vcs-svn/fast_export.c

   1 /*
   2  * Licensed under a two-clause BSD-style license.
   3  * See LICENSE for details.
   4  */
   5
   6 #include "cache.h"
   7 #include "quote.h"
   8 #include "fast_export.h"
   9 #include "repo_tree.h"
  10 #include "strbuf.h"
  11 #include "svndiff.h"
  12 #include "sliding_window.h"
  13 #include "line_buffer.h"
  14
  15 #define MAX_GITSVN_LINE_LEN 4096
  16
  17 static uint32_t first_commit_done;
  18 static struct line_buffer postimage = LINE_BUFFER_INIT;
  19 static struct line_buffer report_buffer = LINE_BUFFER_INIT;
  20
  21 /* NEEDSWORK: move to fast_export_init() */
  22 static int init_postimage(void)
  23 {
  24         static int postimage_initialized;
  25         if (postimage_initialized)
  26                 return 0;
  27         postimage_initialized = 1;
  28         return buffer_tmpfile_init(&postimage);
  29 }
  30
  31 void fast_export_init(int fd)
  32 {
  33         first_commit_done = 0;
  34         if (buffer_fdinit(&report_buffer, fd))
  35                 die_errno("cannot read from file descriptor %d", fd);
  36 }
  37
  38 void fast_export_deinit(void)
  39 {
  40         if (buffer_deinit(&report_buffer))
  41                 die_errno("error closing fast-import feedback stream");
  42 }
  43
  44 void fast_export_delete(const char *path)
  45 {
  46         putchar('D');
  47         putchar(' ');
  48         quote_c_style(path, NULL, stdout, 0);
  49         putchar('\n');
  50 }
  51
  52 static void fast_export_truncate(const char *path, uint32_t mode)
  53 {
  54         fast_export_modify(path, mode, "inline");
  55         printf("data 0\n\n");
  56 }
  57
  58 void fast_export_modify(const char *path, uint32_t mode, const char *dataref)
  59 {
  60         /* Mode must be 100644, 100755, 120000, or 160000. */
  61         if (!dataref) {
  62                 fast_export_truncate(path, mode);
  63                 return;
  64         }
  65         printf("M %06"PRIo32" %s ", mode, dataref);
  66         quote_c_style(path, NULL, stdout, 0);
  67         putchar('\n');
  68 }
  69
  70 void fast_export_begin_note(uint32_t revision, const char *author,
  71                 const char *log, unsigned long timestamp, const char *note_ref)
  72 {
  73         static int firstnote = 1;
  74         size_t loglen = strlen(log);
  75         printf("commit %s\n", note_ref);
  76         printf("committer %s <%s@%s> %ld +0000\n", author, author, "local", timestamp);
  77         printf("data %"PRIuMAX"\n", (uintmax_t)loglen);
  78         fwrite(log, loglen, 1, stdout);
  79         if (firstnote) {
  80                 if (revision > 1)
  81                         printf("from %s^0", note_ref);
  82                 firstnote = 0;
  83         }
  84         fputc('\n', stdout);
  85 }
  86
  87 void fast_export_note(const char *committish, const char *dataref)
  88 {
  89         printf("N %s %s\n", dataref, committish);
  90 }
  91
  92 static char gitsvnline[MAX_GITSVN_LINE_LEN];
  93 void fast_export_begin_commit(uint32_t revision, const char *author,
  94                         const struct strbuf *log,
  95                         const char *uuid, const char *url,
  96                         unsigned long timestamp, const char *local_ref)
  97 {
  98         static const struct strbuf empty = STRBUF_INIT;
  99         if (!log)
 100                 log = &empty;
 101         if (*uuid && *url) {
 102                 snprintf(gitsvnline, MAX_GITSVN_LINE_LEN,
 103                                 "\n\ngit-svn-id: %s@%"PRIu32" %s\n",
 104                                  url, revision, uuid);
 105         } else {
 106                 *gitsvnline = '\0';
 107         }
 108         printf("commit %s\n", local_ref);
 109         printf("mark :%"PRIu32"\n", revision);
 110         printf("committer %s <%s@%s> %ld +0000\n",
 111                    *author ? author : "nobody",
 112                    *author ? author : "nobody",
 113                    *uuid ? uuid : "local", timestamp);
 114         printf("data %"PRIuMAX"\n",
 115                 (uintmax_t) (log->len + strlen(gitsvnline)));
 116         fwrite(log->buf, log->len, 1, stdout);
 117         printf("%s\n", gitsvnline);
 118         if (!first_commit_done) {
 119                 if (revision > 1)
 120                         printf("from :%"PRIu32"\n", revision - 1);
 121                 first_commit_done = 1;
