Mercurial > hg > nginx
comparison src/http/ngx_http_huff_encode.c @ 7977:336084ff943b
Moved Huffman coding out of HTTP/2.
ngx_http_v2_huff_decode.c and ngx_http_v2_huff_encode.c are renamed
to ngx_http_huff_decode.c and ngx_http_huff_encode.c.
author | Ruslan Ermilov <ru@nginx.com> |
---|---|
date | Tue, 21 Dec 2021 07:54:16 +0300 |
parents | src/http/v2/ngx_http_v2_huff_encode.c@dcfe355dfda4 |
children |
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7976:76aea0ad78e5 | 7977:336084ff943b |
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1 | |
2 /* | |
3 * Copyright (C) Nginx, Inc. | |
4 * Copyright (C) Valentin V. Bartenev | |
5 * Copyright (C) 2015 Vlad Krasnov | |
6 */ | |
7 | |
8 | |
9 #include <ngx_config.h> | |
10 #include <ngx_core.h> | |
11 #include <ngx_http.h> | |
12 | |
13 | |
14 typedef struct { | |
15 uint32_t code; | |
16 uint32_t len; | |
17 } ngx_http_huff_encode_code_t; | |
18 | |
19 | |
20 static ngx_http_huff_encode_code_t ngx_http_huff_encode_table[256] = | |
21 { | |
22 {0x00001ff8, 13}, {0x007fffd8, 23}, {0x0fffffe2, 28}, {0x0fffffe3, 28}, | |
23 {0x0fffffe4, 28}, {0x0fffffe5, 28}, {0x0fffffe6, 28}, {0x0fffffe7, 28}, | |
24 {0x0fffffe8, 28}, {0x00ffffea, 24}, {0x3ffffffc, 30}, {0x0fffffe9, 28}, | |
25 {0x0fffffea, 28}, {0x3ffffffd, 30}, {0x0fffffeb, 28}, {0x0fffffec, 28}, | |
26 {0x0fffffed, 28}, {0x0fffffee, 28}, {0x0fffffef, 28}, {0x0ffffff0, 28}, | |
27 {0x0ffffff1, 28}, {0x0ffffff2, 28}, {0x3ffffffe, 30}, {0x0ffffff3, 28}, | |
28 {0x0ffffff4, 28}, {0x0ffffff5, 28}, {0x0ffffff6, 28}, {0x0ffffff7, 28}, | |
29 {0x0ffffff8, 28}, {0x0ffffff9, 28}, {0x0ffffffa, 28}, {0x0ffffffb, 28}, | |
30 {0x00000014, 6}, {0x000003f8, 10}, {0x000003f9, 10}, {0x00000ffa, 12}, | |
31 {0x00001ff9, 13}, {0x00000015, 6}, {0x000000f8, 8}, {0x000007fa, 11}, | |
32 {0x000003fa, 10}, {0x000003fb, 10}, {0x000000f9, 8}, {0x000007fb, 11}, | |
33 {0x000000fa, 8}, {0x00000016, 6}, {0x00000017, 6}, {0x00000018, 6}, | |
34 {0x00000000, 5}, {0x00000001, 5}, {0x00000002, 5}, {0x00000019, 6}, | |
35 {0x0000001a, 6}, {0x0000001b, 6}, {0x0000001c, 6}, {0x0000001d, 6}, | |
36 {0x0000001e, 6}, {0x0000001f, 6}, {0x0000005c, 7}, {0x000000fb, 8}, | |
37 {0x00007ffc, 15}, {0x00000020, 6}, {0x00000ffb, 12}, {0x000003fc, 10}, | |
38 {0x00001ffa, 13}, {0x00000021, 6}, {0x0000005d, 7}, {0x0000005e, 7}, | |
39 {0x0000005f, 7}, {0x00000060, 7}, {0x00000061, 7}, {0x00000062, 7}, | |
40 {0x00000063, 7}, {0x00000064, 7}, {0x00000065, 7}, {0x00000066, 7}, | |
41 {0x00000067, 7}, {0x00000068, 7}, {0x00000069, 7}, {0x0000006a, 7}, | |
42 {0x0000006b, 7}, {0x0000006c, 7}, {0x0000006d, 7}, {0x0000006e, 7}, | |
43 {0x0000006f, 7}, {0x00000070, 7}, {0x00000071, 7}, {0x00000072, 7}, | |
