
| * is directly used as sliding window. |
| */ |
| |
| this.prev = null; |
| /* 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. |
| */ |
| |
| this.head = null; /* Heads of the hash chains or NIL. */ |
| |
| this.ins_h = 0; /* hash index of string to be inserted */ |
| this.hash_size = 0; /* number of elements in hash table */ |
| this.hash_bits = 0; /* log2(hash_size) */ |
| this.hash_mask = 0; /* hash_size-1 */ |
| |
| this.hash_shift = 0; |
| /* 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 |
| */ |
| |
| this.block_start = 0; |
| /* Window position at the beginning of the current output block. Gets |
| * negative when the window is moved backwards. |
| */ |
| |
| this.match_length = 0; /* length of best match */ |
| this.prev_match = 0; /* previous match */ |
| this.match_available = 0; /* set if previous match exists */ |
| this.strstart = 0; /* start of string to insert */ |
| this.match_start = 0; /* start of matching string */ |
| this.lookahead = 0; /* number of valid bytes ahead in window */ |
| |
| this.prev_length = 0; |
| /* Length of the best match at previous step. Matches not greater than this |
| * are discarded. This is used in the lazy match evaluation. |
| */ |
| |
| this.max_chain_length = 0; |
| /* To speed up deflation, hash chains are never searched beyond this |
| * length. A higher limit improves compression ratio but degrades the |
| * speed. |
| */ |
| |
| this.max_lazy_match = 0; |
| /* 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. |
| */ |
| // That's alias to max_lazy_match, don't use directly |
| //this.max_insert_length = 0; |
| /* 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. |
| */ |
| |
| this.level = 0; /* compression level (1..9) */ |
| this.strategy = 0; /* favor or force Huffman coding*/ |
| |
| this.good_match = 0; |
| /* Use a faster search when the previous match is longer than this */ |
| |
| this.nice_match = 0; /* Stop searching when current match exceeds this */ |
| |
| /* used by trees.c: */ |
| |
| /* Didn't use ct_data typedef below to suppress compiler warning */ |
| |
| // struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ |
| // struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ |
| // struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ |
| |
| // Use flat array of DOUBLE size, with interleaved fata, |
| // because JS does not support effective |
| this.dyn_ltree = new utils.Buf16(HEAP_SIZE * 2); |
| this.dyn_dtree = new utils.Buf16((2 * D_CODES + 1) * 2); |
| this.bl_tree = new utils.Buf16((2 * BL_CODES + 1) * 2); |
| zero(this.dyn_ltree); |
| zero(this.dyn_dtree); |
| zero(this.bl_tree); |
| |
| this.l_desc = null; /* desc. for literal tree */ |
| this.d_desc = null; /* desc. for distance tree */ |
| this.bl_desc = null; /* desc. for bit length tree */ |
| |
| //ush bl_count[MAX_BITS+1]; |
| this.bl_count = new utils.Buf16(MAX_BITS + 1); |
| /* number of codes at each bit length for an optimal tree */ |
| |
| //int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ |
| this.heap = new utils.Buf16(2 * L_CODES + 1); /* heap used to build the Huffman trees */ |
| zero(this.heap); |
| |
| this.heap_len = 0; /* number of elements in the heap */ |
| this.heap_max = 0; /* 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. |
| */ |
| |
| this.depth = new utils.Buf16(2 * L_CODES + 1); //uch depth[2*L_CODES+1]; |
