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