2 56e7a15f 2021-03-10 stsp * Copyright (c) 2020 Ori Bernstein
3 69aa0e90 2021-03-10 stsp * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
5 2a0e67f7 2021-03-10 stsp * Permission to use, copy, modify, and distribute this software for any
6 2a0e67f7 2021-03-10 stsp * purpose with or without fee is hereby granted, provided that the above
7 2a0e67f7 2021-03-10 stsp * copyright notice and this permission notice appear in all copies.
9 2a0e67f7 2021-03-10 stsp * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 2a0e67f7 2021-03-10 stsp * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 2a0e67f7 2021-03-10 stsp * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 2a0e67f7 2021-03-10 stsp * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 2a0e67f7 2021-03-10 stsp * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 2a0e67f7 2021-03-10 stsp * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 2a0e67f7 2021-03-10 stsp * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 f364801d 2021-03-10 stsp #include <sys/types.h>
19 f364801d 2021-03-10 stsp #include <sys/queue.h>
21 f364801d 2021-03-10 stsp #include <assert.h>
22 22403ab7 2021-03-22 naddy #include <endian.h>
23 69aa0e90 2021-03-10 stsp #include <errno.h>
24 f364801d 2021-03-10 stsp #include <limits.h>
25 f364801d 2021-03-10 stsp #include <stdint.h>
26 f364801d 2021-03-10 stsp #include <stdio.h>
27 f364801d 2021-03-10 stsp #include <stdlib.h>
28 f364801d 2021-03-10 stsp #include <string.h>
30 f364801d 2021-03-10 stsp #include "got_error.h"
32 69aa0e90 2021-03-10 stsp #include "got_lib_deltify.h"
33 2b474c25 2022-02-11 stsp #include "murmurhash2.h"
36 69aa0e90 2021-03-10 stsp #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
40 f736d93a 2021-10-07 stsp * The algorihm used here is FastCDC (Fast Content-Defined Chunking)
41 f736d93a 2021-10-07 stsp * https://www.usenix.org/conference/atc16/technical-sessions/presentation/xia
44 d58ddaf3 2022-03-17 naddy static const uint32_t geartab[256] = {
45 69aa0e90 2021-03-10 stsp 0x67ed26b7, 0x32da500c, 0x53d0fee0, 0xce387dc7, 0xcd406d90, 0x2e83a4d4,
46 69aa0e90 2021-03-10 stsp 0x9fc9a38d, 0xb67259dc, 0xca6b1722, 0x6d2ea08c, 0x235cea2e, 0x3149bb5f,
47 69aa0e90 2021-03-10 stsp 0x1beda787, 0x2a6b77d5, 0x2f22d9ac, 0x91fc0544, 0xe413acfa, 0x5a30ff7a,
48 69aa0e90 2021-03-10 stsp 0xad6fdde0, 0x444fd0f5, 0x7ad87864, 0x58c5ff05, 0x8d2ec336, 0x2371f853,
49 69aa0e90 2021-03-10 stsp 0x550f8572, 0x6aa448dd, 0x7c9ddbcf, 0x95221e14, 0x2a82ec33, 0xcbec5a78,
50 69aa0e90 2021-03-10 stsp 0xc6795a0d, 0x243995b7, 0x1c909a2f, 0x4fded51c, 0x635d334b, 0x0e2b9999,
51 69aa0e90 2021-03-10 stsp 0x2702968d, 0x856de1d5, 0x3325d60e, 0xeb6a7502, 0xec2a9844, 0x0905835a,
52 69aa0e90 2021-03-10 stsp 0xa1820375, 0xa4be5cab, 0x96a6c058, 0x2c2ccd70, 0xba40fce3, 0xd794c46b,
53 69aa0e90 2021-03-10 stsp 0x8fbae83e, 0xc3aa7899, 0x3d3ff8ed, 0xa0d42b5b, 0x571c0c97, 0xd2811516,
54 69aa0e90 2021-03-10 stsp 0xf7e7b96c, 0x4fd2fcbd, 0xe2fdec94, 0x282cc436, 0x78e8e95c, 0x80a3b613,
55 69aa0e90 2021-03-10 stsp 0xcfbee20c, 0xd4a32d1c, 0x2a12ff13, 0x6af82936, 0xe5630258, 0x8efa6a98,
56 69aa0e90 2021-03-10 stsp 0x294fb2d1, 0xdeb57086, 0x5f0fddb3, 0xeceda7ce, 0x4c87305f, 0x3a6d3307,
57 69aa0e90 2021-03-10 stsp 0xe22d2942, 0x9d060217, 0x1e42ed02, 0xb6f63b52, 0x4367f39f, 0x055cf262,
58 69aa0e90 2021-03-10 stsp 0x03a461b2, 0x5ef9e382, 0x386bc03a, 0x2a1e79c7, 0xf1a0058b, 0xd4d2dea9,
59 69aa0e90 2021-03-10 stsp 0x56baf37d, 0x5daff6cc, 0xf03a951d, 0xaef7de45, 0xa8f4581e, 0x3960b555,
60 69aa0e90 2021-03-10 stsp 0xffbfff6d, 0xbe702a23, 0x8f5b6d6f, 0x061739fb, 0x98696f47, 0x3fd596d4,
61 69aa0e90 2021-03-10 stsp 0x151eac6b, 0xa9fcc4f5, 0x69181a12, 0x3ac5a107, 0xb5198fe7, 0x96bcb1da,
62 69aa0e90 2021-03-10 stsp 0x1b5ddf8e, 0xc757d650, 0x65865c3a, 0x8fc0a41a, 0x87435536, 0x99eda6f2,
63 69aa0e90 2021-03-10 stsp 0x41874794, 0x29cff4e8, 0xb70efd9a, 0x3103f6e7, 0x84d2453b, 0x15a450bd,
64 69aa0e90 2021-03-10 stsp 0x74f49af1, 0x60f664b1, 0xa1c86935, 0xfdafbce1, 0xe36353e3, 0x5d9ba739,
65 69aa0e90 2021-03-10 stsp 0xbc0559ba, 0x708b0054, 0xd41d808c, 0xb2f31723, 0x9027c41f, 0xf136d165,
66 69aa0e90 2021-03-10 stsp 0xb5374b12, 0x9420a6ac, 0x273958b6, 0xe6c2fad0, 0xebdc1f21, 0xfb33af8b,
67 69aa0e90 2021-03-10 stsp 0xc71c25cd, 0xe9a2d8e5, 0xbeb38a50, 0xbceb7cc2, 0x4e4e73f0, 0xcd6c251d,
68 69aa0e90 2021-03-10 stsp 0xde4c032c, 0x4b04ac30, 0x725b8b21, 0x4eb8c33b, 0x20d07b75, 0x0567aa63,
69 69aa0e90 2021-03-10 stsp 0xb56b2bb7, 0xc1f5fd3a, 0xcafd35ca, 0x470dd4da, 0xfe4f94cd, 0xfb8de424,
70 69aa0e90 2021-03-10 stsp 0xe8dbcf40, 0xfe50a37a, 0x62db5b5d, 0xf32f4ab6, 0x2c4a8a51, 0x18473dc0,
71 69aa0e90 2021-03-10 stsp 0xfe0cbb6e, 0xfe399efd, 0xdf34ecc9, 0x6ccd5055, 0x46097073, 0x139135c2,
