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Diffstat (limited to 'webclients/novnc/vendor/pako/lib/zlib/trees.js')
| -rw-r--r-- | webclients/novnc/vendor/pako/lib/zlib/trees.js | 1195 |
1 files changed, 1195 insertions, 0 deletions
diff --git a/webclients/novnc/vendor/pako/lib/zlib/trees.js b/webclients/novnc/vendor/pako/lib/zlib/trees.js new file mode 100644 index 0000000..a69b8a5 --- /dev/null +++ b/webclients/novnc/vendor/pako/lib/zlib/trees.js @@ -0,0 +1,1195 @@ +import * as utils from "../utils/common.js"; + +/* Public constants ==========================================================*/ +/* ===========================================================================*/ + + +//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; + +/*============================================================================*/ + + +function zero(buf) { var len = buf.length; while (--len >= 0) { buf[len] = 0; } } + +// From zutil.h + +var STORED_BLOCK = 0; +var STATIC_TREES = 1; +var DYN_TREES = 2; +/* The three kinds of block type */ + +var MIN_MATCH = 3; +var MAX_MATCH = 258; +/* The minimum and maximum match lengths */ + +// From deflate.h +/* =========================================================================== + * Internal compression state. + */ + +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 Buf_size = 16; +/* size of bit buffer in bi_buf */ + + +/* =========================================================================== + * Constants + */ + +var MAX_BL_BITS = 7; +/* Bit length codes must not exceed MAX_BL_BITS bits */ + +var END_BLOCK = 256; +/* end of block literal code */ + +var REP_3_6 = 16; +/* repeat previous bit length 3-6 times (2 bits of repeat count) */ + +var REPZ_3_10 = 17; +/* repeat a zero length 3-10 times (3 bits of repeat count) */ + +var REPZ_11_138 = 18; +/* repeat a zero length 11-138 times (7 bits of repeat count) */ + +/* eslint-disable comma-spacing,array-bracket-spacing */ +var extra_lbits = /* extra bits for each length code */ + [0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0]; + +var extra_dbits = /* extra bits for each distance code */ + [0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13]; + +var extra_blbits = /* extra bits for each bit length code */ + [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7]; + +var bl_order = + [16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15]; +/* eslint-enable comma-spacing,array-bracket-spacing */ + +/* The lengths of the bit length codes are sent in order of decreasing + * probability, to avoid transmitting the lengths for unused bit length codes. + */ + +/* =========================================================================== + * Local data. These are initialized only once. + */ + +// We pre-fill arrays with 0 to avoid uninitialized gaps + +var DIST_CODE_LEN = 512; /* see definition of array dist_code below */ + +// !!!! Use flat array insdead of structure, Freq = i*2, Len = i*2+1 +var static_ltree = new Array((L_CODES + 2) * 2); +zero(static_ltree); +/* The static literal tree. Since the bit lengths are imposed, there is no + * need for the L_CODES extra codes used during heap construction. However + * The codes 286 and 287 are needed to build a canonical tree (see _tr_init + * below). + */ + +var static_dtree = new Array(D_CODES * 2); +zero(static_dtree); +/* The static distance tree. (Actually a trivial tree since all codes use + * 5 bits.) + */ + +var _dist_code = new Array(DIST_CODE_LEN); +zero(_dist_code); +/* Distance codes. The first 256 values correspond to the distances + * 3 .. 258, the last 256 values correspond to the top 8 bits of + * the 15 bit distances. + */ + +var _length_code = new Array(MAX_MATCH - MIN_MATCH + 1); +zero(_length_code); +/* length code for each normalized match length (0 == MIN_MATCH) */ + +var base_length = new Array(LENGTH_CODES); +zero(base_length); +/* First normalized length for each code (0 = MIN_MATCH) */ + +var base_dist = new Array(D_CODES); +zero(base_dist); +/* First normalized distance for each code (0 = distance of 1) */ + + +function StaticTreeDesc(static_tree, extra_bits, extra_base, elems, max_length) { + + this.static_tree = static_tree; /* static tree or NULL */ + this.extra_bits = extra_bits; /* extra bits for each code or NULL */ + this.extra_base = extra_base; /* base index for extra_bits */ + this.elems = elems; /* max number of elements in the tree */ + this.max_length = max_length; /* max bit length for the codes */ + + // show if `static_tree` has data or dummy - needed for monomorphic objects + this.has_stree = static_tree && static_tree.length; +} + + +var static_l_desc; +var static_d_desc; +var static_bl_desc; + + +function TreeDesc(dyn_tree, stat_desc) { + this.dyn_tree = dyn_tree; /* the dynamic tree */ + this.max_code = 0; /* largest code with non zero frequency */ + this.stat_desc = stat_desc; /* the corresponding static tree */ +} + + + +function d_code(dist) { + return dist < 256 ? _dist_code[dist] : _dist_code[256 + (dist >>> 7)]; +} + + +/* =========================================================================== + * Output a short LSB first on the stream. + * IN assertion: there is enough room in pendingBuf. + */ +function put_short(s, w) { +// put_byte(s, (uch)((w) & 0xff)); +// put_byte(s, (uch)((ush)(w) >> 8)); + s.pending_buf[s.pending++] = (w) & 0xff; + s.pending_buf[s.pending++] = (w >>> 8) & 0xff; +} + + +/* =========================================================================== + * Send a value on a given number of bits. + * IN assertion: length <= 16 and value fits in length bits. + */ +function send_bits(s, value, length) { + if (s.bi_valid > (Buf_size - length)) { + s.bi_buf |= (value << s.bi_valid) & 0xffff; + put_short(s, s.bi_buf); + s.bi_buf = value >> (Buf_size - s.bi_valid); + s.bi_valid += length - Buf_size; + } else { + s.bi_buf |= (value << s.bi_valid) & 0xffff; + s.bi_valid += length; + } +} + + +function send_code(s, c, tree) { + send_bits(s, tree[c * 2]/*.Code*/, tree[c * 2 + 1]/*.Len*/); +} + + +/* =========================================================================== + * Reverse the first len bits of a code, using straightforward code (a faster + * method would use a table) + * IN assertion: 1 <= len <= 15 + */ +function bi_reverse(code, len) { + var res = 0; + do { + res |= code & 1; + code >>>= 1; + res <<= 1; + } while (--len > 0); + return res >>> 1; +} + + +/* =========================================================================== + * Flush the bit buffer, keeping at most 7 bits in it. + */ +function bi_flush(s) { + if (s.bi_valid === 16) { + put_short(s, s.bi_buf); + s.bi_buf = 0; + s.bi_valid = 0; + + } else if (s.bi_valid >= 8) { + s.pending_buf[s.pending++] = s.bi_buf & 0xff; + s.bi_buf >>= 8; + s.bi_valid -= 8; + } +} + + +/* =========================================================================== + * Compute the optimal bit lengths for a tree and update the total bit length + * for the current block. + * IN assertion: the fields freq and dad are set, heap[heap_max] and + * above are the tree nodes sorted by increasing frequency. + * OUT assertions: the field len is set to the optimal bit length, the + * array bl_count contains the frequencies for each bit length. + * The length opt_len is updated; static_len is also updated if stree is + * not null. + */ +function gen_bitlen(s, desc) +// deflate_state *s; +// tree_desc *desc; /* the tree descriptor */ +{ + var tree = desc.dyn_tree; + var max_code = desc.max_code; + var stree = desc.stat_desc.static_tree; + var has_stree = desc.stat_desc.has_stree; + var extra = desc.stat_desc.extra_bits; + var base = desc.stat_desc.extra_base; + var max_length = desc.stat_desc.max_length; + var h; /* heap index */ + var n, m; /* iterate over the tree elements */ + var bits; /* bit length */ + var xbits; /* extra bits */ + var f; /* frequency */ + var overflow = 0; /* number of elements with bit length too large */ + + for (bits = 0; bits <= MAX_BITS; bits++) { + s.bl_count[bits] = 0; + } + + /* In a first pass, compute the optimal bit lengths (which may + * overflow in the case of the bit length tree). + */ + tree[s.heap[s.heap_max] * 2 + 1]/*.Len*/ = 0; /* root of the heap */ + + for (h = s.heap_max + 1; h < HEAP_SIZE; h++) { + n = s.heap[h]; + bits = tree[tree[n * 2 + 1]/*.Dad*/ * 2 + 1]/*.Len*/ + 1; + if (bits > max_length) { + bits = max_length; + overflow++; + } + tree[n * 2 + 1]/*.Len*/ = bits; + /* We overwrite tree[n].Dad which is no longer needed */ + + if (n > max_code) { continue; } /* not a leaf node */ + + s.bl_count[bits]++; + xbits = 0; + if (n >= base) { + xbits = extra[n - base]; + } + f = tree[n * 2]/*.Freq*/; + s.opt_len += f * (bits + xbits); + if (has_stree) { + s.static_len += f * (stree[n * 2 + 1]/*.Len*/ + xbits); + } + } + if (overflow === 0) { return; } + + // Trace((stderr,"\nbit length overflow\n")); + /* This happens for example on obj2 and pic of the Calgary corpus */ + + /* Find the first bit length which could increase: */ + do { + bits = max_length - 1; + while (s.bl_count[bits] === 0) { bits--; } + s.bl_count[bits]--; /* move one leaf down the tree */ + s.bl_count[bits + 1] += 2; /* move one overflow item as its brother */ + s.bl_count[max_length]--; + /* The brother of the overflow item also moves one step up, + * but this does not affect bl_count[max_length] + */ + overflow -= 2; + } while (overflow > 0); + + /* Now recompute all bit lengths, scanning in increasing frequency. + * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all + * lengths instead of fixing only the wrong ones. This idea is taken + * from 'ar' written by Haruhiko Okumura.) + */ + for (bits = max_length; bits !== 0; bits--) { + n = s.bl_count[bits]; + while (n !== 0) { + m = s.heap[--h]; + if (m > max_code) { continue; } + if (tree[m * 2 + 1]/*.Len*/ !== bits) { + // Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); + s.opt_len += (bits - tree[m * 2 + 1]/*.Len*/) * tree[m * 2]/*.Freq*/; + tree[m * 2 + 1]/*.Len*/ = bits; + } + n--; + } + } +} + + +/* =========================================================================== + * Generate the codes for a given tree and bit counts (which need not be + * optimal). + * IN assertion: the array bl_count contains the bit length statistics for + * the given tree and the field len is set for all tree elements. + * OUT assertion: the field code is set for all tree elements of non + * zero code length. + */ +function gen_codes(tree, max_code, bl_count) +// ct_data *tree; /* the tree to decorate */ +// int max_code; /* largest code with non zero frequency */ +// ushf *bl_count; /* number of codes at each bit length */ +{ + var next_code = new Array(MAX_BITS + 1); /* next code value for each bit length */ + var code = 0; /* running code value */ + var bits; /* bit index */ + var n; /* code index */ + + /* The distribution counts are first used to generate the code values + * without bit reversal. + */ + for (bits = 1; bits <= MAX_BITS; bits++) { + next_code[bits] = code = (code + bl_count[bits - 1]) << 1; + } + /* Check that the bit counts in bl_count are consistent. The last code + * must be all ones. + */ + //Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, + // "inconsistent bit counts"); + //Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); + + for (n = 0; n <= max_code; n++) { + var len = tree[n * 2 + 1]/*.Len*/; + if (len === 0) { continue; } + /* Now reverse the bits */ + tree[n * 2]/*.Code*/ = bi_reverse(next_code[len]++, len); + + //Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", + // n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); + } +} + + +/* =========================================================================== + * Initialize the various 'constant' tables. + */ +function tr_static_init() { + var n; /* iterates over tree elements */ + var bits; /* bit counter */ + var length; /* length value */ + var code; /* code value */ + var dist; /* distance index */ + var bl_count = new Array(MAX_BITS + 1); + /* number of codes at each bit length for an optimal tree */ + + // do check in _tr_init() + //if (static_init_done) return; + + /* For some embedded targets, global variables are not initialized: */ +/*#ifdef NO_INIT_GLOBAL_POINTERS + static_l_desc.static_tree = static_ltree; + static_l_desc.extra_bits = extra_lbits; + static_d_desc.static_tree = static_dtree; + static_d_desc.extra_bits = extra_dbits; + static_bl_desc.extra_bits = extra_blbits; +#endif*/ + + /* Initialize the mapping length (0..255) -> length code (0..28) */ + length = 0; + for (code = 0; code < LENGTH_CODES - 1; code++) { + base_length[code] = length; + for (n = 0; n < (1 << extra_lbits[code]); n++) { + _length_code[length++] = code; + } + } + //Assert (length == 256, "tr_static_init: length != 256"); + /* Note that the length 255 (match length 258) can be represented + * in two different ways: code 284 + 5 bits or code 285, so we + * overwrite length_code[255] to use the best encoding: + */ + _length_code[length - 1] = code; + + /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ + dist = 0; + for (code = 