trust-append.diff

   1 This patch adds a --trust-append option that, in combination with --append,
   2 makes rsync exclude the portion of a transferred file that was already on the
   3 receiver from the post-transfer checksum.  In my limited testing, it seems to
   4 work.
   5
   6 -- Matt McCutchen <hashproduct@gmail.com>
   7
   8 --- old/match.c
   9 +++ new/match.c
  10 @@ -25,6 +25,7 @@ extern int verbose;
  11  extern int do_progress;
  12  extern int checksum_seed;
  13  extern int append_mode;
  14 +extern int trust_append;
  15
  16  int updating_basis_file;
  17
  18 @@ -315,21 +316,23 @@ void match_sums(int f, struct sum_struct
  19         sum_init(checksum_seed);
  20
  21         if (append_mode > 0) {
  22 -               OFF_T j = 0;
  23 -               for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) {
  24 -                       if (buf && do_progress)
  25 -                               show_progress(last_match, buf->file_size);
  26 -                       sum_update(map_ptr(buf, last_match, CHUNK_SIZE),
  27 -                                  CHUNK_SIZE);
  28 -                       last_match = j;
  29 -               }
  30 -               if (last_match < s->flength) {
  31 -                       int32 n = (int32)(s->flength - last_match);
  32 -                       if (buf && do_progress)
  33 -                               show_progress(last_match, buf->file_size);
  34 -                       sum_update(map_ptr(buf, last_match, n), n);
  35 -                       last_match = s->flength;
  36 +               if (!trust_append) {
  37 +                       OFF_T j = 0;
  38 +                       for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) {
  39 +                               if (buf && do_progress)
  40 +                                       show_progress(last_match, buf->file_size);
  41 +                               sum_update(map_ptr(buf, last_match, CHUNK_SIZE),
  42 +                                          CHUNK_SIZE);
  43 +                               last_match = j;
  44 +                       }
  45 +                       if (last_match < s->flength) {
  46 +                               int32 n = (int32)(s->flength - last_match);
  47 +                               if (buf && do_progress)
  48 +                                       show_progress(last_match, buf->file_size);
  49 +                               sum_update(map_ptr(buf, last_match, n), n);
  50 +                       }
  51                 }
  52 +               last_match = s->flength;
  53                 s->count = 0;
  54         }
  55
  56 --- old/options.c
  57 +++ new/options.c
  58 @@ -41,6 +41,7 @@ int make_backups = 0;
  59  int whole_file = -1;
  60
  61  int append_mode = 0;
  62 +int trust_append = 0;
  63  int keep_dirlinks = 0;
  64  int copy_dirlinks = 0;
  65  int copy_links = 0;
  66 @@ -313,6 +314,7 @@ void usage(enum logcode F)
  67    rprintf(F," -u, --update                skip files that are newer on the receiver\n");
  68    rprintf(F,"     --inplace               update destination files in-place (SEE MAN PAGE)\n");
  69    rprintf(F,"     --append                append data onto shorter files\n");
  70 +  rprintf(F,"     --trust-append          ... and don't checksum portion already on dest\n");
  71    rprintf(F," -d, --dirs                  transfer directories without recursing\n");
  72    rprintf(F," -l, --links                 copy symlinks as symlinks\n");
  73    rprintf(F," -L, --copy-links            transform symlink into referent file/dir\n");
  74 @@ -517,6 +519,7 @@ static struct poptOption long_options[]
  75    {"sparse",          'S', POPT_ARG_NONE,   &sparse_files, 0, 0, 0 },
  76    {"inplace",          0,  POPT_ARG_NONE,   &inplace, 0, 0, 0 },
  77    {"append",           0,  POPT_ARG_VAL,    &append_mode, 1, 0, 0 },
  78 +  {"trust-append",     0,  POPT_ARG_NONE,   &trust_append, 0, 0, 0 },
  79    {"del",              0,  POPT_ARG_NONE,   &delete_during, 0, 0, 0 },
  80    {"delete",           0,  POPT_ARG_NONE,   &delete_mode, 0, 0, 0 },
  81    {"delete-before",    0,  POPT_ARG_NONE,   &delete_before, 0, 0, 0 },
  82 @@ -1898,9 +1901,11 @@ void server_options(char **args,int *arg
  83                 }
  84         }
  85