44 {0x000000fc, 8}, {0x00000073, 7}, {0x000000fd, 8}, {0x00001ffb, 13}, | |
45 {0x0007fff0, 19}, {0x00001ffc, 13}, {0x00003ffc, 14}, {0x00000022, 6}, | |
46 {0x00007ffd, 15}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, | |
47 {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, | |
48 {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, | |
49 {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, | |
50 {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, | |
51 {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, | |
52 {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00007ffe, 15}, | |
53 {0x000007fc, 11}, {0x00003ffd, 14}, {0x00001ffd, 13}, {0x0ffffffc, 28}, | |
54 {0x000fffe6, 20}, {0x003fffd2, 22}, {0x000fffe7, 20}, {0x000fffe8, 20}, | |
55 {0x003fffd3, 22}, {0x003fffd4, 22}, {0x003fffd5, 22}, {0x007fffd9, 23}, | |
56 {0x003fffd6, 22}, {0x007fffda, 23}, {0x007fffdb, 23}, {0x007fffdc, 23}, | |
57 {0x007fffdd, 23}, {0x007fffde, 23}, {0x00ffffeb, 24}, {0x007fffdf, 23}, | |
58 {0x00ffffec, 24}, {0x00ffffed, 24}, {0x003fffd7, 22}, {0x007fffe0, 23}, | |
59 {0x00ffffee, 24}, {0x007fffe1, 23}, {0x007fffe2, 23}, {0x007fffe3, 23}, | |
60 {0x007fffe4, 23}, {0x001fffdc, 21}, {0x003fffd8, 22}, {0x007fffe5, 23}, | |
61 {0x003fffd9, 22}, {0x007fffe6, 23}, {0x007fffe7, 23}, {0x00ffffef, 24}, | |
62 {0x003fffda, 22}, {0x001fffdd, 21}, {0x000fffe9, 20}, {0x003fffdb, 22}, | |
63 {0x003fffdc, 22}, {0x007fffe8, 23}, {0x007fffe9, 23}, {0x001fffde, 21}, | |
64 {0x007fffea, 23}, {0x003fffdd, 22}, {0x003fffde, 22}, {0x00fffff0, 24}, | |
65 {0x001fffdf, 21}, {0x003fffdf, 22}, {0x007fffeb, 23}, {0x007fffec, 23}, | |
66 {0x001fffe0, 21}, {0x001fffe1, 21}, {0x003fffe0, 22}, {0x001fffe2, 21}, | |
67 {0x007fffed, 23}, {0x003fffe1, 22}, {0x007fffee, 23}, {0x007fffef, 23}, | |
68 {0x000fffea, 20}, {0x003fffe2, 22}, {0x003fffe3, 22}, {0x003fffe4, 22}, | |
69 {0x007ffff0, 23}, {0x003fffe5, 22}, {0x003fffe6, 22}, {0x007ffff1, 23}, | |
70 {0x03ffffe0, 26}, {0x03ffffe1, 26}, {0x000fffeb, 20}, {0x0007fff1, 19}, | |
71 {0x003fffe7, 22}, {0x007ffff2, 23}, {0x003fffe8, 22}, {0x01ffffec, 25}, | |
72 {0x03ffffe2, 26}, {0x03ffffe3, 26}, {0x03ffffe4, 26}, {0x07ffffde, 27}, | |
73 {0x07ffffdf, 27}, {0x03ffffe5, 26}, {0x00fffff1, 24}, {0x01ffffed, 25}, | |
74 {0x0007fff2, 19}, {0x001fffe3, 21}, {0x03ffffe6, 26}, {0x07ffffe0, 27}, | |
75 {0x07ffffe1, 27}, {0x03ffffe7, 26}, {0x07ffffe2, 27}, {0x00fffff2, 24}, | |
76 {0x001fffe4, 21}, {0x001fffe5, 21}, {0x03ffffe8, 26}, {0x03ffffe9, 26}, | |
77 {0x0ffffffd, 28}, {0x07ffffe3, 27}, {0x07ffffe4, 27}, {0x07ffffe5, 27}, | |
78 {0x000fffec, 20}, {0x00fffff3, 24}, {0x000fffed, 20}, {0x001fffe6, 21}, | |
79 {0x003fffe9, 22}, {0x001fffe7, 21}, {0x001fffe8, 21}, {0x007ffff3, 23}, | |