0; code < 16; code++) { + base_dist[code] = dist; + for (n = 0; n < (1 << extra_dbits[code]); n++) { + _dist_code[dist++] = code; + } + } + //Assert (dist == 256, "tr_static_init: dist != 256"); + dist >>= 7; /* from now on, all distances are divided by 128 */ + for (; code < D_CODES; code++) { + base_dist[code] = dist << 7; + for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) { + _dist_code[256 + dist++] = code; + } + } + //Assert (dist == 256, "tr_static_init: 256+dist != 512"); + + /* Construct the codes of the static literal tree */ + for (bits = 0; bits <= MAX_BITS; bits++) { + bl_count[bits] = 0; + } + + n = 0; + while (n <= 143) { + static_ltree[n * 2 + 1]/*.Len*/ = 8; + n++; + bl_count[8]++; + } + while (n <= 255) { + static_ltree[n * 2 + 1]/*.Len*/ = 9; + n++; + bl_count[9]++; + } + while (n <= 279) { + static_ltree[n * 2 + 1]/*.Len*/ = 7; + n++; + bl_count[7]++; + } + while (n <= 287) { + static_ltree[n * 2 + 1]/*.Len*/ = 8; + n++; + bl_count[8]++; + } + /* Codes 286 and 287 do not exist, but we must include them in the + * tree construction to get a canonical Huffman tree (longest code + * all ones) + */ + gen_codes(static_ltree, L_CODES + 1, bl_count); + + /* The static distance tree is trivial: */ + for (n = 0; n < D_CODES; n++) { + static_dtree[n * 2 + 1]/*.Len*/ = 5; + static_dtree[n * 2]/*.Code*/ = bi_reverse(n, 5); + } + + // Now data ready and we can init static trees + static_l_desc = new StaticTreeDesc(static_ltree, extra_lbits, LITERALS + 1, L_CODES, MAX_BITS); + static_d_desc = new StaticTreeDesc(static_dtree, extra_dbits, 0, D_CODES, MAX_BITS); + static_bl_desc = new StaticTreeDesc(new Array(0), extra_blbits, 0, BL_CODES, MAX_BL_BITS); + + //static_init_done = true; +} + + +/* =========================================================================== + * Initialize a new block. + */ +function init_block(s) { + var n; /* iterates over tree elements */ + + /* Initialize the trees. */ + for (n = 0; n < L_CODES; n++) { s.dyn_ltree[n * 2]/*.Freq*/ = 0; } + for (n = 0; n < D_CODES; n++) { s.dyn_dtree[n * 2]/*.Freq*/ = 0; } + for (n = 0; n < BL_CODES; n++) { s.bl_tree[n * 2]/*.Freq*/ = 0; } + + s.dyn_ltree[END_BLOCK * 2]/*.Freq*/ = 1; + s.opt_len = s.static_len = 0; + s.last_lit = s.matches = 0; +} + + +/* =========================================================================== + * Flush the bit buffer and align the output on a byte boundary + */ +function bi_windup(s) +{ + if (s.bi_valid > 8) { + put_short(s, s.bi_buf); + } else if (s.bi_valid > 0) { + //put_byte(s, (Byte)s->bi_buf); + s.pending_buf[s.pending++] = s.bi_buf; + } + s.bi_buf = 0; + s.bi_valid = 0; +} + +/* =========================================================================== + * Copy a stored block, storing first the length and its + * one's complement if requested. + */ +function copy_block(s, buf, len, header) +//DeflateState *s; +//charf *buf; /* the input data */ +//unsigned len; /* its length */ +//int header; /* true if block header must be written */ +{ + bi_windup(s); /* align on byte boundary */ + + if (header) { + put_short(s, len); + put_short(s, ~len); + } +// while (len--) { +// put_byte(s, *buf++); +// } + utils.arraySet(s.pending_buf, s.window, buf, len, s.pending); + s.pending += len; +} + +/* =========================================================================== + * Compares to subtrees, using the tree depth as tie breaker when + * the subtrees have equal frequency. This minimizes the worst case length. + */ +function smaller(tree, n, m, depth) { + var _n2 = n * 2; + var _m2 = m * 2; + return (tree[_n2]/*.Freq*/ < tree[_m2]/*.Freq*/ || + (tree[_n2]/*.Freq*/ === tree[_m2]/*.Freq*/ && depth[n] <= depth[m])); +} + +/* =========================================================================== + * 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). + */ +function pqdownheap(s, tree, k) +// deflate_state *s; +// ct_data *tree; /* the tree to restore */ +// int k; /* node to move down */ +{ + var v = s.heap[k]; + var j = k << 1; /* left son of k */ + while (j <= s.heap_len) { + /* Set j to the smallest of the two sons: */ + if (j < s.heap_len && + smaller(tree, s.heap[j + 1], s.heap[j], s.depth)) { + j++; + } + /* Exit if v is smaller than both sons */ + if (smaller(tree, v, s.heap[j], s.depth)) { break; } + + /* Exchange v with the smallest son */ + s.heap[k] = s.heap[j]; + k = j; + + /* And continue down the tree, setting j to the left son of k */ + j <<= 1; + } + s.heap[k] = v; +} + + +// inlined manually +// var SMALLEST = 1; + +/* =========================================================================== + * Send the block data compressed using the given Huffman trees + */ +function compress_block(s, ltree, dtree) +// deflate_state *s; +// const ct_data *ltree; /* literal tree */ +// const ct_data *dtree; /* distance tree */ +{ + var dist; /* distance of matched string */ + var lc; /* match length or unmatched char (if dist == 0) */ + var lx = 0; /* running index in l_buf */ + var code; /* the code to send */ + var extra; /* number of extra bits to send */ + + if (s.last_lit !== 0) { + do { + dist = (s.pending_buf[s.d_buf + lx * 2] << 8) | (s.pending_buf[s.d_buf + lx * 2 + 1]); + lc = s.pending_buf[s.l_buf + lx]; + lx++; + + if (dist === 0) { + send_code(s, lc, ltree); /* send a literal byte */ + //Tracecv(isgraph(lc), (stderr," '%c' ", lc)); + } else { + /* Here, lc is the match length - MIN_MATCH */ + code = _length_code[lc]; + send_code(s, code + LITERALS + 1, ltree); /* send the length code */ + extra = extra_lbits[code]; + if (extra !== 0) { + lc -= base_length[code]; + send_bits(s, lc, extra); /* send the extra length bits */ + } + dist--; /* dist is now the match distance - 1 */ + code = d_code(dist); + //Assert (code < D_CODES, "bad d_code"); + + send_code(s, code, dtree); /* send the distance code */ + extra = extra_dbits[code]; + if (extra !== 0) { + dist -= base_dist[code]; + send_bits(s, 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: */ + //Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx, + // "pendingBuf overflow"); + + } while (lx < s.last_lit); + } + + send_code(s, END_BLOCK, ltree); +} + + +/* =========================================================================== + * Construct one Huffman tree and assigns the code bit strings and lengths. + * Update the total bit length for the current block. + * IN assertion: the field freq is set for all tree elements. + * OUT assertions: the fields len and code are set to the optimal bit length + * and corresponding code. The length opt_len is updated; static_len is + * also updated if stree is not null. The field max_code is set. + */ +function build_tree(s, desc) +// deflate_state *s; +// tree_desc *desc; /* the tree descriptor */ +{ + var tree = desc.dyn_tree; + var stree = desc.stat_desc.static_tree; + var has_stree = desc.stat_desc.has_stree; + var elems = desc.stat_desc.elems; + var n, m; /* iterate over heap elements */ + var max_code = -1; /* largest code with non zero frequency */ + var node; /* new node being created */ + + /* Construct the initial heap, with least frequent element in + * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. + * heap[0] is not used. + */ + s.heap_len = 0; + s.heap_max = HEAP_SIZE; + + for (n = 0; n < elems; n++) { + if (tree[n * 2]/*.Freq*/ !== 0) { + s.heap[++s.heap_len] = max_code = n; + s.depth[n] = 0; + + } else { + tree[n * 2 + 1]/*.Len*/ = 0; + } + } + + /* The pkzip format requires that at least one distance code exists, + * and that at least one bit should be sent even if there is only one + * possible code. So to avoid special checks later on we force at least + * two codes of non zero frequency. + */ + while (s.heap_len < 2) { + node = s.heap[++s.heap_len] = (max_code < 2 ? ++max_code : 0); + tree[node * 2]/*.Freq*/ = 1; + s.depth[node] = 0; + s.opt_len--; + + if (has_stree) { + s.static_len -= stree[node * 2 + 1]/*.Len*/; + } + /* node is 0 or 1 so it does not have extra bits */ + } + desc.max_code = max_code; + + /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, + * establish sub-heaps of increasing lengths: + */ + for (n = (s.heap_len >> 1/*int /2*/); n >= 1; n--) { pqdownheap(s, tree, n); } + + /* Construct the Huffman tree by repeatedly combining the least two + * frequent nodes. + */ + node = elems; /* next internal node of the tree */ + do { + //pqremove(s, tree, n); /* n = node of least frequency */ + /*** pqremove ***/ + n = s.heap[1/*SMALLEST*/]; + s.heap[1/*SMALLEST*/] = s.heap[s.heap_len--]; + pqdownheap(s, tree, 1/*SMALLEST*/); + /***/ + + m = s.heap[1/*SMALLEST*/]; /* m = node of next least frequency */ + + s.heap[--s.heap_max] = n; /* keep the nodes sorted by frequency */ + s.heap[--s.heap_max] = m; + + /* Create