diff options
Diffstat (limited to 'rerere.c')
| -rw-r--r-- | rerere.c | 1041 |
1 files changed, 774 insertions, 267 deletions
@@ -8,6 +8,7 @@ #include "ll-merge.h" #include "attr.h" #include "pathspec.h" +#include "sha1-lookup.h" #define RESOLVED 0 #define PUNTED 1 @@ -20,47 +21,216 @@ static int rerere_enabled = -1; /* automatically update cleanly resolved paths to the index */ static int rerere_autoupdate; -static char *merge_rr_path; +static int rerere_dir_nr; +static int rerere_dir_alloc; -const char *rerere_path(const char *hex, const char *file) +#define RR_HAS_POSTIMAGE 1 +#define RR_HAS_PREIMAGE 2 +static struct rerere_dir { + unsigned char sha1[20]; + int status_alloc, status_nr; + unsigned char *status; +} **rerere_dir; + +static void free_rerere_dirs(void) { - return git_path("rr-cache/%s/%s", hex, file); + int i; + for (i = 0; i < rerere_dir_nr; i++) { + free(rerere_dir[i]->status); + free(rerere_dir[i]); + } + free(rerere_dir); + rerere_dir_nr = rerere_dir_alloc = 0; + rerere_dir = NULL; } -static int has_rerere_resolution(const char *hex) +static void free_rerere_id(struct string_list_item *item) { - struct stat st; - return !stat(rerere_path(hex, "postimage"), &st); + free(item->util); } -static void read_rr(struct string_list *rr) +static const char *rerere_id_hex(const struct rerere_id *id) +{ + return sha1_to_hex(id->collection->sha1); +} + +static void fit_variant(struct rerere_dir *rr_dir, int variant) +{ + variant++; + ALLOC_GROW(rr_dir->status, variant, rr_dir->status_alloc); + if (rr_dir->status_nr < variant) { + memset(rr_dir->status + rr_dir->status_nr, + '\0', variant - rr_dir->status_nr); + rr_dir->status_nr = variant; + } +} + +static void assign_variant(struct rerere_id *id) +{ + int variant; + struct rerere_dir *rr_dir = id->collection; + + variant = id->variant; + if (variant < 0) { + for (variant = 0; variant < rr_dir->status_nr; variant++) + if (!rr_dir->status[variant]) + break; + } + fit_variant(rr_dir, variant); + id->variant = variant; +} + +const char *rerere_path(const struct rerere_id *id, const char *file) +{ + if (!file) + return git_path("rr-cache/%s", rerere_id_hex(id)); + + if (id->variant <= 0) + return git_path("rr-cache/%s/%s", rerere_id_hex(id), file); + + return git_path("rr-cache/%s/%s.%d", + rerere_id_hex(id), file, id->variant); +} + +static int is_rr_file(const char *name, const char *filename, int *variant) +{ + const char *suffix; + char *ep; + + if (!strcmp(name, filename)) { + *variant = 0; + return 1; + } + if (!skip_prefix(name, filename, &suffix) || *suffix != '.') + return 0; + + errno = 0; + *variant = strtol(suffix + 1, &ep, 10); + if (errno || *ep) + return 0; + return 1; +} + +static void scan_rerere_dir(struct rerere_dir *rr_dir) +{ + struct dirent *de; + DIR *dir = opendir(git_path("rr-cache/%s", sha1_to_hex(rr_dir->sha1))); + + if (!dir) + return; + while ((de = readdir(dir)) != NULL) { + int variant; + + if (is_rr_file(de->d_name, "postimage", &variant)) { + fit_variant(rr_dir, variant); + rr_dir->status[variant] |= RR_HAS_POSTIMAGE; + } else if (is_rr_file(de->d_name, "preimage", &variant)) { + fit_variant(rr_dir, variant); + rr_dir->status[variant] |= RR_HAS_PREIMAGE; + } + } + closedir(dir); +} + +static const unsigned char *rerere_dir_sha1(size_t i, void *table) +{ + struct rerere_dir **rr_dir = table; + return rr_dir[i]->sha1; +} + +static struct rerere_dir *find_rerere_dir(const char *hex) { unsigned char sha1[20]; - char buf[PATH_MAX]; - FILE *in = fopen(merge_rr_path, "r"); + struct rerere_dir *rr_dir; + int pos; + + if (get_sha1_hex(hex, sha1)) + return NULL; /* BUG */ + pos = sha1_pos(sha1, rerere_dir, rerere_dir_nr, rerere_dir_sha1); + if (pos < 0) { + rr_dir = xmalloc(sizeof(*rr_dir)); + hashcpy(rr_dir->sha1, sha1); + rr_dir->status = NULL; + rr_dir->status_nr = 0; + rr_dir->status_alloc = 0; + pos = -1 - pos; + + /* Make sure the array is big enough ... */ + ALLOC_GROW(rerere_dir, rerere_dir_nr + 1, rerere_dir_alloc); + /* ... and add it in. */ + rerere_dir_nr++; + memmove(rerere_dir + pos + 1, rerere_dir + pos, + (rerere_dir_nr - pos - 1) * sizeof(*rerere_dir)); + rerere_dir[pos] = rr_dir; + scan_rerere_dir(rr_dir); + } + return rerere_dir[pos]; +} + +static int has_rerere_resolution(const struct rerere_id *id) +{ + const int both = RR_HAS_POSTIMAGE|RR_HAS_PREIMAGE; + int variant = id->variant; + + if (variant < 0) + return 0; + return ((id->collection->status[variant] & both) == both); +} + +static struct rerere_id *new_rerere_id_hex(char *hex) +{ + struct rerere_id *id = xmalloc(sizeof(*id)); + id->collection = find_rerere_dir(hex); + id->variant = -1; /* not known yet */ + return id; +} + +static struct rerere_id *new_rerere_id(unsigned char *sha1) +{ + return new_rerere_id_hex(sha1_to_hex(sha1)); +} + +/* + * $GIT_DIR/MERGE_RR file is a collection of records, each of which is + * "conflict ID", a HT and pathname, terminated with a NUL, and is + * used to keep track of the set of paths that "rerere" may need to + * work on (i.e. what is left by the previous invocation of "git + * rerere" during the current conflict resolution session). + */ +static void read_rr(struct string_list *rr) +{ + struct strbuf buf = STRBUF_INIT; + FILE *in = fopen(git_path_merge_rr(), "r"); + if (!in) return; - while (fread(buf, 40, 1, in) == 1) { - int i; - char *name; - if (get_sha1_hex(buf, sha1)) + while (!strbuf_getwholeline(&buf, in, '\0')) { + char *path; + unsigned char sha1[20]; + struct rerere_id *id; + int variant; + + /* There has to be the hash, tab, path and then NUL */ + if (buf.len < 42 || get_sha1_hex(buf.buf, sha1)) die("corrupt MERGE_RR"); - buf[40] = '\0'; - name = xstrdup(buf); - if (fgetc(in) != '\t') - die("corrupt MERGE_RR"); - for (i = 0; i < sizeof(buf); i++) { - int c = fgetc(in); - if (c < 0) + + if (buf.buf[40] != '.') { + variant = 0; + path = buf.buf + 40; + } else { + errno = 0; + variant = strtol(buf.buf + 41, &path, 10); + if (errno) die("corrupt MERGE_RR"); - buf[i] = c; - if (c == 0) - break; } - if (i == sizeof(buf)) - die("filename too long"); - string_list_insert(rr, buf)->util = name; + if (*(path++) != '\t') + die("corrupt MERGE_RR"); + buf.buf[40] = '\0'; + id = new_rerere_id_hex(buf.buf); + id->variant = variant; + string_list_insert(rr, path)->util = id; } + strbuf_release(&buf); fclose(in); } @@ -70,22 +240,49 @@ static int write_rr(struct string_list *rr, int out_fd) { int i; for (i = 0; i < rr->nr; i++) { - const char *path; - int length; - if (!rr->items[i].util) + struct strbuf buf = STRBUF_INIT; + struct rerere_id *id; + + assert(rr->items[i].util != RERERE_RESOLVED); + + id = rr->items[i].util; + if (!id) continue; - path = rr->items[i].string; - length = strlen(path) + 1; - if (write_in_full(out_fd, rr->items[i].util, 40) != 40 || - write_str_in_full(out_fd, "\t") != 1 || - write_in_full(out_fd, path, length) != length) + assert(id->variant >= 0); + if (0 < id->variant) + strbuf_addf(&buf, "%s.%d\t%s%c", + rerere_id_hex(id), id->variant, + rr->items[i].string, 0); + else + strbuf_addf(&buf, "%s\t%s%c", + rerere_id_hex(id), + rr->items[i].string, 0); + + if (write_in_full(out_fd, buf.buf, buf.len) != buf.len) die("unable to write rerere record"); + + strbuf_release(&buf); } if (commit_lock_file(&write_lock) != 0) die("unable to write rerere record"); return 0; } +/* + * "rerere" interacts with conflicted file contents using this I/O + * abstraction. It reads a conflicted contents from one place via + * "getline()" method, and optionally can write it out after + * normalizing the conflicted hunks to the "output". Subclasses of + * rerere_io embed this structure at the beginning of their own + * rerere_io object. + */ +struct rerere_io { + int (*getline)(struct strbuf *, struct rerere_io *); + FILE *output; + int wrerror; + /* some more stuff */ +}; + static void ferr_write(const void *p, size_t count, FILE *fp, int *err) { if (!count || *err) @@ -99,31 +296,34 @@ static inline void ferr_puts(const char *s, FILE *fp, int *err) ferr_write(s, strlen(s), fp, err); } -struct rerere_io { - int (*getline)(struct strbuf *, struct rerere_io *); - FILE *output; - int wrerror; - /* some more stuff */ -}; - static void rerere_io_putstr(const char *str, struct rerere_io *io) { if (io->output) ferr_puts(str, io->output, &io->wrerror); } +/* + * Write a conflict marker to io->output (if defined). + */ static void rerere_io_putconflict(int ch, int size, struct rerere_io *io) { char buf[64]; while (size) { - if (size < sizeof(buf) - 2) { + if (size <= sizeof(buf) - 2) { memset(buf, ch, size); buf[size] = '\n'; buf[size + 1] = '\0'; size = 0; } else { int sz = sizeof(buf) - 1; + + /* + * Make sure we will not write everything out + * in this round by leaving at least 1 byte + * for the next round, giving the next round + * a chance to add the terminating LF. Yuck. + */ if (size <= sz) sz -= (sz - size) + 1; memset(buf, ch, sz); @@ -140,19 +340,42 @@ static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io) ferr_write(mem, sz, io->output, &io->wrerror); } +/* + * Subclass of rerere_io that reads from an on-disk file + */ struct rerere_io_file { struct rerere_io io; FILE *input; }; +/* + * ... and its getline() method implementation + */ static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_) { struct rerere_io_file *io = (struct rerere_io_file *)io_; return strbuf_getwholeline(sb, io->input, '\n'); } -static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp) +/* + * Require the exact number of conflict marker letters, no more, no + * less, followed by SP or any whitespace + * (including LF). + */ +static int is_cmarker(char *buf, int marker_char, int marker_size) { + int want_sp; + + /* + * The beginning of our version and the end of their version + * always are labeled like "<<<<< ours" or ">>>>> theirs", + * hence we set want_sp for them. Note that the version from + * the common ancestor in diff3-style output is not always + * labelled (e.g. "||||| common" is often seen but "|||||" + * alone is also valid), so we do not set want_sp. + */ + want_sp = (marker_char == '<') || (marker_char == '>'); + while (marker_size--) if (*buf++ != marker_char) return 0; @@ -161,6 +384,21 @@ static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp) return isspace(*buf); } +/* + * Read contents a file with conflicts, normalize the conflicts + * by (1) discarding the common ancestor version in diff3-style, + * (2) reordering our side and their side so that whichever sorts + * alphabetically earlier comes before the other one, while + * computing the "conflict ID", which is just an SHA-1 hash of + * one side of the conflict, NUL, the other side of the conflict, + * and NUL concatenated together. + * + * Return the number of conflict hunks found. + * + * NEEDSWORK: the logic and theory of operation behind this conflict + * normalization may deserve to be documented somewhere, perhaps in + * Documentation/technical/rerere.txt. + */ static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size) { git_SHA_CTX ctx; @@ -175,19 +413,19 @@ static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_siz git_SHA1_Init(&ctx); while (!io->getline(&buf, io)) { - if (is_cmarker(buf.buf, '<', marker_size, 1)) { + if (is_cmarker(buf.buf, '<', marker_size)) { if (hunk != RR_CONTEXT) goto bad; hunk = RR_SIDE_1; - } else if (is_cmarker(buf.buf, '|', marker_size, 0)) { + } else if (is_cmarker(buf.buf, '|', marker_size)) { if (hunk != RR_SIDE_1) goto bad; hunk = RR_ORIGINAL; - } else if (is_cmarker(buf.buf, '=', marker_size, 0)) { + } else if (is_cmarker(buf.buf, '=', marker_size)) { if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL) goto bad; hunk = RR_SIDE_2; - } else if (is_cmarker(buf.buf, '>', marker_size, 1)) { + } else if (is_cmarker(buf.buf, '>', marker_size)) { if (hunk != RR_SIDE_2) goto bad; if (strbuf_cmp(&one, &two) > 0) @@ -231,6 +469,10 @@ static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_siz return hunk_no; } +/* + * Scan the path for conflicts, do the "handle_path()" thing above, and + * return the number of conflict hunks found. + */ static int handle_file(const char *path, unsigned char *sha1, const char *output) { int hunk_no = 0; @@ -259,8 +501,7 @@ static int handle_file(const char *path, unsigned char *sha1, const char *output error("There were errors while writing %s (%s)", path, strerror(io.io.wrerror)); if (io.io.output && fclose(io.io.output)) - io.io.wrerror = error("Failed to flush %s: %s", - path, strerror(errno)); + io.io.wrerror = error_errno("Failed to flush %s", path); if (hunk_no < 0) { if (output) @@ -272,93 +513,14 @@ static int handle_file(const char *path, unsigned char *sha1, const char *output return hunk_no; } -struct rerere_io_mem { - struct rerere_io io; - struct strbuf input; -}; - -static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_) -{ - struct rerere_io_mem *io = (struct rerere_io_mem *)io_; - char *ep; - size_t len; - - strbuf_release(sb); - if (!io->input.len) - return -1; - ep = memchr(io->input.buf, '\n', io->input.len); - if (!ep) - ep = io->input.buf + io->input.len; - else if (*ep == '\n') - ep++; - len = ep - io->input.buf; - strbuf_add(sb, io->input.buf, len); - strbuf_remove(&io->input, 0, len); - return 0; -} - -static int handle_cache(const char *path, unsigned char *sha1, const char *output) -{ - mmfile_t mmfile[3] = {{NULL}}; - mmbuffer_t result = {NULL, 0}; - const struct cache_entry *ce; - int pos, len, i, hunk_no; - struct rerere_io_mem io; - int marker_size = ll_merge_marker_size(path); - - /* - * Reproduce the conflicted merge in-core - */ - len = strlen(path); - pos = cache_name_pos(path, len); - if (0 <= pos) - return -1; - pos = -pos - 1; - - for (i = 0; i < 3; i++) { - enum object_type type; - unsigned long size; - int j; - - if (active_nr <= pos) - break; - ce = active_cache[pos++]; - if (ce_namelen(ce) != len || memcmp(ce->name, path, len)) - continue; - j = ce_stage(ce) - 1; - mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size); - mmfile[j].size = size; - } - for (i = 0; i < 3; i++) { - if (!mmfile[i].ptr && !mmfile[i].size) - mmfile[i].ptr = xstrdup(""); - } - /* - * NEEDSWORK: handle conflicts from merges with - * merge.renormalize set, too - */ - ll_merge(&result, path, &mmfile[0], NULL, - &mmfile[1], "ours", - &mmfile[2], "theirs", NULL); - for (i = 0; i < 3; i++) - free(mmfile[i].ptr); - - memset(&io, 0, sizeof(io)); - io.io.getline = rerere_mem_getline; - if (output) - io.io.output = fopen(output, "w"); - else - io.io.output = NULL; - strbuf_init(&io.input, 0); - strbuf_attach(&io.input, result.ptr, result.size, result.size); - - hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size); - strbuf_release(&io.input); - if (io.io.output) - fclose(io.io.output); - return hunk_no; -} - +/* + * Look at a cache entry at "i" and see if it is not conflicting, + * conflicting and we are willing to handle, or conflicting and + * we are unable to handle, and return the determination in *type. + * Return the cache index to be looked at next, by skipping the + * stages we have already looked at in this invocation of this + * function. + */ static int check_one_conflict(int i, int *type) { const struct cache_entry *e = active_cache[i]; @@ -369,10 +531,8 @@ static int check_one_conflict(int i, int *type) } *type = PUNTED; - if (ce_stage(e) == 1) { - if (active_nr <= ++i) - return i + 1; - } + while (ce_stage(active_cache[i]) == 1) + i++; /* Only handle regular files with both stages #2 and #3 */ if (i + 1 < active_nr) { @@ -392,6 +552,17 @@ static int check_one_conflict(int i, int *type) return i; } +/* + * Scan the index and find paths that have conflicts that rerere can + * handle, i.e. the ones that has both stages #2 and #3. + * + * NEEDSWORK: we do not record or replay a previous "resolve by + * deletion" for a delete-modify conflict, as that is inherently risky + * without knowing what modification is being discarded. The only + * safe case, i.e. both side doing the deletion and modification that + * are identical to the previous round, might want to be handled, + * though. + */ static int find_conflict(struct string_list *conflict) { int i; @@ -408,9 +579,26 @@ static int find_conflict(struct string_list *conflict) return 0; } +/* + * The merge_rr list is meant to hold outstanding conflicted paths + * that rerere could handle. Abuse the list by adding other types of + * entries to allow the caller to show "rerere remaining". + * + * - Conflicted paths that rerere does not handle are added + * - Conflicted paths that have been resolved are marked as such + * by storing RERERE_RESOLVED to .util field (where conflict ID + * is expected to be stored). + * + * Do *not* write MERGE_RR file out after calling this function. + * + * NEEDSWORK: we may want to fix the caller that implements "rerere + * remaining" to do this without abusing merge_rr. + */ int rerere_remaining(struct string_list *merge_rr) { int i; + if (setup_rerere(merge_rr, RERERE_READONLY)) + return 0; if (read_cache() < 0) return error("Could not read index"); @@ -424,7 +612,7 @@ int rerere_remaining(struct string_list *merge_rr) struct string_list_item *it; it = string_list_lookup(merge_rr, (const char *)e->name); if (it != NULL) { - free(it->util); + free_rerere_id(it); it->util = RERERE_RESOLVED; } } @@ -432,44 +620,83 @@ int rerere_remaining(struct string_list *merge_rr) return 0; } -static int merge(const char *name, const char *path) +/* + * Try using the given conflict resolution "ID" to see + * if that recorded conflict resolves cleanly what we + * got in the "cur". + */ +static int try_merge(const struct rerere_id *id, const char *path, + mmfile_t *cur, mmbuffer_t *result) { int ret; - mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0}; - mmbuffer_t result = {NULL, 0}; + mmfile_t base = {NULL, 0}, other = {NULL, 0}; - if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0) - return 1; + if (read_mmfile(&base, rerere_path(id, "preimage")) || + read_mmfile(&other, rerere_path(id, "postimage"))) + ret = 1; + else + /* + * A three-way merge. Note that this honors user-customizable + * low-level merge driver settings. + */ + ret = ll_merge(result, path, &base, NULL, cur, "", &other, "", NULL); + + free(base.ptr); + free(other.ptr); + + return ret; +} + +/* + * Find the conflict identified by "id"; the change between its + * "preimage" (i.e. a previous contents with conflict markers) and its + * "postimage" (i.e. the corresponding