1 | /* |
1 | /* |
2 | * Copyright (c) 2000-2005 Marc Alexander Lehmann <schmorp@schmorp.de> |
2 | * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de> |
3 | * |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without modifica- |
4 | * Redistribution and use in source and binary forms, with or without modifica- |
5 | * tion, are permitted provided that the following conditions are met: |
5 | * tion, are permitted provided that the following conditions are met: |
6 | * |
6 | * |
7 | * 1. Redistributions of source code must retain the above copyright notice, |
7 | * 1. Redistributions of source code must retain the above copyright notice, |
8 | * this list of conditions and the following disclaimer. |
8 | * this list of conditions and the following disclaimer. |
9 | * |
9 | * |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
11 | * notice, this list of conditions and the following disclaimer in the |
11 | * notice, this list of conditions and the following disclaimer in the |
12 | * documentation and/or other materials provided with the distribution. |
12 | * documentation and/or other materials provided with the distribution. |
13 | * |
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14 | * 3. The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
13 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
18 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- |
15 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- |
19 | * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
16 | * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
20 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- |
17 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- |
… | |
… | |
24 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- |
21 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- |
25 | * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
22 | * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
26 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
23 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | * |
24 | * |
28 | * Alternatively, the contents of this file may be used under the terms of |
25 | * Alternatively, the contents of this file may be used under the terms of |
29 | * the GNU General Public License version 2 (the "GPL"), in which case the |
26 | * the GNU General Public License ("GPL") version 2 or any later version, |
30 | * provisions of the GPL are applicable instead of the above. If you wish to |
27 | * in which case the provisions of the GPL are applicable instead of |
31 | * allow the use of your version of this file only under the terms of the |
28 | * the above. If you wish to allow the use of your version of this file |
32 | * GPL and not to allow others to use your version of this file under the |
29 | * only under the terms of the GPL and not to allow others to use your |
33 | * BSD license, indicate your decision by deleting the provisions above and |
30 | * version of this file under the BSD license, indicate your decision |
34 | * replace them with the notice and other provisions required by the GPL. If |
31 | * by deleting the provisions above and replace them with the notice |
35 | * you do not delete the provisions above, a recipient may use your version |
32 | * and other provisions required by the GPL. If you do not delete the |
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33 | * provisions above, a recipient may use your version of this file under |
36 | * of this file under either the BSD or the GPL. |
34 | * either the BSD or the GPL. |
37 | */ |
35 | */ |
38 | |
36 | |
39 | #include "lzfP.h" |
37 | #include "lzfP.h" |
40 | |
38 | |
41 | #define HSIZE (1 << (HLOG)) |
39 | #define HSIZE (1 << (HLOG)) |
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44 | * don't play with this unless you benchmark! |
42 | * don't play with this unless you benchmark! |
45 | * decompression is not dependent on the hash function |
43 | * decompression is not dependent on the hash function |
46 | * the hashing function might seem strange, just believe me |
44 | * the hashing function might seem strange, just believe me |
47 | * it works ;) |
45 | * it works ;) |
48 | */ |
46 | */ |
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47 | #ifndef FRST |
49 | #define FRST(p) (((p[0]) << 8) + p[1]) |
48 | # define FRST(p) (((p[0]) << 8) | p[1]) |
50 | #define NEXT(v,p) (((v) << 8) + p[2]) |
49 | # define NEXT(v,p) (((v) << 8) | p[2]) |
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50 | # if ULTRA_FAST |
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51 | # define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1)) |
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52 | # elif VERY_FAST |
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53 | # define IDX(h) ((( h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
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54 | # else |
51 | #define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
55 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
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56 | # endif |
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57 | #endif |
52 | /* |
58 | /* |
53 | * IDX works because it is very similar to a multiplicative hash, e.g. |
59 | * IDX works because it is very similar to a multiplicative hash, e.g. |
54 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
60 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
55 | * the latter is also quite fast on newer CPUs, and sligthly better |
61 | * the latter is also quite fast on newer CPUs, and compresses similarly. |
56 | * |
62 | * |
57 | * the next one is also quite good, albeit slow ;) |
63 | * the next one is also quite good, albeit slow ;) |
58 | * (int)(cos(h & 0xffffff) * 1e6) |
64 | * (int)(cos(h & 0xffffff) * 1e6) |
59 | */ |
65 | */ |
60 | |
66 | |
… | |
… | |
65 | # define IDX(h) ((h) & (HSIZE - 1)) |
71 | # define IDX(h) ((h) & (HSIZE - 1)) |
66 | #endif |
72 | #endif |
67 | |
73 | |
