From c44a4c650c66eb7b8d50c57fd4e1bff1add7bf77 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 14 Jul 2017 16:45:31 +0200 Subject: rebase -i: rearrange fixup/squash lines using the rebase--helper This operation has quadratic complexity, which is especially painful on Windows, where shell scripts are *already* slow (mainly due to the overhead of the POSIX emulation layer). Let's reimplement this with linear complexity (using a hash map to match the commits' subject lines) for the common case; Sadly, the fixup/squash feature's design neglected performance considerations, allowing arbitrary prefixes (read: `fixup! hell` will match the commit subject `hello world`), which means that we are stuck with quadratic performance in the worst case. The reimplemented logic also happens to fix a bug where commented-out lines (representing empty patches) were dropped by the previous code. While at it, clarify how the fixup/squash feature works in `git rebase -i`'s man page. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt index 4f6bed6..a3c01df 100644 --- a/Documentation/git-rebase.txt +++ b/Documentation/git-rebase.txt @@ -430,13 +430,15 @@ without an explicit `--interactive`. --autosquash:: --no-autosquash:: When the commit log message begins with "squash! ..." (or - "fixup! ..."), and there is a commit whose title begins with - the same ..., automatically modify the todo list of rebase -i - so that the commit marked for squashing comes right after the - commit to be modified, and change the action of the moved - commit from `pick` to `squash` (or `fixup`). Ignores subsequent - "fixup! " or "squash! " after the first, in case you referred to an - earlier fixup/squash with `git commit --fixup/--squash`. + "fixup! ..."), and there is already a commit in the todo list that + matches the same `...`, automatically modify the todo list of rebase + -i so that the commit marked for squashing comes right after the + commit to be modified, and change the action of the moved commit + from `pick` to `squash` (or `fixup`). A commit matches the `...` if + the commit subject matches, or if the `...` refers to the commit's + hash. As a fall-back, partial matches of the commit subject work, + too. The recommended way to create fixup/squash commits is by using + the `--fixup`/`--squash` options of linkgit:git-commit[1]. + This option is only valid when the `--interactive` option is used. + diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c index 057ae71..f851936 100644 --- a/builtin/rebase--helper.c +++ b/builtin/rebase--helper.c @@ -15,7 +15,7 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix) int keep_empty = 0; enum { CONTINUE = 1, ABORT, MAKE_SCRIPT, SHORTEN_SHA1S, EXPAND_SHA1S, - CHECK_TODO_LIST, SKIP_UNNECESSARY_PICKS + CHECK_TODO_LIST, SKIP_UNNECESSARY_PICKS, REARRANGE_SQUASH } command = 0; struct option options[] = { OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")), @@ -34,6 +34,8 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix) N_("check the todo list"), CHECK_TODO_LIST), OPT_CMDMODE(0, "skip-unnecessary-picks", &command, N_("skip unnecessary picks"), SKIP_UNNECESSARY_PICKS), + OPT_CMDMODE(0, "rearrange-squash", &command, + N_("rearrange fixup/squash lines"), REARRANGE_SQUASH), OPT_END() }; @@ -60,5 +62,7 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix) return !!check_todo_list(); if (command == SKIP_UNNECESSARY_PICKS && argc == 1) return !!skip_unnecessary_picks(); + if (command == REARRANGE_SQUASH && argc == 1) + return !!rearrange_squash(); usage_with_options(builtin_rebase_helper_usage, options); } diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh index af8d7bd..3b0340e 100644 --- a/git-rebase--interactive.sh +++ b/git-rebase--interactive.sh @@ -721,94 +721,6 @@ collapse_todo_ids() { git rebase--helper --shorten-ids } -# Rearrange the todo list that has both "pick sha1 msg" and -# "pick sha1 fixup!/squash! msg" appears in it so that the latter -# comes immediately after the former, and change "pick" to -# "fixup"/"squash". -# -# Note that if the config has specified a custom instruction format -# each log message will be re-retrieved in order to normalize the -# autosquash arrangement -rearrange_squash () { - format=$(git config --get rebase.instructionFormat) - # extract fixup!