contents with conflicts + * resolved) may apply cleanly to the contents stored in "path", i.e. + * the conflict this time around. + * + * Returns 0 for successful replay of recorded resolution, or non-zero + * for failure. + */ +static int merge(const struct rerere_id *id, const char *path) +{ + FILE *f; + int ret; + mmfile_t cur = {NULL, 0}; + mmbuffer_t result = {NULL, 0}; - if (read_mmfile(&cur, rerere_path(name, "thisimage")) || - read_mmfile(&base, rerere_path(name, "preimage")) || - read_mmfile(&other, rerere_path(name, "postimage"))) { + /* + * Normalize the conflicts in path and write it out to + * "thisimage" temporary file. + */ + if ((handle_file(path, NULL, rerere_path(id, "thisimage")) < 0) || + read_mmfile(&cur, rerere_path(id, "thisimage"))) { ret = 1; goto out; } - ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL); - if (!ret) { - FILE *f; - - if (utime(rerere_path(name, "postimage"), NULL) < 0) - warning("failed utime() on %s: %s", - rerere_path(name, "postimage"), - strerror(errno)); - f = fopen(path, "w"); - if (!f) - return error("Could not open %s: %s", path, - strerror(errno)); - if (fwrite(result.ptr, result.size, 1, f) != 1) - error("Could not write %s: %s", path, strerror(errno)); - if (fclose(f)) - return error("Writing %s failed: %s", path, - strerror(errno)); - } + + ret = try_merge(id, path, &cur, &result); + if (ret) + goto out; + + /* + * A successful replay of recorded resolution. + * Mark that "postimage" was used to help gc. + */ + if (utime(rerere_path(id, "postimage"), NULL) < 0) + warning_errno("failed utime() on %s", + rerere_path(id, "postimage")); + + /* Update "path" with the resolution */ + f = fopen(path, "w"); + if (!f) + return error_errno("Could not open %s", path); + if (fwrite(result.ptr, result.size, 1, f) != 1) + error_errno("Could not write %s", path); + if (fclose(f)) + return error_errno("Writing %s failed", path); out: free(cur.ptr); - free(base.ptr); - free(other.ptr); free(result.ptr); return ret; @@ -481,12 +708,14 @@ static void update_paths(struct string_list *update) { int i; - hold_locked_index(&index_lock, 1); + hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR); for (i = 0; i < update->nr; i++) { struct string_list_item *item = &update->items[i]; if (add_file_to_cache(item->string, 0)) exit(128); + fprintf(stderr, "Staged '%s' using previous resolution.\n", + item->string); } if (active_cache_changed) { @@ -496,6 +725,92 @@ static void update_paths(struct string_list *update) rollback_lock_file(&index_lock); } +static void remove_variant(struct rerere_id *id) +{ + unlink_or_warn(rerere_path(id, "postimage")); + unlink_or_warn(rerere_path(id, "preimage")); + id->collection->status[id->variant] = 0; +} + +/* + * The path indicated by rr_item may still have conflict for which we + * have a recorded resolution, in which case replay it and optionally + * update it. Or it may have been resolved by the user and we may + * only have the preimage for that conflict, in which case the result + * needs to be recorded as a resolution in a postimage file. + */ +static void do_rerere_one_path(struct string_list_item *rr_item, + struct string_list *update) +{ + const char *path = rr_item->string; + struct rerere_id *id = rr_item->util; + struct rerere_dir *rr_dir = id->collection; + int variant; + + variant = id->variant; + + /* Has the user resolved it already? */ + if (variant >= 0) { + if (!handle_file(path, NULL, NULL)) { + copy_file(rerere_path(id, "postimage"), path, 0666); + id->collection->status[variant] |= RR_HAS_POSTIMAGE; + fprintf(stderr, "Recorded resolution for '%s'.\n", path); + free_rerere_id(rr_item); + rr_item->util = NULL; + return; + } + /* + * There may be other variants that can cleanly + * replay. Try them and update the variant number for + * this one. + */ + } + + /* Does any existing resolution apply cleanly? */ + for (variant = 0; variant < rr_dir->status_nr; variant++) { + const int both = RR_HAS_PREIMAGE | RR_HAS_POSTIMAGE; + struct rerere_id vid = *id; + + if ((rr_dir->status[variant] & both) != both) + continue; + + vid.variant = variant; + if (merge(&vid, path)) + continue; /* failed to replay */ + + /* + * If there already is a different variant that applies + * cleanly, there is no point maintaining our own variant. + */ + if (0 <= id->variant && id->variant != variant) + remove_variant(id); + + if (rerere_autoupdate) + string_list_insert(update, path); + else + fprintf(stderr, + "Resolved '%s' using previous resolution.