2 * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 #include <sys/queue.h>
26 #include "got_error.h"
27 #include "got_repository.h"
28 #include "got_object.h"
30 #include "got_lib_delta.h"
31 #include "got_lib_path.h"
32 #include "got_lib_zbuf.h"
35 #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
39 got_delta_open(const char *path_packfile, off_t offset, size_t tslen,
40 int type, size_t size, off_t data_offset, uint8_t *delta_buf,
43 struct got_delta *delta;
45 delta = calloc(1, sizeof(*delta));
49 delta->path_packfile = strdup(path_packfile);
50 if (delta->path_packfile == NULL) {
55 delta->offset = offset;
58 delta->data_offset = data_offset;
59 delta->delta_buf = delta_buf;
60 delta->delta_len = delta_len;
65 got_delta_close(struct got_delta *delta)
67 free(delta->path_packfile);
68 free(delta->delta_buf);
72 const struct got_error *
73 got_delta_chain_get_base_type(int *type, struct got_delta_chain *deltas)
75 struct got_delta *delta;
77 /* The first delta in the chain should represent the base object. */
78 delta = SIMPLEQ_FIRST(&deltas->entries);
79 if (delta->type == GOT_OBJ_TYPE_COMMIT ||
80 delta->type == GOT_OBJ_TYPE_TREE ||
81 delta->type == GOT_OBJ_TYPE_BLOB ||
82 delta->type == GOT_OBJ_TYPE_TAG) {
87 return got_error(GOT_ERR_BAD_DELTA_CHAIN);
90 /* Fetch another (required) byte from the delta stream. */
91 static const struct got_error *
92 next_delta_byte(const uint8_t **p, size_t *remain)
95 return got_error(GOT_ERR_BAD_DELTA);
100 static const struct got_error *
101 parse_size(uint64_t *size, const uint8_t **p, size_t *remain)
103 const struct got_error *err = NULL;
108 /* We do not support size values which don't fit in 64 bit. */
110 return got_error(GOT_ERR_NO_SPACE);
113 *size = ((**p) & GOT_DELTA_SIZE_VAL_MASK);
115 size_t shift = GOT_DELTA_SIZE_SHIFT * i;
116 *size |= (((**p) & GOT_DELTA_SIZE_VAL_MASK) << shift);
119 if (((**p) & GOT_DELTA_SIZE_MORE) == 0)
122 err = next_delta_byte(p, remain);
123 } while (err == NULL);
128 static const struct got_error *
129 parse_opcode(off_t *offset, size_t *len, const uint8_t **p, size_t *remain)
131 const struct got_error *err = NULL;
134 uint8_t opcode = **p;
136 if (opcode & GOT_DELTA_COPY_OFF1) {
137 err = next_delta_byte(p, remain);
142 if (opcode & GOT_DELTA_COPY_OFF2) {
143 err = next_delta_byte(p, remain);
146 o |= ((off_t)(**p)) << 8;
148 if (opcode & GOT_DELTA_COPY_OFF3) {
149 err = next_delta_byte(p, remain);
152 o |= ((off_t)(**p)) << 16;
154 if (opcode & GOT_DELTA_COPY_OFF4) {
155 err = next_delta_byte(p, remain);
158 o |= ((off_t)(**p)) << 24;
161 if (opcode & GOT_DELTA_COPY_LEN1) {
162 err = next_delta_byte(p, remain);
167 if (opcode & GOT_DELTA_COPY_LEN2) {
168 err = next_delta_byte(p, remain);
171 l |= ((off_t)(**p)) << 8;
173 if (opcode & GOT_DELTA_COPY_LEN3) {
174 err = next_delta_byte(p, remain);
177 l |= ((off_t)(**p)) << 16;
181 o = GOT_DELTA_COPY_DEFAULT_OFF;
183 l = GOT_DELTA_COPY_DEFAULT_LEN;
190 static const struct got_error *
191 copy_from_base(FILE *base_file, off_t offset, size_t size, FILE *outfile)
193 if (fseeko(base_file, offset, SEEK_SET) != 0)
194 return got_error_from_errno();
198 size_t len = MIN(size, sizeof(data));
201 n = fread(data, len, 1, base_file);
203 return got_ferror(base_file, GOT_ERR_IO);
205 n = fwrite(data, len, 1, outfile);
