1 | /* |
1 | /* |
2 | * Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com> |
2 | * Copyright (c) 2000-2010 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- |
… | |
… | |
22 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
19 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
23 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
20 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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. |
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24 | * |
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25 | * Alternatively, the contents of this file may be used under the terms of |
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26 | * the GNU General Public License ("GPL") version 2 or any later version, |
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27 | * in which case the provisions of the GPL are applicable instead of |
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28 | * the above. If you wish to allow the use of your version of this file |
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29 | * only under the terms of the GPL and not to allow others to use your |
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30 | * version of this file under the BSD license, indicate your decision |
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31 | * by deleting the provisions above and replace them with the notice |
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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 |
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34 | * either the BSD or the GPL. |
27 | */ |
35 | */ |
28 | |
36 | |
29 | #include "lzfP.h" |
37 | #include "lzfP.h" |
30 | |
38 | |
31 | #define HSIZE (1 << (HLOG)) |
39 | #define HSIZE (1 << (HLOG)) |
32 | |
40 | |
33 | /* |
41 | /* |
34 | * don't play with this unless you benchmark! |
42 | * don't play with this unless you benchmark! |
35 | * decompression is not dependent on the hash function |
43 | * the data format is not dependent on the hash function. |
36 | * the hashing function might seem strange, just believe me |
44 | * the hash function might seem strange, just believe me, |
37 | * it works ;) |
45 | * it works ;) |
38 | */ |
46 | */ |
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47 | #ifndef FRST |
39 | #define FRST(p) (((p[0]) << 8) + p[1]) |
48 | # define FRST(p) (((p[0]) << 8) | p[1]) |
40 | #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 |
41 | #define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) + h*3) & (HSIZE - 1)) |
56 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
42 | /* |
57 | # endif |
43 | * IDX works because it is very similar to a multiplicative hash, e.g. |
58 | # else |
44 | * (h * 57321 >> (3*8 - HLOG)) |
59 | /* this one was developed with sesse, |
45 | * the next one is also quite good, albeit slow ;) |
60 | * and is very similar to the one in snappy. |
46 | * (int)(cos(h & 0xffffff) * 1e6) |
61 | * it does need a modern enough cpu with a fast multiplication. |
47 | */ |
62 | */ |
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63 | # define IDX(h) (((h * 0x1e35a7bdU) >> (32 - HLOG - 8)) & (HSIZE - 1)) |
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64 | # endif |
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65 | #endif |
48 | |
66 | |
49 | #if 0 |
67 | #if 0 |
50 | /* original lzv-like hash function */ |
68 | /* original lzv-like hash function, much worse and thus slower */ |
51 | # define FRST(p) (p[0] << 5) ^ p[1] |
69 | # define FRST(p) (p[0] << 5) ^ p[1] |
52 | # define NEXT(v,p) ((v) << 5) ^ p[2] |
70 | # define NEXT(v,p) ((v) << 5) ^ p[2] |
53 | # define IDX(h) ((h) & (HSIZE - 1)) |
71 | # define IDX(h) ((h) & (HSIZE - 1)) |
54 | #endif |
72 | #endif |
55 | |
73 | |
56 | #define MAX_LIT (1 << 5) |
74 | #define MAX_LIT (1 << 5) |
57 | #define MAX_OFF (1 << 13) |
75 | #define MAX_OFF (1 << 13) |
58 | #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) |
59 | |
88 | |
60 | /* |
89 | /* |
61 | * compressed format |
90 | * compressed format |
62 | * |
91 | * |
63 | * 000LLLLL <L+1> ; literal |
92 | * 000LLLLL <L+1> ; literal, L+1=1..33 octets |
64 | * LLLOOOOO oooooooo ; backref L |
93 | * LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset |
65 | * 111OOOOO LLLLLLLL oooooooo ; backref L+7 |
94 | * 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset |
66 | * |
95 | * |
67 | */ |
96 | */ |
68 | |
97 | |
69 | unsigned int |
98 | unsigned int |
70 | lzf_compress (const void *const in_data, unsigned int in_len, |
99 | lzf_compress (const void *const in_data, unsigned int in_len, |
71 | void *out_data, unsigned int out_len |
100 | void *out_data, unsigned int out_len |
72 | #if !LZF_STATE_ARG |
101 | #if LZF_STATE_ARG |
73 | , LZF_STATE *htab |
102 | , LZF_STATE htab |
74 | #endif |
103 | #endif |
75 | ) |
104 | ) |
76 | { |
105 | { |
77 | #if LZF_STATE_ARG |
106 | #if !LZF_STATE_ARG |
78 | LZF_STATE htab; |
107 | LZF_STATE htab; |
79 | #endif |
108 | #endif |
80 | const u8 **hslot; |
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81 | const u8 *ip = (const u8 *)in_data; |
109 | const u8 *ip = (const u8 *)in_data; |
82 | u8 *op = (u8 *)out_data; |
110 | u8 *op = (u8 *)out_data; |
83 | const u8 *in_end = ip + in_len; |
111 | const u8 *in_end = ip + in_len; |
84 | u8 *out_end = op + out_len; |
112 | u8 *out_end = op + out_len; |
85 | const u8 *ref; |
113 | const u8 *ref; |
86 | |
114 | |
87 | unsigned int hval = FRST (ip); |
115 | /* off requires a type wide enough to hold a general pointer difference. |
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116 | * ISO C doesn't have that (size_t might not be enough and ptrdiff_t only |
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117 | * works for differences within a single object). We also assume that no |