80 {0x003fffea, 22}, {0x003fffeb, 22}, {0x01ffffee, 25}, {0x01ffffef, 25}, | |
81 {0x00fffff4, 24}, {0x00fffff5, 24}, {0x03ffffea, 26}, {0x007ffff4, 23}, | |
82 {0x03ffffeb, 26}, {0x07ffffe6, 27}, {0x03ffffec, 26}, {0x03ffffed, 26}, | |
83 {0x07ffffe7, 27}, {0x07ffffe8, 27}, {0x07ffffe9, 27}, {0x07ffffea, 27}, | |
84 {0x07ffffeb, 27}, {0x0ffffffe, 28}, {0x07ffffec, 27}, {0x07ffffed, 27}, | |
85 {0x07ffffee, 27}, {0x07ffffef, 27}, {0x07fffff0, 27}, {0x03ffffee, 26} | |
86 }; | |
87 | |
88 | |
89 /* same as above, but embeds lowercase transformation */ | |
90 static ngx_http_huff_encode_code_t ngx_http_huff_encode_table_lc[256] = | |
91 { | |
92 {0x00001ff8, 13}, {0x007fffd8, 23}, {0x0fffffe2, 28}, {0x0fffffe3, 28}, | |
93 {0x0fffffe4, 28}, {0x0fffffe5, 28}, {0x0fffffe6, 28}, {0x0fffffe7, 28}, | |
94 {0x0fffffe8, 28}, {0x00ffffea, 24}, {0x3ffffffc, 30}, {0x0fffffe9, 28}, | |
95 {0x0fffffea, 28}, {0x3ffffffd, 30}, {0x0fffffeb, 28}, {0x0fffffec, 28}, | |
96 {0x0fffffed, 28}, {0x0fffffee, 28}, {0x0fffffef, 28}, {0x0ffffff0, 28}, | |
97 {0x0ffffff1, 28}, {0x0ffffff2, 28}, {0x3ffffffe, 30}, {0x0ffffff3, 28}, | |
98 {0x0ffffff4, 28}, {0x0ffffff5, 28}, {0x0ffffff6, 28}, {0x0ffffff7, 28}, | |
99 {0x0ffffff8, 28}, {0x0ffffff9, 28}, {0x0ffffffa, 28}, {0x0ffffffb, 28}, | |
100 {0x00000014, 6}, {0x000003f8, 10}, {0x000003f9, 10}, {0x00000ffa, 12}, | |
101 {0x00001ff9, 13}, {0x00000015, 6}, {0x000000f8, 8}, {0x000007fa, 11}, | |
102 {0x000003fa, 10}, {0x000003fb, 10}, {0x000000f9, 8}, {0x000007fb, 11}, | |
103 {0x000000fa, 8}, {0x00000016, 6}, {0x00000017, 6}, {0x00000018, 6}, | |
104 {0x00000000, 5}, {0x00000001, 5}, {0x00000002, 5}, {0x00000019, 6}, | |
105 {0x0000001a, 6}, {0x0000001b, 6}, {0x0000001c, 6}, {0x0000001d, 6}, | |
106 {0x0000001e, 6}, {0x0000001f, 6}, {0x0000005c, 7}, {0x000000fb, 8}, | |
107 {0x00007ffc, 15}, {0x00000020, 6}, {0x00000ffb, 12}, {0x000003fc, 10}, | |
108 {0x00001ffa, 13}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, | |
109 {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, | |
110 {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, | |
111 {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, | |
112 {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, | |
113 {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, | |
114 {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00001ffb, 13}, | |
115 {0x0007fff0, 19}, {0x00001ffc, 13}, {0x00003ffc, 14}, {0x00000022, 6}, | |
116 {0x00007ffd, 15}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, | |
117 {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, | |
118 {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, | |