207 return got_ferror(outfile, GOT_ERR_IO);
215 static const struct got_error *
216 copy_from_delta(const uint8_t **p, size_t *remain, size_t len, FILE *outfile)
221 return got_error(GOT_ERR_BAD_DELTA);
223 n = fwrite(*p, len, 1, outfile);
225 return got_ferror(outfile, GOT_ERR_IO);
232 static const struct got_error *
233 parse_delta_sizes(uint64_t *base_size, uint64_t *result_size,
234 const uint8_t **p, size_t *remain)
236 const struct got_error *err;
238 /* Read the two size fields at the beginning of the stream. */
239 err = parse_size(base_size, p, remain);
242 err = next_delta_byte(p, remain);
245 err = parse_size(result_size, p, remain);
252 const struct got_error *
253 got_delta_get_sizes(uint64_t *base_size, uint64_t *result_size,
254 const uint8_t *delta_buf, size_t delta_len)
259 if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
260 return got_error(GOT_ERR_BAD_DELTA);
264 return parse_delta_sizes(base_size, result_size, &p, &remain);
267 const struct got_error *
268 got_delta_apply_in_mem(uint8_t *base_buf, const uint8_t *delta_buf,
269 size_t delta_len, uint8_t *outbuf, size_t *outsize)
271 const struct got_error *err = NULL;
272 uint64_t base_size, result_size;
278 if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
279 return got_error(GOT_ERR_BAD_DELTA);
283 err = parse_delta_sizes(&base_size, &result_size, &p, &remain);
287 /* Decode and execute copy instructions from the delta stream. */
288 err = next_delta_byte(&p, &remain);
289 while (err == NULL && remain > 0) {
290 if (*p & GOT_DELTA_BASE_COPY) {
293 err = parse_opcode(&offset, &len, &p, &remain);
296 memcpy(outbuf + *outsize, base_buf + offset, len);
305 size_t len = (size_t)*p;
307 err = got_error(GOT_ERR_BAD_DELTA);
310 err = next_delta_byte(&p, &remain);
314 return got_error(GOT_ERR_BAD_DELTA);
315 memcpy(outbuf + *outsize, p, len);
322 if (*outsize != result_size)
323 err = got_error(GOT_ERR_BAD_DELTA);
327 const struct got_error *
328 got_delta_apply(FILE *base_file, const uint8_t *delta_buf,
329 size_t delta_len, FILE *outfile, size_t *outsize)
331 const struct got_error *err = NULL;
332 uint64_t base_size, result_size;
335 FILE *memstream = NULL;
336 char *memstream_buf = NULL;
337 size_t memstream_size = 0;
341 if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
342 return got_error(GOT_ERR_BAD_DELTA);
346 err = parse_delta_sizes(&base_size, &result_size, &p, &remain);
350 if (result_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX)
351 memstream = open_memstream(&memstream_buf, &memstream_size);
353 /* Decode and execute copy instructions from the delta stream. */
354 err = next_delta_byte(&p, &remain);
355 while (err == NULL && remain > 0) {
356 if (*p & GOT_DELTA_BASE_COPY) {
359 err = parse_opcode(&offset, &len, &p, &remain);
362 err = copy_from_base(base_file, offset, len,
363 memstream ? memstream : outfile);
372 size_t len = (size_t)*p;
374 err = got_error(GOT_ERR_BAD_DELTA);
377 err = next_delta_byte(&p, &remain);
380 err = copy_from_delta(&p, &remain, len,
381 memstream ? memstream : outfile);
387 if (*outsize != result_size)
388 err = got_error(GOT_ERR_BAD_DELTA);
390 if (memstream != NULL) {
394 n = fwrite(memstream_buf, 1, memstream_size, outfile);
395 if (n != memstream_size)
396 err = got_ferror(outfile, GOT_ERR_IO);