[PATCH 2/4] Refactor patch-id filtering out of git-cherry and git-format-patch.
This implements the patch-id computation and recording library, patch-ids.c, and rewrites the get_patch_ids() function used in cherry and format-patch to use it, so that they do not pollute the object namespace. Earlier code threw non-objects into the in-core object database, and hoped for not getting bitten by SHA-1 collisions. While it may be practically Ok, it still was an ugly hack.
Signed-off-by: Junio C Hamano <junkio@cox.net>
---
* Replacement of the previous one. I wanted to clean-up the
mess first.
Makefile | 3 +-
builtin-log.c | 44 ++++---------
patch-ids.c | 192 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
patch-ids.h | 21 ++++++
4 files changed, 228 insertions(+), 32 deletions(-)
create mode 100644 patch-ids.c
create mode 100644 patch-ids.h
diff --git a/Makefile b/Makefile
index a77d31d..f956c3d 100644
--- a/Makefile
+++ b/Makefile
@@ -283,7 +283,7 @@ LIB_H = \
diff.h object.h pack.h pkt-line.h quote.h refs.h list-objects.h sideband.h \
run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h \
- utf8.h reflog-walk.h
+ utf8.h reflog-walk.h patch-ids.h
DIFF_OBJS = \
diff.o diff-lib.o diffcore-break.o diffcore-order.o \
@@ -295,6 +295,7 @@ LIB_OBJS = \
date.o diff-delta.o entry.o exec_cmd.o ident.o \
interpolate.o \
lockfile.o \
+ patch-ids.o \
object.o pack-check.o patch-delta.o path.o pkt-line.o sideband.o \
reachable.o reflog-walk.o \
quote.o read-cache.o refs.o run-command.o dir.o object-refs.o \
diff --git a/builtin-log.c b/builtin-log.c
index 71df957..df676df 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -12,6 +12,7 @@
#include "builtin.h"
#include "tag.h"
#include "reflog-walk.h"
+#include "patch-ids.h"
static int default_show_root = 1;
@@ -333,25 +334,12 @@ static int reopen_stdout(struct commit *commit, int nr, int keep_subject)
}
-static int get_patch_id(struct commit *commit, struct diff_options *options,
- unsigned char *sha1)
-{
- if (commit->parents)
- diff_tree_sha1(commit->parents->item->object.sha1,
- commit->object.sha1, "", options);
- else
- diff_root_tree_sha1(commit->object.sha1, "", options);
- diffcore_std(options);
- return diff_flush_patch_id(options, sha1);
-}
-
-static void get_patch_ids(struct rev_info *rev, struct diff_options *options, const char *prefix)
+static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
{
struct rev_info check_rev;
struct commit *commit;
struct object *o1, *o2;
unsigned flags1, flags2;
- unsigned char sha1[20];
if (rev->pending.nr != 2)
die("Need exactly one range.");
@@ -364,10 +352,7 @@ static void get_patch_ids(struct rev_info *rev, struct diff_options *options, co
if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
die("Not a range.");
- diff_setup(options);
- options->recursive = 1;
- if (diff_setup_done(options) < 0)
- die("diff_setup_done failed");
+ init_patch_ids(ids);
/* given a range a..b get all patch ids for b..a */
init_revisions(&check_rev, prefix);
@@ -382,8 +367,7 @@ static void get_patch_ids(struct rev_info *rev, struct diff_options *options, co
if (commit->parents && commit->parents->next)
continue;
- if (!get_patch_id(commit, options, sha1))
- created_object(sha1, xcalloc(1, sizeof(struct object)));
+ add_commit_patch_id(commit, ids);
}
/* reset for next revision walk */
@@ -420,7 +404,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
int ignore_if_in_upstream = 0;
int thread = 0;
const char *in_reply_to = NULL;
- struct diff_options patch_id_opts;
+ struct patch_ids ids;
char *add_signoff = NULL;
char message_id[1024];
char ref_message_id[1024];
@@ -554,22 +538,19 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
}
if (ignore_if_in_upstream)
- get_patch_ids(&rev, &patch_id_opts, prefix);
+ get_patch_ids(&rev, &ids, prefix);
if (!use_stdout)
realstdout = fdopen(dup(1), "w");
prepare_revision_walk(&rev);
while ((commit = get_revision(&rev)) != NULL) {
- unsigned char sha1[20];
-
/* ignore merges */
if (commit->parents && commit->parents->next)
continue;
if (ignore_if_in_upstream &&
- !get_patch_id(commit, &patch_id_opts, sha1) &&
- lookup_object(sha1))
+ has_commit_patch_id(commit, &ids))
continue;
nr++;
