1 | /* |
1 | /* |
2 | * Copyright (c) 2000-2005 Marc Alexander Lehmann <schmorp@schmorp.de> |
2 | * Copyright (c) 2000-2010,2012 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 | * |
13 | * |
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 | * |
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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- |
21 | * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
18 | * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
… | |
… | |
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)) |
42 | |
40 | |
43 | /* |
41 | /* |
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 | * the data format is not dependent on the hash function. |
46 | * the hashing function might seem strange, just believe me |
44 | * the hash function might seem strange, just believe me, |
47 | * it works ;) |
45 | * it works ;) |
48 | */ |
46 | */ |
49 | #ifndef FRST |
47 | #ifndef FRST |
50 | # define FRST(p) (((p[0]) << 8) | p[1]) |
48 | # define FRST(p) (((p[0]) << 8) | p[1]) |
51 | # define NEXT(v,p) (((v) << 8) | p[2]) |
49 | # define NEXT(v,p) (((v) << 8) | p[2]) |
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50 | # if MULTIPLICATION_IS_SLOW |
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51 | # if ULTRA_FAST |
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52 | # define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1)) |
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53 | # elif VERY_FAST |
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54 | # define IDX(h) ((( h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
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55 | # else |
52 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
56 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
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57 | # endif |
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58 | # else |
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59 | /* this one was developed with sesse, |
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60 | * and is very similar to the one in snappy. |
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61 | * it does need a modern enough cpu with a fast multiplication. |
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62 | */ |
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63 | # define IDX(h) (((h * 0x1e35a7bdU) >> (32 - HLOG - 8)) & (HSIZE - 1)) |
53 | #endif |
64 | # endif |
54 | /* |
65 | #endif |
55 | * IDX works because it is very similar to a multiplicative hash, e.g. |
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56 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
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57 | * the latter is also quite fast on newer CPUs, and sligthly better |
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58 | * |
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59 | * the next one is also quite good, albeit slow ;) |
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60 | * (int)(cos(h & 0xffffff) * 1e6) |
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61 | */ |
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62 | |
66 | |
63 | #if 0 |
67 | #if 0 |
64 | /* original lzv-like hash function, much worse and thus slower */ |
68 | /* original lzv-like hash function, much worse and thus slower */ |
65 | # define FRST(p) (p[0] << 5) ^ p[1] |
69 | # define FRST(p) (p[0] << 5) ^ p[1] |
66 | # define NEXT(v,p) ((v) << 5) ^ p[2] |
70 | # define NEXT(v,p) ((v) << 5) ^ p[2] |
67 | # define IDX(h) ((h) & (HSIZE - 1)) |
71 | # define IDX(h) ((h) & (HSIZE - 1)) |
68 | #endif |
72 | #endif |
69 | |
73 | |
70 | #define MAX_LIT (1 << 5) |
74 | #if __GNUC__ >= 3 |
71 | #define MAX_OFF (1 << 13) |
75 | # define expect(expr,value) __builtin_expect ((expr),(value)) |
72 | #define MAX_REF ((1 << 8) + (1 << 3)) |
76 | # define inline inline |
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77 | #else |
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78 | # define expect(expr,value) (expr) |
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79 | # define inline static |
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80 | #endif |
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81 | |
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82 | #define expect_false(expr) expect ((expr) != 0, 0) |
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83 | #define expect_true(expr) expect ((expr) != 0, 1) |
73 | |
84 | |
74 | /* |
85 | /* |
75 | * compressed format |
86 | * compressed format |
76 | * |
87 | * |
77 | * 000LLLLL <L+1> ; literal |
88 | * 000LLLLL <L+1> ; literal, L+1=1..33 octets |
78 | * LLLooooo oooooooo ; backref L |
89 | * LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset |
79 | * 111ooooo LLLLLLLL oooooooo ; backref L+7 |
90 | * 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset |
80 | * |
91 | * |
81 | */ |
92 | */ |
82 | |
93 | |
83 | unsigned int |
94 | unsigned int |
84 | lzf_compress (const void *const in_data, unsigned int in_len, |
95 | lzf_compress (const void *const in_data, unsigned int in_len, |
… | |
… | |
89 | ) |
100 | ) |
90 | { |
101 | { |
91 | #if !LZF_STATE_ARG |
102 | #if !LZF_STATE_ARG |
92 | LZF_STATE htab; |
103 | LZF_STATE htab; |
93 | #endif |
104 | #endif |
94 | const u8 **hslot; |
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95 | const u8 *ip = (const u8 *)in_data; |
105 | const u8 *ip = (const u8 *)in_data; |
96 | u8 *op = (u8 *)out_data; |
106 | u8 *op = (u8 *)out_data; |
97 | const u8 *in_end = ip + in_len; |
107 | const u8 *in_end = ip + in_len; |
98 | u8 *out_end = op + out_len; |
108 | u8 *out_end = op + out_len; |
99 | const u8 *ref; |
109 | const u8 *ref; |
100 | |
110 | |
101 | unsigned int hval = FRST (ip); |
111 | /* off requires a type wide enough to hold a general pointer difference. |
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112 | * ISO C doesn't have that (size_t might not be enough and ptrdiff_t only |
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113 | * works for differences within a single object). We also assume that |
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114 | * no bit pattern traps. Since the only platform that is both non-POSIX |
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115 | * and fails to support both assumptions is windows 64 bit, we make a |
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116 | * special workaround for it. |
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117 | */ |
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118 | #if defined (_WIN32) && defined (_M_X64) |
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119 | /* workaround for missing POSIX compliance */ |
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120 | #if __GNUC__ |
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121 | unsigned long long off; |
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122 | #else |
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123 | unsigned __int64 off; |
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124 | #endif |
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125 | #else |
102 | unsigned long off; |
126 | unsigned long off; |
103 | 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; |
104 | |
133 | |
105 | #if INIT_HTAB |
134 | #if INIT_HTAB |
106 | # if USE_MEMCPY |
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107 | memset (htab, 0, sizeof (htab)); |
135 | memset (htab, 0, sizeof (LZF_STATE)); |
108 | # else |
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109 | for (hslot = htab; hslot < htab + HSIZE; hslot++) |