72 69aa0e90 2021-03-10 stsp 0x721c76f6, 0x1c6a94b4, 0x6eee014d, 0x8a508e02, 0x3da538f5, 0x280d394f,
73 69aa0e90 2021-03-10 stsp 0x5248a0c4, 0x3ce94c6c, 0x9a71ad3a, 0x8493dd05, 0xe43f0ab6, 0x18e4ed42,
74 69aa0e90 2021-03-10 stsp 0x6c5c0e09, 0x42b06ec9, 0x8d330343, 0xa45b6f59, 0x2a573c0c, 0xd7fd3de6,
75 69aa0e90 2021-03-10 stsp 0xeedeab68, 0x5c84dafc, 0xbbd1b1a8, 0xa3ce1ad1, 0x85b70bed, 0xb6add07f,
76 69aa0e90 2021-03-10 stsp 0xa531309c, 0x8f8ab852, 0x564de332, 0xeac9ed0c, 0x73da402c, 0x3ec52761,
77 69aa0e90 2021-03-10 stsp 0x43af2f4d, 0xd6ff45c8, 0x4c367462, 0xd553bd6a, 0x44724855, 0x3b2aa728,
78 69aa0e90 2021-03-10 stsp 0x56e5eb65, 0xeaf16173, 0x33fa42ff, 0xd714bb5d, 0xfbd0a3b9, 0xaf517134,
79 69aa0e90 2021-03-10 stsp 0x9416c8cd, 0x534cf94f, 0x548947c2, 0x34193569, 0x32f4389a, 0xfe7028bc,
80 69aa0e90 2021-03-10 stsp 0xed73b1ed, 0x9db95770, 0x468e3922, 0x0440c3cd, 0x60059a62, 0x33504562,
81 69aa0e90 2021-03-10 stsp 0x2b229fbd, 0x5174dca5, 0xf7028752, 0xd63c6aa8, 0x31276f38, 0x0646721c,
82 69aa0e90 2021-03-10 stsp 0xb0191da8, 0xe00e6de0, 0x9eac1a6e, 0x9f7628a5, 0xed6c06ea, 0x0bb8af15,
83 69aa0e90 2021-03-10 stsp 0xf119fb12, 0x38693c1c, 0x732bc0fe, 0x84953275, 0xb82ec888, 0x33a4f1b3,
84 69aa0e90 2021-03-10 stsp 0x3099835e, 0x028a8782, 0x5fdd51d7, 0xc6c717b3, 0xb06caf71, 0x17c8c111,
85 69aa0e90 2021-03-10 stsp 0x61bad754, 0x9fd03061, 0xe09df1af, 0x3bc9eb73, 0x85878413, 0x9889aaf2,
86 69aa0e90 2021-03-10 stsp 0x3f5a9e46, 0x42c9f01f, 0x9984a4f4, 0xd5de43cc, 0xd294daed, 0xbecba2d2,
87 69aa0e90 2021-03-10 stsp 0xf1f6e72c, 0x5551128a, 0x83af87e2, 0x6f0342ba,
90 2b474c25 2022-02-11 stsp static uint32_t
91 69aa0e90 2021-03-10 stsp hashblk(const unsigned char *p, off_t n)
93 2b474c25 2022-02-11 stsp return murmurhash2(p, n, 0x1d7c5ac3);
96 f364801d 2021-03-10 stsp static const struct got_error *
97 740bba1c 2021-06-18 stsp addblk(struct got_delta_table *dt, FILE *f, off_t file_offset0, off_t len,
98 f6027426 2022-02-12 naddy off_t offset, uint32_t h)
100 69aa0e90 2021-03-10 stsp const struct got_error *err = NULL;
102 69aa0e90 2021-03-10 stsp uint8_t buf[GOT_DELTIFY_MAXCHUNK];
103 0d15f6dc 2021-06-13 stsp uint8_t buf2[GOT_DELTIFY_MAXCHUNK];
104 69aa0e90 2021-03-10 stsp size_t r = 0;
106 69aa0e90 2021-03-10 stsp if (len == 0)
107 69aa0e90 2021-03-10 stsp return NULL;
109 69aa0e90 2021-03-10 stsp i = h % dt->nalloc;
110 69aa0e90 2021-03-10 stsp while (dt->blocks[i].len != 0) {
112 69aa0e90 2021-03-10 stsp * Avoid adding duplicate blocks.
113 69aa0e90 2021-03-10 stsp * NB: A matching hash is insufficient for detecting equality.
114 51a494da 2021-06-11 stsp * The hash can only detect inequality.
116 51a494da 2021-06-11 stsp if (len == dt->blocks[i].len && h == dt->blocks[i].hash) {
117 0d15f6dc 2021-06-13 stsp if (r == 0) {
118 740bba1c 2021-06-18 stsp if (fseeko(f, file_offset0 + offset, SEEK_SET) == -1)
119 0d15f6dc 2021-06-13 stsp return got_error_from_errno("fseeko");
120 0d15f6dc 2021-06-13 stsp r = fread(buf, 1, len, f);
121 0d15f6dc 2021-06-13 stsp if (r != len) {
122 0d15f6dc 2021-06-13 stsp if (!ferror(f))
123 0d15f6dc 2021-06-13 stsp return NULL;
124 0d15f6dc 2021-06-13 stsp return got_ferror(f, GOT_ERR_IO);
127 740bba1c 2021-06-18 stsp if (fseeko(f, file_offset0 + dt->blocks[i].offset,
128 740bba1c 2021-06-18 stsp SEEK_SET) == -1)
129 69aa0e90 2021-03-10 stsp return got_error_from_errno("fseeko");
130 69aa0e90 2021-03-10 stsp if (fread(buf2, 1, len, f) != len)
131 69aa0e90 2021-03-10 stsp return got_ferror(f, GOT_ERR_IO);
132 69aa0e90 2021-03-10 stsp if (memcmp(buf, buf2, len) == 0)
133 69aa0e90 2021-03-10 stsp return NULL;
136 69aa0e90 2021-03-10 stsp i = (i + 1) % dt->nalloc;
138 69aa0e90 2021-03-10 stsp assert(dt->blocks[i].len == 0);
139 69aa0e90 2021-03-10 stsp dt->blocks[i].len = len;
140 69aa0e90 2021-03-10 stsp dt->blocks[i].offset = offset;
141 69aa0e90 2021-03-10 stsp dt->blocks[i].hash = h;
142 69aa0e90 2021-03-10 stsp dt->nblocks++;
143 e89540a9 2021-06-11 stsp if (dt->nalloc < dt->nblocks + 64) {
144 69aa0e90 2021-03-10 stsp struct got_delta_block *db;
145 e89540a9 2021-06-11 stsp size_t old_size = dt->nalloc;
146 69aa0e90 2021-03-10 stsp db = dt->blocks;
147 e89540a9 2021-06-11 stsp dt->blocks = calloc(dt->nalloc + 64,
148 e89540a9 2021-06-11 stsp sizeof(struct got_delta_block));
149 69aa0e90 2021-03-10 stsp if (dt->blocks == NULL) {
150 69aa0e90 2021-03-10 stsp err = got_error_from_errno("calloc");
151 69aa0e90 2021-03-10 stsp dt->blocks = db;
152 69aa0e90 2021-03-10 stsp return err;
154 e89540a9 2021-06-11 stsp dt->nalloc += 64;
156 69aa0e90 2021-03-10 stsp * Recompute all block positions. Hash-based indices of blocks
157 69aa0e90 2021-03-10 stsp * in the array depend on the allocated length of the array.