| zero(this.depth); |
| /* Depth of each subtree used as tie breaker for trees of equal frequency |
| */ |
| |
| this.l_buf = 0; /* buffer index for literals or lengths */ |
| |
| this.lit_bufsize = 0; |
| /* 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 |
| */ |
| |
| this.last_lit = 0; /* running index in l_buf */ |
| |
| this.d_buf = 0; |
| /* Buffer index 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. |
| */ |
| |
| this.opt_len = 0; /* bit length of current block with optimal trees */ |
| this.static_len = 0; /* bit length of current block with static trees */ |
| this.matches = 0; /* number of string matches in current block */ |
| this.insert = 0; /* bytes at end of window left to insert */ |
| |
| |
| this.bi_buf = 0; |
| /* Output buffer. bits are inserted starting at the bottom (least |
| * significant bits). |
| */ |
| this.bi_valid = 0; |
| /* Number of valid bits in bi_buf. All bits above the last valid bit |
| * are always zero. |
| */ |
| |
| // Used for window memory init. We safely ignore it for JS. That makes |
| // sense only for pointers and memory check tools. |
| //this.high_water = 0; |
| /* High water mark offset in window for initialized bytes -- bytes above |
| * this are set to zero in order to avoid memory check warnings when |
| * longest match routines access bytes past the input. This is then |
| * updated to the new high water mark. |
| */ |
| } |
| |
| |
| function deflateResetKeep(strm) { |
| var s; |
| |
| if (!strm || !strm.state) { |
| return err(strm, Z_STREAM_ERROR); |
| } |
| |
| strm.total_in = strm.total_out = 0; |
| strm.data_type = Z_UNKNOWN; |
| |
| s = strm.state; |
| s.pending = 0; |
| s.pending_out = 0; |
| |
| if (s.wrap < 0) { |
| s.wrap = -s.wrap; |
| /* was made negative by deflate(..., Z_FINISH); */ |
| } |
| s.status = (s.wrap ? INIT_STATE : BUSY_STATE); |
| strm.adler = (s.wrap === 2) ? |
| 0 // crc32(0, Z_NULL, 0) |
| : |
| 1; // adler32(0, Z_NULL, 0) |
| s.last_flush = Z_NO_FLUSH; |
| trees._tr_init(s); |
| return Z_OK; |
| } |
| |
| |
| function deflateReset(strm) { |
| var ret = deflateResetKeep(strm); |
| if (ret === Z_OK) { |
| lm_init(strm.state); |
| } |
| return ret; |
| } |
| |
| |
| function deflateSetHeader(strm, head) { |
| if (!strm || !strm.state) { return Z_STREAM_ERROR; } |
| if (strm.state.wrap !== 2) { return Z_STREAM_ERROR; } |
| strm.state.gzhead = head; |
| return Z_OK; |
| } |
| |
| |
| function deflateInit2(strm, level, method, windowBits, memLevel, strategy) { |
| if (!strm) { // === Z_NULL |
| return Z_STREAM_ERROR; |
| } |
| var wrap = 1; |
| |
| if (level === Z_DEFAULT_COMPRESSION) { |
| level = 6; |
| } |
| |
| if (windowBits < 0) { /* suppress zlib wrapper */ |
| wrap = 0; |
| windowBits = -windowBits; |
| } |
| |
| else if (windowBits > 15) { |
| wrap = 2; /* write gzip wrapper instead */ |
| windowBits -= 16; |
| } |
| |
| |
| if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method !== Z_DEFLATED || |
| windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || |
| strategy < 0 || strategy > Z_FIXED) { |
| return err(strm, Z_STREAM_ERROR); |
| } |
| |
| |
| if (windowBits === 8) { |
| windowBits = 9; |
| } |
| /* until 256-byte window bug fixed */ |
| |
| var s = new DeflateState(); |
| |
| strm.state = s; |
| s.strm = strm; |
| |
| s.wrap = wrap; |
| s.gzhead = null; |
| s.w_bits = windowBits; |
| s.w_size = 1 << s.w_bits; |