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110 | *hslot++ = ip; |
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111 | # endif |
136 | #endif |
112 | #endif |
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113 | |
137 | |
114 | for (;;) |
138 | lit = 0; op++; /* start run */ |
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139 | |
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140 | hval = FRST (ip); |
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141 | while (ip < in_end - 2) |
115 | { |
142 | { |
116 | if (ip < in_end - 2) |
143 | LZF_HSLOT *hslot; |
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144 | |
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145 | hval = NEXT (hval, ip); |
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146 | hslot = htab + IDX (hval); |
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147 | ref = *hslot + LZF_HSLOT_BIAS; *hslot = ip - LZF_HSLOT_BIAS; |
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148 | |
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149 | if (1 |
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150 | #if INIT_HTAB |
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151 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
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152 | #endif |
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153 | && (off = ip - ref - 1) < LZF_MAX_OFF |
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154 | && ref > (u8 *)in_data |
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155 | && ref[2] == ip[2] |
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156 | #if STRICT_ALIGN |
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157 | && ((ref[1] << 8) | ref[0]) == ((ip[1] << 8) | ip[0]) |
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158 | #else |
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159 | && *(u16 *)ref == *(u16 *)ip |
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160 | #endif |
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161 | ) |
117 | { |
162 | { |
118 | hval = NEXT (hval, ip); |
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119 | hslot = htab + IDX (hval); |
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120 | ref = *hslot; *hslot = ip; |
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121 | |
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122 | if (1 |
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123 | #if INIT_HTAB && !USE_MEMCPY |
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124 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
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125 | #endif |
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126 | && (off = ip - ref - 1) < MAX_OFF |
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127 | && ip + 4 < in_end |
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128 | && ref > (u8 *)in_data |
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129 | #if STRICT_ALIGN |
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130 | && ref[0] == ip[0] |
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131 | && ref[1] == ip[1] |
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132 | && ref[2] == ip[2] |
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133 | #else |
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134 | && *(u16 *)ref == *(u16 *)ip |
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135 | && ref[2] == ip[2] |
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136 | #endif |
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137 | ) |
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138 | { |
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139 | /* match found at *ref++ */ |
163 | /* match found at *ref++ */ |
140 | unsigned int len = 2; |
164 | unsigned int len = 2; |
141 | unsigned int maxlen = in_end - ip - len; |
165 | unsigned int maxlen = in_end - ip - len; |
142 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
166 | maxlen = maxlen > LZF_MAX_REF ? LZF_MAX_REF : maxlen; |
143 | |
167 | |
144 | if (op + lit + 1 + 3 >= out_end) |
168 | if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */ |
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169 | if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */ |
145 | return 0; |
170 | return 0; |
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171 | |
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172 | op [- lit - 1] = lit - 1; /* stop run */ |
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173 | op -= !lit; /* undo run if length is zero */ |
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174 | |
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175 | for (;;) |
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176 | { |
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177 | if (expect_true (maxlen > 16)) |
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178 | { |
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179 | len++; if (ref [len] != ip [len]) break; |
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180 | len++; if (ref [len] != ip [len]) break; |
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181 | len++; if (ref [len] != ip [len]) break; |
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182 | len++; if (ref [len] != ip [len]) break; |
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183 | |
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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 | len++; if (ref [len] != ip [len]) break; |
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188 | |
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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 | len++; if (ref [len] != ip [len]) break; |
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193 | |
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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 | len++; if (ref [len] != ip [len]) break; |
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198 | } |
146 | |
199 | |
147 | do |
200 | do |
148 | len++; |
201 | len++; |
149 | while (len < maxlen && ref[len] == ip[len]); |
202 | while (len < maxlen && ref[len] == ip[len]); |
150 | |
203 | |
151 | if (lit) |
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152 | { |
204 | break; |
153 | *op++ = lit - 1; |
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154 | lit = -lit; |
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155 | do |
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156 | *op++ = ip[lit]; |
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157 | while (++lit); |
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158 | } |
205 | } |
159 | |
206 | |
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207 | len -= 2; /* len is now #octets - 1 */ |
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208 | ip++; |
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209 | |
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210 | if (len < 7) |
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211 | { |
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212 | *op++ = (off >> 8) + (len << 5); |
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213 | } |
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214 | else |
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215 | { |
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216 | *op++ = (off >> 8) + ( 7 << 5); |
160 | len -= 2; |
217 | *op++ = len - 7; |
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218 | } |
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219 | |