68 | #define MAX_LIT (1 << 5) |
74 | #define MAX_LIT (1 << 5) |
69 | #define MAX_OFF (1 << 13) |
75 | #define MAX_OFF (1 << 13) |
70 | #define MAX_REF ((1 << 8) + (1 << 3)) |
76 | #define MAX_REF ((1 << 8) + (1 << 3)) |
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77 | |
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78 | #if __GNUC__ >= 3 |
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79 | # define expect(expr,value) __builtin_expect ((expr),(value)) |
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80 | # define inline inline |
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81 | #else |
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82 | # define expect(expr,value) (expr) |
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83 | # define inline static |
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84 | #endif |
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85 | |
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86 | #define expect_false(expr) expect ((expr) != 0, 0) |
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87 | #define expect_true(expr) expect ((expr) != 0, 1) |
71 | |
88 | |
72 | /* |
89 | /* |
73 | * compressed format |
90 | * compressed format |
74 | * |
91 | * |
75 | * 000LLLLL <L+1> ; literal |
92 | * 000LLLLL <L+1> ; literal |
76 | * LLLOOOOO oooooooo ; backref L |
93 | * LLLooooo oooooooo ; backref L |
77 | * 111OOOOO LLLLLLLL oooooooo ; backref L+7 |
94 | * 111ooooo LLLLLLLL oooooooo ; backref L+7 |
78 | * |
95 | * |
79 | */ |
96 | */ |
80 | |
97 | |
81 | unsigned int |
98 | unsigned int |
82 | lzf_compress (const void *const in_data, unsigned int in_len, |
99 | lzf_compress (const void *const in_data, unsigned int in_len, |
83 | void *out_data, unsigned int out_len |
100 | void *out_data, unsigned int out_len |
84 | #if LZF_STATE_ARG |
101 | #if LZF_STATE_ARG |
85 | , LZF_STATE *htab |
102 | , LZF_STATE htab |
86 | #endif |
103 | #endif |
87 | ) |
104 | ) |
88 | { |
105 | { |
89 | #if !LZF_STATE_ARG |
106 | #if !LZF_STATE_ARG |
90 | LZF_STATE htab; |
107 | LZF_STATE htab; |
… | |
… | |
94 | u8 *op = (u8 *)out_data; |
111 | u8 *op = (u8 *)out_data; |
95 | const u8 *in_end = ip + in_len; |
112 | const u8 *in_end = ip + in_len; |
96 | u8 *out_end = op + out_len; |
113 | u8 *out_end = op + out_len; |
97 | const u8 *ref; |
114 | const u8 *ref; |
98 | |
115 | |
99 | unsigned int hval = FRST (ip); |
116 | /* off requires a type wide enough to hold a general pointer difference. |
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117 | * ISO C doesn't have that (size_t might not be enough and ptrdiff_t only |
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118 | * works for differences within a single object). We also assume that no |
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119 | * no bit pattern traps. Since the only platform that is both non-POSIX |
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120 | * and fails to support both assumptions is windows 64 bit, we make a |
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121 | * special workaround for it. |
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122 | */ |
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123 | #if defined (WIN32) && defined (_M_X64) |
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124 | unsigned _int64 off; /* workaround for missing POSIX compliance */ |
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125 | #else |
100 | unsigned long off; |
126 | unsigned long off; |
101 | int lit = 0; |
127 | #endif |
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128 | unsigned int hval; |
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129 | int lit; |
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130 | |
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131 | if (!in_len || !out_len) |
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132 | return 0; |
102 | |
133 | |
103 | #if INIT_HTAB |
134 | #if INIT_HTAB |
104 | # if USE_MEMCPY |
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105 | memset (htab, 0, sizeof (htab)); |
135 | memset (htab, 0, sizeof (htab)); |
106 | # else |
136 | # if 0 |
107 | for (hslot = htab; hslot < htab + HSIZE; hslot++) |
137 | for (hslot = htab; hslot < htab + HSIZE; hslot++) |
108 | *hslot++ = ip; |
138 | *hslot++ = ip; |
109 | # endif |
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110 | #endif |
139 | # endif |
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140 | #endif |
111 | |
141 | |
112 | for (;;) |
142 | lit = 0; op++; /* start run */ |
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143 | |
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144 | hval = FRST (ip); |
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145 | while (ip < in_end - 2) |
113 | { |
146 | { |
114 | if (ip < in_end - 2) |
147 | hval = NEXT (hval, ip); |
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148 | hslot = htab + IDX (hval); |
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149 | ref = *hslot; *hslot = ip; |
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150 | |
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151 | if (1 |
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152 | #if INIT_HTAB |
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153 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
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154 | #endif |
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155 | && (off = ip - ref - 1) < MAX_OFF |
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156 | && ip + 4 < in_end |
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157 | && ref > (u8 *)in_data |
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158 | #if STRICT_ALIGN |
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159 | && ref[0] == ip[0] |
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160 | && ref[1] == ip[1] |
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161 | && ref[2] == ip[2] |
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162 | #else |
