--- /dev/null
+/*
+# Small Deflate
+`sdefl` is a small bare bone lossless compression library in ANSI C (ISO C90)
+which implements the Deflate (RFC 1951) compressed data format specification standard.
+It is mainly tuned to get as much speed and compression ratio from as little code
+as needed to keep the implementation as concise as possible.
+
+## Features
+- Portable single header and source file duo written in ANSI C (ISO C90)
+- Dual license with either MIT or public domain
+- Small implementation
+ - Deflate: 525 LoC
+ - Inflate: 320 LoC
+- Webassembly:
+ - Deflate ~3.7 KB (~2.2KB compressed)
+ - Inflate ~3.6 KB (~2.2KB compressed)
+
+## Usage:
+This file behaves differently depending on what symbols you define
+before including it.
+
+Header-File mode:
+If you do not define `SDEFL_IMPLEMENTATION` before including this file, it
+will operate in header only mode. In this mode it declares all used structs
+and the API of the library without including the implementation of the library.
+
+Implementation mode:
+If you define `SDEFL_IMPLEMENTATION` before including this file, it will
+compile the implementation . Make sure that you only include
+this file implementation in *one* C or C++ file to prevent collisions.
+
+### Benchmark
+
+| Compressor name | Compression| Decompress.| Compr. size | Ratio |
+| ------------------------| -----------| -----------| ----------- | ----- |
+| sdefl 1.0 -0 | 127 MB/s | 233 MB/s | 40004116 | 39.88 |
+| sdefl 1.0 -1 | 111 MB/s | 259 MB/s | 38940674 | 38.82 |
+| sdefl 1.0 -5 | 45 MB/s | 275 MB/s | 36577183 | 36.46 |
+| sdefl 1.0 -7 | 38 MB/s | 276 MB/s | 36523781 | 36.41 |
+| zlib 1.2.11 -1 | 72 MB/s | 307 MB/s | 42298774 | 42.30 |
+| zlib 1.2.11 -6 | 24 MB/s | 313 MB/s | 36548921 | 36.55 |
+| zlib 1.2.11 -9 | 20 MB/s | 314 MB/s | 36475792 | 36.48 |
+| miniz 1.0 -1 | 122 MB/s | 208 MB/s | 48510028 | 48.51 |
+| miniz 1.0 -6 | 27 MB/s | 260 MB/s | 36513697 | 36.51 |
+| miniz 1.0 -9 | 23 MB/s | 261 MB/s | 36460101 | 36.46 |
+| libdeflate 1.3 -1 | 147 MB/s | 667 MB/s | 39597378 | 39.60 |
+| libdeflate 1.3 -6 | 69 MB/s | 689 MB/s | 36648318 | 36.65 |
+| libdeflate 1.3 -9 | 13 MB/s | 672 MB/s | 35197141 | 35.20 |
+| libdeflate 1.3 -12 | 8.13 MB/s | 670 MB/s | 35100568 | 35.10 |
+
+### Compression
+Results on the [Silesia compression corpus](http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia):
+
+| File | Original | `sdefl 0` | `sdefl 5` | `sdefl 7` |
+| :------ | ---------: | -----------------: | ---------: | ----------: |
+| dickens | 10.192.446 | 4,260,187| 3,845,261| 3,833,657 |
+| mozilla | 51.220.480 | 20,774,706 | 19,607,009 | 19,565,867 |
