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Commit | Line | Data |
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568508e7 JH |
1 | /* |
2 | * Copyright (c) 2011, Google Inc. | |
3 | */ | |
4 | #include "bulk-checkin.h" | |
5 | #include "csum-file.h" | |
6 | #include "pack.h" | |
58892711 | 7 | #include "strbuf.h" |
568508e7 JH |
8 | |
9 | static int pack_compression_level = Z_DEFAULT_COMPRESSION; | |
10 | ||
11 | static struct bulk_checkin_state { | |
12 | unsigned plugged:1; | |
13 | ||
14 | char *pack_tmp_name; | |
15 | struct sha1file *f; | |
16 | off_t offset; | |
17 | struct pack_idx_option pack_idx_opts; | |
18 | ||
19 | struct pack_idx_entry **written; | |
20 | uint32_t alloc_written; | |
21 | uint32_t nr_written; | |
22 | } state; | |
23 | ||
24 | static void finish_bulk_checkin(struct bulk_checkin_state *state) | |
25 | { | |
26 | unsigned char sha1[20]; | |
58892711 | 27 | struct strbuf packname = STRBUF_INIT; |
568508e7 JH |
28 | int i; |
29 | ||
30 | if (!state->f) | |
31 | return; | |
32 | ||
33 | if (state->nr_written == 0) { | |
34 | close(state->f->fd); | |
35 | unlink(state->pack_tmp_name); | |
36 | goto clear_exit; | |
37 | } else if (state->nr_written == 1) { | |
38 | sha1close(state->f, sha1, CSUM_FSYNC); | |
39 | } else { | |
40 | int fd = sha1close(state->f, sha1, 0); | |
41 | fixup_pack_header_footer(fd, sha1, state->pack_tmp_name, | |
42 | state->nr_written, sha1, | |
43 | state->offset); | |
44 | close(fd); | |
45 | } | |
46 | ||
58892711 SH |
47 | strbuf_addf(&packname, "%s/pack/pack-", get_object_directory()); |
48 | finish_tmp_packfile(&packname, state->pack_tmp_name, | |
568508e7 JH |
49 | state->written, state->nr_written, |
50 | &state->pack_idx_opts, sha1); | |
51 | for (i = 0; i < state->nr_written; i++) | |
52 | free(state->written[i]); | |
53 | ||
54 | clear_exit: | |
55 | free(state->written); | |
56 | memset(state, 0, sizeof(*state)); | |
57 | ||
58892711 | 58 | strbuf_release(&packname); |
568508e7 JH |
59 | /* Make objects we just wrote available to ourselves */ |
60 | reprepare_packed_git(); | |
61 | } | |
62 | ||
63 | static int already_written(struct bulk_checkin_state *state, unsigned char sha1[]) | |
64 | { | |
65 | int i; | |
66 | ||
67 | /* The object may already exist in the repository */ | |
68 | if (has_sha1_file(sha1)) | |
69 | return 1; | |
70 | ||
71 | /* Might want to keep the list sorted */ | |
72 | for (i = 0; i < state->nr_written; i++) | |
73 | if (!hashcmp(state->written[i]->sha1, sha1)) | |
74 | return 1; | |
75 | ||
76 | /* This is a new object we need to keep */ | |
77 | return 0; | |
78 | } | |
79 | ||
80 | /* | |
81 | * Read the contents from fd for size bytes, streaming it to the | |
82 | * packfile in state while updating the hash in ctx. Signal a failure | |
83 | * by returning a negative value when the resulting pack would exceed | |
84 | * the pack size limit and this is not the first object in the pack, | |
85 | * so that the caller can discard what we wrote from the current pack | |
86 | * by truncating it and opening a new one. The caller will then call | |
87 | * us again after rewinding the input fd. | |
88 | * | |