a new node father of n and m */ + tree[node * 2]/*.Freq*/ = tree[n * 2]/*.Freq*/ + tree[m * 2]/*.Freq*/; + s.depth[node] = (s.depth[n] >= s.depth[m] ? s.depth[n] : s.depth[m]) + 1; + tree[n * 2 + 1]/*.Dad*/ = tree[m * 2 + 1]/*.Dad*/ = node; + + /* and insert the new node in the heap */ + s.heap[1/*SMALLEST*/] = node++; + pqdownheap(s, tree, 1/*SMALLEST*/); + + } while (s.heap_len >= 2); + + s.heap[--s.heap_max] = s.heap[1/*SMALLEST*/]; + + /* At this point, the fields freq and dad are set. We can now + * generate the bit lengths. + */ + gen_bitlen(s, desc); + + /* The field len is now set, we can generate the bit codes */ + gen_codes(tree, max_code, s.bl_count); +} + + +/* =========================================================================== + * Scan a literal or distance tree to determine the frequencies of the codes + * in the bit length tree. + */ +function scan_tree(s, tree, max_code) +// deflate_state *s; +// ct_data *tree; /* the tree to be scanned */ +// int max_code; /* and its largest code of non zero frequency */ +{ + var n; /* iterates over all tree elements */ + var prevlen = -1; /* last emitted length */ + var curlen; /* length of current code */ + + var nextlen = tree[0 * 2 + 1]/*.Len*/; /* length of next code */ + + var count = 0; /* repeat count of the current code */ + var max_count = 7; /* max repeat count */ + var min_count = 4; /* min repeat count */ + + if (nextlen === 0) { + max_count = 138; + min_count = 3; + } + tree[(max_code + 1) * 2 + 1]/*.Len*/ = 0xffff; /* guard */ + + for (n = 0; n <= max_code; n++) { + curlen = nextlen; + nextlen = tree[(n + 1) * 2 + 1]/*.Len*/; + + if (++count < max_count && curlen === nextlen) { + continue; + + } else if (count < min_count) { + s.bl_tree[curlen * 2]/*.Freq*/ += count; + + } else if (curlen !== 0) { + + if (curlen !== prevlen) { s.bl_tree[curlen * 2]/*.Freq*/++; } + s.bl_tree[REP_3_6 * 2]/*.Freq*/++; + + } else if (count <= 10) { + s.bl_tree[REPZ_3_10 * 2]/*.Freq*/++; + + } else { + s.bl_tree[REPZ_11_138 * 2]/*.Freq*/++; + } + + 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; + } + } +} + + +/* =========================================================================== + * Send a literal or distance tree in compressed form, using the codes in + * bl_tree. + */ +function send_tree(s, tree, max_code) +// deflate_state *s; +// ct_data *tree; /* the tree to be scanned */ +// int max_code; /* and its largest code of non zero frequency */ +{ + var n; /* iterates over all tree elements */ + var prevlen = -1; /* last emitted length */ + var curlen; /* length of current code */ + + var nextlen = tree[0 * 2 + 1]/*.Len*/; /* length of next code */ + + var count = 0; /* repeat count of the current code */ + var max_count = 7; /* max repeat count */ + var min_count = 4; /* min repeat count */ + + /* tree[max_code+1].Len = -1; */ /* guard already set */ + if (nextlen === 0) { + max_count = 138; + min_count = 3; + } + + for (n = 0; n <= max_code; n++) { + curlen = nextlen; + nextlen = tree[(n + 1) * 2 + 1]/*.Len*/; + + if (++count < max_count && curlen === nextlen) { + continue; + + } else if (count < min_count) { + do { send_code(s, curlen, s.bl_tree); } while (--count !== 0); + + } else if (curlen !== 0) { + if (curlen !== prevlen) { + send_code(s, curlen, s.bl_tree); + count--; + } + //Assert(count >= 3 && count <= 6, " 3_6?"); + send_code(s, REP_3_6, s.bl_tree); + send_bits(s, count - 3, 2); + + } else if (count <= 10) { + send_code(s, REPZ_3_10, s.bl_tree); + send_bits(s, count - 3, 3); + + } else { + send_code(s, REPZ_11_138, s.bl_tree); + send_bits(s, 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; + } + } +} + + +/* =========================================================================== + * Construct the Huffman tree for the bit lengths and return the index in + * bl_order of the last bit length code to send. + */ +function build_bl_tree(s) { + var max_blindex; /* index of last bit length code of non zero freq */ + + /* Determine the bit length frequencies for literal and distance trees */ + scan_tree(s, s.dyn_ltree, s.l_desc.max_code); + scan_tree(s, s.dyn_dtree, s.d_desc.max_code); + + /* Build the bit length tree: */ + build_tree(s, s.bl_desc); + /* 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 (s.bl_tree[bl_order[max_blindex] * 2 + 1]/*.Len*/ !