+| mr | 9.970.564 | 3,860,531 | 3,673,460 | 3,665,627 |
+| nci | 33.553.445 | 4,030,283 | 3,094,526 | 3,006,075 |
+| ooffice | 6.152.192 | 3,320,063 | 3,186,373 | 3,183,815 |
+| osdb | 10.085.684 | 3,919,646 | 3,649,510 | 3,649,477 |
+| reymont | 6.627.202 | 2,263,378 | 1,857,588 | 1,827,237 |
+| samba | 21.606.400 | 6,121,797 | 5,462,670 | 5,450,762 |
+| sao | 7.251.944 | 5,612,421 | 5,485,380 | 5,481,765 |
+| webster | 41.458.703 | 13,972,648 | 12,059,432 | 11,991,421 |
+| xml | 5.345.280 | 886,620| 674,009 | 662,141 |
+| x-ray | 8.474.240 | 6,304,655 | 6,244,779 | 6,244,779 |
+
+## License
+```
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2020 Micha Mettke
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+```
+*/
+#ifndef SDEFL_H_INCLUDED
+#define SDEFL_H_INCLUDED
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SDEFL_MAX_OFF (1 << 15)
+#define SDEFL_WIN_SIZ SDEFL_MAX_OFF
+#define SDEFL_WIN_MSK (SDEFL_WIN_SIZ-1)
+
+#define SDEFL_HASH_BITS 15
+#define SDEFL_HASH_SIZ (1 << SDEFL_HASH_BITS)
+#define SDEFL_HASH_MSK (SDEFL_HASH_SIZ-1)
+
+#define SDEFL_MIN_MATCH 4
+#define SDEFL_BLK_MAX (256*1024)
+#define SDEFL_SEQ_SIZ ((SDEFL_BLK_MAX + SDEFL_MIN_MATCH)/SDEFL_MIN_MATCH)
+
+#define SDEFL_SYM_MAX (288)
+#define SDEFL_OFF_MAX (32)
+#define SDEFL_PRE_MAX (19)
+
+#define SDEFL_LVL_MIN 0
+#define SDEFL_LVL_DEF 5
+#define SDEFL_LVL_MAX 8
+
+struct sdefl_freq {
+ unsigned lit[SDEFL_SYM_MAX];
+ unsigned off[SDEFL_OFF_MAX];
+};
+struct sdefl_code_words {
+ unsigned lit[SDEFL_SYM_MAX];
+ unsigned off[SDEFL_OFF_MAX];
+};
+struct sdefl_lens {
+ unsigned char lit[SDEFL_SYM_MAX];
+ unsigned char off[SDEFL_OFF_MAX];
+};
+struct sdefl_codes {
+ struct sdefl_code_words word;
+ struct sdefl_lens len;
+};
+struct sdefl_seqt {
+ int off, len;
+};
+struct sdefl {
+ int bits, bitcnt;
+ int tbl[SDEFL_HASH_SIZ];
+ int prv[SDEFL_WIN_SIZ];
+
+ int seq_cnt;
+ struct sdefl_seqt seq[SDEFL_SEQ_SIZ];
+ struct sdefl_freq freq;
+ struct sdefl_codes cod;
+};
+extern int sdefl_bound(int in_len);
+extern int sdeflate(struct sdefl *s, void *o, const void *i, int n, int lvl);
+extern int zsdeflate(struct sdefl *s, void *o, const void *i, int n, int lvl);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SDEFL_H_INCLUDED */
+
+#ifdef SDEFL_IMPLEMENTATION
+
+#include <assert.h> /* assert */
+#include <string.h> /* memcpy */
+#include <limits.h> /* CHAR_BIT */
+
+#define SDEFL_NIL (-1)
+#define SDEFL_MAX_MATCH 258
+#define SDEFL_MAX_CODE_LEN (15)
+#define SDEFL_SYM_BITS (10u)
+#define SDEFL_SYM_MSK ((1u << SDEFL_SYM_BITS)-1u)
+#define SDEFL_LIT_LEN_CODES (14)
+#define SDEFL_OFF_CODES (15)
+#define SDEFL_PRE_CODES (7)
