This patch adds the --detect-renamed option which makes rsync notice files that either (1) match in size & modify-time (plus the basename, if possible) or (2) match in size & checksum (when --checksum was also specified) and use each match as an alternate basis file to speed up the transfer. The algorithm attempts to scan the receiving-side's files in an efficient manner. If --delete[-before] is enabled, we'll take advantage of the pre-transfer delete pass to prepare any alternate-basis-file matches we might find. If --delete-before is not enabled, rsync does the rename scan during the regular file-sending scan (scanning each directory right before the generator starts updating files from that dir). In this latter mode, rsync might delay the updating of a file (if no alternate-basis match was yet found) until the full scan of the receiving side is complete, at which point any delayed files are processed. I chose to hard-link the alternate-basis files into a ".~tmp~" subdir that takes advantage of rsync's pre-existing partial-dir logic. This uses less memory than trying to keep track of the matches internally, and also allows any deletions or file-updates to occur normally without interfering with these alternate-basis discoveries. To use this patch, run these commands for a successful build: patch -p1 basename || !S_ISREG(f1->mode) || !len1) { + if (!f2->basename || !S_ISREG(f2->mode) || !len2) + return 0; + return 1; + } + if (!f2->basename || !S_ISREG(f2->mode) || !len2) + return -1; + + /* Don't use diff for values that are longer than an int. */ + if (len1 != len2) + return len1 < len2 ? -1 : 1; + + if (always_checksum) { + diff = u_memcmp(F_SUM(f1), F_SUM(f2), checksum_len); + if (diff) + return diff; + } else if (f1->modtime != f2->modtime) + return f1->modtime < f2->modtime ? -1 : 1; + + diff = u_strcmp(f1->basename, f2->basename); + if (diff) + return diff; + + if (f1->dirname == f2->dirname) + return 0; + if (!f1->dirname) + return -1; + if (!f2->dirname) + return 1; + return u_strcmp(f1->dirname, f2->dirname); +} + static void send_directory(int f, struct file_list *flist, char *fbuf, int len, int flags); @@ -2451,6 +2493,25 @@ struct file_list *recv_file_list(int f) flist_sort_and_clean(flist, relative_paths); + if (detect_renamed) { + int j = flist->used; + the_fattr_list.used = j; + the_fattr_list.files = new_array(struct file_struct *, j); + if (!the_fattr_list.files) + out_of_memory("recv_file_list"); + memcpy(the_fattr_list.files, flist->files, + j * sizeof (struct file_struct *)); + qsort(the_fattr_list.files, j, + sizeof the_fattr_list.files[0], (int (*)())fattr_compare); + the_fattr_list.low = 0; + while (j-- > 0) { + struct file_struct *fp = the_fattr_list.files[j]; + if (fp->basename && S_ISREG(fp->mode) && F_LENGTH(fp)) + break; + } + the_fattr_list.high = j; + } + if (protocol_version < 30) { /* Recv the io_error flag */ if (ignore_errors) --- generator.c.orig 2012-04-03 10:38:42.000000000 -0400 +++ generator.c 2012-04-03 23:16:14.000000000 -0400 @@ -79,6 +79,7 @@ extern char *basis_dir[MAX_BASIS_DIRS+1] extern int compare_dest; extern int copy_dest; extern int link_dest; +extern int detect_renamed; extern int whole_file; extern int list_only; extern int read_batch; @@ -97,6 +98,7 @@ extern char *backup_suffix; extern int backup_suffix_len; extern struct file_list *cur_flist, *first_flist, *dir_flist; extern struct