Thread (11 messages) flat view 11 messages, 3 authors, 2016-06-15

Re: [PATCH v3] revision: allow selection of commits that do not match a pattern

From: Jeff King <hidden>
Date: 2016-06-15 22:43:20
Subsystem: kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers: Nathan Chancellor, Nicolas Schier, Linus Torvalds

On Sun, Jul 08, 2007 at 12:57:20PM +0200, Sven Verdoolaege wrote:
We do this by maintaining two lists of patterns, one for
those that should match and one for those that should not match.

A negative pattern is specified by putting a '!' in front.
For example, to show the commits of Jakub Narebski that
are not about gitweb, you'd do a

	git log --author='Narebski' --grep='!gitweb' --all-match
I wondered if the usage might be more natural if we could grep in
separate processes, and then build filtering pipelines (like we would
with regular grep).  For example, something like:

git-rev-list HEAD |
  git-revgrep --author=Narebski |
  git-revgrep -v gitweb |
  git-log -

However, my concern was that things might get a lot slower. And they do:

$ time git-rev-list --grep=Jeff.King HEAD >/dev/null
real    0m0.553s
user    0m0.532s
sys     0m0.020s

$ time git-rev-list HEAD | git-revgrep Jeff.King >/dev/null
real    0m0.662s
user    0m1.072s
sys     0m0.036s

(note the user time -- it's a dual-CPU box, so the wall clock time is
deceptive).

So it really does double your time (or triple, if you have a second
revgrep, and so forth (although as you filter out commits the cost of
each successive revgrep goes down)).  So it's probably not worth
pursuing this approach, but I thought I would throw it out there to
document my dead-end.

Quick and dirty git-revgrep code is below.

-Peff

---
diff --git a/Makefile b/Makefile
index d7541b4..baaf4f1 100644
--- a/Makefile
+++ b/Makefile
@@ -384,7 +384,8 @@ BUILTIN_OBJS = \
 	builtin-verify-pack.o \
 	builtin-write-tree.o \
 	builtin-show-ref.o \
-	builtin-pack-refs.o
+	builtin-pack-refs.o \
+	builtin-revgrep.o
 
 GITLIBS = $(LIB_FILE) $(XDIFF_LIB)
 EXTLIBS = -lz
diff --git a/builtin-revgrep.c b/builtin-revgrep.c
new file mode 100644
index 0000000..35993c8
--- /dev/null
+++ b/builtin-revgrep.c
@@ -0,0 +1,68 @@
+#include "cache.h"
+#include "commit.h"
+#include "grep.h"
+
+static int revgrep_one(const struct commit *commit, struct grep_opt *opt)
+{
+	return grep_buffer(opt, NULL, commit->buffer, strlen(commit->buffer));
+}
+
+static void revgrep_filter(struct grep_opt *opt)
+{
+	char line[1000];
+	unsigned char sha1[20];
+	struct commit *commit;
+
+	while (fgets(line, sizeof(line), stdin) != NULL) {
+		int len = strlen(line);
+		if (line[len - 1] == '\n')
+			line[--len] = 0;
+		if (!len)
+			break;
+		get_sha1_hex(line, sha1);
+		commit = lookup_commit_reference(sha1);
+		if (!commit)
+			continue;
+		if (revgrep_one(commit, opt))
+			printf("%s\n", line);
+	}
+}
+
+int cmd_revgrep(int argc, const char **argv, const char *prefix)
+{
+	struct grep_opt opt;
+
+	memset(&opt, 0, sizeof(opt));
+	opt.pattern_tail = &opt.pattern_list;
+	opt.status_only = 1;
+
+	while (1 < argc) {
+		const char *arg = argv[1];
+		argc--; argv++;
+
+		if (!strcmp(arg, "-i")) {
+			opt.regflags |= REG_ICASE;
+			continue;
+		}
+		if (!strcmp(arg, "-v")) {
+			opt.invert = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-E")) {
+			opt.regflags |= REG_EXTENDED;
+			continue;
+		}
+
+		append_grep_pattern(&opt, arg, "command line", 0,
+				GREP_PATTERN);
+	}
+
+	if (!opt.pattern_list)
+		die("no pattern given");
+
+	compile_grep_patterns(&opt);
+	revgrep_filter(&opt);
+	free_grep_patterns(&opt);
+
+	return 0;
+}
diff --git a/builtin.h b/builtin.h
index 661a92f..d185528 100644
--- a/builtin.h
+++ b/builtin.h
@@ -82,5 +82,6 @@ extern int cmd_write_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_show_ref(int argc, const char **argv, const char *prefix);
 extern int cmd_pack_refs(int argc, const char **argv, const char *prefix);
+extern int cmd_revgrep(int argc, const char **argv, const char *prefix);
 
 #endif
diff --git a/git.c b/git.c
index a647f9c..d9ec129 100644
--- a/git.c
+++ b/git.c
@@ -374,6 +374,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "verify-pack", cmd_verify_pack },
 		{ "show-ref", cmd_show_ref, RUN_SETUP },
 		{ "pack-refs", cmd_pack_refs, RUN_SETUP },
+		{ "revgrep", cmd_revgrep, RUN_SETUP },
 	};
 	int i;
 





quoted hunk ↗ jump to hunk
As an added bonus, this patch also documents --all-match.

Signed-off-by: Sven Verdoolaege <redacted>
---
 Documentation/git-rev-list.txt |   17 ++++++++++
 revision.c                     |   64 +++++++++++++++++++++++++++++++++------
 revision.h                     |    1 +
 3 files changed, 72 insertions(+), 10 deletions(-)
diff --git a/Documentation/git-rev-list.txt b/Documentation/git-rev-list.txt
index 20dcac6..c462f5d 100644
--- a/Documentation/git-rev-list.txt
+++ b/Documentation/git-rev-list.txt
@@ -214,11 +214,19 @@ limiting may be applied.
 