+#define SDEFL_CNT_NUM(n) ((((n)+3u/4u)+3u)&~3u)
+#define SDEFL_EOB (256)
+
+#define sdefl_npow2(n) (1 << (sdefl_ilog2((n)-1) + 1))
+
+static int
+sdefl_ilog2(int n) {
+ if (!n) return 0;
+#ifdef _MSC_VER
+ unsigned long msbp = 0;
+ _BitScanReverse(&msbp, (unsigned long)n);
+ return (int)msbp;
+#elif defined(__GNUC__) || defined(__clang__)
+ return (int)sizeof(unsigned long) * CHAR_BIT - 1 - __builtin_clzl((unsigned long)n);
+#else
+ #define lt(n) n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n
+ static const char tbl[256] = {
+ 0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,lt(4), lt(5), lt(5), lt(6), lt(6), lt(6), lt(6),
+ lt(7), lt(7), lt(7), lt(7), lt(7), lt(7), lt(7), lt(7)};
+ int tt, t;
+ if ((tt = (n >> 16))) {
+ return (t = (tt >> 8)) ? 24 + tbl[t] : 16 + tbl[tt];
+ } else {
+ return (t = (n >> 8)) ? 8 + tbl[t] : tbl[n];
+ }
+ #undef lt
+#endif
+}
+static unsigned
+sdefl_uload32(const void *p) {
+ /* hopefully will be optimized to an unaligned read */
+ unsigned n = 0;
+ memcpy(&n, p, sizeof(n));
+ return n;
+}
+static unsigned
+sdefl_hash32(const void *p) {
+ unsigned n = sdefl_uload32(p);
+ return (n * 0x9E377989) >> (32 - SDEFL_HASH_BITS);
+}
+static void
+sdefl_put(unsigned char **dst, struct sdefl *s, int code, int bitcnt) {
+ s->bits |= (code << s->bitcnt);
+ s->bitcnt += bitcnt;
+ while (s->bitcnt >= 8) {
+ unsigned char *tar = *dst;
+ *tar = (unsigned char)(s->bits & 0xFF);
+ s->bits >>= 8;
+ s->bitcnt -= 8;
+ *dst = *dst + 1;
+ }
+}
+static void
+sdefl_heap_sub(unsigned A[], unsigned len, unsigned sub) {
+ unsigned c, p = sub;
+ unsigned v = A[sub];
+ while ((c = p << 1) <= len) {
+ if (c < len && A[c + 1] > A[c]) c++;
+ if (v >= A[c]) break;
+ A[p] = A[c], p = c;
+ }
+ A[p] = v;
+}
+static void
+sdefl_heap_array(unsigned *A, unsigned len) {
+ unsigned sub;
+ for (sub = len >> 1; sub >= 1; sub--)
+ sdefl_heap_sub(A, len, sub);
+}
+static void
+sdefl_heap_sort(unsigned *A, unsigned n) {
+ A--;
+ sdefl_heap_array(A, n);
+ while (n >= 2) {
+ unsigned tmp = A[n];
+ A[n--] = A[1];
+ A[1] = tmp;
+ sdefl_heap_sub(A, n, 1);
+ }
+}
+static unsigned
+sdefl_sort_sym(unsigned sym_cnt, unsigned *freqs,
+ unsigned char *lens, unsigned *sym_out) {
+ unsigned cnts[SDEFL_CNT_NUM(SDEFL_SYM_MAX)] = {0};
+ unsigned cnt_num = SDEFL_CNT_NUM(sym_cnt);
+ unsigned used_sym = 0;
+ unsigned sym, i;
+ for (sym = 0; sym < sym_cnt; sym++)
+ cnts[freqs[sym] < cnt_num-1 ? freqs[sym]: cnt_num-1]++;
+ for (i = 1; i < cnt_num; i++) {
+ unsigned cnt = cnts[i];
+ cnts[i] = used_sym;
+ used_sym += cnt;
+ }
+ for (sym = 0; sym < sym_cnt; sym++) {
+ unsigned freq = freqs[sym];
+ if (freq) {
