diff options
Diffstat (limited to 'rerere.c')
| -rw-r--r-- | rerere.c | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/rerere.c b/rerere.c new file mode 100644 index 0000000000..d03a69634b --- /dev/null +++ b/rerere.c @@ -0,0 +1,606 @@ +#include "cache.h" +#include "string-list.h" +#include "rerere.h" +#include "xdiff-interface.h" +#include "dir.h" +#include "resolve-undo.h" +#include "ll-merge.h" +#include "attr.h" + +/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */ +static int rerere_enabled = -1; + +/* automatically update cleanly resolved paths to the index */ +static int rerere_autoupdate; + +static char *merge_rr_path; + +const char *rerere_path(const char *hex, const char *file) +{ + return git_path("rr-cache/%s/%s", hex, file); +} + +int has_rerere_resolution(const char *hex) +{ + struct stat st; + return !stat(rerere_path(hex, "postimage"), &st); +} + +static void read_rr(struct string_list *rr) +{ + unsigned char sha1[20]; + char buf[PATH_MAX]; + FILE *in = fopen(merge_rr_path, "r"); + if (!in) + return; + while (fread(buf, 40, 1, in) == 1) { + int i; + char *name; + if (get_sha1_hex(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) && (buf[i] = fgetc(in)); i++) + ; /* do nothing */ + if (i == sizeof(buf)) + die("filename too long"); + string_list_insert(rr, buf)->util = name; + } + fclose(in); +} + +static struct lock_file write_lock; + +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) + 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) + die("unable to write rerere record"); + } + if (commit_lock_file(&write_lock) != 0) + die("unable to write rerere record"); + return 0; +} + +static void ferr_write(const void *p, size_t count, FILE *fp, int *err) +{ + if (!count || *err) + return; + if (fwrite(p, count, 1, fp) != 1) + *err = errno; +} + +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); +} + +static void rerere_io_putconflict(int ch, int size, struct rerere_io *io) +{ + char buf[64]; + + while (size) { + if (size < sizeof(buf) - 2) { + memset(buf, ch, size); + buf[size] = '\n'; + buf[size + 1] = '\0'; + size = 0; + } else { + int sz = sizeof(buf) - 1; + if (size <= sz) + sz -= (sz - size) + 1; + memset(buf, ch, sz); + buf[sz] = '\0'; + size -= sz; + } + rerere_io_putstr(buf, io); + } +} + +static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io) +{ + if (io->output) + ferr_write(mem, sz, io->output, &io->wrerror); +} + +struct rerere_io_file { + struct rerere_io io; + FILE *input; +}; + +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) +{ + while (marker_size--) + if (*buf++ != marker_char) + return 0; + if (want_sp && *buf != ' ') + return 0; + return isspace(*buf); +} + +static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size) +{ + git_SHA_CTX ctx; + int hunk_no = 0; + enum { + RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL + } hunk = RR_CONTEXT; + struct strbuf one = STRBUF_INIT, two = STRBUF_INIT; + struct strbuf buf = STRBUF_INIT; + + if (sha1) + git_SHA1_Init(&ctx); + + while (!io->getline(&buf, io)) { + if (is_cmarker(buf.buf, '<', marker_size, 1)) { + if (hunk != RR_CONTEXT) + goto bad; + hunk = RR_SIDE_1; + } else if (is_cmarker(buf.buf, '|', marker_size, 0)) { + if (hunk != RR_SIDE_1) + goto bad; + hunk = RR_ORIGINAL; + } else if (is_cmarker(buf.buf, '=', marker_size, 0)) { + if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL) + goto bad; + hunk = RR_SIDE_2; + } else if (is_cmarker(buf.buf, '>', marker_size, 1)) { + if (hunk != RR_SIDE_2) + goto bad; + if (strbuf_cmp(&one, &two) > 0) + strbuf_swap(&one, &two); + hunk_no++; + hunk = RR_CONTEXT; + rerere_io_putconflict('<', marker_size, io); + rerere_io_putmem(one.buf, one.len, io); + rerere_io_putconflict('=', marker_size, io); + rerere_io_putmem(two.buf, two.len, io); + rerere_io_putconflict('>', marker_size, io); + if (sha1) { + git_SHA1_Update(&ctx, one.buf ? one.buf : "", + one.len + 1); + git_SHA1_Update(&ctx, two.buf ? two.buf : "", + two.len + 1); + } + strbuf_reset(&one); + strbuf_reset(&two); + } else if (hunk == RR_SIDE_1) + strbuf_addstr(&one, buf.buf); + else if (hunk == RR_ORIGINAL) + ; /* discard */ + else if (hunk == RR_SIDE_2) + strbuf_addstr(&two, buf.buf); + else + rerere_io_putstr(buf.buf, io); + continue; + bad: + hunk = 99; /* force error exit */ + break; + } + strbuf_release(&one); + strbuf_release(&two); + strbuf_release(&buf); + + if (sha1) + git_SHA1_Final(sha1, &ctx); + if (hunk != RR_CONTEXT) + return -1; + return hunk_no; +} + +static int handle_file(const char *path, unsigned char *sha1, const char *output) +{ + int hunk_no = 0; + struct rerere_io_file io; + int marker_size = ll_merge_marker_size(path); + + memset(&io, 0, sizeof(io)); + io.io.getline = rerere_file_getline; + io.input = fopen(path, "r"); + io.io.wrerror = 0; + if (!io.input) + return error("Could not open %s", path); + + if (output) { + io.io.output = fopen(output, "w"); + if (!io.io.output) { + fclose(io.input); + return error("Could not write %s", output); + } + } + + hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size); + + fclose(io.input); + if (io.io.wrerror) + 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)); + + if (hunk_no < 0) { + if (output) + unlink_or_warn(output); + return error("Could not parse conflict hunks in %s", path); + } + if (io.io.wrerror) + return -1; + 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 = strchrnul(io->input.buf, '\n'); + 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]; + mmbuffer_t