89 | * The already_hashed_to pointer is kept untouched by the caller to | |
90 | * make sure we do not hash the same byte when we are called | |
91 | * again. This way, the caller does not have to checkpoint its hash | |
92 | * status before calling us just in case we ask it to call us again | |
93 | * with a new pack. | |
94 | */ | |
95 | static int stream_to_pack(struct bulk_checkin_state *state, | |
96 | git_SHA_CTX *ctx, off_t *already_hashed_to, | |
97 | int fd, size_t size, enum object_type type, | |
98 | const char *path, unsigned flags) | |
99 | { | |
100 | git_zstream s; | |
101 | unsigned char obuf[16384]; | |
102 | unsigned hdrlen; | |
103 | int status = Z_OK; | |
104 | int write_object = (flags & HASH_WRITE_OBJECT); | |
105 | off_t offset = 0; | |
106 | ||
107 | memset(&s, 0, sizeof(s)); | |
108 | git_deflate_init(&s, pack_compression_level); | |
109 | ||
110 | hdrlen = encode_in_pack_object_header(type, size, obuf); | |
111 | s.next_out = obuf + hdrlen; | |
112 | s.avail_out = sizeof(obuf) - hdrlen; | |
113 | ||
114 | while (status != Z_STREAM_END) { | |
115 | unsigned char ibuf[16384]; | |
116 | ||
117 | if (size && !s.avail_in) { | |
118 | ssize_t rsize = size < sizeof(ibuf) ? size : sizeof(ibuf); | |
e92527c9 | 119 | if (read_in_full(fd, ibuf, rsize) != rsize) |
568508e7 JH |
120 | die("failed to read %d bytes from '%s'", |
121 | (int)rsize, path); | |
122 | offset += rsize; | |
123 | if (*already_hashed_to < offset) { | |
124 | size_t hsize = offset - *already_hashed_to; | |
125 | if (rsize < hsize) | |
126 | hsize = rsize; | |
127 | if (hsize) | |
128 | git_SHA1_Update(ctx, ibuf, hsize); | |
129 | *already_hashed_to = offset; | |
130 | } | |
131 | s.next_in = ibuf; | |
132 | s.avail_in = rsize; | |
133 | size -= rsize; | |
134 | } | |
135 | ||
136 | status = git_deflate(&s, size ? 0 : Z_FINISH); | |
137 | ||
138 | if (!s.avail_out || status == Z_STREAM_END) { | |
139 | if (write_object) { | |
140 | size_t written = s.next_out - obuf; | |
141 | ||
142 | /* would we bust the size limit? */ | |
143 | if (state->nr_written && | |
144 | pack_size_limit_cfg && | |
145 | pack_size_limit_cfg < state->offset + written) { | |
146 | git_deflate_abort(&s); | |
147 | return -1; | |
148 | } | |
149 | ||
150 | sha1write(state->f, obuf, written); | |
151 | state->offset += written; | |
152 | } | |
153 | s.next_out = obuf; | |
154 | s.avail_out = sizeof(obuf); | |
155 | } | |
156 | ||
157 | switch (status) { | |
158 | case Z_OK: | |
159 | case Z_BUF_ERROR: | |
160 | case Z_STREAM_END: | |
161 | continue; | |
162 | default: | |
163 | die("unexpected deflate failure: %d", status); | |
164 | } | |
165 | } | |
166 | git_deflate_end(&s); | |
167 | return 0; | |
168 | } | |
169 | ||
170 | /* Lazily create backing packfile for the state */ | |
171 | static void prepare_to_stream(struct bulk_checkin_state *state, | |
172 | unsigned flags) | |
173 | { | |
174 | if (!(flags & HASH_WRITE_OBJECT) || state->f) | |
175 | return; | |
176 | ||
177 | state->f = create_tmp_packfile(&state->pack_tmp_name); | |
178 | reset_pack_idx_option(&state->pack_idx_opts); | |
179 | ||
180 | /* Pretend we are going to write only one object */ | |
181 | state->offset = write_pack_header(state->f, 1); | |