+ unsigned idx = freq < cnt_num-1 ? freq : cnt_num-1;
+ sym_out[cnts[idx]++] = sym | (freq << SDEFL_SYM_BITS);
+ } else lens[sym] = 0;
+ }
+ sdefl_heap_sort(sym_out + cnts[cnt_num-2], cnts[cnt_num-1] - cnts[cnt_num-2]);
+ return used_sym;
+}
+static void
+sdefl_build_tree(unsigned *A, unsigned sym_cnt) {
+ unsigned i = 0, b = 0, e = 0;
+ do {
+ unsigned m, n, freq_shift;
+ if (i != sym_cnt && (b == e || (A[i] >> SDEFL_SYM_BITS) <= (A[b] >> SDEFL_SYM_BITS)))
+ m = i++;
+ else m = b++;
+ if (i != sym_cnt && (b == e || (A[i] >> SDEFL_SYM_BITS) <= (A[b] >> SDEFL_SYM_BITS)))
+ n = i++;
+ else n = b++;
+
+ freq_shift = (A[m] & ~SDEFL_SYM_MSK) + (A[n] & ~SDEFL_SYM_MSK);
+ A[m] = (A[m] & SDEFL_SYM_MSK) | (e << SDEFL_SYM_BITS);
+ A[n] = (A[n] & SDEFL_SYM_MSK) | (e << SDEFL_SYM_BITS);
+ A[e] = (A[e] & SDEFL_SYM_MSK) | freq_shift;
+ } while (sym_cnt - ++e > 1);
+}
+static void
+sdefl_gen_len_cnt(unsigned *A, unsigned root, unsigned *len_cnt,
+ unsigned max_code_len) {
+ int n;
+ unsigned i;
+ for (i = 0; i <= max_code_len; i++)
+ len_cnt[i] = 0;
+ len_cnt[1] = 2;
+
+ A[root] &= SDEFL_SYM_MSK;
+ for (n = (int)root - 1; n >= 0; n--) {
+ unsigned p = A[n] >> SDEFL_SYM_BITS;
+ unsigned pdepth = A[p] >> SDEFL_SYM_BITS;
+ unsigned depth = pdepth + 1;
+ unsigned len = depth;
+
+ A[n] = (A[n] & SDEFL_SYM_MSK) | (depth << SDEFL_SYM_BITS);
+ if (len >= max_code_len) {
+ len = max_code_len;
+ do len--; while (!len_cnt[len]);
+ }
+ len_cnt[len]--;
+ len_cnt[len+1] += 2;
+ }
+}
+static void
+sdefl_gen_codes(unsigned *A, unsigned char *lens, const unsigned *len_cnt,
+ unsigned max_code_word_len, unsigned sym_cnt) {
+ unsigned i, sym, len, nxt[SDEFL_MAX_CODE_LEN + 1];
+ for (i = 0, len = max_code_word_len; len >= 1; len--) {
+ unsigned cnt = len_cnt[len];
+ while (cnt--) lens[A[i++] & SDEFL_SYM_MSK] = (unsigned char)len;
+ }
+ nxt[0] = nxt[1] = 0;
+ for (len = 2; len <= max_code_word_len; len++)
+ nxt[len] = (nxt[len-1] + len_cnt[len-1]) << 1;
+ for (sym = 0; sym < sym_cnt; sym++)
+ A[sym] = nxt[lens[sym]]++;
+}
+static unsigned
+sdefl_rev(unsigned c, unsigned char n) {
+ c = ((c & 0x5555) << 1) | ((c & 0xAAAA) >> 1);
+ c = ((c & 0x3333) << 2) | ((c & 0xCCCC) >> 2);
+ c = ((c & 0x0F0F) << 4) | ((c & 0xF0F0) >> 4);
+ c = ((c & 0x00FF) << 8) | ((c & 0xFF00) >> 8);
+ return c >> (16-n);
+}
+static void
+sdefl_huff(unsigned char *lens, unsigned *codes, unsigned *freqs,
+ unsigned num_syms, unsigned max_code_len) {
+ unsigned c, *A = codes;
+ unsigned len_cnt[SDEFL_MAX_CODE_LEN + 1];
+ unsigned used_syms = sdefl_sort_sym(num_syms, freqs, lens, A);
+ if (!used_syms) return;
+ if (used_syms == 1) {
+ unsigned s = A[0] & SDEFL_SYM_MSK;