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163 | && *(u16 *)ref == *(u16 *)ip |
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164 | && ref[2] == ip[2] |
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165 | #endif |
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166 | ) |
115 | { |
167 | { |
116 | hval = NEXT (hval, ip); |
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117 | hslot = htab + IDX (hval); |
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118 | ref = *hslot; *hslot = ip; |
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119 | |
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120 | if (1 |
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121 | #if INIT_HTAB && !USE_MEMCPY |
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122 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
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123 | #endif |
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124 | && (off = ip - ref - 1) < MAX_OFF |
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125 | && ip + 4 < in_end |
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126 | && ref > (u8 *)in_data |
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127 | #if STRICT_ALIGN |
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128 | && ref[0] == ip[0] |
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129 | && ref[1] == ip[1] |
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130 | && ref[2] == ip[2] |
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131 | #else |
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132 | && *(u16 *)ref == *(u16 *)ip |
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133 | && ref[2] == ip[2] |
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134 | #endif |
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135 | ) |
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136 | { |
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137 | /* match found at *ref++ */ |
168 | /* match found at *ref++ */ |
138 | unsigned int len = 2; |
169 | unsigned int len = 2; |
139 | unsigned int maxlen = in_end - ip - len; |
170 | unsigned int maxlen = in_end - ip - len; |
140 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
171 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
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172 | |
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173 | op [- lit - 1] = lit - 1; /* stop run */ |
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174 | op -= !lit; /* undo run if length is zero */ |
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175 | |
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176 | if (expect_false (op + 3 + 1 >= out_end)) |
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177 | return 0; |
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178 | |
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179 | for (;;) |
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180 | { |
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181 | if (expect_true (maxlen > 16)) |
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182 | { |
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183 | len++; if (ref [len] != ip [len]) break; |
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184 | len++; if (ref [len] != ip [len]) break; |
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185 | len++; if (ref [len] != ip [len]) break; |
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186 | len++; if (ref [len] != ip [len]) break; |
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187 | |
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188 | len++; if (ref [len] != ip [len]) break; |
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189 | len++; if (ref [len] != ip [len]) break; |
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190 | len++; if (ref [len] != ip [len]) break; |
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191 | len++; if (ref [len] != ip [len]) break; |
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192 | |
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193 | len++; if (ref [len] != ip [len]) break; |
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194 | len++; if (ref [len] != ip [len]) break; |
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195 | len++; if (ref [len] != ip [len]) break; |
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196 | len++; if (ref [len] != ip [len]) break; |
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197 | |
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198 | len++; if (ref [len] != ip [len]) break; |
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199 | len++; if (ref [len] != ip [len]) break; |
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200 | len++; if (ref [len] != ip [len]) break; |
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201 | len++; if (ref [len] != ip [len]) break; |
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202 | } |
141 | |
203 | |
142 | do |
204 | do |
143 | len++; |
205 | len++; |
144 | while (len < maxlen && ref[len] == ip[len]); |
206 | while (len < maxlen && ref[len] == ip[len]); |
145 | |
207 | |
146 | if (op + lit + 1 + 3 >= out_end) |
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147 | return 0; |
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148 | |
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149 | if (lit) |
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150 | { |
208 | break; |
151 | *op++ = lit - 1; |
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152 | lit = -lit; |
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153 | do |
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154 | *op++ = ip[lit]; |
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155 | while (++lit); |
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156 | } |
209 | } |
157 | |
210 | |
158 | len -= 2; |