182 | if (!state->offset) | |
183 | die_errno("unable to write pack header"); | |
184 | } | |
185 | ||
186 | static int deflate_to_pack(struct bulk_checkin_state *state, | |
187 | unsigned char result_sha1[], | |
188 | int fd, size_t size, | |
189 | enum object_type type, const char *path, | |
190 | unsigned flags) | |
191 | { | |
192 | off_t seekback, already_hashed_to; | |
193 | git_SHA_CTX ctx; | |
194 | unsigned char obuf[16384]; | |
195 | unsigned header_len; | |
196 | struct sha1file_checkpoint checkpoint; | |
197 | struct pack_idx_entry *idx = NULL; | |
198 | ||
199 | seekback = lseek(fd, 0, SEEK_CUR); | |
200 | if (seekback == (off_t) -1) | |
201 | return error("cannot find the current offset"); | |
202 | ||
203 | header_len = sprintf((char *)obuf, "%s %" PRIuMAX, | |
204 | typename(type), (uintmax_t)size) + 1; | |
205 | git_SHA1_Init(&ctx); | |
206 | git_SHA1_Update(&ctx, obuf, header_len); | |
207 | ||
208 | /* Note: idx is non-NULL when we are writing */ | |
209 | if ((flags & HASH_WRITE_OBJECT) != 0) | |
210 | idx = xcalloc(1, sizeof(*idx)); | |
211 | ||
212 | already_hashed_to = 0; | |
213 | ||
214 | while (1) { | |
215 | prepare_to_stream(state, flags); | |
216 | if (idx) { | |
217 | sha1file_checkpoint(state->f, &checkpoint); | |
218 | idx->offset = state->offset; | |
219 | crc32_begin(state->f); | |
220 | } | |
221 | if (!stream_to_pack(state, &ctx, &already_hashed_to, | |
222 | fd, size, type, path, flags)) | |
223 | break; | |
224 | /* | |
225 | * Writing this object to the current pack will make | |
226 | * it too big; we need to truncate it, start a new | |
227 | * pack, and write into it. | |
228 | */ | |
229 | if (!idx) | |
230 | die("BUG: should not happen"); | |
231 | sha1file_truncate(state->f, &checkpoint); | |
232 | state->offset = checkpoint.offset; | |
233 | finish_bulk_checkin(state); | |
234 | if (lseek(fd, seekback, SEEK_SET) == (off_t) -1) | |
235 | return error("cannot seek back"); | |
236 | } | |
237 | git_SHA1_Final(result_sha1, &ctx); | |
238 | if (!idx) | |
239 | return 0; | |
240 | ||
241 | idx->crc32 = crc32_end(state->f); | |
242 | if (already_written(state, result_sha1)) { | |
243 | sha1file_truncate(state->f, &checkpoint); | |
244 | state->offset = checkpoint.offset; | |
245 | free(idx); | |
246 | } else { | |
247 | hashcpy(idx->sha1, result_sha1); | |
248 | ALLOC_GROW(state->written, | |
249 | state->nr_written + 1, | |
250 | state->alloc_written); | |
251 | state->written[state->nr_written++] = idx; | |
252 | } | |
253 | return 0; | |
254 | } | |
255 | ||
256 | int index_bulk_checkin(unsigned char *sha1, | |
257 | int fd, size_t size, enum object_type type, | |
258 | const char *path, unsigned flags) | |
259 | { | |
260 | int status = deflate_to_pack(&state, sha1, fd, size, type, | |
261 | path, flags); | |
262 | if (!state.plugged) | |
263 | finish_bulk_checkin(&state); | |
264 | return status; | |
265 | } | |
266 | ||
267 | void plug_bulk_checkin(void) | |
268 | { | |
269 | state.plugged = 1; | |
270 | } | |
271 | ||
272 | void unplug_bulk_checkin(void) | |
273 | { | |
274 | state.plugged = 0; | |
275 | if (state.f) | |
276 | finish_bulk_checkin(&state); | |
277 | } |