\n", + path); + free_rerere_id(rr_item); + rr_item->util = NULL; + return; + } + + /* None of the existing one applies; we need a new variant */ + assign_variant(id); + + variant = id->variant; + handle_file(path, NULL, rerere_path(id, "preimage")); + if (id->collection->status[variant] & RR_HAS_POSTIMAGE) { + const char *path = rerere_path(id, "postimage"); + if (unlink(path)) + die_errno("cannot unlink stray '%s'", path); + id->collection->status[variant] &= ~RR_HAS_POSTIMAGE; + } + id->collection->status[variant] |= RR_HAS_PREIMAGE; + fprintf(stderr, "Recorded preimage for '%s'\n", path); +} + static int do_plain_rerere(struct string_list *rr, int fd) { struct string_list conflict = STRING_LIST_INIT_DUP; @@ -505,65 +820,39 @@ static int do_plain_rerere(struct string_list *rr, int fd) find_conflict(&conflict); /* - * MERGE_RR records paths with conflicts immediately after merge - * failed. Some of the conflicted paths might have been hand resolved - * in the working tree since then, but the initial run would catch all - * and register their preimages. + * MERGE_RR records paths with conflicts immediately after + * merge failed. Some of the conflicted paths might have been + * hand resolved in the working tree since then, but the + * initial run would catch all and register their preimages. */ - for (i = 0; i < conflict.nr; i++) { + struct rerere_id *id; + unsigned char sha1[20]; const char *path = conflict.items[i].string; - if (!string_list_has_string(rr, path)) { - unsigned char sha1[20]; - char *hex; - int ret; - ret = handle_file(path, sha1, NULL); - if (ret < 1) - continue; - hex = xstrdup(sha1_to_hex(sha1)); - string_list_insert(rr, path)->util = hex; - if (mkdir_in_gitdir(git_path("rr-cache/%s", hex))) - continue; - handle_file(path, NULL, rerere_path(hex, "preimage")); - fprintf(stderr, "Recorded preimage for '%s'\n", path); - } - } - - /* - * Now some of the paths that had conflicts earlier might have been - * hand resolved. Others may be similar to a conflict already that - * was resolved before. - */ - - for (i = 0; i < rr->nr; i++) { int ret; - const char *path = rr->items[i].string; - const char *name = (const char *)rr->items[i].util; - - if (has_rerere_resolution(name)) { - if (!merge(name, path)) { - const char *msg; - if (rerere_autoupdate) { - string_list_insert(&update, path); - msg = "Staged '%s' using previous resolution.\n"; - } else - msg = "Resolved '%s' using previous resolution.\n"; - fprintf(stderr, msg, path); - goto mark_resolved; - } - } - /* Let's see if we have resolved it. */ - ret = handle_file(path, NULL, NULL); - if (ret) + if (string_list_has_string(rr, path)) + continue; + + /* + * Ask handle_file() to scan and assign a + * conflict ID. No need to write anything out + * yet. + */ + ret = handle_file(path, sha1, NULL); + if (ret < 1) continue; - fprintf(stderr, "Recorded resolution for '%s'.\n", path); - copy_file(rerere_path(name, "postimage"), path, 0666); - mark_resolved: - rr->items[i].util = NULL; + id = new_rerere_id(sha1); + string_list_insert(rr, path)->util = id; + + /* Ensure that the directory exists. */ + mkdir_in_gitdir(rerere_path(id, NULL)); } + for (i = 0; i < rr->nr; i++) + do_rerere_one_path(&rr->items[i], &update); + if (update.nr) update_paths(&update); @@ -577,21 +866,21 @@ static void git_rerere_config(void) git_config(git_default_config, NULL); } +static GIT_PATH_FUNC(git_path_rr_cache, "rr-cache") + static int is_rerere_enabled(void) { - const char *rr_cache; int rr_cache_exists; if (!rerere_enabled) return 0; - rr_cache = git_path("rr-cache"); - rr_cache_exists = is_directory(rr_cache); + rr_cache_exists = is_directory(git_path_rr_cache()); if (rerere_enabled < 0) return rr_cache_exists; - if (!rr_cache_exists && mkdir_in_gitdir(rr_cache)) - die("Could not create directory %s", rr_cache); + if (!rr_cache_exists && mkdir_in_gitdir(git_path_rr_cache())) + die("Could not create directory %s", git_path_rr_cache()); return 1; } @@ -605,48 +894,208 @@ int setup_rerere(struct string_list *merge_rr, int flags) if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE)) rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE); - merge_rr_path = git_pathdup("MERGE_RR"); - fd = hold_lock_file_for_update(&write_lock, merge_rr_path, - LOCK_DIE_ON_ERROR); + if (flags & RERERE_READONLY) + fd = 0; + else + fd = hold_lock_file_for_update(&write_lock, git_path_merge_rr(), + LOCK_DIE_ON_ERROR); read_rr(merge_rr); return fd; } +/* + * The main entry point that is called internally from codepaths that + * perform mergy operations, possibly leaving conflicted index entries + * and working tree files. + */ int rerere(int flags) { struct string_list merge_rr = STRING_LIST_INIT_DUP; - int fd; + int