159 69aa0e90 2021-03-10 stsp dt->nblocks = 0;
160 a893025f 2021-06-11 stsp for (i = 0; i < old_size; i++) {
161 69aa0e90 2021-03-10 stsp if (db[i].len == 0)
163 740bba1c 2021-06-18 stsp err = addblk(dt, f, file_offset0, db[i].len,
164 64a8571e 2022-01-07 stsp db[i].offset, db[i].hash);
171 64a8571e 2022-01-07 stsp return err;
174 64a8571e 2022-01-07 stsp static const struct got_error *
175 64a8571e 2022-01-07 stsp addblk_mem(struct got_delta_table *dt, uint8_t *data, off_t file_offset0,
176 f6027426 2022-02-12 naddy off_t len, off_t offset, uint32_t h)
178 64a8571e 2022-01-07 stsp const struct got_error *err = NULL;
180 64a8571e 2022-01-07 stsp uint8_t *block1;
181 64a8571e 2022-01-07 stsp uint8_t *block2;
183 64a8571e 2022-01-07 stsp if (len == 0)
184 64a8571e 2022-01-07 stsp return NULL;
186 64a8571e 2022-01-07 stsp i = h % dt->nalloc;
187 64a8571e 2022-01-07 stsp while (dt->blocks[i].len != 0) {
189 64a8571e 2022-01-07 stsp * Avoid adding duplicate blocks.
190 64a8571e 2022-01-07 stsp * NB: A matching hash is insufficient for detecting equality.
191 64a8571e 2022-01-07 stsp * The hash can only detect inequality.
193 64a8571e 2022-01-07 stsp if (len == dt->blocks[i].len && h == dt->blocks[i].hash) {
194 64a8571e 2022-01-07 stsp block1 = data + file_offset0 + dt->blocks[i].offset;
195 64a8571e 2022-01-07 stsp block2 = data + file_offset0 + offset;
196 64a8571e 2022-01-07 stsp if (memcmp(block1, block2, len) == 0)
197 64a8571e 2022-01-07 stsp return NULL;
200 64a8571e 2022-01-07 stsp i = (i + 1) % dt->nalloc;
202 64a8571e 2022-01-07 stsp assert(dt->blocks[i].len == 0);
203 64a8571e 2022-01-07 stsp dt->blocks[i].len = len;
204 64a8571e 2022-01-07 stsp dt->blocks[i].offset = offset;
205 64a8571e 2022-01-07 stsp dt->blocks[i].hash = h;
206 64a8571e 2022-01-07 stsp dt->nblocks++;
207 64a8571e 2022-01-07 stsp if (dt->nalloc < dt->nblocks + 64) {
208 64a8571e 2022-01-07 stsp struct got_delta_block *db;
209 64a8571e 2022-01-07 stsp size_t old_size = dt->nalloc;
210 64a8571e 2022-01-07 stsp db = dt->blocks;
211 64a8571e 2022-01-07 stsp dt->blocks = calloc(dt->nalloc + 64,
212 64a8571e 2022-01-07 stsp sizeof(struct got_delta_block));
213 64a8571e 2022-01-07 stsp if (dt->blocks == NULL) {
214 64a8571e 2022-01-07 stsp err = got_error_from_errno("calloc");
215 64a8571e 2022-01-07 stsp dt->blocks = db;
216 64a8571e 2022-01-07 stsp return err;
218 64a8571e 2022-01-07 stsp dt->nalloc += 64;
220 64a8571e 2022-01-07 stsp * Recompute all block positions. Hash-based indices of blocks
221 64a8571e 2022-01-07 stsp * in the array depend on the allocated length of the array.
223 64a8571e 2022-01-07 stsp dt->nblocks = 0;
224 64a8571e 2022-01-07 stsp for (i = 0; i < old_size; i++) {
225 64a8571e 2022-01-07 stsp if (db[i].len == 0)
227 64a8571e 2022-01-07 stsp err = addblk_mem(dt, data, file_offset0, db[i].len,
228 740bba1c 2021-06-18 stsp db[i].offset, db[i].hash);
235 69aa0e90 2021-03-10 stsp return err;
238 69aa0e90 2021-03-10 stsp static const struct got_error *
239 69aa0e90 2021-03-10 stsp lookupblk(struct got_delta_block **block, struct got_delta_table *dt,
240 740bba1c 2021-06-18 stsp unsigned char *p, off_t len, FILE *basefile, off_t basefile_offset0)
243 2b474c25 2022-02-11 stsp uint32_t h;
244 69aa0e90 2021-03-10 stsp uint8_t buf[GOT_DELTIFY_MAXCHUNK];
247 69aa0e90 2021-03-10 stsp *block = NULL;
249 69aa0e90 2021-03-10 stsp h = hashblk(p, len);
250 69aa0e90 2021-03-10 stsp for (i = h % dt->nalloc; dt->blocks[i].len != 0;
251 69aa0e90 2021-03-10 stsp i = (i + 1) % dt->nalloc) {
252 69aa0e90 2021-03-10 stsp if (dt->blocks[i].hash != h ||
253 69aa0e90 2021-03-10 stsp dt->blocks[i].len != len)
255 740bba1c 2021-06-18 stsp if (fseeko(basefile, basefile_offset0 + dt->blocks[i].offset,
256 740bba1c 2021-06-18 stsp SEEK_SET) == -1)
257 69aa0e90 2021-03-10 stsp return got_error_from_errno("fseeko");
258 69aa0e90 2021-03-10 stsp r = fread(buf, 1, len, basefile);
259 69aa0e90 2021-03-10 stsp if (r != len)
260 69aa0e90 2021-03-10 stsp return got_ferror(basefile, GOT_ERR_IO);
261 69aa0e90 2021-03-10 stsp if (memcmp(p, buf, len) == 0) {
262 69aa0e90 2021-03-10 stsp *block = &dt->blocks[i];
266 f364801d 2021-03-10 stsp return NULL;
269 69aa0e90 2021-03-10 stsp static const struct got_error *
270 64a8571e 2022-01-07 stsp lookupblk_mem(struct got_delta_block **block, struct got_delta_table *dt,
271 64a8571e 2022-01-07 stsp unsigned char *p, off_t len, uint8_t *basedata, off_t basefile_offset0)
274 2b474c25 2022-02-11 stsp uint32_t h;
275 64a8571e 2022-01-07 stsp uint8_t *b;
277 64a8571e 2022-01-07 stsp *block = NULL;
279 64a8571e 2022-01-07 stsp h = hashblk(p, len);
280 64a8571e 2022-01-07 stsp for (i = h % dt->nalloc; dt->blocks[i].len != 0;
281 64a8571e 2022-01-07 stsp i = (i + 1) % dt->nalloc) {
282 64a8571e 2022-01-07 stsp if (dt->blocks[i].hash != h ||
283 64a8571e 2022-01-07 stsp dt->blocks[i].len != len)
285 64a8571e 2022-01-07 stsp b = basedata + basefile_offset0 + dt->blocks[i].offset;
286 64a8571e 2022-01-07 stsp if (memcmp(p, b, len) == 0) {