| s.w_mask = s.w_size - 1; |
| |
| s.hash_bits = memLevel + 7; |
| s.hash_size = 1 << s.hash_bits; |
| s.hash_mask = s.hash_size - 1; |
| s.hash_shift = ~~((s.hash_bits + MIN_MATCH - 1) / MIN_MATCH); |
| |
| s.window = new utils.Buf8(s.w_size * 2); |
| s.head = new utils.Buf16(s.hash_size); |
| s.prev = new utils.Buf16(s.w_size); |
| |
| // Don't need mem init magic for JS. |
| //s.high_water = 0; /* nothing written to s->window yet */ |
| |
| s.lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ |
| |
| s.pending_buf_size = s.lit_bufsize * 4; |
| |
| //overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); |
| //s->pending_buf = (uchf *) overlay; |
| s.pending_buf = new utils.Buf8(s.pending_buf_size); |
| |
| // It is offset from `s.pending_buf` (size is `s.lit_bufsize * 2`) |
| //s->d_buf = overlay + s->lit_bufsize/sizeof(ush); |
| s.d_buf = 1 * s.lit_bufsize; |
| |
| //s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; |
| s.l_buf = (1 + 2) * s.lit_bufsize; |
| |
| s.level = level; |
| s.strategy = strategy; |
| s.method = method; |
| |
| return deflateReset(strm); |
| } |
| |
| function deflateInit(strm, level) { |
| return deflateInit2(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY); |
| } |
| |
| |
| function deflate(strm, flush) { |
| var old_flush, s; |
| var beg, val; // for gzip header write only |
| |
| if (!strm || !strm.state || |
| flush > Z_BLOCK || flush < 0) { |
| return strm ? err(strm, Z_STREAM_ERROR) : Z_STREAM_ERROR; |
| } |
| |
| s = strm.state; |
| |
| if (!strm.output || |
| (!strm.input && strm.avail_in !== 0) || |
| (s.status === FINISH_STATE && flush !== Z_FINISH)) { |
| return err(strm, (strm.avail_out === 0) ? Z_BUF_ERROR : Z_STREAM_ERROR); |
| } |
| |
| s.strm = strm; /* just in case */ |
| old_flush = s.last_flush; |
| s.last_flush = flush; |
| |
| /* Write the header */ |
| if (s.status === INIT_STATE) { |
| |
| if (s.wrap === 2) { // GZIP header |
| strm.adler = 0; //crc32(0L, Z_NULL, 0); |
| put_byte(s, 31); |
| put_byte(s, 139); |
| put_byte(s, 8); |
| if (!s.gzhead) { // s->gzhead == Z_NULL |
| put_byte(s, 0); |
| put_byte(s, 0); |
| put_byte(s, 0); |
| put_byte(s, 0); |
| put_byte(s, 0); |
| put_byte(s, s.level === 9 ? 2 : |
| (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2 ? |
| 4 : 0)); |
| put_byte(s, OS_CODE); |
| s.status = BUSY_STATE; |
| } |
| else { |
| put_byte(s, (s.gzhead.text ? 1 : 0) + |
| (s.gzhead.hcrc ? 2 : 0) + |
| (!s.gzhead.extra ? 0 : 4) + |
| (!s.gzhead.name ? 0 : 8) + |
| (!s.gzhead.comment ? 0 : 16) |
| ); |
| put_byte(s, s.gzhead.time & 0xff); |
| put_byte(s, (s.gzhead.time >> 8) & 0xff); |
| put_byte(s, (s.gzhead.time >> 16) & 0xff); |
| put_byte(s, (s.gzhead.time >> 24) & 0xff); |
| put_byte(s, s.level === 9 ? 2 : |
| (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2 ? |
| 4 : 0)); |
| put_byte(s, s.gzhead.os & 0xff); |
| if (s.gzhead.extra && s.gzhead.extra.length) { |
| put_byte(s, s.gzhead.extra.length & 0xff); |
| put_byte(s, (s.gzhead.extra.length >> 8) & 0xff); |
| } |
| if (s.gzhead.hcrc) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending, 0); |
| } |
| s.gzindex = 0; |
| s.status = EXTRA_STATE; |
| } |
| } |
| else // DEFLATE header |
| { |
| var header = (Z_DEFLATED + ((s.w_bits - 8) << 4)) << 8; |
| var level_flags = -1; |
| |
| if (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2) { |
| level_flags = 0; |