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220 | *op++ = off; |
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221 | |
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222 | lit = 0; op++; /* start run */ |
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223 | |
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224 | ip += len + 1; |
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225 | |
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226 | if (expect_false (ip >= in_end - 2)) |
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227 | break; |
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228 | |
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229 | #if ULTRA_FAST || VERY_FAST |
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230 | --ip; |
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231 | # if VERY_FAST && !ULTRA_FAST |
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232 | --ip; |
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233 | # endif |
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234 | hval = FRST (ip); |
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235 | |
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236 | hval = NEXT (hval, ip); |
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237 | htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; |
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238 | ip++; |
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239 | |
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240 | # if VERY_FAST && !ULTRA_FAST |
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241 | hval = NEXT (hval, ip); |
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242 | htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; |
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243 | ip++; |
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244 | # endif |
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245 | #else |
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246 | ip -= len + 1; |
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247 | |
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248 | do |
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249 | { |
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250 | hval = NEXT (hval, ip); |
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251 | htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; |
161 | ip++; |
252 | ip++; |
162 | |
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163 | if (len < 7) |
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164 | { |
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165 | *op++ = (off >> 8) + (len << 5); |
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166 | } |
253 | } |
167 | else |
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168 | { |
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169 | *op++ = (off >> 8) + ( 7 << 5); |
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170 | *op++ = len - 7; |
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171 | } |
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172 | |
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173 | *op++ = off; |
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174 | |
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175 | #if ULTRA_FAST || VERY_FAST |
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176 | ip += len; |
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177 | #if VERY_FAST && !ULTRA_FAST |
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178 | --ip; |
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179 | #endif |
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180 | hval = FRST (ip); |
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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 | |
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186 | #if VERY_FAST && !ULTRA_FAST |
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187 | hval = NEXT (hval, ip); |
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188 | htab[IDX (hval)] = ip; |
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189 | ip++; |
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190 | #endif |
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191 | #else |
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192 | do |
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193 | { |
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194 | hval = NEXT (hval, ip); |
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195 | htab[IDX (hval)] = ip; |
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196 | ip++; |
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197 | } |
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198 | while (len--); |
254 | while (len--); |
199 | #endif |
255 | #endif |
200 | continue; |
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201 | } |
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202 | } |
256 | } |
203 | else if (ip == in_end) |
257 | else |
204 | break; |
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205 | |
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206 | /* one more literal byte we must copy */ |
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207 | lit++; |
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208 | ip++; |
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209 | |
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210 | if (lit == MAX_LIT) |
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211 | { |
258 | { |
212 | if (op + 1 + MAX_LIT >= out_end) |
259 | /* one more literal byte we must copy */ |
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260 | if (expect_false (op >= out_end)) |
213 | return 0; |
261 | return 0; |
214 | |
262 | |
215 | *op++ = MAX_LIT - 1; |
263 | lit++; *op++ = *ip++; |
216 | #if USE_MEMCPY |
264 | |
217 | memcpy (op, ip - MAX_LIT, MAX_LIT); |
265 | if (expect_false (lit == LZF_MAX_LIT)) |
218 | op += MAX_LIT; |
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219 | lit = 0; |
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220 | #else |
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221 | lit = -lit; |
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222 | do |
266 | { |
223 | *op++ = ip[lit]; |
267 | op [- lit - 1] = lit - 1; /* stop run */ |
224 | while (++lit); |
268 | lit = 0; op++; /* start run */ |
225 | #endif |
269 | } |
226 | } |
270 | } |
227 | } |
271 | } |
228 | |
272 | |
229 | if (lit) |
273 | if (op + 3 > out_end) /* at most 3 bytes can be missing here */ |
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274 | return 0; |
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275 | |
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276 | while (ip < in_end) |
230 | { |
277 | { |
231 | if (op + lit + 1 >= out_end) |
278 | lit++; *op++ = *ip++; |
232 | return 0; |
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233 | |
279 | |
234 | *op++ = lit - 1; |
280 | if (expect_false (lit == LZF_MAX_LIT)) |
235 | lit = -lit; |
281 | { |
236 | do |
282 | op [- lit - 1] = lit - 1; /* stop run */ |
237 | *op++ = ip[lit]; |
283 | lit = 0; op++; /* start run */ |
238 | while (++lit); |
284 | } |
239 | } |
285 | } |
240 | |
286 | |
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287 | op [- lit - 1] = lit - 1; /* end run */ |
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288 | op -= !lit; /* undo run if length is zero */ |
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289 | |
241 | return op - (u8 *) out_data; |
290 | return op - (u8 *)out_data; |
242 | } |
291 | } |
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292 | |