287 64a8571e 2022-01-07 stsp *block = &dt->blocks[i];
291 64a8571e 2022-01-07 stsp return NULL;
294 64a8571e 2022-01-07 stsp static const struct got_error *
295 69aa0e90 2021-03-10 stsp nextblk(uint8_t *buf, off_t *blocklen, FILE *f)
297 f364801d 2021-03-10 stsp uint32_t gh;
298 69aa0e90 2021-03-10 stsp const unsigned char *p;
300 69aa0e90 2021-03-10 stsp off_t pos = ftello(f);
302 69aa0e90 2021-03-10 stsp *blocklen = 0;
304 69aa0e90 2021-03-10 stsp r = fread(buf, 1, GOT_DELTIFY_MAXCHUNK, f);
305 69aa0e90 2021-03-10 stsp if (r == 0 && ferror(f))
306 69aa0e90 2021-03-10 stsp return got_ferror(f, GOT_ERR_IO);
307 69aa0e90 2021-03-10 stsp if (r < GOT_DELTIFY_MINCHUNK)
308 69aa0e90 2021-03-10 stsp return NULL; /* no more delta-worthy blocks left */
310 69aa0e90 2021-03-10 stsp /* Got a deltifiable block. Find the split-point where it ends. */
311 69aa0e90 2021-03-10 stsp p = buf + GOT_DELTIFY_MINCHUNK;
313 69aa0e90 2021-03-10 stsp while (p != buf + r) {
314 f364801d 2021-03-10 stsp gh = (gh << 1) + geartab[*p++];
315 69aa0e90 2021-03-10 stsp if ((gh & GOT_DELTIFY_SPLITMASK) == 0)
319 69aa0e90 2021-03-10 stsp *blocklen = (p - buf);
320 69aa0e90 2021-03-10 stsp if (fseeko(f, pos + *blocklen, SEEK_SET) == -1)
321 69aa0e90 2021-03-10 stsp return got_error_from_errno("fseeko");
323 69aa0e90 2021-03-10 stsp return NULL;
326 64a8571e 2022-01-07 stsp static const struct got_error *
327 64a8571e 2022-01-07 stsp nextblk_mem(off_t *blocklen, uint8_t *data, off_t fileoffset, off_t filesize)
329 64a8571e 2022-01-07 stsp uint32_t gh;
330 64a8571e 2022-01-07 stsp const unsigned char *p;
332 64a8571e 2022-01-07 stsp *blocklen = 0;
334 64a8571e 2022-01-07 stsp if (fileoffset >= filesize ||
335 64a8571e 2022-01-07 stsp filesize - fileoffset < GOT_DELTIFY_MINCHUNK)
336 64a8571e 2022-01-07 stsp return NULL; /* no more delta-worthy blocks left */
338 64a8571e 2022-01-07 stsp /* Got a deltifiable block. Find the split-point where it ends. */
339 64a8571e 2022-01-07 stsp p = data + fileoffset + GOT_DELTIFY_MINCHUNK;
341 64a8571e 2022-01-07 stsp while (p != data + MIN(fileoffset + GOT_DELTIFY_MAXCHUNK, filesize)) {
342 64a8571e 2022-01-07 stsp gh = (gh << 1) + geartab[*p++];
343 64a8571e 2022-01-07 stsp if ((gh & GOT_DELTIFY_SPLITMASK) == 0)
347 64a8571e 2022-01-07 stsp *blocklen = (p - (data + fileoffset));
348 64a8571e 2022-01-07 stsp return NULL;
351 f364801d 2021-03-10 stsp const struct got_error *
352 69aa0e90 2021-03-10 stsp got_deltify_init(struct got_delta_table **dt, FILE *f, off_t fileoffset,
353 69aa0e90 2021-03-10 stsp off_t filesize)
355 69aa0e90 2021-03-10 stsp const struct got_error *err = NULL;
356 2b474c25 2022-02-11 stsp uint32_t h;
357 740bba1c 2021-06-18 stsp const off_t offset0 = fileoffset;
359 69aa0e90 2021-03-10 stsp *dt = calloc(1, sizeof(**dt));
360 69aa0e90 2021-03-10 stsp if (*dt == NULL)
361 f364801d 2021-03-10 stsp return got_error_from_errno("calloc");
363 69aa0e90 2021-03-10 stsp (*dt)->nblocks = 0;
364 69aa0e90 2021-03-10 stsp (*dt)->nalloc = 128;
365 69aa0e90 2021-03-10 stsp (*dt)->blocks = calloc((*dt)->nalloc, sizeof(struct got_delta_block));
366 69aa0e90 2021-03-10 stsp if ((*dt)->blocks == NULL) {
367 69aa0e90 2021-03-10 stsp err = got_error_from_errno("calloc");
371 69aa0e90 2021-03-10 stsp if (fseeko(f, fileoffset, SEEK_SET) == -1)
372 69aa0e90 2021-03-10 stsp return got_error_from_errno("fseeko");
374 69aa0e90 2021-03-10 stsp while (fileoffset < filesize) {
375 69aa0e90 2021-03-10 stsp uint8_t buf[GOT_DELTIFY_MAXCHUNK];
376 69aa0e90 2021-03-10 stsp off_t blocklen;
377 69aa0e90 2021-03-10 stsp err = nextblk(buf, &blocklen, f);
380 69aa0e90 2021-03-10 stsp if (blocklen == 0)
382 69aa0e90 2021-03-10 stsp h = hashblk(buf, blocklen);
383 740bba1c 2021-06-18 stsp err = addblk(*dt, f, offset0, blocklen,
384 740bba1c 2021-06-18 stsp fileoffset - offset0, h);
387 69aa0e90 2021-03-10 stsp fileoffset += blocklen;
388 68bdcdc2 2021-06-11 stsp if (fseeko(f, fileoffset, SEEK_SET) == -1)
389 68bdcdc2 2021-06-11 stsp return got_error_from_errno("fseeko");
393 64a8571e 2022-01-07 stsp free((*dt)->blocks);
395 64a8571e 2022-01-07 stsp *dt = NULL;
398 64a8571e 2022-01-07 stsp return err;
401 64a8571e 2022-01-07 stsp const struct got_error *
402 64a8571e 2022-01-07 stsp got_deltify_init_mem(struct got_delta_table **dt, uint8_t *data,
403 64a8571e 2022-01-07 stsp off_t fileoffset, off_t filesize)
405 64a8571e 2022-01-07 stsp const struct got_error *err = NULL;
406 f6027426 2022-02-12 naddy uint32_t h;
407 64a8571e 2022-01-07 stsp const off_t offset0 = fileoffset;
409 64a8571e 2022-01-07 stsp *dt = calloc(1, sizeof(**dt));
410 64a8571e 2022-01-07 stsp if (*dt == NULL)
411 64a8571e 2022-01-07 stsp return got_error_from_errno("calloc");
413 64a8571e 2022-01-07 stsp (*dt)->nblocks = 0;
414 64a8571e 2022-01-07 stsp (*dt)->nalloc = 128;
415 64a8571e 2022-01-07 stsp (*dt)->blocks = calloc((*dt)->nalloc, sizeof(struct got_delta_block));
416 64a8571e 2022-01-07 stsp if ((*dt)->blocks == NULL) {
417 64a8571e 2022-01-07 stsp err = got_error_from_errno("calloc");