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118 | * no bit pattern traps. Since the only platform that is both non-POSIX |
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119 | * and fails to support both assumptions is windows 64 bit, we make a |
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120 | * special workaround for it. |
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121 | */ |
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122 | #if defined (WIN32) && defined (_M_X64) |
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123 | unsigned _int64 off; /* workaround for missing POSIX compliance */ |
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124 | #else |
88 | unsigned long off; |
125 | unsigned long off; |
89 | int lit = 0; |
126 | #endif |
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127 | unsigned int hval; |
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128 | int lit; |
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129 | |
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130 | if (!in_len || !out_len) |
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131 | return 0; |
90 | |
132 | |
91 | #if INIT_HTAB |
133 | #if INIT_HTAB |
92 | # if USE_MEMCPY |
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93 | memset (htab, 0, sizeof (htab)); |
134 | memset (htab, 0, sizeof (htab)); |
94 | # else |
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95 | for (hslot = htab; hslot < htab + HSIZE; hslot++) |
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96 | *hslot++ = ip; |
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97 | # endif |
135 | #endif |
98 | #endif |
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99 | |
136 | |
100 | do |
137 | lit = 0; op++; /* start run */ |
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138 | |
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139 | hval = FRST (ip); |
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140 | while (ip < in_end - 2) |
101 | { |
141 | { |
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142 | LZF_HSLOT *hslot; |
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143 | |
102 | hval = NEXT (hval, ip); |
144 | hval = NEXT (hval, ip); |
103 | hslot = htab + IDX (hval); |
145 | hslot = htab + IDX (hval); |
104 | ref = *hslot; *hslot = ip; |
146 | ref = *hslot + LZF_HSLOT_BIAS; *hslot = ip - LZF_HSLOT_BIAS; |
105 | |
147 | |
106 | if (1 |
148 | if (1 |
107 | #if INIT_HTAB && !USE_MEMCPY |
149 | #if INIT_HTAB |
108 | && ref < ip /* the next test will actually take care of this, but it is faster */ |
150 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
109 | #endif |
151 | #endif |
110 | && (off = ip - ref - 1) < MAX_OFF |
152 | && (off = ip - ref - 1) < MAX_OFF |
111 | && ip + 4 < in_end |
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112 | && ref > (u8 *)in_data |
153 | && ref > (u8 *)in_data |
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154 | && ref[2] == ip[2] |
113 | #if STRICT_ALIGN |
155 | #if STRICT_ALIGN |
114 | && ref[0] == ip[0] |
156 | && ((ref[1] << 8) | ref[0]) == ((ip[1] << 8) | ip[0]) |
115 | && ref[1] == ip[1] |
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116 | && ref[2] == ip[2] |
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117 | #else |
157 | #else |
118 | && *(u16 *)ref == *(u16 *)ip |
158 | && *(u16 *)ref == *(u16 *)ip |
119 | && ref[2] == ip[2] |
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120 | #endif |
159 | #endif |
121 | ) |
160 | ) |
122 | { |
161 | { |
123 | /* match found at *ref++ */ |
162 | /* match found at *ref++ */ |
124 | unsigned int len = 2; |
163 | unsigned int len = 2; |
125 | unsigned int maxlen = in_end - ip - len; |
164 | unsigned int maxlen = in_end - ip - len; |
126 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
165 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
127 | |
166 | |
128 | do |
167 | if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */ |
129 | len++; |
168 | if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */ |
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169 | return 0; |
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170 | |
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171 | op [- lit - 1] = lit - 1; /* stop run */ |
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172 | op -= !lit; /* undo run if length is zero */ |
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173 | |
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174 | for (;;) |
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175 | { |
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176 | if (expect_true (maxlen > 16)) |
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177 | { |
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178 | len++; if (ref [len] != ip [len]) break; |
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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 | |
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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 | |
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199 | do |
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200 | len++; |
130 | while (len < maxlen && ref[len] == ip[len]); |
201 | while (len < maxlen && ref[len] == ip[len]); |
131 | |
202 | |
132 | if (op + lit + 1 + 3 >= out_end) |
203 | break; |
133 | return 0; |
204 | } |
134 | |
205 | |
135 | if (lit) |
206 | len -= 2; /* len is now #octets - 1 */ |
136 | { |
207 | ip++; |
137 | *op++ = lit - 1; |
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138 | lit = -lit; |
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139 | do |
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140 | *op++ = ip[lit]; |
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141 | while (++lit); |
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142 | } |