/squash! lines and resolve any referenced sha1's - while read -r pick sha1 message - do - test -z "${format}" || message=$(git log -n 1 --format="%s" ${sha1}) - case "$message" in - "squash! "*|"fixup! "*) - action="${message%%!*}" - rest=$message - prefix= - # skip all squash! or fixup! (but save for later) - while : - do - case "$rest" in - "squash! "*|"fixup! "*) - prefix="$prefix${rest%%!*}," - rest="${rest#*! }" - ;; - *) - break - ;; - esac - done - printf '%s %s %s %s\n' "$sha1" "$action" "$prefix" "$rest" - # if it's a single word, try to resolve to a full sha1 and - # emit a second copy. This allows us to match on both message - # and on sha1 prefix - if test "${rest#* }" = "$rest"; then - fullsha="$(git rev-parse -q --verify "$rest" 2>/dev/null)" - if test -n "$fullsha"; then - # prefix the action to uniquely identify this line as - # intended for full sha1 match - echo "$sha1 +$action $prefix $fullsha" - fi - fi - esac - done >"$1.sq" <"$1" - test -s "$1.sq" || return - - used= - while read -r pick sha1 message - do - case " $used" in - *" $sha1 "*) continue ;; - esac - printf '%s\n' "$pick $sha1 $message" - test -z "${format}" || message=$(git log -n 1 --format="%s" ${sha1}) - used="$used$sha1 " - while read -r squash action msg_prefix msg_content - do - case " $used" in - *" $squash "*) continue ;; - esac - emit=0 - case "$action" in - +*) - action="${action#+}" - # full sha1 prefix test - case "$msg_content" in "$sha1"*) emit=1;; esac ;; - *) - # message prefix test - case "$message" in "$msg_content"*) emit=1;; esac ;; - esac - if test $emit = 1; then - if test -n "${format}" - then - msg_content=$(git log -n 1 --format="${format}" ${squash}) - else - msg_content="$(echo "$msg_prefix" | sed "s/,/! /g")$msg_content" - fi - printf '%s\n' "$action $squash $msg_content" - used="$used$squash " - fi - done <"$1.sq" - done >"$1.rearranged" <"$1" - cat "$1.rearranged" >"$1" - rm -f "$1.sq" "$1.rearranged" -} - # Add commands after a pick or after a squash/fixup serie # in the todo list. add_exec_commands () { @@ -1068,7 +980,7 @@ then fi test -s "$todo" || echo noop >> "$todo" -test -n "$autosquash" && rearrange_squash "$todo" +test -z "$autosquash" || git rebase--helper --rearrange-squash || exit test -n "$cmd" && add_exec_commands "$todo" todocount=$(git stripspace --strip-comments <"$todo" | wc -l) diff --git a/sequencer.c b/sequencer.c index 96d43ae..c54596f 100644 --- a/sequencer.c +++ b/sequencer.c @@ -20,6 +20,7 @@ #include "trailer.h" #include "log-tree.h" #include "wt-status.h" +#include "hashmap.h" #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION" @@ -2748,3 +2749,198 @@ int skip_unnecessary_picks(void) return 0; } + +struct subject2item_entry { + struct hashmap_entry entry; + int i; + char subject[FLEX_ARRAY]; +}; + +static int subject2item_cmp(const void *fndata, + const struct subject2item_entry *a, + const struct subject2item_entry *b, const void *key) +{ + return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject); +} + +/* + * Rearrange the todo list that has both "pick commit-id msg" and "pick + * commit-id fixup!/squash! msg" in it so that the latter is put immediately + * after the former, and change "pick" to "fixup"/"squash". + * + * Note that if the config has specified a custom instruction format, each log + * message will have to be retrieved from the commit (as the oneline in the + * script cannot be trusted) in order to normalize the autosquash arrangement. + */ +int rearrange_squash(void) +{ + const char *todo_file = rebase_path_todo(); + struct todo_list todo_list = TODO_LIST_INIT; + struct hashmap subject2item; + int res = 0, rearranged = 0, *next, *tail, fd, i; + char **subjects; + + fd = open(todo_file, O_RDONLY); + if (fd < 0) + return error_errno(_("could not open '%s'"), todo_file); + if (strbuf_read(&todo_list.buf, fd, 0) < 0) { + close(fd); + return error(_("could not read '%s'."), todo_file); + } + close(fd); + if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) { + todo_list_release(&todo_list); + return -1; + } + + /* + * The hashmap maps onelines to the respective todo list index. + * + * If any items need to be rearranged, the next[i] value will indicate + * which item was moved directly after the i'th. + * + * In that case, last[i] will indicate the index of the latest item to + * be moved to appear after the i'th. + */ + hashmap_init(&subject2item, (hashmap_cmp_fn) subject2item_cmp, + NULL, todo_list.nr); + ALLOC_ARRAY(next, todo_list.nr); + ALLOC_ARRAY(tail, todo_list.nr); + ALLOC_ARRAY(subjects, todo_list.nr); + for (i = 0; i < todo_list.nr; i++) { + struct strbuf buf = STRBUF_INIT; + struct todo_item *item = todo_list.items + i; + const char *commit_buffer, *subject, *p; + size_t subject_len; + int i2 = -1; + struct subject2item_entry *entry; + + next[i] = tail[i] = -1; + if (item->command >= TODO_EXEC) { + subjects[i] = NULL; + continue; + } + + if (is_fixup(item->command)) { + todo_list_release(&todo_list); + return error(_("the script was already rearranged.")); + } + + item->commit->util = item; + + parse_commit(item->commit); + commit_buffer = get_commit_buffer(item->commit, NULL); + find_commit_subject(commit_buffer, &subject); + format_subject(&buf, subject, " "); + subject = subjects[i] = strbuf_detach(&buf, &subject_len); + unuse_commit_buffer(item->commit, commit_buffer); + if ((skip_prefix(subject, "fixup! ", &p) || + skip_prefix(subject, "squash! ", &p))) { + struct commit *commit2; + + for (;;) { + while (isspace(*p)) + p++; + if (!skip_prefix(p, "fixup! ", &p) && + !skip_prefix(p, "squash! ", &p)) + break; + } + + if ((entry = hashmap_get_from_hash(&subject2item, + strhash(p), p))) + /* found by title */ + i2 = entry->i; + else if (!strchr(p, ' ') && + (commit2 = + lookup_commit_reference_by_name(p)) && + commit2->util) + /* found by commit name */ + i2 = (struct todo_item *)commit2->util + - todo_list.items; + else { + /* copy can be a prefix of the commit subject */ + for (i2 = 0; i2 < i; i2++) + if (subjects[i2] && + starts_with(subjects[i2], p)) + break; + if (i2 == i) + i2 = -1; + } + } + if (i2 >= 0) { + rearranged = 1; + todo_list.items[i].command = + starts_with(subject, "fixup!") ? + TODO_FIXUP : TODO_SQUASH; + if (next[i2] < 0) + next[i2] = i; + else + next[tail[i2]] = i; + tail[i2] = i; + } else if (!hashmap_get_from_hash(&subject2item, + strhash(subject), subject)) { + FLEX_ALLOC_MEM(entry, subject, subject, subject_len); + entry->i = i; + hashmap_entry_init(entry, strhash(entry->subject)); + hashmap_put(&subject2item, entry); + } + } + + if (rearranged) { + struct strbuf buf = STRBUF_INIT; + + for (i = 0; i < todo_list.nr; i++) { + enum todo_command command = todo_list.items[i].command; + int cur = i; + + /* + * Initially, all commands are 'pick's. If it is a + * fixup or a squash now, we have rearranged it. + */ + if (is_fixup(command)) + continue; + + while (cur >= 0) { + int offset = todo_list.items[cur].offset_in_buf; + int end_offset = cur + 1 < todo_list.nr ? + todo_list.items[cur + 1].offset_in_buf : + todo_list.buf.len; + char *bol = todo_list.buf.buf + offset; + char *eol = todo_list.buf.buf + end_offset; + + /* replace 'pick', by 'fixup' or 'squash' */ + command = todo_list.items[cur].command; + if (is_fixup(command)) { + strbuf_addstr(&buf, + todo_command_info[command].str); + bol += strcspn(bol, " \t"); + } + + strbuf_add(&buf, bol, eol - bol); + + cur = next[cur]; + } + } + + fd = open(todo_file, O_WRONLY); + if (fd < 0) + res = error_errno(_("could not open '%s'"), todo_file); + else if (write(fd, buf.buf, buf.len) < 0) + res = error_errno(_("could not read '%s'."), todo_file); + else if (ftruncate(fd, buf.len) < 0) + res = error_errno(_("could not finish '%s'"), + todo_file); + close(fd); + strbuf_release(&buf); + } + + free(next); + free(tail); + for (i = 0; i < todo_list.nr; i++) + free(subjects[i]); + free(subjects); + hashmap_free(&subject2item, 1); + todo_list_release(&todo_list); + + return res; +} diff --git a/sequencer.h b/sequencer.h index 04a57e0..6f3d3df 100644 --- a/sequencer.h +++ b/sequencer.h @@ -51,6 +51,7 @@ int sequencer_make_script(int keep_empty, FILE *out, int transform_todo_ids(int shorten_ids); int check_todo_list(void); int skip_unnecessary_picks(void); +int rearrange_squash(void); extern const char sign_off_header[]; diff --git a/t/t3415-rebase-autosquash.sh b/t/t3415-rebase-autosquash.sh index 62cb977..e364c12 100755 --- a/t/t3415-rebase-autosquash.sh +++ b/t/t3415-rebase-autosquash.sh @@ -290,7 +290,7 @@ set_backup_editor () { test_set_editor "$PWD/backup-editor.sh" } -test_expect_failure 'autosquash with multiple empty patches' ' +test_expect_success 'autosquash with multiple empty patches' ' test_tick && git commit --allow-empty -m "empty" && test_tick && -- cgit v0.10.2-6-g49f6