421 64a8571e 2022-01-07 stsp while (fileoffset < filesize) {
422 64a8571e 2022-01-07 stsp off_t blocklen;
423 64a8571e 2022-01-07 stsp err = nextblk_mem(&blocklen, data, fileoffset, filesize);
426 64a8571e 2022-01-07 stsp if (blocklen == 0)
428 64a8571e 2022-01-07 stsp h = hashblk(data + fileoffset, blocklen);
429 64a8571e 2022-01-07 stsp err = addblk_mem(*dt, data, offset0, blocklen,
430 64a8571e 2022-01-07 stsp fileoffset - offset0, h);
433 64a8571e 2022-01-07 stsp fileoffset += blocklen;
437 69aa0e90 2021-03-10 stsp free((*dt)->blocks);
439 69aa0e90 2021-03-10 stsp *dt = NULL;
442 69aa0e90 2021-03-10 stsp return err;
446 69aa0e90 2021-03-10 stsp got_deltify_free(struct got_delta_table *dt)
448 dbbf4a5f 2021-05-20 stsp if (dt == NULL)
450 69aa0e90 2021-03-10 stsp free(dt->blocks);
454 f364801d 2021-03-10 stsp static const struct got_error *
455 dd29967c 2021-08-22 stsp emitdelta(struct got_delta_instruction **deltas, size_t *nalloc, int *ndeltas,
456 dd29967c 2021-08-22 stsp const size_t alloc_chunk_size, int copy, off_t offset, off_t len)
458 69aa0e90 2021-03-10 stsp struct got_delta_instruction *d, *p;
460 dd29967c 2021-08-22 stsp if (*nalloc < *ndeltas + alloc_chunk_size) {
461 dd29967c 2021-08-22 stsp p = reallocarray(*deltas, *nalloc + alloc_chunk_size,
462 dd29967c 2021-08-22 stsp sizeof(struct got_delta_instruction));
463 dd29967c 2021-08-22 stsp if (p == NULL)
464 2d467c6d 2021-10-13 stsp return got_error_from_errno("reallocarray");
465 dd29967c 2021-08-22 stsp *deltas = p;
466 dd29967c 2021-08-22 stsp *nalloc += alloc_chunk_size;
468 69aa0e90 2021-03-10 stsp *ndeltas += 1;
469 69aa0e90 2021-03-10 stsp d = &(*deltas)[*ndeltas - 1];
470 69aa0e90 2021-03-10 stsp d->copy = copy;
471 69aa0e90 2021-03-10 stsp d->offset = offset;
472 56e7a15f 2021-03-10 stsp d->len = len;
473 f364801d 2021-03-10 stsp return NULL;
476 69aa0e90 2021-03-10 stsp static const struct got_error *
477 740bba1c 2021-06-18 stsp stretchblk(FILE *basefile, off_t base_offset0, struct got_delta_block *block,
478 740bba1c 2021-06-18 stsp FILE *f, off_t filesize, off_t *blocklen)
480 69aa0e90 2021-03-10 stsp uint8_t basebuf[GOT_DELTIFY_MAXCHUNK], buf[GOT_DELTIFY_MAXCHUNK];
481 69aa0e90 2021-03-10 stsp size_t base_r, r, i;
482 69aa0e90 2021-03-10 stsp int buf_equal = 1;
484 5de743f8 2021-08-29 stsp if (fseeko(basefile, base_offset0 + block->offset + *blocklen,
485 5de743f8 2021-08-29 stsp SEEK_SET) == -1)
486 69aa0e90 2021-03-10 stsp return got_error_from_errno("fseeko");
488 69aa0e90 2021-03-10 stsp while (buf_equal && *blocklen < (1 << 24) - 1) {
489 69aa0e90 2021-03-10 stsp base_r = fread(basebuf, 1, sizeof(basebuf), basefile);
490 69aa0e90 2021-03-10 stsp if (base_r == 0) {
491 69aa0e90 2021-03-10 stsp if (ferror(basefile))
492 69aa0e90 2021-03-10 stsp return got_ferror(basefile, GOT_ERR_IO);
495 69aa0e90 2021-03-10 stsp r = fread(buf, 1, sizeof(buf), f);
496 69aa0e90 2021-03-10 stsp if (r == 0) {
497 69aa0e90 2021-03-10 stsp if (ferror(f))
498 69aa0e90 2021-03-10 stsp return got_ferror(f, GOT_ERR_IO);
501 69aa0e90 2021-03-10 stsp for (i = 0; i < MIN(base_r, r); i++) {
502 69aa0e90 2021-03-10 stsp if (buf[i] != basebuf[i]) {
503 69aa0e90 2021-03-10 stsp buf_equal = 0;
506 69aa0e90 2021-03-10 stsp (*blocklen)++;
510 64a8571e 2022-01-07 stsp return NULL;
513 64a8571e 2022-01-07 stsp static const struct got_error *
514 64a8571e 2022-01-07 stsp stretchblk_file_mem(uint8_t *basedata, off_t base_offset0, off_t basefile_size,
515 64a8571e 2022-01-07 stsp struct got_delta_block *block, FILE *f, off_t filesize, off_t *blocklen)
517 64a8571e 2022-01-07 stsp uint8_t buf[GOT_DELTIFY_MAXCHUNK];
518 64a8571e 2022-01-07 stsp size_t r, i;
519 64a8571e 2022-01-07 stsp int buf_equal = 1;
520 64a8571e 2022-01-07 stsp off_t base_offset = base_offset0 + block->offset + *blocklen;
522 64a8571e 2022-01-07 stsp if (base_offset > basefile_size) {
523 64a8571e 2022-01-07 stsp return got_error_fmt(GOT_ERR_RANGE,
524 64a8571e 2022-01-07 stsp "read beyond the size of delta base at offset %llu",
525 64a8571e 2022-01-07 stsp base_offset);
528 64a8571e 2022-01-07 stsp while (buf_equal && *blocklen < (1 << 24) - 1) {
529 64a8571e 2022-01-07 stsp if (base_offset + *blocklen >= basefile_size)
531 64a8571e 2022-01-07 stsp r = fread(buf, 1, sizeof(buf), f);
532 64a8571e 2022-01-07 stsp if (r == 0) {
533 64a8571e 2022-01-07 stsp if (ferror(f))
534 64a8571e 2022-01-07 stsp return got_ferror(f, GOT_ERR_IO);
537 64a8571e 2022-01-07 stsp for (i = 0; i < MIN(basefile_size - base_offset, r); i++) {
538 64a8571e 2022-01-07 stsp if (buf[i] != *(basedata + base_offset + i)) {
539 64a8571e 2022-01-07 stsp buf_equal = 0;
542 64a8571e 2022-01-07 stsp (*blocklen)++;
546 64a8571e 2022-01-07 stsp return NULL;
549 64a8571e 2022-01-07 stsp static const struct got_error *
550 64a8571e 2022-01-07 stsp stretchblk_mem_file(FILE *basefile, off_t base_offset0,
551 64a8571e 2022-01-07 stsp struct got_delta_block *block, uint8_t *data, off_t fileoffset,
552 64a8571e 2022-01-07 stsp off_t filesize, off_t *blocklen)
554 64a8571e 2022-01-07 stsp uint8_t basebuf[GOT_DELTIFY_MAXCHUNK];