filter_list_struct daemon_filter_list; +extern struct file_list the_fattr_list; int ignore_perishable = 0; int non_perishable_cnt = 0; @@ -104,6 +106,7 @@ int maybe_ATTRS_REPORT = 0; static dev_t dev_zero; static int deletion_count = 0; /* used to implement --max-delete */ +static int unexplored_dirs = 1; static int deldelay_size = 0, deldelay_cnt = 0; static char *deldelay_buf = NULL; static int deldelay_fd = -1; @@ -114,7 +117,7 @@ static int need_retouch_dir_times; static int need_retouch_dir_perms; static const char *solo_file = NULL; -/* For calling delete_item() and delete_dir_contents(). */ +/* For calling delete_item(), delete_dir_contents(), and delete_in_dir(). */ #define DEL_NO_UID_WRITE (1<<0) /* file/dir has our uid w/o write perm */ #define DEL_RECURSE (1<<1) /* if dir, delete all contents */ #define DEL_DIR_IS_EMPTY (1<<2) /* internal delete_FUNCTIONS use only */ @@ -123,6 +126,7 @@ static const char *solo_file = NULL; #define DEL_FOR_SYMLINK (1<<5) /* making room for a replacement symlink */ #define DEL_FOR_DEVICE (1<<6) /* making room for a replacement device */ #define DEL_FOR_SPECIAL (1<<7) /* making room for a replacement special */ +#define DEL_NO_DELETIONS (1<<9) /* just check for renames w/o deleting */ #define DEL_MAKE_ROOM (DEL_FOR_FILE|DEL_FOR_DIR|DEL_FOR_SYMLINK|DEL_FOR_DEVICE|DEL_FOR_SPECIAL) @@ -147,11 +151,121 @@ static int is_backup_file(char *fn) return k > 0 && strcmp(fn+k, backup_suffix) == 0; } +/* Search for a regular file that matches either (1) the size & modified + * time (plus the basename, if possible) or (2) the size & checksum. If + * we find an exact match down to the dirname, return -1 because we found + * an up-to-date file in the transfer, not a renamed file. */ +static int fattr_find(struct file_struct *f, char *fname) +{ + int low = the_fattr_list.low, high = the_fattr_list.high; + int mid, ok_match = -1, good_match = -1; + struct file_struct *fmid; + int diff; + + while (low <= high) { + mid = (low + high) / 2; + fmid = the_fattr_list.files[mid]; + if (F_LENGTH(fmid) != F_LENGTH(f)) { + if (F_LENGTH(fmid) < F_LENGTH(f)) + low = mid + 1; + else + high = mid - 1; + continue; + } + if (always_checksum) { + /* We use the FLAG_FILE_SENT flag to indicate when we + * have computed the checksum for an entry. */ + if (!(f->flags & FLAG_FILE_SENT)) { + if (fmid->modtime == f->modtime + && f_name_cmp(fmid, f) == 0) + return -1; /* assume we can't help */ + file_checksum(fname, F_SUM(f), F_LENGTH(f)); + f->flags |= FLAG_FILE_SENT; + } + diff = u_memcmp(F_SUM(fmid), F_SUM(f), checksum_len); + if (diff) { + if (diff < 0) + low = mid + 1; + else + high = mid - 1; + continue; + } + } else { + if (fmid->modtime != f->modtime) { + if (fmid->modtime < f->modtime) + low = mid + 1; + else + high = mid - 1; + continue; + } + } + ok_match = mid; + diff = u_strcmp(fmid->basename, f->basename); + if (diff == 0) { + good_match = mid; + if (fmid->dirname == f->dirname) + return -1; /* file is up-to-date */ + if (!fmid->dirname) { + low = mid + 1; + continue; + } + if (!f->dirname) { + high = mid - 1; + continue; + } + diff = u_strcmp(fmid->dirname, f->dirname); + if (diff == 0) + return -1; /* file is up-to-date */ + } + if (diff < 0) + low = mid + 1; + else + high = mid - 1; + } + + return good_match >= 0 ? good_match : ok_match; +} + +static void look_for_rename(struct file_struct *file, char *fname) +{ + struct file_struct *fp; + char *partialptr, *fn; + STRUCT_STAT st; + int ndx; + + if (!partial_dir || (ndx = fattr_find(file, fname)) < 0) + return; + + fp = the_fattr_list.files[ndx]; + fn = f_name(fp, NULL); + /* We don't provide an alternate-basis file if there is a basis file. */ + if (link_stat(fn, &st, 0) == 0) + return; + + if (!dry_run) { + if ((partialptr = partial_dir_fname(fn)) == NULL + || !handle_partial_dir(partialptr, PDIR_CREATE)) + return; + /* We only use the file if we can hard-link it into our tmp dir. */ + if (link(fname, partialptr) != 0) { + if (errno != EEXIST) + handle_partial_dir(partialptr, PDIR_DELETE); + return; + } + } + + /* I think this falls into the -vv category with "%s is uptodate", etc. */ + if (verbose > 1) + rprintf(FINFO, "found renamed: %s => %s\n", fname, fn); +} + /* Delete a file or directory. If DEL_RECURSE is set in the flags, this will * delete recursively. * * Note that fbuf must point to a MAXPATHLEN buffer if the mode indicates it's * a directory! (The buffer is used for recursion, but returned unchanged.) + * + * Also note: --detect-rename may use this routine with DEL_NO_DELETIONS set! */ static enum delret delete_item(char *fbuf, uint16 mode, uint16 flags) { @@ -178,6 +292,8 @@ static enum delret delete_item(char *fbu goto check_ret; /* OK: try to delete the directory. */ } + if (flags & DEL_NO_DELETIONS) + return DR_SUCCESS; if (!(flags & DEL_MAKE_ROOM) && max_delete >= 0 && ++deletion_count > max_delete) return DR_AT_LIMIT; @@ -233,6 +349,8 @@ static enum delret delete_item(char *fbu * its contents, otherwise just checks for content. Returns DR_SUCCESS or * DR_NOT_EMPTY. Note that fname must point to a MAXPATHLEN buffer! (The * buffer is used for recursion, but returned unchanged.) + * + * Note: --detect-rename may use this routine with DEL_NO_DELETIONS set! */ static enum delret delete_dir_contents(char *fname, uint16 flags) { @@ -252,7 +370,9 @@ static enum delret delete_dir_contents(c save_filters = push_local_filters(fname, dlen); non_perishable_cnt = 0; + file_extra_cnt += SUM_EXTRA_CNT; dirlist = get_dirlist(fname, dlen, 0); + file_extra_cnt -= SUM_EXTRA_CNT; ret = non_perishable_cnt ? DR_NOT_EMPTY : DR_SUCCESS; if (!dirlist->used) @@ -292,7 +412,8 @@ static enum delret delete_dir_contents(c if (S_ISDIR(fp->mode)) { if (delete_dir_contents(fname, flags | DEL_RECURSE) != DR_SUCCESS) ret = DR_NOT_EMPTY; - } + } else if (detect_renamed && S_ISREG(fp->mode)) + look_for_rename(fp, fname); if (delete_item(fname, fp->mode, flags) != DR_SUCCESS) ret = DR_NOT_EMPTY; } @@ -457,13 +578,18 @@ static void do_delayed_deletions(char *d * all the --delete-WHEN options. Note that the fbuf pointer must point to a * MAXPATHLEN buffer with the name of the directory in it (the functions we * call will append names onto the end, but the old dir value will be restored - * on exit). */ -static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev) + * on exit). + * + * Note: --detect-rename may use this routine with DEL_NO_DELETIONS set! + */ +static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev, + int del_flags) { static int already_warned = 0; struct file_list *dirlist; - char delbuf[MAXPATHLEN]; - int dlen, i; + char *p, delbuf[MAXPATHLEN]; + unsigned remainder; + int dlen, i, restore_dot = 0; if (!fbuf) { change_local_filter_dir(NULL, 0, 0); @@ -477,17 +603,22 @@ static void delete_in_dir(char *fbuf, st