+ unsigned i = s ? s : 1;
+ codes[0] = 0, lens[0] = 1;
+ codes[i] = 1, lens[i] = 1;
+ return;
+ }
+ sdefl_build_tree(A, used_syms);
+ sdefl_gen_len_cnt(A, used_syms-2, len_cnt, max_code_len);
+ sdefl_gen_codes(A, lens, len_cnt, max_code_len, num_syms);
+ for (c = 0; c < num_syms; c++) {
+ codes[c] = sdefl_rev(codes[c], lens[c]);
+ }
+}
+struct sdefl_symcnt {
+ int items;
+ int lit;
+ int off;
+};
+static void
+sdefl_precode(struct sdefl_symcnt *cnt, unsigned *freqs, unsigned *items,
+ const unsigned char *litlen, const unsigned char *offlen) {
+ unsigned *at = items;
+ unsigned run_start = 0;
+
+ unsigned total = 0;
+ unsigned char lens[SDEFL_SYM_MAX + SDEFL_OFF_MAX];
+ for (cnt->lit = SDEFL_SYM_MAX; cnt->lit > 257; cnt->lit--)
+ if (litlen[cnt->lit - 1]) break;
+ for (cnt->off = SDEFL_OFF_MAX; cnt->off > 1; cnt->off--)
+ if (offlen[cnt->off - 1]) break;
+
+ total = (unsigned)(cnt->lit + cnt->off);
+ memcpy(lens, litlen, sizeof(unsigned char) * cnt->lit);
+ memcpy(lens + cnt->lit, offlen, sizeof(unsigned char) * cnt->off);
+ do {
+ unsigned len = lens[run_start];
+ unsigned run_end = run_start;
+ do run_end++; while (run_end != total && len == lens[run_end]);
+ if (!len) {
+ while ((run_end - run_start) >= 11) {
+ unsigned n = (run_end - run_start) - 11;
+ unsigned xbits = n < 0x7f ? n : 0x7f;
+ freqs[18]++;
+ *at++ = 18u | (xbits << 5u);
+ run_start += 11 + xbits;
+ }
+ if ((run_end - run_start) >= 3) {
+ unsigned n = (run_end - run_start) - 3;
+ unsigned xbits = n < 0x7 ? n : 0x7;
+ freqs[17]++;
+ *at++ = 17u | (xbits << 5u);
+ run_start += 3 + xbits;
+ }
+ } else if ((run_end - run_start) >= 4) {
+ freqs[len]++;
+ *at++ = len;
+ run_start++;
+ do {
+ unsigned xbits = (run_end - run_start) - 3;
+ xbits = xbits < 0x03 ? xbits : 0x03;
+ *at++ = 16 | (xbits << 5);
+ run_start += 3 + xbits;
+ freqs[16]++;
+ } while ((run_end - run_start) >= 3);
+ }
+ while (run_start != run_end) {
+ freqs[len]++;
+ *at++ = len;
+ run_start++;
+ }
+ } while (run_start != total);
+ cnt->items = (int)(at - items);
+}
+struct sdefl_match_codes {
+ int ls, lc;
+ int dc, dx;
+};
+static void
+sdefl_match_codes(struct sdefl_match_codes *cod, int dist, int len) {
+ static const short dxmax[] = {0,6,12,24,48,96,192,384,768,1536,3072,6144,12288,24576};
+ static const unsigned char lslot[258+1] = {
+ 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12,
+ 12, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16,
+ 16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18,
+ 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20,
+ 20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
+ 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