| } else if (s.level < 6) { |
| level_flags = 1; |
| } else if (s.level === 6) { |
| level_flags = 2; |
| } else { |
| level_flags = 3; |
| } |
| header |= (level_flags << 6); |
| if (s.strstart !== 0) { header |= PRESET_DICT; } |
| header += 31 - (header % 31); |
| |
| s.status = BUSY_STATE; |
| putShortMSB(s, header); |
| |
| /* Save the adler32 of the preset dictionary: */ |
| if (s.strstart !== 0) { |
| putShortMSB(s, strm.adler >>> 16); |
| putShortMSB(s, strm.adler & 0xffff); |
| } |
| strm.adler = 1; // adler32(0L, Z_NULL, 0); |
| } |
| } |
| |
| //#ifdef GZIP |
| if (s.status === EXTRA_STATE) { |
| if (s.gzhead.extra/* != Z_NULL*/) { |
| beg = s.pending; /* start of bytes to update crc */ |
| |
| while (s.gzindex < (s.gzhead.extra.length & 0xffff)) { |
| if (s.pending === s.pending_buf_size) { |
| if (s.gzhead.hcrc && s.pending > beg) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg); |
| } |
| flush_pending(strm); |
| beg = s.pending; |
| if (s.pending === s.pending_buf_size) { |
| break; |
| } |
| } |
| put_byte(s, s.gzhead.extra[s.gzindex] & 0xff); |
| s.gzindex++; |
| } |
| if (s.gzhead.hcrc && s.pending > beg) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg); |
| } |
| if (s.gzindex === s.gzhead.extra.length) { |
| s.gzindex = 0; |
| s.status = NAME_STATE; |
| } |
| } |
| else { |
| s.status = NAME_STATE; |
| } |
| } |
| if (s.status === NAME_STATE) { |
| if (s.gzhead.name/* != Z_NULL*/) { |
| beg = s.pending; /* start of bytes to update crc */ |
| //int val; |
| |
| do { |
| if (s.pending === s.pending_buf_size) { |
| if (s.gzhead.hcrc && s.pending > beg) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg); |
| } |
| flush_pending(strm); |
| beg = s.pending; |
| if (s.pending === s.pending_buf_size) { |
| val = 1; |
| break; |
| } |
| } |
| // JS specific: little magic to add zero terminator to end of string |
| if (s.gzindex < s.gzhead.name.length) { |
| val = s.gzhead.name.charCodeAt(s.gzindex++) & 0xff; |
| } else { |
| val = 0; |
| } |
| put_byte(s, val); |
| } while (val !== 0); |
| |
| if (s.gzhead.hcrc && s.pending > beg) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg); |
| } |
| if (val === 0) { |
| s.gzindex = 0; |
| s.status = COMMENT_STATE; |
| } |
| } |
| else { |
| s.status = COMMENT_STATE; |
| } |
| } |
| if (s.status === COMMENT_STATE) { |
| if (s.gzhead.comment/* != Z_NULL*/) { |
| beg = s.pending; /* start of bytes to update crc */ |
| //int val; |
| |
| do { |
| if (s.pending === s.pending_buf_size) { |
| if (s.gzhead.hcrc && s.pending > beg) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg); |
| } |
| flush_pending(strm); |
| beg = s.pending; |
| if (s.pending === s.pending_buf_size) { |
| val = 1; |
| break; |
| } |
| } |
| // JS specific: little magic to add zero terminator to end of string |
| if (s.gzindex < s.gzhead.comment.length) { |
| val = s.gzhead.comment.charCodeAt(s.gzindex++) & 0xff; |
| } else { |
| val = 0; |
| } |
| put_byte(s, val); |
| } while (val !== 0); |
| |
| if (s.gzhead.hcrc && s.pending > beg) { |
| strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg); |
| } |
| if (val === 0) { |
| s.status = HCRC_STATE; |
| } |
| } |
| else { |
| s.status = HCRC_STATE; |
| } |
| } |
| if (s.status === HCRC_STATE) { |
| if (s.gzhead.hcrc) { |
| if (s.pending + 2 > s.pending_buf_size) { |
| flush_pending(strm); |
| } |
| if (s.pending + 2 <= s.pending_buf_size) { |