maybe_send_keepalive(); if (io_error && !ignore_errors) { - if (already_warned) + if (!already_warned) { + rprintf(FINFO, + "IO error encountered -- skipping file deletion\n"); + already_warned = 1; + } + if (!detect_renamed) return; - rprintf(FINFO, - "IO error encountered -- skipping file deletion\n"); - already_warned = 1; - return; + del_flags |= DEL_NO_DELETIONS; } dlen = strlen(fbuf); change_local_filter_dir(fbuf, dlen, F_DEPTH(file)); + if (detect_renamed) + unexplored_dirs--; + if (one_file_system) { if (file->flags & FLAG_TOP_DIR) filesystem_dev = *fs_dev; @@ -497,6 +628,14 @@ static void delete_in_dir(char *fbuf, st dirlist = get_dirlist(fbuf, dlen, 0); + p = fbuf + dlen; + if (dlen == 1 && *fbuf == '.') { + restore_dot = 1; + p = fbuf; + } else if (dlen != 1 || *fbuf != '/') + *p++ = '/'; + remainder = MAXPATHLEN - (p - fbuf); + /* If an item in dirlist is not found in flist, delete it * from the filesystem. */ for (i = dirlist->used; i--; ) { @@ -509,6 +648,10 @@ static void delete_in_dir(char *fbuf, st f_name(fp, NULL)); continue; } + if (detect_renamed && S_ISREG(fp->mode)) { + strlcpy(p, fp->basename, remainder); + look_for_rename(fp, fbuf); + } /* Here we want to match regardless of file type. Replacement * of a file with one of another type is handled separately by * a delete_item call with a DEL_MAKE_ROOM flag. */ @@ -517,14 +660,19 @@ static void delete_in_dir(char *fbuf, st if (!(fp->mode & S_IWUSR) && !am_root && fp->flags & FLAG_OWNED_BY_US) flags |= DEL_NO_UID_WRITE; f_name(fp, delbuf); - if (delete_during == 2) { - if (!remember_delete(fp, delbuf, flags)) + if (delete_during == 2 && !(del_flags & DEL_NO_DELETIONS)) { + if (!remember_delete(fp, delbuf, del_flags | flags)) break; } else - delete_item(delbuf, fp->mode, flags); - } + delete_item(delbuf, fp->mode, del_flags | flags); + } else if (detect_renamed && S_ISDIR(fp->mode)) + unexplored_dirs++; } + if (restore_dot) + fbuf[0] = '.'; + fbuf[dlen] = '\0'; + flist_free(dirlist); } @@ -557,9 +705,9 @@ static void do_delete_pass(void) || !S_ISDIR(st.st_mode)) continue; - delete_in_dir(fbuf, file, &st.st_dev); + delete_in_dir(fbuf, file, &st.st_dev, 0); } - delete_in_dir(NULL, NULL, &dev_zero); + delete_in_dir(NULL, NULL, &dev_zero, 0); if (do_progress && !am_server) rprintf(FINFO, " \r"); @@ -1278,6 +1426,7 @@ static void list_file_entry(struct file_ } } +static struct bitbag *delayed_bits = NULL; static int phase = 0; static int dflt_perms; @@ -1567,9 +1716,12 @@ static void recv_generator(char *fname, } else if (delete_during && f_out != -1 && !phase && !(file->flags & FLAG_MISSING_DIR)) { - if (file->flags & FLAG_CONTENT_DIR) - delete_in_dir(fname, file, &real_sx.st.st_dev); - else + if (file->flags & FLAG_CONTENT_DIR) { + if (detect_renamed && real_ret != 0) + unexplored_dirs++; + delete_in_dir(fname, file, &real_sx.st.st_dev, + delete_during < 0 ? DEL_NO_DELETIONS : 0); + } else change_local_filter_dir(fname, strlen(fname), F_DEPTH(file)); } goto cleanup; @@ -1853,8 +2005,14 @@ static void recv_generator(char *fname, goto cleanup; } #endif - if (stat_errno == ENOENT) + if (stat_errno == ENOENT) { + if (detect_renamed && unexplored_dirs > 0 + && F_LENGTH(file)) { + bitbag_set_bit(delayed_bits, ndx); + return; + } goto notify_others; + } rsyserr(FERROR_XFER, stat_errno, "recv_generator: failed to stat %s", full_fname(fname)); goto cleanup; @@ -2263,6 +2421,12 @@ void