diff_file.c

subversion-1.4.3-1.tar.gz 配置svn的源码

  idx = svn_diff__file_datasource_to_index(datasource);

  curp = file_baton->curp[idx];
  endp = file_baton->endp[idx];

  last_chunk = offset_to_chunk(file_baton->size[idx]);

  if (curp == endp
      && last_chunk == file_baton->chunk[idx])
    {
      return SVN_NO_ERROR;
    }

  /* Get a new token */
  file_token = file_baton->tokens;
  if (file_token)
    {
      file_baton->tokens = file_token->next;
    }
  else
    {
      file_token = apr_palloc(file_baton->pool, sizeof(*file_token));
    }

  file_token->datasource = datasource;
  file_token->offset = chunk_to_offset(file_baton->chunk[idx])
                       + (curp - file_baton->buffer[idx]);
  file_token->raw_length = 0;
  file_token->length = 0;

  while (1)
    {
      eol = find_eol_start(curp, endp - curp);
      if (eol)
        {
          had_cr = (*eol == '\r');
          eol++;
          /* If we have the whole eol sequence in the chunk... */
          if (!had_cr || eol != endp)
            {
              if (had_cr && *eol == '\n')
                ++eol;
              break;
            }
        }

      if (file_baton->chunk[idx] == last_chunk)
        {
          eol = endp;
          break;
        }

      length = endp - curp;
      file_token->raw_length += length;
      normalize(curp, &length, &file_baton->normalize_state[idx],
                file_baton->options);
      file_token->length += length;
      h = svn_diff__adler32(h, curp, length);

      curp = endp = file_baton->buffer[idx];
      file_baton->chunk[idx]++;
      length = file_baton->chunk[idx] == last_chunk ? 
        offset_in_chunk(file_baton->size[idx]) : CHUNK_SIZE;
      endp += length;
      file_baton->endp[idx] = endp;

      SVN_ERR(read_chunk(file_baton->file[idx], file_baton->path[idx],
                         curp, length, 
                         chunk_to_offset(file_baton->chunk[idx]),
                         file_baton->pool));

      /* If the last chunk ended in a CR, we're done. */
      if (had_cr)
        {
          eol = curp;
          if (*curp == '\n')
            ++eol;
          break;
        }
    }

  length = eol - curp;
  file_token->raw_length += length;
  file_baton->curp[idx] = eol;

  /* If the file length is exactly a multiple of CHUNK_SIZE, we will end up
   * with a spurious empty token.  Avoid returning it.
   * Note that we use the unnormalized length; we don't want a line containing
   * only spaces (and no trailing newline) to appear like a non-existent
   * line. */
  if (file_token->raw_length > 0)
    {
      normalize(curp, &length, &file_baton->normalize_state[idx],
                file_baton->options);
      file_token->length += length;

      *hash = svn_diff__adler32(h, curp, length);
      *token = file_token;
    }

  return SVN_NO_ERROR;
}

#define COMPARE_CHUNK_SIZE 4096

/* Implements svn_diff_fns_t::token_compare */
static svn_error_t *
svn_diff__file_token_compare(void *baton,
                             void *token1,
                             void *token2,
                             int *compare)
{
  svn_diff__file_baton_t *file_baton = baton;
  svn_diff__file_token_t *file_token[2];
  char buffer[2][COMPARE_CHUNK_SIZE];
  char *bufp[2];
  apr_off_t offset[2];
  int idx[2];
  apr_off_t length[2];
  apr_off_t total_length;
  /* How much is left to read of each token from the file. */
  apr_off_t raw_length[2];
  int i;
  int chunk[2];
  normalize_state_t state[2];

  file_token[0] = token1;
  file_token[1] = token2;
  if (file_token[0]->length < file_token[1]->length)
    {
      *compare = -1;
      return SVN_NO_ERROR;
    }

  if (file_token[0]->length > file_token[1]->length)
    {
      *compare = 1;
      return SVN_NO_ERROR;
    }

  total_length = file_token[0]->length;
  if (total_length == 0)
    {
      *compare = 0;
      return SVN_NO_ERROR;
    }