555 64a8571e 2022-01-07 stsp size_t base_r, i;
556 64a8571e 2022-01-07 stsp int buf_equal = 1;
558 64a8571e 2022-01-07 stsp if (fileoffset > filesize) {
559 64a8571e 2022-01-07 stsp return got_error_fmt(GOT_ERR_RANGE,
560 64a8571e 2022-01-07 stsp "read beyond the size of deltify file at offset %llu",
561 64a8571e 2022-01-07 stsp fileoffset);
564 64a8571e 2022-01-07 stsp if (fseeko(basefile, base_offset0 + block->offset + *blocklen,
565 64a8571e 2022-01-07 stsp SEEK_SET) == -1)
566 64a8571e 2022-01-07 stsp return got_error_from_errno("fseeko");
568 64a8571e 2022-01-07 stsp while (buf_equal && *blocklen < (1 << 24) - 1) {
569 64a8571e 2022-01-07 stsp if (fileoffset + *blocklen >= filesize)
571 64a8571e 2022-01-07 stsp base_r = fread(basebuf, 1, sizeof(basebuf), basefile);
572 64a8571e 2022-01-07 stsp if (base_r == 0) {
573 64a8571e 2022-01-07 stsp if (ferror(basefile))
574 64a8571e 2022-01-07 stsp return got_ferror(basefile, GOT_ERR_IO);
577 64a8571e 2022-01-07 stsp for (i = 0; i < MIN(base_r, filesize - fileoffset); i++) {
578 64a8571e 2022-01-07 stsp if (*(data + fileoffset + i) != basebuf[i]) {
579 64a8571e 2022-01-07 stsp buf_equal = 0;
582 64a8571e 2022-01-07 stsp (*blocklen)++;
586 64a8571e 2022-01-07 stsp return NULL;
589 64a8571e 2022-01-07 stsp static const struct got_error *
590 64a8571e 2022-01-07 stsp stretchblk_mem_mem(uint8_t *basedata, off_t base_offset0, off_t basefile_size,
591 64a8571e 2022-01-07 stsp struct got_delta_block *block, uint8_t *data, off_t fileoffset,
592 64a8571e 2022-01-07 stsp off_t filesize, off_t *blocklen)
594 64a8571e 2022-01-07 stsp off_t i, maxlen;
595 64a8571e 2022-01-07 stsp off_t base_offset = base_offset0 + block->offset + *blocklen;
596 64a8571e 2022-01-07 stsp uint8_t *p, *q;
598 64a8571e 2022-01-07 stsp if (base_offset > basefile_size) {
599 64a8571e 2022-01-07 stsp return got_error_fmt(GOT_ERR_RANGE,
600 64a8571e 2022-01-07 stsp "read beyond the size of delta base at offset %llu",
601 64a8571e 2022-01-07 stsp base_offset);
604 64a8571e 2022-01-07 stsp if (fileoffset > filesize) {
605 64a8571e 2022-01-07 stsp return got_error_fmt(GOT_ERR_RANGE,
606 64a8571e 2022-01-07 stsp "read beyond the size of deltify file at offset %llu",
607 64a8571e 2022-01-07 stsp fileoffset);
610 64a8571e 2022-01-07 stsp p = data + fileoffset;
611 64a8571e 2022-01-07 stsp q = basedata + base_offset;
612 64a8571e 2022-01-07 stsp maxlen = MIN(basefile_size - base_offset, filesize - fileoffset);
613 64a8571e 2022-01-07 stsp for (i = 0; i < maxlen && *blocklen < (1 << 24) - 1; i++) {
614 64a8571e 2022-01-07 stsp if (p[i] != q[i])
616 64a8571e 2022-01-07 stsp (*blocklen)++;
619 69aa0e90 2021-03-10 stsp return NULL;
622 69aa0e90 2021-03-10 stsp const struct got_error *
623 69aa0e90 2021-03-10 stsp got_deltify(struct got_delta_instruction **deltas, int *ndeltas,
624 69aa0e90 2021-03-10 stsp FILE *f, off_t fileoffset, off_t filesize,
625 69aa0e90 2021-03-10 stsp struct got_delta_table *dt, FILE *basefile,
626 f34b169e 2021-06-18 stsp off_t basefile_offset0, off_t basefile_size)
628 69aa0e90 2021-03-10 stsp const struct got_error *err = NULL;
629 69aa0e90 2021-03-10 stsp const off_t offset0 = fileoffset;
630 dd29967c 2021-08-22 stsp size_t nalloc = 0;
631 dd29967c 2021-08-22 stsp const size_t alloc_chunk_size = 64;
633 69aa0e90 2021-03-10 stsp *deltas = NULL;
634 69aa0e90 2021-03-10 stsp *ndeltas = 0;
637 69aa0e90 2021-03-10 stsp * offset0 indicates where data to be deltified begins.
638 69aa0e90 2021-03-10 stsp * For example, we want to avoid deltifying a Git object header at
639 69aa0e90 2021-03-10 stsp * the beginning of the file.
641 69aa0e90 2021-03-10 stsp if (fseeko(f, offset0, SEEK_SET) == -1)
642 69aa0e90 2021-03-10 stsp return got_error_from_errno("fseeko");
644 dd29967c 2021-08-22 stsp *deltas = reallocarray(NULL, alloc_chunk_size,
645 dd29967c 2021-08-22 stsp sizeof(struct got_delta_instruction));
646 dd29967c 2021-08-22 stsp if (*deltas == NULL)
647 dd29967c 2021-08-22 stsp return got_error_from_errno("reallocarray");
648 dd29967c 2021-08-22 stsp nalloc = alloc_chunk_size;
650 69aa0e90 2021-03-10 stsp while (fileoffset < filesize) {
651 69aa0e90 2021-03-10 stsp uint8_t buf[GOT_DELTIFY_MAXCHUNK];
652 69aa0e90 2021-03-10 stsp off_t blocklen;
653 69aa0e90 2021-03-10 stsp struct got_delta_block *block;
654 69aa0e90 2021-03-10 stsp err = nextblk(buf, &blocklen, f);
657 9a8dc2b3 2021-06-18 stsp if (blocklen == 0) {
658 9a8dc2b3 2021-06-18 stsp /* Source remainder from the file itself. */
659 9a8dc2b3 2021-06-18 stsp if (fileoffset < filesize) {
660 dd29967c 2021-08-22 stsp err = emitdelta(deltas, &nalloc, ndeltas,
661 dd29967c 2021-08-22 stsp alloc_chunk_size, 0, fileoffset - offset0,
662 9a8dc2b3 2021-06-18 stsp filesize - fileoffset);
666 740bba1c 2021-06-18 stsp err = lookupblk(&block, dt, buf, blocklen, basefile,
667 740bba1c 2021-06-18 stsp basefile_offset0);
670 69aa0e90 2021-03-10 stsp if (block != NULL) {
672 69aa0e90 2021-03-10 stsp * We have found a matching block in the delta base.