generate_files(int f_out, const cha if (verbose > 2) rprintf(FINFO, "generator starting pid=%ld\n", (long)getpid()); + if (detect_renamed) { + delayed_bits = bitbag_create(cur_flist->used); + if (!delete_before && !delete_during) + delete_during = -1; + } + if (delete_before && !solo_file && cur_flist->used > 0) do_delete_pass(); if (delete_during == 2) { @@ -2273,7 +2437,7 @@ void generate_files(int f_out, const cha } do_progress = 0; - if (append_mode > 0 || whole_file < 0) + if (append_mode > 0 || detect_renamed || whole_file < 0) whole_file = 0; if (verbose >= 2) { rprintf(FINFO, "delta-transmission %s\n", @@ -2315,7 +2479,7 @@ void generate_files(int f_out, const cha dirdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp)); } else dirdev = MAKEDEV(0, 0); - delete_in_dir(fbuf, fp, &dirdev); + delete_in_dir(fbuf, fp, &dirdev, 0); } else change_local_filter_dir(fbuf, strlen(fbuf), F_DEPTH(fp)); } @@ -2362,7 +2526,21 @@ void generate_files(int f_out, const cha } while ((cur_flist = cur_flist->next) != NULL); if (delete_during) - delete_in_dir(NULL, NULL, &dev_zero); + delete_in_dir(NULL, NULL, &dev_zero, 0); + if (detect_renamed) { + if (delete_during < 0) + delete_during = 0; + detect_renamed = 0; + + for (i = -1; (i = bitbag_next_bit(delayed_bits, i)) >= 0; ) { + struct file_struct *file = cur_flist->files[i]; + if (local_name) + strlcpy(fbuf, local_name, sizeof fbuf); + else + f_name(file, fbuf); + recv_generator(fbuf, file, i, itemizing, code, f_out); + } + } phase++; if (verbose > 2) rprintf(FINFO, "generate_files phase=%d\n", phase); --- options.c.orig 2012-04-03 10:38:42.000000000 -0400 +++ options.c 2012-04-03 10:38:42.000000000 -0400 @@ -82,6 +82,7 @@ int am_sender = 0; int am_starting_up = 1; int relative_paths = -1; int implied_dirs = 1; +int detect_renamed = 0; int numeric_ids = 0; int allow_8bit_chars = 0; int force_delete = 0; @@ -392,6 +393,7 @@ void usage(enum logcode F) rprintf(F," --modify-window=NUM compare mod-times with reduced accuracy\n"); rprintf(F," -T, --temp-dir=DIR create temporary files in directory DIR\n"); rprintf(F," -y, --fuzzy find similar file for basis if no dest file\n"); + rprintf(F," --detect-renamed try to find renamed files to speed up the transfer\n"); rprintf(F," --compare-dest=DIR also compare destination files relative to DIR\n"); rprintf(F," --copy-dest=DIR ... and include copies of unchanged files\n"); rprintf(F," --link-dest=DIR hardlink to files in DIR when unchanged\n"); @@ -582,6 +584,7 @@ static struct poptOption long_options[] {"compare-dest", 0, POPT_ARG_STRING, 0, OPT_COMPARE_DEST, 0, 0 }, {"copy-dest", 0, POPT_ARG_STRING, 0, OPT_COPY_DEST, 0, 0 }, {"link-dest", 0, POPT_ARG_STRING, 0, OPT_LINK_DEST, 0, 0 }, + {"detect-renamed", 0, POPT_ARG_NONE, &detect_renamed, 0, 0, 0 }, {"fuzzy", 'y', POPT_ARG_VAL, &fuzzy_basis, 1, 0, 0 }, {"no-fuzzy", 0, POPT_ARG_VAL, &fuzzy_basis, 0, 0, 0 }, {"no-y", 0, POPT_ARG_VAL, &fuzzy_basis, 0, 0, 0 }, @@ -1606,7 +1609,7 @@ int parse_arguments(int *argc_p, const c inplace = 1; } - if (delay_updates && !partial_dir) + if ((delay_updates || detect_renamed) && !partial_dir) partial_dir = tmp_partialdir; if (inplace) { @@ -1615,6 +1618,7 @@ int parse_arguments(int *argc_p, const c snprintf(err_buf, sizeof err_buf, "--%s cannot be used with --%s\n", append_mode ? "append" : "inplace", + detect_renamed ? "detect-renamed" : delay_updates ? "delay-updates" : "partial-dir"); return 