  for (i = 0; i < 2; ++i)
    {
      idx[i] = svn_diff__file_datasource_to_index(file_token[i]->datasource);
      offset[i] = file_token[i]->offset;
      chunk[i] = file_baton->chunk[idx[i]];
      state[i] = state_normal;

      if (offset_to_chunk(offset[i]) == chunk[i])
        {
          /* If the start of the token is in memory, the entire token is
           * in memory.
           */
          bufp[i] = file_baton->buffer[idx[i]];
          bufp[i] += offset_in_chunk(offset[i]);
          
          length[i] = total_length;
          raw_length[i] = 0;
        }
      else
        {
          length[i] = 0;
          raw_length[i] = file_token[i]->raw_length;
        }
    }

  do
    {
      apr_off_t len;
      for (i = 0; i < 2; i++)
        {
          if (length[i] == 0)
            {
              /* Error if raw_length is 0, that's an unexpected change
               * of the file that can happen when ingoring whitespace
               * and that can lead to an infinite loop. */
              if (raw_length[i] == 0)
                return svn_error_createf(SVN_ERR_DIFF_DATASOURCE_MODIFIED,
                                         NULL,
                                         _("The file '%s' changed unexpectedly"
                                           " during diff"),
                                         file_baton->path[idx[i]]);

              /* Read a chunk from disk into a buffer */
              bufp[i] = buffer[i];
              length[i] = raw_length[i] > COMPARE_CHUNK_SIZE ? 
                COMPARE_CHUNK_SIZE : raw_length[i];

              SVN_ERR(read_chunk(file_baton->file[idx[i]],
                                 file_baton->path[idx[i]],
                                 bufp[i], length[i], offset[i],
                                 file_baton->pool));
              offset[i] += length[i];
              raw_length[i] -= length[i];
              normalize(bufp[i], &length[i], &state[i], file_baton->options);
            }
        }

      len = length[0] > length[1] ? length[1] : length[0];

      /* Compare two chunks (that could be entire tokens if they both reside
       * in memory).
       */
      *compare = memcmp(bufp[0], bufp[1], len);
      if (*compare != 0)
        return SVN_NO_ERROR;

      total_length -= len;
      length[0] -= len;
      length[1] -= len;
      bufp[0] += len;
      bufp[1] += len;
    }
  while(total_length > 0);

  *compare = 0;
  return SVN_NO_ERROR;
}


/* Implements svn_diff_fns_t::token_discard */
static void
svn_diff__file_token_discard(void *baton,
                             void *token)
{
  svn_diff__file_baton_t *file_baton = baton;
  svn_diff__file_token_t *file_token = token;

  file_token->next = file_baton->tokens;
  file_baton->tokens = file_token;
}


/* Implements svn_diff_fns_t::token_discard_all */
static void
svn_diff__file_token_discard_all(void *baton)
{
  svn_diff__file_baton_t *file_baton = baton;

  /* Discard all memory in use by the tokens, and close all open files. */
  svn_pool_clear(file_baton->pool);
}


static const svn_diff_fns_t svn_diff__file_vtable =
{
  svn_diff__file_datasource_open,
  svn_diff__file_datasource_close,
  svn_diff__file_datasource_get_next_token,
  svn_diff__file_token_compare,
  svn_diff__file_token_discard,
  svn_diff__file_token_discard_all
};

/* Id for the --ignore-eol-style option, which doesn't have a short name. */
#define SVN_DIFF__OPT_IGNORE_EOL_STYLE 256