== 0) { + break; + } + } + /* Update opt_len to include the bit length tree and counts */ + s.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4; + //Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", + // s->opt_len, s->static_len)); + + 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. + */ +function send_all_trees(s, lcodes, dcodes, blcodes) +// deflate_state *s; +// int lcodes, dcodes, blcodes; /* number of codes for each tree */ +{ + var rank; /* index in bl_order */ + + //Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); + //Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, + // "too many codes"); + //Tracev((stderr, "\nbl counts: ")); + send_bits(s, lcodes - 257, 5); /* not +255 as stated in appnote.txt */ + send_bits(s, dcodes - 1, 5); + send_bits(s, blcodes - 4, 4); /* not -3 as stated in appnote.txt */ + for (rank = 0; rank < blcodes; rank++) { + //Tracev((stderr, "\nbl code %2d ", bl_order[rank])); + send_bits(s, s.bl_tree[bl_order[rank] * 2 + 1]/*.Len*/, 3); + } + //Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); + + send_tree(s, s.dyn_ltree, lcodes - 1); /* literal tree */ + //Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); + + send_tree(s, s.dyn_dtree, dcodes - 1); /* distance tree */ + //Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); +} + + +/* =========================================================================== + * Check if the data type is TEXT or BINARY, using the following algorithm: + * - TEXT if the two conditions below are satisfied: + * a) There are no non-portable control characters belonging to the + * "black list" (0..6, 14..25, 28..31). + * b) There is at least one printable character belonging to the + * "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255). + * - BINARY otherwise. + * - The following partially-portable control characters form a + * "gray list" that is ignored in this detection algorithm: + * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}). + * IN assertion: the fields Freq of dyn_ltree are set. + */ +function detect_data_type(s) { + /* black_mask is the bit mask of black-listed bytes + * set bits 0..6, 14..25, and 28..31 + * 0xf3ffc07f = binary 11110011111111111100000001111111 + */ + var black_mask = 0xf3ffc07f; + var n; + + /* Check for non-textual ("black-listed") bytes. */ + for (n = 0; n <= 31; n++, black_mask >>>= 1) { + if ((black_mask & 1) && (s.dyn_ltree[n * 2]/*.Freq*/ !== 0)) { + return Z_BINARY; + } + } + + /* Check for textual ("white-listed") bytes. */ + if (s.dyn_ltree[9 * 2]/*.Freq*/ !== 0 || s.dyn_ltree[10 * 2]/*.Freq*/ !== 0 || + s.dyn_ltree[13 * 2]/*.Freq*/ !== 0) { + return Z_TEXT; + } + for (n = 32; n < LITERALS; n++) { + if (s.dyn_ltree[n * 2]/*.Freq*/ !== 0) { + return Z_TEXT; + } + } + + /* There are no "black-listed" or "white-listed" bytes: + * this stream either is empty or has tolerated ("gray-listed") bytes only. + */ + return Z_BINARY; +} + + +var static_init_done = false; + +/* =========================================================================== + * Initialize the tree data structures for a new zlib stream. + */ +function _tr_init(s) +{ + + if (!static_init_done) { + tr_static_init(); + static_init_done = true; + } + + s.l_desc = new TreeDesc(s.dyn_ltree, static_l_desc); + s.d_desc = new TreeDesc(s.dyn_dtree, static_d_desc); + s.bl_desc = new TreeDesc(s.bl_tree, static_bl_desc); + + s.bi_buf = 0; + s.bi_valid = 0; + + /* Initialize the first block of the first file: */ + init_block(s); +} + + +/* =========================================================================== + * Send a stored block + */ +function _tr_stored_block(s, buf, stored_len, last) +//DeflateState *s; +//charf *buf; /* input block */ +//ulg stored_len; /* length of input block */ +//int last; /* one if this is the last block for a file */ +{ + send_bits(s, (STORED_BLOCK << 1) + (last ? 