673 69aa0e90 2021-03-10 stsp * Attempt to stretch the block as far as possible and
674 69aa0e90 2021-03-10 stsp * generate a copy instruction.
676 740bba1c 2021-06-18 stsp err = stretchblk(basefile, basefile_offset0, block,
677 740bba1c 2021-06-18 stsp f, filesize, &blocklen);
680 dd29967c 2021-08-22 stsp err = emitdelta(deltas, &nalloc, ndeltas,
681 dd29967c 2021-08-22 stsp alloc_chunk_size, 1, block->offset, blocklen);
686 69aa0e90 2021-03-10 stsp * No match.
687 69aa0e90 2021-03-10 stsp * This block needs to be sourced from the file itself.
689 dd29967c 2021-08-22 stsp err = emitdelta(deltas, &nalloc, ndeltas,
690 dd29967c 2021-08-22 stsp alloc_chunk_size, 0, fileoffset - offset0, blocklen);
694 69aa0e90 2021-03-10 stsp fileoffset += blocklen;
695 0af64e86 2021-08-22 stsp if (fseeko(f, fileoffset, SEEK_SET) == -1) {
696 0af64e86 2021-08-22 stsp err = got_error_from_errno("fseeko");
702 69aa0e90 2021-03-10 stsp free(*deltas);
703 69aa0e90 2021-03-10 stsp *deltas = NULL;
704 69aa0e90 2021-03-10 stsp *ndeltas = 0;
706 69aa0e90 2021-03-10 stsp return err;
709 64a8571e 2022-01-07 stsp const struct got_error *
710 64a8571e 2022-01-07 stsp got_deltify_file_mem(struct got_delta_instruction **deltas, int *ndeltas,
711 64a8571e 2022-01-07 stsp FILE *f, off_t fileoffset, off_t filesize,
712 64a8571e 2022-01-07 stsp struct got_delta_table *dt, uint8_t *basedata,
713 64a8571e 2022-01-07 stsp off_t basefile_offset0, off_t basefile_size)
715 64a8571e 2022-01-07 stsp const struct got_error *err = NULL;
716 64a8571e 2022-01-07 stsp const off_t offset0 = fileoffset;
717 64a8571e 2022-01-07 stsp size_t nalloc = 0;
718 64a8571e 2022-01-07 stsp const size_t alloc_chunk_size = 64;
720 64a8571e 2022-01-07 stsp *deltas = NULL;
721 64a8571e 2022-01-07 stsp *ndeltas = 0;
724 64a8571e 2022-01-07 stsp * offset0 indicates where data to be deltified begins.
725 64a8571e 2022-01-07 stsp * For example, we want to avoid deltifying a Git object header at
726 64a8571e 2022-01-07 stsp * the beginning of the file.
728 64a8571e 2022-01-07 stsp if (fseeko(f, offset0, SEEK_SET) == -1)
729 64a8571e 2022-01-07 stsp return got_error_from_errno("fseeko");
731 64a8571e 2022-01-07 stsp *deltas = reallocarray(NULL, alloc_chunk_size,
732 64a8571e 2022-01-07 stsp sizeof(struct got_delta_instruction));
733 64a8571e 2022-01-07 stsp if (*deltas == NULL)
734 64a8571e 2022-01-07 stsp return got_error_from_errno("reallocarray");
735 64a8571e 2022-01-07 stsp nalloc = alloc_chunk_size;
737 64a8571e 2022-01-07 stsp while (fileoffset < filesize) {
738 64a8571e 2022-01-07 stsp uint8_t buf[GOT_DELTIFY_MAXCHUNK];
739 64a8571e 2022-01-07 stsp off_t blocklen;
740 64a8571e 2022-01-07 stsp struct got_delta_block *block;
741 64a8571e 2022-01-07 stsp err = nextblk(buf, &blocklen, f);
744 64a8571e 2022-01-07 stsp if (blocklen == 0) {
745 64a8571e 2022-01-07 stsp /* Source remainder from the file itself. */
746 64a8571e 2022-01-07 stsp if (fileoffset < filesize) {
747 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
748 64a8571e 2022-01-07 stsp alloc_chunk_size, 0, fileoffset - offset0,
749 64a8571e 2022-01-07 stsp filesize - fileoffset);
753 64a8571e 2022-01-07 stsp err = lookupblk_mem(&block, dt, buf, blocklen, basedata,
754 64a8571e 2022-01-07 stsp basefile_offset0);
757 64a8571e 2022-01-07 stsp if (block != NULL) {
759 64a8571e 2022-01-07 stsp * We have found a matching block in the delta base.
760 64a8571e 2022-01-07 stsp * Attempt to stretch the block as far as possible and
761 64a8571e 2022-01-07 stsp * generate a copy instruction.
763 64a8571e 2022-01-07 stsp err = stretchblk_file_mem(basedata, basefile_offset0,
764 64a8571e 2022-01-07 stsp basefile_size, block, f, filesize, &blocklen);
767 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
768 64a8571e 2022-01-07 stsp alloc_chunk_size, 1, block->offset, blocklen);
773 64a8571e 2022-01-07 stsp * No match.
774 64a8571e 2022-01-07 stsp * This block needs to be sourced from the file itself.