fd, status; fd = setup_rerere(&merge_rr, flags); if (fd < 0) return 0; - return do_plain_rerere(&merge_rr, fd); + status = do_plain_rerere(&merge_rr, fd); + free_rerere_dirs(); + return status; +} + +/* + * Subclass of rerere_io that reads from an in-core buffer that is a + * strbuf + */ +struct rerere_io_mem { + struct rerere_io io; + struct strbuf input; +}; + +/* + * ... and its getline() method implementation + */ +static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_) +{ + struct rerere_io_mem *io = (struct rerere_io_mem *)io_; + char *ep; + size_t len; + + strbuf_release(sb); + if (!io->input.len) + return -1; + ep = memchr(io->input.buf, '\n', io->input.len); + if (!ep) + ep = io->input.buf + io->input.len; + else if (*ep == '\n') + ep++; + len = ep - io->input.buf; + strbuf_add(sb, io->input.buf, len); + strbuf_remove(&io->input, 0, len); + return 0; +} + +static int handle_cache(const char *path, unsigned char *sha1, const char *output) +{ + mmfile_t mmfile[3] = {{NULL}}; + mmbuffer_t result = {NULL, 0}; + const struct cache_entry *ce; + int pos, len, i, hunk_no; + struct rerere_io_mem io; + int marker_size = ll_merge_marker_size(path); + + /* + * Reproduce the conflicted merge in-core + */ + len = strlen(path); + pos = cache_name_pos(path, len); + if (0 <= pos) + return -1; + pos = -pos - 1; + + while (pos < active_nr) { + enum object_type type; + unsigned long size; + + ce = active_cache[pos++]; + if (ce_namelen(ce) != len || memcmp(ce->name, path, len)) + break; + i = ce_stage(ce) - 1; + if (!mmfile[i].ptr) { + mmfile[i].ptr = read_sha1_file(ce->oid.hash, &type, + &size); + mmfile[i].size = size; + } + } + for (i = 0; i < 3; i++) + if (!mmfile[i].ptr && !mmfile[i].size) + mmfile[i].ptr = xstrdup(""); + + /* + * NEEDSWORK: handle conflicts from merges with + * merge.renormalize set, too? + */ + ll_merge(&result, path, &mmfile[0], NULL, + &mmfile[1], "ours", + &mmfile[2], "theirs", NULL); + for (i = 0; i < 3; i++) + free(mmfile[i].ptr); + + memset(&io, 0, sizeof(io)); + io.io.getline = rerere_mem_getline; + if (output) + io.io.output = fopen(output, "w"); + else + io.io.output = NULL; + strbuf_init(&io.input, 0); + strbuf_attach(&io.input, result.ptr, result.size, result.size); + + /* + * Grab the conflict ID and optionally write the original + * contents with conflict markers out. + */ + hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size); + strbuf_release(&io.input); + if (io.io.output) + fclose(io.io.output); + return hunk_no; } static int rerere_forget_one_path(const char *path, struct string_list *rr) { const char *filename; - char *hex; + struct rerere_id *id; unsigned char sha1[20]; int ret; + struct string_list_item *item; + /* + * Recreate the original conflict from the stages in the + * index and compute the conflict ID + */ ret = handle_cache(path, sha1, NULL); if (ret < 1) return error("Could not parse conflict hunks in '%s'", path); - hex = xstrdup(sha1_to_hex(sha1)); - filename = rerere_path(hex, "postimage"); - if (unlink(filename)) - return (errno == ENOENT - ? error("no remembered resolution for %s", path) - : error("cannot unlink %s: %s", filename, strerror(errno))); - - handle_cache(path, sha1, rerere_path(hex, "preimage")); - fprintf(stderr, "Updated preimage for '%s'\n", path); + /* Nuke the recorded resolution for the conflict */ + id = new_rerere_id(sha1); + + for (id->variant = 0; + id->variant < id->collection->status_nr; + id->variant++) { + mmfile_t cur = { NULL, 0 }; + mmbuffer_t result = {NULL, 0}; + int cleanly_resolved; + + if (!has_rerere_resolution(id)) + continue; + + handle_cache(path, sha1, rerere_path(id, "thisimage")); + if (read_mmfile(&cur, rerere_path(id, "thisimage"))) { + free(cur.ptr); + error("Failed to update conflicted state in '%s'", path); + goto fail_exit; + } + cleanly_resolved = !try_merge(id, path, &cur, &result); + free(result.ptr); + free(cur.ptr); + if (cleanly_resolved) + break; + } + + if (id->collection->status_nr <= id->variant) { + error("no remembered resolution for '%s'", path); + goto fail_exit; + } + + filename = rerere_path(id, "postimage"); + if (unlink(filename)) { + if (errno == ENOENT) + error("no remembered resolution for %s", path); + else + error_errno("cannot unlink %s", filename); + goto fail_exit; + } + + /* + * Update the preimage so that the user can resolve the + * conflict in the working tree, run us again to record + * the postimage. + */ + handle_cache(path, sha1, rerere_path(id, "preimage")); + fprintf(stderr, "Updated preimage for '%s'\n", path); - string_list_insert(rr, path)->util = hex; + /* + * And remember that we