1 : 0), 3); /* send block type */ + copy_block(s, buf, stored_len, true); /* with header */ +} + + +/* =========================================================================== + * Send one empty static block to give enough lookahead for inflate. + * This takes 10 bits, of which 7 may remain in the bit buffer. + */ +function _tr_align(s) { + send_bits(s, STATIC_TREES << 1, 3); + send_code(s, END_BLOCK, static_ltree); + bi_flush(s); +} + + +/* =========================================================================== + * Determine the best encoding for the current block: dynamic trees, static + * trees or store, and output the encoded block to the zip file. + */ +function _tr_flush_block(s, buf, stored_len, last) +//DeflateState *s; +//charf *buf; /* input block, or NULL if too old */ +//ulg stored_len; /* length of input block */ +//int last; /* one if this is the last block for a file */ +{ + var opt_lenb, static_lenb; /* opt_len and static_len in bytes */ + var max_blindex = 0; /* index of last bit length code of non zero freq */ + + /* Build the Huffman trees unless a stored block is forced */ + if (s.level > 0) { + + /* Check if the file is binary or text */ + if (s.strm.data_type === Z_UNKNOWN) { + s.strm.data_type = detect_data_type(s); + } + + /* Construct the literal and distance trees */ + build_tree(s, s.l_desc); + // Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, + // s->static_len)); + + build_tree(s, s.d_desc); + // Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, + // s->static_len)); + /* 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(s); + + /* Determine the best encoding. Compute the block lengths in bytes. */ + opt_lenb = (s.opt_len + 3 + 7) >>> 3; + static_lenb = (s.static_len + 3 + 7) >>> 3; + + // Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", + // opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, + // s->last_lit)); + + if (static_lenb <= opt_lenb) { opt_lenb = static_lenb; } + + } else { + // Assert(buf != (char*)0, "lost buf"); + 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(s, buf, stored_len, last); + + } else if (s.strategy === Z_FIXED || static_lenb === opt_lenb) { + + send_bits(s, (STATIC_TREES << 1) + (last ? 1 : 0), 3); + compress_block(s, static_ltree, static_dtree); + + } else { + send_bits(s, (DYN_TREES << 1) + (last ? 1 : 0), 3); + send_all_trees(s, s.l_desc.max_code + 1, s.d_desc.max_code + 1, max_blindex + 1); + compress_block(s, s.dyn_ltree, s.dyn_dtree); + } + // Assert (s->compressed_len == s->bits_sent, "bad compressed size"); + /* The above check is made mod 2^32, for files larger than 512 MB + * and uLong implemented on 32 bits. + */ + init_block(s); + + if (last) { + bi_windup(s); + } + // Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, + // s->compressed_len-7*last)); +} + +/* =========================================================================== + * Save the match info and tally the frequency counts. Return true if + * the current block must be flushed. + */ +function _tr_tally(s, dist, lc) +// deflate_state *s; +// unsigned dist; /* distance of matched string */ +// unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ +{ + //var out_length, in_length, dcode; + + s.pending_buf[s.d_buf + s.last_lit * 2] = (dist >>> 8) & 0xff; + s.pending_buf[s.d_buf + s.last_lit * 2 + 1] = dist & 0xff; + + s.pending_buf[s.l_buf + s.last_lit] = lc & 0xff; + s.last_lit++; + + if (dist === 0) { + /* lc is the unmatched char */ + s.dyn_ltree[lc * 2]/*.Freq*/++; + } else { + s.matches++; + /* Here, lc is the match length - MIN_MATCH */ + dist--; /* dist = match distance - 1 */ + //Assert((ush)dist < (ush)MAX_DIST(s) && + // (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && + // (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); + + s.dyn_ltree[(_length_code[lc] + LITERALS + 1) * 2]/*.Freq*/++; + s.dyn_dtree[d_code(dist) * 2]/*.Freq*/++; + } + +// (!) This block is disabled in zlib defailts, +// don't enable it for binary compatibility + +//#ifdef TRUNCATE_BLOCK +// /* Try to guess if it is profitable to stop the current block here */ +// if ((s.last_lit & 0x1fff) === 0 && s.level > 2) { +// /* Compute an upper bound for the compressed length */ +// out_length = s.last_lit*8; +// in_length = s.strstart - s.block_start; +// +// for (dcode = 0; dcode < D_CODES; dcode++) { +// out_length += s.dyn_dtree[dcode*2]/*.Freq*/ * (5 + extra_dbits[dcode]); +// } +// out_length >>>= 3; +// //Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", +// // s->last_lit, in_length, out_length, +// // 100L - out_length*100L/in_length)); +// if (s.matches < (s.last_lit>>1)/*int /2*/ && out_length < (in_length>>1)/*int /2*/) { +// return true; +// } +// } +//#endif + + return (s.last_lit === s.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. + */ +} + +export { _tr_init, _tr_stored_block, _tr_flush_block, _tr_tally, _tr_align }; |