 	Limit the commits output to ones with author/committer
 	header lines that match the specified pattern (regular expression).
+	A pattern starting with a '!' will show only commits that do
+	not match the remainder of the pattern.
+	To match lines starting with '!', escape the initial '!'
+	with a backslash.
 
 --grep='pattern'::
 
 	Limit the commits output to ones with log message that
 	matches the specified pattern (regular expression).
+	A pattern starting with a '!' will show only commits that do
+	not match the remainder of the pattern.
+	To match lines starting with '!', escape the initial '!'
+	with a backslash.
 
 --regexp-ignore-case::
 
@@ -229,6 +237,15 @@ limiting may be applied.
 	Consider the limiting patterns to be extended regular expressions
 	instead of the default basic regular expressions.
 
+--all-match::
+
+	Without this option, a commit is shown if any of the
+	(positive or negative) patterns matches, i.e., there
+	is at least one positive match or not all of the negative
+	patterns match.  With this options, a commit is only
+	shown if all of the patterns match, i.e., all positive
+	patterns match and no negative pattern matches.
+
 --remove-empty::
 
 	Stop when a given path disappears from the tree.
diff --git a/revision.c b/revision.c
index 5184716..0035d40 100644
--- a/revision.c
+++ b/revision.c
@@ -821,34 +821,50 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
 	return 0;
 }
 
-static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
+static void add_grep(struct rev_info *revs, const char *ptn,
+		    enum grep_pat_token what)
 {
-	if (!revs->grep_filter) {
+	int negated = 0;
+	struct grep_opt **filter;
+
+	if (ptn[0] == '\\' && ptn[1] == '!')
+		ptn++;
+	if (*ptn == '!') {
+		negated = 1;
+		ptn++;
+	}
+	filter = negated ? &revs->grep_neg_filter : &revs->grep_filter;
+	if (!*filter) {
 		struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 		opt->status_only = 1;
 		opt->pattern_tail = &(opt->pattern_list);
 		opt->regflags = REG_NEWLINE;
-		revs->grep_filter = opt;
+		*filter = opt;
 	}
-	append_grep_pattern(revs->grep_filter, ptn,
-			    "command line", 0, what);
+	append_grep_pattern(*filter, ptn, "command line", 0, what);
 }
 
-static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
+static void add_header_grep(struct rev_info *revs, const char *field,
+			    const char *pattern)
 {
 	char *pat;
-	const char *prefix;
+	const char *prefix, *negated;
 	int patlen, fldlen;
 
 	fldlen = strlen(field);
 	patlen = strlen(pattern);
 	pat = xmalloc(patlen + fldlen + 10);
+	negated = "";
+	if (*pattern == '!') {
+		negated = "!";
+		pattern++;
+	}
 	prefix = ".*";
 	if (*pattern == '^') {
 		prefix = "";
 		pattern++;
 	}
-	sprintf(pat, "^%s %s%s", field, prefix, pattern);
+	sprintf(pat, "%s^%s %s%s", negated, field, prefix, pattern);
 	add_grep(revs, pat, GREP_PATTERN_HEAD);
 }
 
@@ -1212,6 +1228,9 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 	if (revs->grep_filter)
 		revs->grep_filter->regflags |= regflags;
 
+	if (revs->grep_neg_filter)
+		revs->grep_neg_filter->regflags |= regflags;
+
 	if (show_merge)
 		prepare_show_merge(revs);
 	if (def && !revs->pending.nr) {
@@ -1249,6 +1268,11 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		compile_grep_patterns(revs->grep_filter);
 	}
 
+	if (revs->grep_neg_filter) {
+		revs->grep_neg_filter->all_match = !all_match;
+		compile_grep_patterns(revs->grep_neg_filter);
+	}
+
 	return left;
 }
 
@@ -1327,11 +1351,31 @@ static int rewrite_parents(struct rev_info *revs, struct commit *commit)
 	return 0;
 }
 
+/*
+ * If all_match is set, then a commit matches if all the positive
+ * patterns match and not one of the negative patterns matches.
+ * If all_match is not set, then a commit matches if at least one
+ * of the positive patterns matches or not all of the negative
+ * patterns match.
+ */
 static int commit_match(struct commit *commit, struct rev_info *opt)
 {
-	if (!opt->grep_filter)
+	int pos_match, all_match;
+
+	pos_match = !opt->grep_filter ||
+		    grep_buffer(opt->grep_filter,
+			   NULL, /* we say nothing, not even filename */
+			   commit->buffer, strlen(commit->buffer));
+	if (!opt->grep_neg_filter)
+		return pos_match;
+
+	all_match = !opt->grep_neg_filter->all_match;
+	if (!all_match && opt->grep_filter && pos_match)
 		return 1;
-	return grep_buffer(opt->grep_filter,
+	if (all_match && !pos_match)
+		return 0;
+
+	return !grep_buffer(opt->grep_neg_filter,
 			   NULL, /* we say nothing, not even filename */
 			   commit->buffer, strlen(commit->buffer));
 }
diff --git a/revision.h b/revision.h
index f46b4d5..9728d4c 100644
--- a/revision.h
+++ b/revision.h
@@ -84,6 +84,7 @@ struct rev_info {
 
 	/* Filter by commit log message */
 	struct grep_opt	*grep_filter;
+	struct grep_opt	*grep_neg_filter;
 
 	/* special limits */
 	int skip_count;
-- 
1.5.3.rc0.65.ge75d-dirty

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