+ 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
+ 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+ 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 25, 25, 25,
+ 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+ 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26,
+ 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+ 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+ 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+ 27, 27, 28
+ };
+ cod->ls = lslot[len];
+ cod->lc = 257 + cod->ls;
+ cod->dx = sdefl_ilog2(sdefl_npow2(dist) >> 2);
+ cod->dc = cod->dx ? ((cod->dx + 1) << 1) + (dist > dxmax[cod->dx]) : dist-1;
+}
+static void
+sdefl_match(unsigned char **dst, struct sdefl *s, int dist, int len) {
+ static const char lxn[] = {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};
+ static const short lmin[] = {3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,
+ 51,59,67,83,99,115,131,163,195,227,258};
+ static const short dmin[] = {1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,
+ 385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577};
+
+ struct sdefl_match_codes cod;
+ sdefl_match_codes(&cod, dist, len);
+ sdefl_put(dst, s, (int)s->cod.word.lit[cod.lc], s->cod.len.lit[cod.lc]);
+ sdefl_put(dst, s, len - lmin[cod.ls], lxn[cod.ls]);
+ sdefl_put(dst, s, (int)s->cod.word.off[cod.dc], s->cod.len.off[cod.dc]);
+ sdefl_put(dst, s, dist - dmin[cod.dc], cod.dx);
+}
+static void
+sdefl_flush(unsigned char **dst, struct sdefl *s, int is_last,
+ const unsigned char *in) {
+ int j, i = 0, item_cnt = 0;
+ struct sdefl_symcnt symcnt = {0};
+ unsigned codes[SDEFL_PRE_MAX];
+ unsigned char lens[SDEFL_PRE_MAX];
+ unsigned freqs[SDEFL_PRE_MAX] = {0};
+ unsigned items[SDEFL_SYM_MAX + SDEFL_OFF_MAX];
+ static const unsigned char perm[SDEFL_PRE_MAX] = {16,17,18,0,8,7,9,6,10,5,11,
+ 4,12,3,13,2,14,1,15};
+
+ /* huffman codes */
+ s->freq.lit[SDEFL_EOB]++;
+ sdefl_huff(s->cod.len.lit, s->cod.word.lit, s->freq.lit, SDEFL_SYM_MAX, SDEFL_LIT_LEN_CODES);
+ sdefl_huff(s->cod.len.off, s->cod.word.off, s->freq.off, SDEFL_OFF_MAX, SDEFL_OFF_CODES);
+ sdefl_precode(&symcnt, freqs, items, s->cod.len.lit, s->cod.len.off);
+ sdefl_huff(lens, codes, freqs, SDEFL_PRE_MAX, SDEFL_PRE_CODES);
+ for (item_cnt = SDEFL_PRE_MAX; item_cnt > 4; item_cnt--) {
+ if (lens[perm[item_cnt - 1]]) break;
+ }
+ /* block header */
+ sdefl_put(dst, s, is_last ? 0x01 : 0x00, 1); /* block */
+ sdefl_put(dst, s, 0x02, 2); /* dynamic huffman */
+ sdefl_put(dst, s, symcnt.lit - 257, 5);
+ sdefl_put(dst, s, symcnt.off - 1, 5);
+ sdefl_put(dst, s, item_cnt - 4, 4);