776 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
777 64a8571e 2022-01-07 stsp alloc_chunk_size, 0, fileoffset - offset0, blocklen);
781 64a8571e 2022-01-07 stsp fileoffset += blocklen;
782 64a8571e 2022-01-07 stsp if (fseeko(f, fileoffset, SEEK_SET) == -1) {
783 64a8571e 2022-01-07 stsp err = got_error_from_errno("fseeko");
789 64a8571e 2022-01-07 stsp free(*deltas);
790 64a8571e 2022-01-07 stsp *deltas = NULL;
791 64a8571e 2022-01-07 stsp *ndeltas = 0;
793 64a8571e 2022-01-07 stsp return err;
796 64a8571e 2022-01-07 stsp const struct got_error *
797 64a8571e 2022-01-07 stsp got_deltify_mem_file(struct got_delta_instruction **deltas, int *ndeltas,
798 64a8571e 2022-01-07 stsp uint8_t *data, off_t fileoffset, off_t filesize,
799 64a8571e 2022-01-07 stsp struct got_delta_table *dt, FILE *basefile,
800 64a8571e 2022-01-07 stsp off_t basefile_offset0, off_t basefile_size)
802 64a8571e 2022-01-07 stsp const struct got_error *err = NULL;
803 64a8571e 2022-01-07 stsp const off_t offset0 = fileoffset;
804 64a8571e 2022-01-07 stsp size_t nalloc = 0;
805 64a8571e 2022-01-07 stsp const size_t alloc_chunk_size = 64;
807 64a8571e 2022-01-07 stsp *deltas = NULL;
808 64a8571e 2022-01-07 stsp *ndeltas = 0;
810 64a8571e 2022-01-07 stsp *deltas = reallocarray(NULL, alloc_chunk_size,
811 64a8571e 2022-01-07 stsp sizeof(struct got_delta_instruction));
812 64a8571e 2022-01-07 stsp if (*deltas == NULL)
813 64a8571e 2022-01-07 stsp return got_error_from_errno("reallocarray");
814 64a8571e 2022-01-07 stsp nalloc = alloc_chunk_size;
816 64a8571e 2022-01-07 stsp while (fileoffset < filesize) {
817 64a8571e 2022-01-07 stsp off_t blocklen;
818 64a8571e 2022-01-07 stsp struct got_delta_block *block;
819 64a8571e 2022-01-07 stsp err = nextblk_mem(&blocklen, data, fileoffset, filesize);
822 64a8571e 2022-01-07 stsp if (blocklen == 0) {
823 64a8571e 2022-01-07 stsp /* Source remainder from the file itself. */
824 64a8571e 2022-01-07 stsp if (fileoffset < filesize) {
825 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
826 64a8571e 2022-01-07 stsp alloc_chunk_size, 0, fileoffset - offset0,
827 64a8571e 2022-01-07 stsp filesize - fileoffset);
831 64a8571e 2022-01-07 stsp err = lookupblk(&block, dt, data + fileoffset, blocklen,
832 64a8571e 2022-01-07 stsp basefile, basefile_offset0);
835 64a8571e 2022-01-07 stsp if (block != NULL) {
837 64a8571e 2022-01-07 stsp * We have found a matching block in the delta base.
838 64a8571e 2022-01-07 stsp * Attempt to stretch the block as far as possible and
839 64a8571e 2022-01-07 stsp * generate a copy instruction.
841 64a8571e 2022-01-07 stsp err = stretchblk_mem_file(basefile, basefile_offset0,
842 64a8571e 2022-01-07 stsp block, data, fileoffset + blocklen, filesize,
843 64a8571e 2022-01-07 stsp &blocklen);
846 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
847 64a8571e 2022-01-07 stsp alloc_chunk_size, 1, block->offset, blocklen);
852 64a8571e 2022-01-07 stsp * No match.
853 64a8571e 2022-01-07 stsp * This block needs to be sourced from the file itself.
855 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
856 64a8571e 2022-01-07 stsp alloc_chunk_size, 0, fileoffset - offset0, blocklen);
860 64a8571e 2022-01-07 stsp fileoffset += blocklen;
864 64a8571e 2022-01-07 stsp free(*deltas);
865 64a8571e 2022-01-07 stsp *deltas = NULL;
866 64a8571e 2022-01-07 stsp *ndeltas = 0;
868 64a8571e 2022-01-07 stsp return err;
871 64a8571e 2022-01-07 stsp const struct got_error *
872 64a8571e 2022-01-07 stsp got_deltify_mem_mem(struct got_delta_instruction **deltas, int *ndeltas,
873 64a8571e 2022-01-07 stsp uint8_t *data, off_t fileoffset, off_t filesize,
874 64a8571e 2022-01-07 stsp struct got_delta_table *dt, uint8_t *basedata,
875 64a8571e 2022-01-07 stsp off_t basefile_offset0, off_t basefile_size)
877 64a8571e 2022-01-07 stsp const struct got_error *err = NULL;
878 64a8571e 2022-01-07 stsp const off_t offset0 = fileoffset;
879 64a8571e 2022-01-07 stsp size_t nalloc = 0;
880 64a8571e 2022-01-07 stsp const size_t alloc_chunk_size = 64;
882 64a8571e 2022-01-07 stsp *deltas = NULL;
883 64a8571e 2022-01-07 stsp *ndeltas = 0;
885 64a8571e 2022-01-07 stsp *deltas = reallocarray(NULL, alloc_chunk_size,
886 64a8571e 2022-01-07 stsp sizeof(struct got_delta_instruction));
887 64a8571e 2022-01-07 stsp if (*deltas == NULL)
888 64a8571e 2022-01-07 stsp return got_error_from_errno("reallocarray");
889 64a8571e 2022-01-07 stsp nalloc = alloc_chunk_size;
891 64a8571e 2022-01-07 stsp while (fileoffset < filesize) {
892 64a8571e 2022-01-07 stsp off_t blocklen;
893 64a8571e 2022-01-07 stsp struct got_delta_block *block;
894 64a8571e 2022-01-07 stsp err = nextblk_mem(&blocklen, data, fileoffset, filesize);
897 64a8571e 2022-01-07 stsp if (blocklen == 0) {
898 64a8571e 2022-01-07 stsp /* Source remainder from the file itself. */
899 64a8571e 2022-01-07 stsp if (fileoffset < filesize) {
900 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
901 64a8571e 2022-01-07 stsp alloc_chunk_size, 0, fileoffset - offset0,
902 64a8571e 2022-01-07 stsp filesize - fileoffset);
906 64a8571e 2022-01-07 stsp err = lookupblk_mem(&block, dt, data + fileoffset, blocklen,
907 64a8571e 2022-01-07 stsp basedata, basefile_offset0);
910 64a8571e 2022-01-07 stsp if (block != NULL) {
912 64a8571e 2022-01-07 stsp * We have found a matching block in the delta base.
913 64a8571e 2022-01-07 stsp * Attempt to stretch the block as far as possible and
914 64a8571e 2022-01-07 stsp * generate a copy instruction.
916 64a8571e 2022-01-07 stsp err = stretchblk_mem_mem(basedata, basefile_offset0,
917 64a8571e 2022-01-07 stsp basefile_size, block, data, fileoffset + blocklen,
918 64a8571e 2022-01-07 stsp filesize, &blocklen);
921 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
922 64a8571e 2022-01-07 stsp alloc_chunk_size, 1, block->offset, blocklen);
927 64a8571e 2022-01-07 stsp * No match.
928 64a8571e 2022-01-07 stsp * This block needs to be sourced from the file itself.
930 64a8571e 2022-01-07 stsp err = emitdelta(deltas, &nalloc, ndeltas,
931 64a8571e 2022-01-07 stsp alloc_chunk_size, 0, fileoffset - offset0, blocklen);
935 64a8571e 2022-01-07 stsp fileoffset += blocklen;
939 64a8571e 2022-01-07 stsp free(*deltas);
940 64a8571e 2022-01-07 stsp *deltas = NULL;
941 64a8571e 2022-01-07 stsp *ndeltas = 0;
943 64a8571e 2022-01-07 stsp return err;