0; } @@ -1979,6 +1983,8 @@ void server_options(char **args, int *ar args[ac++] = "--super"; if (size_only) args[ac++] = "--size-only"; + if (detect_renamed) + args[ac++] = "--detect-renamed"; } else { if (skip_compress) { if (asprintf(&arg, "--skip-compress=%s", skip_compress) < 0) --- rsync.yo.orig 2012-04-03 10:38:42.000000000 -0400 +++ rsync.yo 2012-04-03 10:38:42.000000000 -0400 @@ -403,6 +403,7 @@ to the detailed description below for a --modify-window=NUM compare mod-times with reduced accuracy -T, --temp-dir=DIR create temporary files in directory DIR -y, --fuzzy find similar file for basis if no dest file + --detect-renamed try to find renamed files to speed the xfer --compare-dest=DIR also compare received files relative to DIR --copy-dest=DIR ... and include copies of unchanged files --link-dest=DIR hardlink to files in DIR when unchanged @@ -1597,6 +1598,21 @@ Note that the use of the bf(--delete) op fuzzy-match files, so either use bf(--delete-after) or specify some filename exclusions if you need to prevent this. +dit(bf(--detect-renamed)) With this option, for each new source file +(call it em(src/S)), rsync looks for a file em(dest/D) anywhere in the +destination that passes the quick check with em(src/S). If such a em(dest/D) +is found, rsync uses it as an alternate basis for transferring em(S). The +idea is that if em(src/S) was renamed from em(src/D) (as opposed to em(src/S) +passing the quick check with em(dest/D) by coincidence), the delta-transfer +algorithm will find that all the data matches between em(src/S) and em(dest/D), +and the transfer will be really fast. + +By default, alternate-basis files are hard-linked into a directory named +".~tmp~" in each file's destination directory, but if you've specified +the bf(--partial-dir) option, that directory will be used instead. These +potential alternate-basis files will be removed as the transfer progresses. +This option conflicts with bf(--inplace) and bf(--append). + dit(bf(--compare-dest=DIR)) This option instructs rsync to use em(DIR) on the destination machine as an additional hierarchy to compare destination files against doing transfers (if the files are missing in the destination --- syscall.c.orig 2011-02-21 14:32:51.000000000 -0500 +++ syscall.c 2012-04-04 11:01:33.000000000 -0400 @@ -217,6 +217,22 @@ void trim_trailing_slashes(char *name) } } +int do_mkdir_path(char *fname, mode_t mode) +{ + char fnametmp[MAXPATHLEN], *fnametmpptr; + STRUCT_STAT st; + + if (fname) { + strcpy(fnametmp, fname); + if ((fnametmpptr = strrchr(fnametmp, '/')) != NULL) { + *fnametmpptr = '\0'; + if (do_stat(fnametmp, &st) < 0) + do_mkdir_path(fnametmp, mode); + } + } + return do_mkdir(fname, mode); +} + int do_mkdir(char *fname, mode_t mode) { if (dry_run) return 0; --- util.c.orig 2012-04-03 10:38:42.000000000 -0400 +++ util.c 2012-04-03 23:15:12.000000000 -0400 @@ -1172,7 +1172,7 @@ int handle_partial_dir(const char *fname } statret = -1; } - if (statret < 0 && do_mkdir(dir, 0700) < 0) { + if (statret < 0 && do_mkdir_path(dir, 0700) < 0) { *fn = '/'; return 0; } @@ -1183,6 +1183,32 @@ int handle_partial_dir(const char *fname return 1; } +/* We need to supply our own strcmp function for file list comparisons + * to ensure that signed/unsigned usage is consistent between machines. */ +int u_strcmp(const char *p1, const char *p2) +{ + for ( ; *p1; p1++, p2++) { + if (*p1 != *p2) + break; + } + + return (int)*(uchar*)p1 - (int)*(uchar*)p2; +} + +/* We need a memcmp function compares unsigned-byte values. */ +int u_memcmp(const void *p1, const void *p2, size_t len) +{ + const uchar *u1 = p1; + const uchar *u2 = p2; + + while (len--) { + if (*u1 != *u2) + return (int)*u1 - (int)*u2; + } + + return 0; +} + /* Determine if a symlink points outside the current directory tree. * This is considered "unsafe" because e.g. when mirroring somebody * else's machine it might allow them to establish a symlink to --- proto.h.orig 2012-04-03 10:38:42.000000000 -0400 +++ proto.h 2012-04-03 23:29:23.000000000 -0400 @@ -305,6 +305,7 @@ int do_chmod(const char *path, mode_t mo int do_rename(const char *fname1, const char *fname2); int do_ftruncate(int fd, OFF_T size); void trim_trailing_slashes(char *name); +int do_mkdir_path(char *fname, mode_t mode); int do_mkdir(char *fname, mode_t mode); int do_mkstemp(char *template, mode_t perms); int do_stat(const char *fname, STRUCT_STAT *st); @@ -362,6 +363,8 @@ char *normalize_path(char *path, BOOL fo char *full_fname(const char *fn); char *partial_dir_fname(const char *fname); int handle_partial_dir(const char *fname, int create); +int u_strcmp(const char *p1, const char *p2); +int u_memcmp(const void *p1, const void *p2, size_t len); int unsafe_symlink(const char *dest, const char *src); char *human_num(int64 num); char *human_dnum(double dnum, int decimal_digits); --- rsync.1.orig 2012-04-03 10:38:42.000000000 -0400 +++ rsync.1 2012-04-03 21:48:49.000000000 -0400 @@ -479,6 +479,7 @@ to the detailed description below for a \-\-modify\-window=NUM compare mod\-times with reduced accuracy \-T, \-\-temp\-dir=DIR create temporary files in directory DIR \-y, \-\-fuzzy find similar file for basis if no dest file + \-\-detect\-renamed try to find renamed files to speed the xfer \-\-compare\-dest=DIR also compare received files relative to DIR \-\-copy\-dest=DIR ... and include copies of unchanged files \-\-link\-dest=DIR hardlink to files in DIR when unchanged @@ -1828,6 +1829,22 @@ Note that the use of the \fB\-\-delete\f fuzzy\-match files, so either use \fB\-\-delete\-after\fP or specify some filename exclusions if you need to prevent this. .IP +.IP "\fB\-\-detect\-renamed\fP" +With this option, for each new source file +(call it \fIsrc/S\fP), rsync looks for a file \fIdest/D\fP anywhere in the +destination that passes the quick check with \fIsrc/S\fP. If such a \fIdest/D\fP +is found, rsync uses it as an alternate basis for transferring \fIS\fP. The +idea is that if \fIsrc/S\fP was renamed from \fIsrc/D\fP (as opposed to \fIsrc/S\fP +passing the quick check with \fIdest/D\fP by coincidence), the delta\-transfer +algorithm will find that all the data matches between \fIsrc/S\fP and \fIdest/D\fP, +and the transfer will be really fast. +.IP +By default, alternate\-basis files are hard\-linked into a directory named +\(dq\&.~tmp~\(dq\& in each file\(cq\&s destination directory, but if you\(cq\&ve specified +the \fB\-\-partial\-dir\fP option, that directory will be used instead. These +potential alternate\-basis files will be removed as the transfer progresses. +This option conflicts with \fB\-\-inplace\fP and \fB\-\-append\fP. +.IP .IP "\fB\-\-compare\-dest=DIR\fP" This option instructs rsync to use \fIDIR\fP on the destination machine as an additional hierarchy to compare destination