+ for (i = 0; i < item_cnt; ++i)
+ sdefl_put(dst, s, lens[perm[i]], 3);
+ for (i = 0; i < symcnt.items; ++i) {
+ unsigned sym = items[i] & 0x1F;
+ sdefl_put(dst, s, (int)codes[sym], lens[sym]);
+ if (sym < 16) continue;
+ if (sym == 16) sdefl_put(dst, s, items[i] >> 5, 2);
+ else if(sym == 17) sdefl_put(dst, s, items[i] >> 5, 3);
+ else sdefl_put(dst, s, items[i] >> 5, 7);
+ }
+ /* block sequences */
+ for (i = 0; i < s->seq_cnt; ++i) {
+ if (s->seq[i].off >= 0)
+ for (j = 0; j < s->seq[i].len; ++j) {
+ int c = in[s->seq[i].off + j];
+ sdefl_put(dst, s, (int)s->cod.word.lit[c], s->cod.len.lit[c]);
+ }
+ else sdefl_match(dst, s, -s->seq[i].off, s->seq[i].len);
+ }
+ sdefl_put(dst, s, (int)(s)->cod.word.lit[SDEFL_EOB], (s)->cod.len.lit[SDEFL_EOB]);
+ memset(&s->freq, 0, sizeof(s->freq));
+ s->seq_cnt = 0;
+}
+static void
+sdefl_seq(struct sdefl *s, int off, int len) {
+ assert(s->seq_cnt + 2 < SDEFL_SEQ_SIZ);
+ s->seq[s->seq_cnt].off = off;
+ s->seq[s->seq_cnt].len = len;
+ s->seq_cnt++;
+}
+static void
+sdefl_reg_match(struct sdefl *s, int off, int len) {
+ struct sdefl_match_codes cod;
+ sdefl_match_codes(&cod, off, len);
+ s->freq.lit[cod.lc]++;
+ s->freq.off[cod.dc]++;
+}
+struct sdefl_match {
+ int off;
+ int len;
+};
+static void
+sdefl_fnd(struct sdefl_match *m, const struct sdefl *s,
+ int chain_len, int max_match, const unsigned char *in, int p) {
+ int i = s->tbl[sdefl_hash32(&in[p])];
+ int limit = ((p-SDEFL_WIN_SIZ)<SDEFL_NIL)?SDEFL_NIL:(p-SDEFL_WIN_SIZ);
+ while (i > limit) {
+ if (in[i+m->len] == in[p+m->len] &&
+ (sdefl_uload32(&in[i]) == sdefl_uload32(&in[p]))){
+ int n = SDEFL_MIN_MATCH;
+ while (n < max_match && in[i+n] == in[p+n]) n++;
+ if (n > m->len) {
+ m->len = n, m->off = p - i;
+ if (n == max_match) break;
+ }
+ }
+ if (!(--chain_len)) break;
+ i = s->prv[i&SDEFL_WIN_MSK];
+ }
+}
+static int
+sdefl_compr(struct sdefl *s, unsigned char *out, const unsigned char *in,
+ int in_len, int lvl) {
+ unsigned char *q = out;
+ static const unsigned char pref[] = {8,10,14,24,30,48,65,96,130};
+ int max_chain = (lvl < 8) ? (1 << (lvl + 1)): (1 << 13);
+ int n, i = 0, litlen = 0;
+ for (n = 0; n < SDEFL_HASH_SIZ; ++n) {
+ s->tbl[n] = SDEFL_NIL;
+ }
+ do {int blk_end = i + SDEFL_BLK_MAX < in_len ? i + SDEFL_BLK_MAX : in_len;
+ while (i < blk_end) {
+ struct sdefl_match m = {0};
+ int max_match = ((in_len-i)>SDEFL_MAX_MATCH) ? SDEFL_MAX_MATCH:(in_len-i);
+ int nice_match = pref[lvl] < max_match ? pref[lvl] : max_match;
+ int run = 1, inc = 1, run_inc;
+ if (max_match > SDEFL_MIN_MATCH) {
+ sdefl_fnd(&m, s, max_chain, max_match, in, i);
+ }
+ if (lvl >= 5 && m.len >= SDEFL_MIN_MATCH && m.len < nice_match){
