vcs-svn/fast_export.c

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