can record resolution for this + * conflict when the user is done. + */ + item = string_list_insert(rr, path); + free_rerere_id(item); + item->util = id; fprintf(stderr, "Forgot resolution for %s\n", path); return 0; + +fail_exit: + free(id); + return -1; } int rerere_forget(struct pathspec *pathspec) @@ -662,6 +1111,11 @@ int rerere_forget(struct pathspec *pathspec) if (fd < 0) return 0; + /* + * The paths may have been resolved (incorrectly); + * recover the original conflicted state and then + * find the conflicted paths. + */ unmerge_cache(pathspec); find_conflict(&conflict); for (i = 0; i < conflict.nr; i++) { @@ -674,24 +1128,51 @@ int rerere_forget(struct pathspec *pathspec) return write_rr(&merge_rr, fd); } -static time_t rerere_created_at(const char *name) +/* + * Garbage collection support + */ + +static time_t rerere_created_at(struct rerere_id *id) { struct stat st; - return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime; + + return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime; } -static time_t rerere_last_used_at(const char *name) +static time_t rerere_last_used_at(struct rerere_id *id) { struct stat st; - return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime; + + return stat(rerere_path(id, "postimage"), &st) ? (time_t) 0 : st.st_mtime; +} + +/* + * Remove the recorded resolution for a given conflict ID + */ +static void unlink_rr_item(struct rerere_id *id) +{ + unlink_or_warn(rerere_path(id, "thisimage")); + remove_variant(id); + id->collection->status[id->variant] = 0; } -static void unlink_rr_item(const char *name) +static void prune_one(struct rerere_id *id, time_t now, + int cutoff_resolve, int cutoff_noresolve) { - unlink(rerere_path(name, "thisimage")); - unlink(rerere_path(name, "preimage")); - unlink(rerere_path(name, "postimage")); - rmdir(git_path("rr-cache/%s", name)); + time_t then; + int cutoff; + + then = rerere_last_used_at(id); + if (then) + cutoff = cutoff_resolve; + else { + then = rerere_created_at(id); + if (!then) + return; + cutoff = cutoff_noresolve; + } + if (then < now - cutoff * 86400) + unlink_rr_item(id); } void rerere_gc(struct string_list *rr) @@ -699,47 +1180,73 @@ void rerere_gc(struct string_list *rr) struct string_list to_remove = STRING_LIST_INIT_DUP; DIR *dir; struct dirent *e; - int i, cutoff; - time_t now = time(NULL), then; + int i; + time_t now = time(NULL); int cutoff_noresolve = 15; int cutoff_resolve = 60; + if (setup_rerere(rr, 0) < 0) + return; + git_config_get_int("gc.rerereresolved", &cutoff_resolve); git_config_get_int("gc.rerereunresolved", &cutoff_noresolve); git_config(git_default_config, NULL); dir = opendir(git_path("rr-cache")); if (!dir) die_errno("unable to open rr-cache directory"); + /* Collect stale conflict IDs ... */ while ((e = readdir(dir))) { + struct rerere_dir *rr_dir; + struct rerere_id id; + int now_empty; + if (is_dot_or_dotdot(e->d_name)) continue; - - then = rerere_last_used_at(e->d_name); - if (then) { - cutoff = cutoff_resolve; - } else { - then = rerere_created_at(e->d_name); - if (!then) - continue; - cutoff = cutoff_noresolve; + rr_dir = find_rerere_dir(e->d_name); + if (!rr_dir) + continue; /* or should we remove e->d_name? */ + + now_empty = 1; + for (id.variant = 0, id.collection = rr_dir; + id.variant < id.collection->status_nr; + id.variant++) { + prune_one(&id, now, cutoff_resolve, cutoff_noresolve); + if (id.collection->status[id.variant]) + now_empty = 0; } - if (then < now - cutoff * 86400) + if (now_empty) string_list_append(&to_remove, e->d_name); } closedir(dir); + + /* ... and then remove the empty directories */ for (i = 0; i < to_remove.nr; i++) - unlink_rr_item(to_remove.items[i].string); + rmdir(git_path("rr-cache/%s", to_remove.items[i].string)); string_list_clear(&to_remove, 0); + rollback_lock_file(&write_lock); } +/* + * During a conflict resolution, after "rerere" recorded the + * preimages, abandon them if the user did not resolve them or + * record their resolutions. And drop $GIT_DIR/MERGE_RR. + * + * NEEDSWORK: shouldn't we be calling this from "reset --hard"? + */ void rerere_clear(struct string_list *merge_rr) { int i; + if (setup_rerere(merge_rr, 0) < 0) + return; + for (i = 0; i < merge_rr->nr; i++) { - const char *name = (const char *)merge_rr->items[i].util; - if (!has_rerere_resolution(name)) - unlink_rr_item(name); + struct rerere_id *id = merge_rr->items[i].util; + if (!has_rerere_resolution(id)) { + unlink_rr_item(id); + rmdir(rerere_path(id, NULL)); + } } - unlink_or_warn(git_path("MERGE_RR")); + unlink_or_warn(git_path_merge_rr()); + rollback_lock_file(&write_lock); } |