/* Options supported by svn_diff_file_options_parse(). */
static const apr_getopt_option_t diff_options[] =
{
  { "ignore-space-change", 'b', 0, NULL },
  { "ignore-all-space", 'w', 0, NULL },
  { "ignore-eol-style", SVN_DIFF__OPT_IGNORE_EOL_STYLE, 0, NULL },
  /* ### For compatibility; we don't support the argument to -u, because
   * ### we don't have optional argument support. */
  { "unified", 'u', 0, NULL },
  { NULL, 0, 0, NULL }
};

svn_diff_file_options_t *
svn_diff_file_options_create(apr_pool_t *pool)
{
  return apr_pcalloc(pool, sizeof(svn_diff_file_options_t));
}

svn_error_t *
svn_diff_file_options_parse(svn_diff_file_options_t *options,
                            const apr_array_header_t *args,
                            apr_pool_t *pool)
{
  apr_getopt_t *os;
  /* Make room for each option (starting at index 1) plus trailing NULL. */
  const char **argv = apr_palloc(pool, sizeof(char*) * (args->nelts + 2));

  argv[0] = "";
  memcpy(argv + 1, args->elts, sizeof(char*) * args->nelts);
  argv[args->nelts + 1] = NULL;
  
  apr_getopt_init(&os, pool, args->nelts + 1, argv);
  /* No printing of error messages, please! */
  os->errfn = NULL;
  while (1)
    {
      const char *opt_arg;
      int opt_id;
      apr_status_t err = apr_getopt_long(os, diff_options, &opt_id, &opt_arg);

      if (APR_STATUS_IS_EOF(err))
        break;
      if (err)
        return svn_error_wrap_apr(err, _("Error parsing diff options"));

      switch (opt_id)
        {
        case 'b':
          /* -w takes precedence over -b. */
          if (! options->ignore_space)
            options->ignore_space = svn_diff_file_ignore_space_change;
          break;
        case 'w':
          options->ignore_space = svn_diff_file_ignore_space_all;
          break;
        case SVN_DIFF__OPT_IGNORE_EOL_STYLE:
          options->ignore_eol_style = TRUE;
          break;
        default:
          break;
        }
    }

  /* Check for spurious arguments. */
  if (os->ind < os->argc)
    return svn_error_createf(SVN_ERR_INVALID_DIFF_OPTION, NULL,
                             _("Invalid argument '%s' in diff options"),
                             os->argv[os->ind]);

  return SVN_NO_ERROR;
}

svn_error_t *
svn_diff_file_diff_2(svn_diff_t **diff,
                     const char *original,
                     const char *modified,
                     const svn_diff_file_options_t *options,
                     apr_pool_t *pool)
{
  svn_diff__file_baton_t baton;

  memset(&baton, 0, sizeof(baton));
  baton.options = options;
  baton.path[0] = original;
  baton.path[1] = modified;
  baton.pool = svn_pool_create(pool);

  SVN_ERR(svn_diff_diff(diff, &baton, &svn_diff__file_vtable, pool));

  svn_pool_destroy(baton.pool);
  return SVN_NO_ERROR;
}

svn_error_t *
svn_diff_file_diff(svn_diff_t **diff,
                   const char *original,
                   const char *modified,
                   apr_pool_t *pool)
{
  return svn_diff_file_diff_2(diff, original, modified,
                              svn_diff_file_options_create(pool), pool);
}

svn_error_t *
svn_diff_file_diff3_2(svn_diff_t **diff,
                      const char *original,
                      const char *modified,
                      const char *latest,
                      const svn_diff_file_options_t *options,
                      apr_pool_t *pool)
{
  svn_diff__file_baton_t baton;

  memset(&baton, 0, sizeof(baton));
  baton.options = options;
  baton.path[0] = original;
  baton.path[1] = modified;
  baton.path[2] = latest;
  baton.pool = svn_pool_create(pool);

  SVN_ERR(svn_diff_diff3(diff, &baton, &svn_diff__file_vtable, pool));

  svn_pool_destroy(baton.pool);
  return SVN_NO_ERROR;
}

svn_error_t *
svn_diff_file_diff3(svn_diff_t **diff,
                    const char *original,
                    const char *modified,
                    const char *latest,
                    apr_pool_t *pool)
{
  return svn_diff_file_diff3_2(diff, original, modified, latest,
                               svn_diff_file_options_create(pool), pool);
}

svn_error_t *
svn_diff_file_diff4_2(svn_diff_t **diff,
                      const char *original,
                      const char *modified,
                      const char *latest,