  86 -       if (append_mode)
  87 +       if (append_mode) {
  88                 args[ac++] = "--append";
  89 -       else if (inplace)
  90 +               if (trust_append)
  91 +                       args[ac++] = "--trust-append";
  92 +       } else if (inplace)
  93                 args[ac++] = "--inplace";
  94
  95         if (files_from && (!am_sender || filesfrom_host)) {
  96 --- old/receiver.c
  97 +++ new/receiver.c
  98 @@ -44,6 +44,7 @@ extern int make_backups;
  99  extern int cleanup_got_literal;
 100  extern int remove_source_files;
 101  extern int append_mode;
 102 +extern int trust_append;
 103  extern int sparse_files;
 104  extern int keep_partial;
 105  extern int checksum_seed;
 106 @@ -157,20 +158,22 @@ static int receive_data(int f_in, char *
 107                 sum.flength = (OFF_T)sum.count * sum.blength;
 108                 if (sum.remainder)
 109                         sum.flength -= sum.blength - sum.remainder;
 110 -               for (j = CHUNK_SIZE; j < sum.flength; j += CHUNK_SIZE) {
 111 -                       if (do_progress)
 112 -                               show_progress(offset, total_size);
 113 -                       sum_update(map_ptr(mapbuf, offset, CHUNK_SIZE),
 114 -                                  CHUNK_SIZE);
 115 -                       offset = j;
 116 -               }
 117 -               if (offset < sum.flength) {
 118 -                       int32 len = (int32)(sum.flength - offset);
 119 -                       if (do_progress)
 120 -                               show_progress(offset, total_size);
 121 -                       sum_update(map_ptr(mapbuf, offset, len), len);
 122 -                       offset = sum.flength;
 123 +               if (!trust_append) {
 124 +                       for (j = CHUNK_SIZE; j < sum.flength; j += CHUNK_SIZE) {
 125 +                               if (do_progress)
 126 +                                       show_progress(offset, total_size);
 127 +                               sum_update(map_ptr(mapbuf, offset, CHUNK_SIZE),
 128 +                                          CHUNK_SIZE);
 129 +                               offset = j;
 130 +                       }
 131 +                       if (offset < sum.flength) {
 132 +                               int32 len = (int32)(sum.flength - offset);
 133 +                               if (do_progress)
 134 +                                       show_progress(offset, total_size);
 135 +                               sum_update(map_ptr(mapbuf, offset, len), len);
 136 +                       }
 137                 }
 138 +               offset = sum.flength;
 139                 if (fd != -1 && (j = do_lseek(fd, offset, SEEK_SET)) != offset) {
 140                         rsyserr(FERROR, errno, "lseek of %s returned %.0f, not %.0f",
 141                                 full_fname(fname), (double)j, (double)offset);
 142 --- old/rsync.yo
 143 +++ new/rsync.yo
 144 @@ -318,6 +318,7 @@ to the detailed description below for a
 145   -u, --update                skip files that are newer on the receiver
 146       --inplace               update destination files in-place
 147       --append                append data onto shorter files
 148 +     --trust-append          ... and don't checksum portion already on dest
 149   -d, --dirs                  transfer directories without recursing
 150   -l, --links                 copy symlinks as symlinks
 151   -L, --copy-links            transform symlink into referent file/dir
 152 @@ -709,6 +710,12 @@ Implies bf(--inplace), but does not conf
 153  bf(--sparse) option will be auto-disabled if a resend of the already-existing
 154  data is required).
 155
 156 +dit(bf(--trust-append)) In combination with bf(--append), this option excludes
 157 +the portion of a transferred file that was already on the receiver from the
 158 +post-transfer checksum.  You can use this option to improve performance if you
 159 +are certain that the receiver's file is identical to the start of the sender's
 160 +file.
 161 +
 162  dit(bf(-d, --dirs)) Tell the sending side to include any directories that
 163  are encountered.  Unlike bf(--recursive), a directory's contents are not copied
 164  unless the directory name specified is "." or ends with a trailing slash