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143 | |
208 | |
144 | len -= 2; |
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145 | ip++; |
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146 | |
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147 | if (len < 7) |
209 | if (len < 7) |
148 | { |
210 | { |
149 | *op++ = (off >> 8) + (len << 5); |
211 | *op++ = (off >> 8) + (len << 5); |
150 | } |
212 | } |
151 | else |
213 | else |
152 | { |
214 | { |
153 | *op++ = (off >> 8) + ( 7 << 5); |
215 | *op++ = (off >> 8) + ( 7 << 5); |
154 | *op++ = len - 7; |
216 | *op++ = len - 7; |
155 | } |
217 | } |
156 | |
218 | |
157 | *op++ = off; |
219 | *op++ = off; |
158 | |
220 | |
159 | #if ULTRA_FAST |
221 | lit = 0; op++; /* start run */ |
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222 | |
160 | ip += len; |
223 | ip += len + 1; |
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224 | |
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225 | if (expect_false (ip >= in_end - 2)) |
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226 | break; |
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227 | |
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228 | #if ULTRA_FAST || VERY_FAST |
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229 | --ip; |
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230 | # if VERY_FAST && !ULTRA_FAST |
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231 | --ip; |
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232 | # endif |
161 | hval = FRST (ip); |
233 | hval = FRST (ip); |
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234 | |
162 | hval = NEXT (hval, ip); |
235 | hval = NEXT (hval, ip); |
163 | htab[IDX (hval)] = ip; |
236 | htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; |
164 | ip++; |
237 | ip++; |
165 | #else |
238 | |
166 | do |
239 | # if VERY_FAST && !ULTRA_FAST |
167 | { |
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168 | hval = NEXT (hval, ip); |
240 | hval = NEXT (hval, ip); |
169 | htab[IDX (hval)] = ip; |
241 | htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; |
170 | ip++; |
242 | ip++; |
171 | } |
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172 | while (len--); |
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173 | #endif |
243 | # endif |
174 | } |
244 | #else |
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245 | ip -= len + 1; |
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246 | |
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247 | do |
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248 | { |
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249 | hval = NEXT (hval, ip); |
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250 | htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; |
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251 | ip++; |
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252 | } |
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253 | while (len--); |
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254 | #endif |
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255 | } |
175 | else |
256 | else |
176 | { |
257 | { |
177 | /* one more literal byte we must copy */ |
258 | /* one more literal byte we must copy */ |
178 | lit++; |
259 | if (expect_false (op >= out_end)) |
179 | ip++; |
260 | return 0; |
180 | |
261 | |
181 | if (lit == MAX_LIT) |
262 | lit++; *op++ = *ip++; |
182 | { |
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183 | if (op + 1 + MAX_LIT >= out_end) |
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184 | return 0; |
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185 | |
263 | |
186 | *op++ = MAX_LIT - 1; |
264 | if (expect_false (lit == MAX_LIT)) |
187 | #if USE_MEMCPY |
265 | { |
188 | memcpy (op, ip - MAX_LIT, MAX_LIT); |
266 | op [- lit - 1] = lit - 1; /* stop run */ |
189 | op += MAX_LIT; |
267 | lit = 0; op++; /* start run */ |
190 | lit = 0; |
268 | } |
191 | #else |
269 | } |
192 | lit = -lit; |
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193 | do |
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194 | *op++ = ip[lit]; |
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195 | while (++lit); |
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196 | #endif |
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197 | } |
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198 | } |
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199 | } |
270 | } |
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271 | |
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272 | if (op + 3 > out_end) /* at most 3 bytes can be missing here */ |
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273 | return 0; |
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274 | |
200 | while (ip < in_end); |
275 | while (ip < in_end) |
201 | |
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202 | if (lit) |
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203 | { |
276 | { |
204 | if (op + lit + 1 >= out_end) |
277 | lit++; *op++ = *ip++; |
205 | return 0; |
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206 | |
278 | |
207 | *op++ = lit - 1; |
279 | if (expect_false (lit == MAX_LIT)) |
208 | lit = -lit; |
280 | { |
209 | do |
281 | op [- lit - 1] = lit - 1; /* stop run */ |
210 | *op++ = ip[lit]; |
282 | lit = 0; op++; /* start run */ |
211 | while (++lit); |
283 | } |
212 | } |
284 | } |
213 | |
285 | |
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286 | op [- lit - 1] = lit - 1; /* end run */ |
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287 | op -= !lit; /* undo run if length is zero */ |
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288 | |
214 | return op - (u8 *) out_data; |
289 | return op - (u8 *)out_data; |
215 | } |
290 | } |
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291 | |