result = {NULL, 0}; + 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; + + mmfile[i].size = 0; + mmfile[i].ptr = NULL; + if (active_nr <= pos) + break; + ce = active_cache[pos++]; + if (ce_namelen(ce) != len || memcmp(ce->name, path, len) + || ce_stage(ce) != i + 1) + break; + mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size); + mmfile[i].size = size; + } + for (i = 0; i < 3; i++) { + if (!mmfile[i].ptr && !mmfile[i].size) + mmfile[i].ptr = xstrdup(""); + } + ll_merge(&result, path, &mmfile[0], NULL, + &mmfile[1], "ours", + &mmfile[2], "theirs", 0); + 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; +} + +static int find_conflict(struct string_list *conflict) +{ + int i; + if (read_cache() < 0) + return error("Could not read index"); + for (i = 0; i+1 < active_nr; i++) { + struct cache_entry *e2 = active_cache[i]; + struct cache_entry *e3 = active_cache[i+1]; + if (ce_stage(e2) == 2 && + ce_stage(e3) == 3 && + ce_same_name(e2, e3) && + S_ISREG(e2->ce_mode) && + S_ISREG(e3->ce_mode)) { + string_list_insert(conflict, (const char *)e2->name); + i++; /* skip over both #2 and #3 */ + } + } + return 0; +} + +static int merge(const char *name, const char *path) +{ + int ret; + mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0}; + mmbuffer_t result = {NULL, 0}; + + if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0) + return 1; + + if (read_mmfile(&cur, rerere_path(name, "thisimage")) || + read_mmfile(&base, rerere_path(name, "preimage")) || + read_mmfile(&other, rerere_path(name, "postimage"))) { + ret = 1; + goto out; + } + ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", 0); + if (!ret) { + FILE *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)); + } + +out: + free(cur.ptr); + free(base.ptr); + free(other.ptr); + free(result.ptr); + + return ret; +} + +static struct lock_file index_lock; + +static int update_paths(struct string_list *update) +{ + int i; + int fd = hold_locked_index(&index_lock, 0); + int status = 0; + + if (fd < 0) + return -1; + + for (i = 0; i < update->nr; i++) { + struct string_list_item *item = &update->items[i]; + if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS)) + status = -1; + } + + if (!status && active_cache_changed) { + if (write_cache(fd, active_cache, active_nr) || + commit_locked_index(&index_lock)) + die("Unable to write new index file"); + } else if (fd >= 0) + rollback_lock_file(&index_lock); + return status; +} + +static int do_plain_rerere(struct string_list *rr, int fd) +{ + struct string_list conflict = { NULL, 0, 0, 1 }; + struct string_list update = { NULL, 0, 0, 1 }; + int i; + + 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. + */ + + for (i = 0; i < conflict.nr; i++) { + 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(git_path("rr-cache/%s", hex), 0755)) + 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)) { + if (rerere_autoupdate) + string_list_insert(&update, path); + fprintf(stderr, + "%s '%s' using previous resolution.\n", + rerere_autoupdate + ? "Staged" : "Resolved", + path); + goto mark_resolved; + } + } + + /* Let's see if we have resolved it. */ + ret = handle_file(path, NULL, NULL); + if (ret) + continue; + + fprintf(stderr, "Recorded resolution for '%s'.\n", path); + copy_file(rerere_path(name, "postimage"), path, 0666); + mark_resolved: + rr->items[i].util = NULL; + } + + if (update.nr) + update_paths(&update); + + return write_rr(rr, fd); +} + +static int git_rerere_config(const char *var, const char *value, void *cb) +{ + if (!strcmp(var, "rerere.enabled")) + rerere_enabled = git_config_bool(var, value); + else if (!strcmp(var, "rerere.autoupdate")) + rerere_autoupdate = git_config_bool(var, value); + else + return git_default_config(var, value, cb); + return 0; +} + +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); + if (rerere_enabled < 0) + return rr_cache_exists; + + if (!rr_cache_exists && + (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache))) + die("Could not create directory %s", rr_cache); + return 1; +} + +int setup_rerere(struct string_list *merge_rr, int flags) +{ + int fd; + + git_config(git_rerere_config, NULL); + if (!is_rerere_enabled()) + return -1; + + 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); + read_rr(merge_rr); + return fd; +} + +int rerere(int flags) +{ + struct string_list merge_rr = { NULL, 0, 0, 1 }; + int fd; + + fd = setup_rerere(&merge_rr, flags); + if (fd < 0) + return 0; + return do_plain_rerere(&merge_rr, fd); +} + +static int rerere_forget_one_path(const char *path, struct string_list *rr) +{ + const char *filename; + char *hex; + unsigned char sha1[20]; + int ret; + + 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); + + + string_list_insert(rr, path)->util = hex; + fprintf(stderr, "Forgot resolution for %s\n", path); + return 0; +} + +int rerere_forget(const char **pathspec) +{ + int i, fd; + struct string_list conflict = { NULL, 0, 0, 1 }; + struct string_list merge_rr = { NULL, 0, 0, 1 }; + + if (read_cache() < 0) + return error("Could not read index"); + + fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE); + + unmerge_cache(pathspec); + find_conflict(&conflict); + for (i = 0; i < conflict.nr; i++) { + struct string_list_item *it = &conflict.items[i]; + if (!match_pathspec(pathspec, it->string, strlen(it->string), + 0, NULL)) + continue; + rerere_forget_one_path(it->string, &merge_rr); + } + return write_rr(&merge_rr, fd); +} |