119 {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, | |
120 {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, | |
121 {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, | |
122 {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00007ffe, 15}, | |
123 {0x000007fc, 11}, {0x00003ffd, 14}, {0x00001ffd, 13}, {0x0ffffffc, 28}, | |
124 {0x000fffe6, 20}, {0x003fffd2, 22}, {0x000fffe7, 20}, {0x000fffe8, 20}, | |
125 {0x003fffd3, 22}, {0x003fffd4, 22}, {0x003fffd5, 22}, {0x007fffd9, 23}, | |
126 {0x003fffd6, 22}, {0x007fffda, 23}, {0x007fffdb, 23}, {0x007fffdc, 23}, | |
127 {0x007fffdd, 23}, {0x007fffde, 23}, {0x00ffffeb, 24}, {0x007fffdf, 23}, | |
128 {0x00ffffec, 24}, {0x00ffffed, 24}, {0x003fffd7, 22}, {0x007fffe0, 23}, | |
129 {0x00ffffee, 24}, {0x007fffe1, 23}, {0x007fffe2, 23}, {0x007fffe3, 23}, | |
130 {0x007fffe4, 23}, {0x001fffdc, 21}, {0x003fffd8, 22}, {0x007fffe5, 23}, | |
131 {0x003fffd9, 22}, {0x007fffe6, 23}, {0x007fffe7, 23}, {0x00ffffef, 24}, | |
132 {0x003fffda, 22}, {0x001fffdd, 21}, {0x000fffe9, 20}, {0x003fffdb, 22}, | |
133 {0x003fffdc, 22}, {0x007fffe8, 23}, {0x007fffe9, 23}, {0x001fffde, 21}, | |
134 {0x007fffea, 23}, {0x003fffdd, 22}, {0x003fffde, 22}, {0x00fffff0, 24}, | |
135 {0x001fffdf, 21}, {0x003fffdf, 22}, {0x007fffeb, 23}, {0x007fffec, 23}, | |
136 {0x001fffe0, 21}, {0x001fffe1, 21}, {0x003fffe0, 22}, {0x001fffe2, 21}, | |
137 {0x007fffed, 23}, {0x003fffe1, 22}, {0x007fffee, 23}, {0x007fffef, 23}, | |
138 {0x000fffea, 20}, {0x003fffe2, 22}, {0x003fffe3, 22}, {0x003fffe4, 22}, | |
139 {0x007ffff0, 23}, {0x003fffe5, 22}, {0x003fffe6, 22}, {0x007ffff1, 23}, | |
140 {0x03ffffe0, 26}, {0x03ffffe1, 26}, {0x000fffeb, 20}, {0x0007fff1, 19}, | |
141 {0x003fffe7, 22}, {0x007ffff2, 23}, {0x003fffe8, 22}, {0x01ffffec, 25}, | |
142 {0x03ffffe2, 26}, {0x03ffffe3, 26}, {0x03ffffe4, 26}, {0x07ffffde, 27}, | |
143 {0x07ffffdf, 27}, {0x03ffffe5, 26}, {0x00fffff1, 24}, {0x01ffffed, 25}, | |
144 {0x0007fff2, 19}, {0x001fffe3, 21}, {0x03ffffe6, 26}, {0x07ffffe0, 27}, | |
145 {0x07ffffe1, 27}, {0x03ffffe7, 26}, {0x07ffffe2, 27}, {0x00fffff2, 24}, | |
146 {0x001fffe4, 21}, {0x001fffe5, 21}, {0x03ffffe8, 26}, {0x03ffffe9, 26}, | |
147 {0x0ffffffd, 28}, {0x07ffffe3, 27}, {0x07ffffe4, 27}, {0x07ffffe5, 27}, | |
148 {0x000fffec, 20}, {0x00fffff3, 24}, {0x000fffed, 20}, {0x001fffe6, 21}, | |
149 {0x003fffe9, 22}, {0x001fffe7, 21}, {0x001fffe8, 21}, {0x007ffff3, 23}, | |
150 {0x003fffea, 22}, {0x003fffeb, 22}, {0x01ffffee, 25}, {0x01ffffef, 25}, | |
151 {0x00fffff4, 24}, {0x00fffff5, 24}, {0x03ffffea, 26}, {0x007ffff4, 23}, | |
152 {0x03ffffeb, 26}, {0x07ffffe6, 27}, {0x03ffffec, 26}, {0x03ffffed, 26}, | |
153 {0x07ffffe7, 27}, {0x07ffffe8, 27}, {0x07ffffe9, 27}, {0x07ffffea, 27}, | |