 122         }
 123 }
 124
 125 void fast_export_end_commit(uint32_t revision)
 126 {
 127         printf("progress Imported commit %"PRIu32".\n\n", revision);
 128 }
 129
 130 static void ls_from_rev(uint32_t rev, const char *path)
 131 {
 132         /* ls :5 path/to/old/file */
 133         printf("ls :%"PRIu32" ", rev);
 134         quote_c_style(path, NULL, stdout, 0);
 135         putchar('\n');
 136         fflush(stdout);
 137 }
 138
 139 static void ls_from_active_commit(const char *path)
 140 {
 141         /* ls "path/to/file" */
 142         printf("ls \"");
 143         quote_c_style(path, NULL, stdout, 1);
 144         printf("\"\n");
 145         fflush(stdout);
 146 }
 147
 148 static const char *get_response_line(void)
 149 {
 150         const char *line = buffer_read_line(&report_buffer);
 151         if (line)
 152                 return line;
 153         if (buffer_ferror(&report_buffer))
 154                 die_errno("error reading from fast-import");
 155         die("unexpected end of fast-import feedback");
 156 }
 157
 158 static void die_short_read(struct line_buffer *input)
 159 {
 160         if (buffer_ferror(input))
 161                 die_errno("error reading dump file");
 162         die("invalid dump: unexpected end of file");
 163 }
 164
 165 static int ends_with(const char *s, size_t len, const char *suffix)
 166 {
 167         const size_t suffixlen = strlen(suffix);
 168         if (len < suffixlen)
 169                 return 0;
 170         return !memcmp(s + len - suffixlen, suffix, suffixlen);
 171 }
 172
 173 static int parse_cat_response_line(const char *header, off_t *len)
 174 {
 175         size_t headerlen = strlen(header);
 176         uintmax_t n;
 177         const char *type;
 178         const char *end;
 179
 180         if (ends_with(header, headerlen, " missing"))
 181                 return error("cat-blob reports missing blob: %s", header);
 182         type = strstr(header, " blob ");
 183         if (!type)
 184                 return error("cat-blob header has wrong object type: %s", header);
 185         n = strtoumax(type + strlen(" blob "), (char **) &end, 10);
 186         if (end == type + strlen(" blob "))
 187                 return error("cat-blob header does not contain length: %s", header);
 188         if (memchr(type + strlen(" blob "), '-', end - type - strlen(" blob ")))
 189                 return error("cat-blob header contains negative length: %s", header);
 190         if (n == UINTMAX_MAX || n > maximum_signed_value_of_type(off_t))
 191                 return error("blob too large for current definition of off_t");
 192         *len = n;
 193         if (*end)
 194                 return error("cat-blob header contains garbage after length: %s", header);
 195         return 0;
 196 }
 197
 198 static void check_preimage_overflow(off_t a, off_t b)
 199 {
 200         if (signed_add_overflows(a, b))
 201                 die("blob too large for current definition of off_t");
 202 }
 203
 204 static long apply_delta(off_t len, struct line_buffer *input,
 205                         const char *old_data, uint32_t old_mode)
 206 {
 207         long ret;
 208         struct sliding_view preimage = SLIDING_VIEW_INIT(&report_buffer, 0);
 209         FILE *out;
 210
 211         if (init_postimage() || !(out = buffer_tmpfile_rewind(&postimage)))
 212                 die("cannot open temporary file for blob retrieval");
 213         if (old_data) {
 214                 const char *response;
 215                 printf("cat-blob %s\n", old_data);
 216                 fflush(stdout);
 217                 response = get_response_line();
 218                 if (parse_cat_response_line(response, &preimage.max_off))
 219                         die("invalid cat-blob response: %s", response);
 220                 check_preimage_overflow(preimage.max_off, 1);
 221         }
 222         if (old_mode == REPO_MODE_LNK) {
 223                 strbuf_addstr(&preimage.buf, "link ");
 224                 check_preimage_overflow(preimage.max_off, strlen("link "));
 225                 preimage.max_off += strlen("link ");
 226                 check_preimage_overflow(preimage.max_off, 1);
 227         }
 228         if (svndiff0_apply(input, len, &preimage, out))
 229                 die("cannot apply delta");
 230         if (old_data) {
 231                 /* Read the remainder of preimage and trailing newline. */