211 | len -= 2; /* len is now #octets - 1 */ |
159 | ip++; |
212 | ip++; |
160 | |
213 | |
161 | if (len < 7) |
214 | if (len < 7) |
162 | { |
215 | { |
163 | *op++ = (off >> 8) + (len << 5); |
216 | *op++ = (off >> 8) + (len << 5); |
164 | } |
217 | } |
165 | else |
218 | else |
166 | { |
219 | { |
167 | *op++ = (off >> 8) + ( 7 << 5); |
220 | *op++ = (off >> 8) + ( 7 << 5); |
168 | *op++ = len - 7; |
221 | *op++ = len - 7; |
169 | } |
222 | } |
170 | |
223 | |
171 | *op++ = off; |
224 | *op++ = off; |
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225 | lit = 0; op++; /* start run */ |
172 | |
226 | |
173 | #if ULTRA_FAST |
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174 | ip += len; |
227 | ip += len + 1; |
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228 | |
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229 | if (expect_false (ip > in_end - 2)) |
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230 | break; |
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231 | |
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232 | #if ULTRA_FAST || VERY_FAST |
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233 | --ip; |
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234 | # if VERY_FAST && !ULTRA_FAST |
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235 | --ip; |
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236 | # endif |
175 | hval = FRST (ip); |
237 | hval = FRST (ip); |
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238 | |
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239 | hval = NEXT (hval, ip); |
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240 | htab[IDX (hval)] = ip; |
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241 | ip++; |
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242 | |
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243 | # if VERY_FAST && !ULTRA_FAST |
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244 | hval = NEXT (hval, ip); |
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245 | htab[IDX (hval)] = ip; |
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246 | ip++; |
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247 | # endif |
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248 | #else |
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249 | ip -= len + 1; |
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250 | |
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251 | do |
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252 | { |
176 | hval = NEXT (hval, ip); |
253 | hval = NEXT (hval, ip); |
177 | htab[IDX (hval)] = ip; |
254 | htab[IDX (hval)] = ip; |
178 | ip++; |
255 | ip++; |
179 | #else |
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180 | do |
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181 | { |
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182 | hval = NEXT (hval, ip); |
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183 | htab[IDX (hval)] = ip; |
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184 | ip++; |
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185 | } |
256 | } |
186 | while (len--); |
257 | while (len--); |
187 | #endif |
258 | #endif |
188 | continue; |
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189 | } |
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190 | } |
259 | } |
191 | else if (ip == in_end) |
260 | else |
192 | break; |
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193 | |
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194 | /* one more literal byte we must copy */ |
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195 | lit++; |
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196 | ip++; |
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197 | |
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198 | if (lit == MAX_LIT) |
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199 | { |
261 | { |
200 | if (op + 1 + MAX_LIT >= out_end) |
262 | /* one more literal byte we must copy */ |
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263 | if (expect_false (op >= out_end)) |
201 | return 0; |
264 | return 0; |
202 | |
265 | |
203 | *op++ = MAX_LIT - 1; |
266 | lit++; *op++ = *ip++; |
204 | #if USE_MEMCPY |
267 | |
205 | memcpy (op, ip - MAX_LIT, MAX_LIT); |
268 | if (expect_false (lit == MAX_LIT)) |
206 | op += MAX_LIT; |
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207 | lit = 0; |
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208 | #else |
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209 | lit = -lit; |
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210 | do |
269 | { |
211 | *op++ = ip[lit]; |
270 | op [- lit - 1] = lit - 1; /* stop run */ |
212 | while (++lit); |
271 | lit = 0; op++; /* start run */ |
213 | #endif |
272 | } |
214 | } |
273 | } |
215 | } |
274 | } |
216 | |
275 | |
217 | if (lit) |
276 | if (op + 3 > out_end) /* at most 3 bytes can be missing here */ |
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277 | return 0; |
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278 | |
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279 | while (ip < in_end) |
218 | { |
280 | { |
219 | if (op + lit + 1 >= out_end) |
281 | lit++; *op++ = *ip++; |
220 | return 0; |
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221 | |
282 | |
222 | *op++ = lit - 1; |
283 | if (expect_false (lit == MAX_LIT)) |
223 | lit = -lit; |
284 | { |
224 | do |
285 | op [- lit - 1] = lit - 1; /* stop run */ |
225 | *op++ = ip[lit]; |
286 | lit = 0; op++; /* start run */ |
226 | while (++lit); |
287 | } |
227 | } |
288 | } |
228 | |
289 | |
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290 | op [- lit - 1] = lit - 1; /* end run */ |
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291 | op -= !lit; /* undo run if length is zero */ |
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292 | |
229 | return op - (u8 *) out_data; |
293 | return op - (u8 *)out_data; |
230 | } |
294 | } |
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295 | |