154 {0x07ffffeb, 27}, {0x0ffffffe, 28}, {0x07ffffec, 27}, {0x07ffffed, 27}, | |
155 {0x07ffffee, 27}, {0x07ffffef, 27}, {0x07fffff0, 27}, {0x03ffffee, 26} | |
156 }; | |
157 | |
158 | |
159 #if (NGX_PTR_SIZE == 8) | |
160 | |
161 #if (NGX_HAVE_LITTLE_ENDIAN) | |
162 | |
163 #if (NGX_HAVE_GCC_BSWAP64) | |
164 #define ngx_http_huff_encode_buf(dst, buf) \ | |
165 (*(uint64_t *) (dst) = __builtin_bswap64(buf)) | |
166 #else | |
167 #define ngx_http_huff_encode_buf(dst, buf) \ | |
168 ((dst)[0] = (u_char) ((buf) >> 56), \ | |
169 (dst)[1] = (u_char) ((buf) >> 48), \ | |
170 (dst)[2] = (u_char) ((buf) >> 40), \ | |
171 (dst)[3] = (u_char) ((buf) >> 32), \ | |
172 (dst)[4] = (u_char) ((buf) >> 24), \ | |
173 (dst)[5] = (u_char) ((buf) >> 16), \ | |
174 (dst)[6] = (u_char) ((buf) >> 8), \ | |
175 (dst)[7] = (u_char) (buf)) | |
176 #endif | |
177 | |
178 #else /* !NGX_HAVE_LITTLE_ENDIAN */ | |
179 #define ngx_http_huff_encode_buf(dst, buf) \ | |
180 (*(uint64_t *) (dst) = (buf)) | |
181 #endif | |
182 | |
183 #else /* NGX_PTR_SIZE == 4 */ | |
184 | |
185 #define ngx_http_huff_encode_buf(dst, buf) \ | |
186 (*(uint32_t *) (dst) = htonl(buf)) | |
187 | |
188 #endif | |
189 | |
190 | |
191 size_t | |
192 ngx_http_huff_encode(u_char *src, size_t len, u_char *dst, ngx_uint_t lower) | |
193 { | |
194 u_char *end; | |
195 size_t hlen; | |
196 ngx_uint_t buf, pending, code; | |
197 ngx_http_huff_encode_code_t *table, *next; | |
198 | |
199 table = lower ? ngx_http_huff_encode_table_lc | |
200 : ngx_http_huff_encode_table; | |
201 hlen = 0; | |
202 buf = 0; | |
203 pending = 0; | |
204 | |
205 end = src + len; | |
206 | |
207 while (src != end) { | |
208 next = &table[*src++]; | |
209 | |
210 code = next->code; | |
211 pending += next->len; | |
212 | |
213 /* accumulate bits */ | |
214 if (pending < sizeof(buf) * 8) { | |
215 buf |= code << (sizeof(buf) * 8 - pending); | |
216 continue; | |
217 } | |
218 | |
219 if (hlen + sizeof(buf) >= len) { | |
220 return 0; | |
221 } | |
222 | |
223 pending -= sizeof(buf) * 8; | |
224 | |
225 buf |= code >> pending; | |
226 | |
227 ngx_http_huff_encode_buf(&dst[hlen], buf); | |
228 | |
229 hlen += sizeof(buf); | |
230 | |
231 buf = pending ? code << (sizeof(buf) * 8 - pending) : 0; | |
232 } | |
233 | |
234 if (pending == 0) { | |
235 return hlen; | |
236 } | |
237 | |
238 buf |= (ngx_uint_t) -1 >> pending; | |
239 | |
240 pending = ngx_align(pending, 8); | |
241 | |
242 if (hlen + pending / 8 >= len) { | |
243 return 0; | |
244 } | |
245 | |
246 buf >>= sizeof(buf) * 8 - pending; | |
247 | |
248 do { | |
249 pending -= 8; | |
250 dst[hlen++] = (u_char) (buf >> pending); | |
251 } while (pending); | |
252 | |
253 return hlen; | |
254 } |