| put_byte(s, strm.adler & 0xff); |
| put_byte(s, (strm.adler >> 8) & 0xff); |
| strm.adler = 0; //crc32(0L, Z_NULL, 0); |
| s.status = BUSY_STATE; |
| } |
| } |
| else { |
| s.status = BUSY_STATE; |
| } |
| } |
| //#endif |
| |
| /* Flush as much pending output as possible */ |
| if (s.pending !== 0) { |
| flush_pending(strm); |
| 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: |
| */ |
| s.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_BUF_ERROR. |
| */ |
| } else if (strm.avail_in === 0 && rank(flush) <= rank(old_flush) && |
| flush !== Z_FINISH) { |
| return err(strm, Z_BUF_ERROR); |
| } |
| |
| /* User must not provide more input after the first FINISH: */ |
| if (s.status === FINISH_STATE && strm.avail_in !== 0) { |
| return err(strm, Z_BUF_ERROR); |
| } |
| |
| /* Start a new block or continue the current one. |
| */ |
| if (strm.avail_in !== 0 || s.lookahead !== 0 || |
| (flush !== Z_NO_FLUSH && s.status !== FINISH_STATE)) { |
| var bstate = (s.strategy === Z_HUFFMAN_ONLY) ? deflate_huff(s, flush) : |
| (s.strategy === Z_RLE ? deflate_rle(s, flush) : |
| configuration_table[s.level].func(s, flush)); |
| |
| if (bstate === BS_FINISH_STARTED || bstate === BS_FINISH_DONE) { |
| s.status = FINISH_STATE; |
| } |
| if (bstate === BS_NEED_MORE || bstate === BS_FINISH_STARTED) { |
| if (strm.avail_out === 0) { |
| s.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 === BS_BLOCK_DONE) { |
| if (flush === Z_PARTIAL_FLUSH) { |
| trees._tr_align(s); |
| } |
| else if (flush !== Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ |
| |
| trees._tr_stored_block(s, 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) { |
| /*** CLEAR_HASH(s); ***/ /* forget history */ |
| zero(s.head); // Fill with NIL (= 0); |
| |
| if (s.lookahead === 0) { |
| s.strstart = 0; |
| s.block_start = 0; |
| s.insert = 0; |
| } |
| } |
| } |
| flush_pending(strm); |
| if (strm.avail_out === 0) { |
| s.last_flush = -1; /* avoid BUF_ERROR at next call, see above */ |
| return Z_OK; |
| } |
| } |
| } |
| //Assert(strm->avail_out > 0, "bug2"); |
| //if (strm.avail_out <= 0) { throw new Error("bug2");} |
| |
| if (flush !== Z_FINISH) { return Z_OK; } |
| if (s.wrap <= 0) { return Z_STREAM_END; } |
| |
| /* Write the trailer */ |
| if (s.wrap === 2) { |
| put_byte(s, strm.adler & 0xff); |
| put_byte(s, (strm.adler >> 8) & 0xff); |
| put_byte(s, (strm.adler >> 16) & 0xff); |
| put_byte(s, (strm.adler >> 24) & 0xff); |
| put_byte(s, strm.total_in & 0xff); |
| put_byte(s, (strm.total_in >> 8) & 0xff); |
| put_byte(s, (strm.total_in >> 16) & 0xff); |
| put_byte(s, (strm.total_in >> 24) & 0xff); |
| } |
| else |
| { |
| putShortMSB(s, strm.adler >>> 16); |
| putShortMSB(s, strm.adler & 0xffff); |
| } |
| |
| flush_pending(strm); |
| /* If avail_out is zero, the application will call deflate again |
| * to flush the rest. |
| */ |
| if (s.wrap > 0) { s.wrap = -s.wrap; } |
| /* write the trailer only once! */ |
| return s.pending !== 0 ? Z_OK : Z_STREAM_END; |
| } |
| |
| function deflateEnd(strm) { |
| var status; |
| |
| if (!strm/*== Z_NULL*/ || !strm.state/*== Z_NULL*/) { |
| return Z_STREAM_ERROR; |
| } |
| |
| status = strm.state.status; |
| if (status !== INIT_STATE && |
| status !== EXTRA_STATE && |
| status !== NAME_STATE && |
| status !== COMMENT_STATE && |
| status !== HCRC_STATE && |
| status !== BUSY_STATE && |
| status !== FINISH_STATE |
