dir.h: move struct exclude declaration to top level
[git.git] / bulk-checkin.c
blob98e651c284254b3c96c59b4f444cbc0f54edd90e
1 /*
2 * Copyright (c) 2011, Google Inc.
3 */
4 #include "bulk-checkin.h"
5 #include "csum-file.h"
6 #include "pack.h"
7 #include "strbuf.h"
9 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
11 static struct bulk_checkin_state {
12 unsigned plugged:1;
14 char *pack_tmp_name;
15 struct sha1file *f;
16 off_t offset;
17 struct pack_idx_option pack_idx_opts;
19 struct pack_idx_entry **written;
20 uint32_t alloc_written;
21 uint32_t nr_written;
22 } state;
24 static void finish_bulk_checkin(struct bulk_checkin_state *state)
26 unsigned char sha1[20];
27 struct strbuf packname = STRBUF_INIT;
28 int i;
30 if (!state->f)
31 return;
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);
47 strbuf_addf(&packname, "%s/pack/pack-", get_object_directory());
48 finish_tmp_packfile(&packname, state->pack_tmp_name,
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]);
54 clear_exit:
55 free(state->written);
56 memset(state, 0, sizeof(*state));
58 strbuf_release(&packname);
59 /* Make objects we just wrote available to ourselves */
60 reprepare_packed_git();
63 static int already_written(struct bulk_checkin_state *state, unsigned char sha1[])
65 int i;
67 /* The object may already exist in the repository */
68 if (has_sha1_file(sha1))
69 return 1;
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;
76 /* This is a new object we need to keep */
77 return 0;
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.
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.
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)
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;
107 memset(&s, 0, sizeof(s));
108 git_deflate_init(&s, pack_compression_level);
110 hdrlen = encode_in_pack_object_header(type, size, obuf);
111 s.next_out = obuf + hdrlen;
112 s.avail_out = sizeof(obuf) - hdrlen;
114 while (status != Z_STREAM_END) {
115 unsigned char ibuf[16384];
117 if (size && !s.avail_in) {
118 ssize_t rsize = size < sizeof(ibuf) ? size : sizeof(ibuf);
119 if (read_in_full(fd, ibuf, rsize) != rsize)
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;
131 s.next_in = ibuf;
132 s.avail_in = rsize;
133 size -= rsize;
136 status = git_deflate(&s, size ? 0 : Z_FINISH);
138 if (!s.avail_out || status == Z_STREAM_END) {
139 if (write_object) {
140 size_t written = s.next_out - obuf;
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;
150 sha1write(state->f, obuf, written);
151 state->offset += written;
153 s.next_out = obuf;
154 s.avail_out = sizeof(obuf);
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);
166 git_deflate_end(&s);
167 return 0;
170 /* Lazily create backing packfile for the state */
171 static void prepare_to_stream(struct bulk_checkin_state *state,
172 unsigned flags)
174 if (!(flags & HASH_WRITE_OBJECT) || state->f)
175 return;
177 state->f = create_tmp_packfile(&state->pack_tmp_name);
178 reset_pack_idx_option(&state->pack_idx_opts);
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");
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)
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;
199 seekback = lseek(fd, 0, SEEK_CUR);
200 if (seekback == (off_t) -1)
201 return error("cannot find the current offset");
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);
208 /* Note: idx is non-NULL when we are writing */
209 if ((flags & HASH_WRITE_OBJECT) != 0)
210 idx = xcalloc(1, sizeof(*idx));
212 already_hashed_to = 0;
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);
221 if (!stream_to_pack(state, &ctx, &already_hashed_to,
222 fd, size, type, path, flags))
223 break;
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.
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");
237 git_SHA1_Final(result_sha1, &ctx);
238 if (!idx)
239 return 0;
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;
253 return 0;
256 int index_bulk_checkin(unsigned char *sha1,
257 int fd, size_t size, enum object_type type,
258 const char *path, unsigned flags)
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;
267 void plug_bulk_checkin(void)
269 state.plugged = 1;
272 void unplug_bulk_checkin(void)
274 state.plugged = 0;
275 if (state.f)
276 finish_bulk_checkin(&state);