 232                 assert(!signed_add_overflows(preimage.max_off, 1));
 233                 preimage.max_off++;     /* room for newline */
 234                 if (move_window(&preimage, preimage.max_off - 1, 1))
 235                         die("cannot seek to end of input");
 236                 if (preimage.buf.buf[0] != '\n')
 237                         die("missing newline after cat-blob response");
 238         }
 239         ret = buffer_tmpfile_prepare_to_read(&postimage);
 240         if (ret < 0)
 241                 die("cannot read temporary file for blob retrieval");
 242         strbuf_release(&preimage.buf);
 243         return ret;
 244 }
 245
 246 void fast_export_buf_to_data(const struct strbuf *data)
 247 {
 248         printf("data %"PRIuMAX"\n", (uintmax_t)data->len);
 249         fwrite(data->buf, data->len, 1, stdout);
 250         fputc('\n', stdout);
 251 }
 252
 253 void fast_export_data(uint32_t mode, off_t len, struct line_buffer *input)
 254 {
 255         assert(len >= 0);
 256         if (mode == REPO_MODE_LNK) {
 257                 /* svn symlink blobs start with "link " */
 258                 if (len < 5)
 259                         die("invalid dump: symlink too short for \"link\" prefix");
 260                 len -= 5;
 261                 if (buffer_skip_bytes(input, 5) != 5)
 262                         die_short_read(input);
 263         }
 264         printf("data %"PRIuMAX"\n", (uintmax_t) len);
 265         if (buffer_copy_bytes(input, len) != len)
 266                 die_short_read(input);
 267         fputc('\n', stdout);
 268 }
 269
 270 static int parse_ls_response(const char *response, uint32_t *mode,
 271                                         struct strbuf *dataref)
 272 {
 273         const char *tab;
 274         const char *response_end;
 275
 276         assert(response);
 277         response_end = response + strlen(response);
 278
 279         if (*response == 'm') { /* Missing. */
 280                 errno = ENOENT;
 281                 return -1;
 282         }
 283
 284         /* Mode. */
 285         if (response_end - response < (signed) strlen("100644") ||
 286             response[strlen("100644")] != ' ')
 287                 die("invalid ls response: missing mode: %s", response);
 288         *mode = 0;
 289         for (; *response != ' '; response++) {
 290                 char ch = *response;
 291                 if (ch < '0' || ch > '7')
 292                         die("invalid ls response: mode is not octal: %s", response);
 293                 *mode *= 8;
 294                 *mode += ch - '0';
 295         }
 296
 297         /* ' blob ' or ' tree ' */
 298         if (response_end - response < (signed) strlen(" blob ") ||
 299             (response[1] != 'b' && response[1] != 't'))
 300                 die("unexpected ls response: not a tree or blob: %s", response);
 301         response += strlen(" blob ");
 302
 303         /* Dataref. */
 304         tab = memchr(response, '\t', response_end - response);
 305         if (!tab)
 306                 die("invalid ls response: missing tab: %s", response);
 307         strbuf_add(dataref, response, tab - response);
 308         return 0;
 309 }
 310
 311 int fast_export_ls_rev(uint32_t rev, const char *path,
 312                                 uint32_t *mode, struct strbuf *dataref)
 313 {
 314         ls_from_rev(rev, path);
 315         return parse_ls_response(get_response_line(), mode, dataref);
 316 }
 317
 318 int fast_export_ls(const char *path, uint32_t *mode, struct strbuf *dataref)
 319 {
 320         ls_from_active_commit(path);
 321         return parse_ls_response(get_response_line(), mode, dataref);
 322 }
 323
 324 void fast_export_blob_delta(uint32_t mode,
 325                                 uint32_t old_mode, const char *old_data,
 326                                 off_t len, struct line_buffer *input)
 327 {
 328         long postimage_len;
 329
 330         assert(len >= 0);
 331         postimage_len = apply_delta(len, input, old_data, old_mode);
 332         if (mode == REPO_MODE_LNK) {
 333                 buffer_skip_bytes(&postimage, strlen("link "));
 334                 postimage_len -= strlen("link ");
 335         }
 336         printf("data %ld\n", postimage_len);
 337         buffer_copy_bytes(&postimage, postimage_len);
 338         fputc('\n', stdout);
 339 }