| ) { |
| return err(strm, Z_STREAM_ERROR); |
| } |
| |
| strm.state = null; |
| |
| return status === BUSY_STATE ? err(strm, Z_DATA_ERROR) : Z_OK; |
| } |
| |
| |
| /* ========================================================================= |
| * Initializes the compression dictionary from the given byte |
| * sequence without producing any compressed output. |
| */ |
| function deflateSetDictionary(strm, dictionary) { |
| var dictLength = dictionary.length; |
| |
| var s; |
| var str, n; |
| var wrap; |
| var avail; |
| var next; |
| var input; |
| var tmpDict; |
| |
| if (!strm/*== Z_NULL*/ || !strm.state/*== Z_NULL*/) { |
| return Z_STREAM_ERROR; |
| } |
| |
| s = strm.state; |
| wrap = s.wrap; |
| |
| if (wrap === 2 || (wrap === 1 && s.status !== INIT_STATE) || s.lookahead) { |
| return Z_STREAM_ERROR; |
| } |
| |
| /* when using zlib wrappers, compute Adler-32 for provided dictionary */ |
| if (wrap === 1) { |
| /* adler32(strm->adler, dictionary, dictLength); */ |
| strm.adler = adler32(strm.adler, dictionary, dictLength, 0); |
| } |
| |
| s.wrap = 0; /* avoid computing Adler-32 in read_buf */ |
| |
| /* if dictionary would fill window, just replace the history */ |
| if (dictLength >= s.w_size) { |
| if (wrap === 0) { /* already empty otherwise */ |
| /*** CLEAR_HASH(s); ***/ |
| zero(s.head); // Fill with NIL (= 0); |
| s.strstart = 0; |
| s.block_start = 0; |
| s.insert = 0; |
| } |
| /* use the tail */ |
| // dictionary = dictionary.slice(dictLength - s.w_size); |
| tmpDict = new utils.Buf8(s.w_size); |
| utils.arraySet(tmpDict, dictionary, dictLength - s.w_size, s.w_size, 0); |
| dictionary = tmpDict; |
| dictLength = s.w_size; |
| } |
| /* insert dictionary into window and hash */ |
| avail = strm.avail_in; |
| next = strm.next_in; |
| input = strm.input; |
| strm.avail_in = dictLength; |
| strm.next_in = 0; |
| strm.input = dictionary; |
| fill_window(s); |
| while (s.lookahead >= MIN_MATCH) { |
| str = s.strstart; |
| n = s.lookahead - (MIN_MATCH - 1); |
| do { |
| /* UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); */ |
| s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[str + MIN_MATCH - 1]) & s.hash_mask; |
| |
| s.prev[str & s.w_mask] = s.head[s.ins_h]; |
| |
| s.head[s.ins_h] = str; |
| str++; |
| } while (--n); |
| s.strstart = str; |
| s.lookahead = MIN_MATCH - 1; |
| fill_window(s); |
| } |
| s.strstart += s.lookahead; |
| s.block_start = s.strstart; |
| s.insert = s.lookahead; |
| s.lookahead = 0; |
| s.match_length = s.prev_length = MIN_MATCH - 1; |
| s.match_available = 0; |
| strm.next_in = next; |
| strm.input = input; |
| strm.avail_in = avail; |
| s.wrap = wrap; |
| return Z_OK; |
| } |
| |
| |
| exports.deflateInit = deflateInit; |
| exports.deflateInit2 = deflateInit2; |
| exports.deflateReset = deflateReset; |
| exports.deflateResetKeep = deflateResetKeep; |
| exports.deflateSetHeader = deflateSetHeader; |
| exports.deflate = deflate; |
| exports.deflateEnd = deflateEnd; |
| exports.deflateSetDictionary = deflateSetDictionary; |
| exports.deflateInfo = 'pako deflate (from Nodeca project)'; |
| |
| /* Not implemented |
| exports.deflateBound = deflateBound; |
| exports.deflateCopy = deflateCopy; |
| exports.deflateParams = deflateParams; |
| exports.deflatePending = deflatePending; |
| exports.deflatePrime = deflatePrime; |
| exports.deflateTune = deflateTune; |
| */ |