+ struct sdefl_match m2 = {0};
+ sdefl_fnd(&m2, s, max_chain, m.len+1, in, i+1);
+ m.len = (m2.len > m.len) ? 0 : m.len;
+ }
+ if (m.len >= SDEFL_MIN_MATCH) {
+ if (litlen) {
+ sdefl_seq(s, i - litlen, litlen);
+ litlen = 0;
+ }
+ sdefl_seq(s, -m.off, m.len);
+ sdefl_reg_match(s, m.off, m.len);
+ if (lvl < 2 && m.len >= nice_match) {
+ inc = m.len;
+ } else {
+ run = m.len;
+ }
+ } else {
+ s->freq.lit[in[i]]++;
+ litlen++;
+ }
+ run_inc = run * inc;
+ if (in_len - (i + run_inc) > SDEFL_MIN_MATCH) {
+ while (run-- > 0) {
+ unsigned h = sdefl_hash32(&in[i]);
+ s->prv[i&SDEFL_WIN_MSK] = s->tbl[h];
+ s->tbl[h] = i, i += inc;
+ }
+ } else {
+ i += run_inc;
+ }
+ }
+ if (litlen) {
+ sdefl_seq(s, i - litlen, litlen);
+ litlen = 0;
+ }
+ sdefl_flush(&q, s, blk_end == in_len, in);
+ } while (i < in_len);
+
+ if (s->bitcnt)
+ sdefl_put(&q, s, 0x00, 8 - s->bitcnt);
+ return (int)(q - out);
+}
+extern int
+sdeflate(struct sdefl *s, void *out, const void *in, int n, int lvl) {
+ s->bits = s->bitcnt = 0;
+ return sdefl_compr(s, (unsigned char*)out, (const unsigned char*)in, n, lvl);
+}
+static unsigned
+sdefl_adler32(unsigned adler32, const unsigned char *in, int in_len) {
+ #define SDEFL_ADLER_INIT (1)
+ const unsigned ADLER_MOD = 65521;
+ unsigned s1 = adler32 & 0xffff;
+ unsigned s2 = adler32 >> 16;
+ unsigned blk_len, i;
+
+ blk_len = in_len % 5552;
+ while (in_len) {
+ for (i = 0; i + 7 < blk_len; i += 8) {
+ s1 += in[0]; s2 += s1;
+ s1 += in[1]; s2 += s1;
+ s1 += in[2]; s2 += s1;
+ s1 += in[3]; s2 += s1;
+ s1 += in[4]; s2 += s1;
+ s1 += in[5]; s2 += s1;
+ s1 += in[6]; s2 += s1;
+ s1 += in[7]; s2 += s1;
+ in += 8;
+ }
+ for (; i < blk_len; ++i) {
+ s1 += *in++, s2 += s1;
+ }
+ s1 %= ADLER_MOD;
+ s2 %= ADLER_MOD;
+ in_len -= blk_len;
+ blk_len = 5552;
+ }
+ return (unsigned)(s2 << 16) + (unsigned)s1;
+}
+extern int
+zsdeflate(struct sdefl *s, void *out, const void *in, int n, int lvl) {
+ int p = 0;
+ unsigned a = 0;
+ unsigned char *q = (unsigned char*)out;
+
+ s->bits = s->bitcnt = 0;
+ sdefl_put(&q, s, 0x78, 8); /* deflate, 32k window */
+ sdefl_put(&q, s, 0x01, 8); /* fast compression */
+ q += sdefl_compr(s, q, (const unsigned char*)in, n, lvl);
+
+ /* append adler checksum */
+ a = sdefl_adler32(SDEFL_ADLER_INIT, (const unsigned char*)in, n);
+ for (p = 0; p < 4; ++p) {
+ sdefl_put(&q, s, (a >> 24) & 0xFF, 8);
+ a <<= 8;
+ }
+ return (int)(q - (unsigned char*)out);
+}
+extern int
+sdefl_bound(int len) {
+ int a = 128 + (len * 110) / 100;
+ int b = 128 + len + ((len / (31 * 1024)) + 1) * 5;
+ return (a > b) ? a : b;
+}
+#endif /* SDEFL_IMPLEMENTATION */
+
projects / pistorm / blobdiff