@@ -624,6 +605,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
fclose(stdout);
}
free(list);
+ if (ignore_if_in_upstream)
+ free_patch_ids(&ids);
return 0;
}
@@ -646,7 +629,7 @@ static const char cherry_usage[] =
int cmd_cherry(int argc, const char **argv, const char *prefix)
{
struct rev_info revs;
- struct diff_options patch_id_opts;
+ struct patch_ids ids;
struct commit *commit;
struct commit_list *list = NULL;
const char *upstream;
@@ -692,7 +675,7 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
return 0;
}
- get_patch_ids(&revs, &patch_id_opts, prefix);
+ get_patch_ids(&revs, &ids, prefix);
if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
die("Unknown commit %s", limit);
@@ -708,12 +691,10 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
}
while (list) {
- unsigned char sha1[20];
char sign = '+';
commit = list->item;
- if (!get_patch_id(commit, &patch_id_opts, sha1) &&
- lookup_object(sha1))
+ if (has_commit_patch_id(commit, &ids))
sign = '-';
if (verbose) {
@@ -731,5 +712,6 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
list = list->next;
}
+ free_patch_ids(&ids);
return 0;
}
diff --git a/patch-ids.c b/patch-ids.c
new file mode 100644
index 0000000..a288fac
--- /dev/null
+++ b/patch-ids.c
@@ -0,0 +1,192 @@
+#include "cache.h"
+#include "diff.h"
+#include "commit.h"
+#include "patch-ids.h"
+
+static int commit_patch_id(struct commit *commit, struct diff_options *options,
+ unsigned char *sha1)
+{
+ if (commit->parents)
+ diff_tree_sha1(commit->parents->item->object.sha1,
+ commit->object.sha1, "", options);
+ else
+ diff_root_tree_sha1(commit->object.sha1, "", options);
+ diffcore_std(options);
+ return diff_flush_patch_id(options, sha1);
+}
+
+static uint32_t take2(const unsigned char *id)
+{
+ return ((id[0] << 8) | id[1]);
+}
+
+/*
+ * Conventional binary search loop looks like this:
+ *
+ * do {
+ * int mi = (lo + hi) / 2;
+ * int cmp = "entry pointed at by mi" minus "target";
+ * if (!cmp)
+ * return (mi is the wanted one)
+ * if (cmp > 0)
+ * hi = mi; "mi is larger than target"
+ * else
+ * lo = mi+1; "mi is smaller than target"
+ * } while (lo < hi);
+ *
+ * The invariants are:
+ *
+ * - When entering the loop, lo points at a slot that is never
+ * above the target (it could be at the target), hi points at a
+ * slot that is guaranteed to be above the target (it can never
+ * be at the target).
+ *
+ * - We find a point 'mi' between lo and hi (mi could be the same
+ * as lo, but never can be the same as hi), and check if it hits
+ * the target. There are three cases:
+ *
+ * - if it is a hit, we are happy.
+ *
+ * - if it is strictly higher than the target, we update hi with
+ * it.
+ *
+ * - if it is strictly lower than the target, we update lo to be
+ * one slot after it, because we allow lo to be at the target.
+ *
+ * When choosing 'mi', we do not have to take the "middle" but
+ * anywhere in between lo and hi, as long as lo <= mi < hi is
+ * satisfied. When we somehow know that the distance between the
+ * target and lo is much shorter than the target and hi, we could
+ * pick mi that is much closer to lo than the midway.
+ */
+static int patch_pos(struct patch_id **table, int nr, const unsigned char *id)
+{
+ int hi = nr;
+ int lo = 0;
+ int mi = 0;
+
+ if (!nr)
+ return -1;
+
+ if (nr != 1) {
+ unsigned lov, hiv, miv, ofs;
+
+ for (ofs = 0; ofs < 18; ofs += 2) {
+ lov = take2(table[0]->patch_id + ofs);
+ hiv = take2(table[nr-1]->patch_id + ofs);
+ miv = take2(id + ofs);
+ if (miv < lov)
+ return -1;
+ if (hiv < miv)
+ return -1 - nr;
+ if (lov != hiv) {
+ /*
+ * At this point miv could be equal
+ * to hiv (but id could still be higher);
+ * the invariant of (mi < hi) should be
+ * kept.
+ */
+ mi = (nr-1) * (miv - lov) / (hiv - lov);
+ if (lo <= mi && mi < hi)
+ break;
+ die("oops");
+ }
+ }
+ if (18 <= ofs)
+ die("cannot happen -- lo and hi are identical");
+ }
+
+ do {
+ int cmp;
+ cmp = hashcmp(table[mi]->patch_id, id);
+ if (!cmp)
+ return mi;
+ if (cmp > 0)
+ hi = mi;
+ else
+ lo = mi + 1;
+ mi = (hi + lo) / 2;
+ } while (lo < hi);
+ return -lo-1;
+}
+
+#define BUCKET_SIZE 190 /* 190 * 21 = 3990, with slop close enough to 4K */
+struct patch_id_bucket {
+ struct patch_id_bucket *next;
+ int nr;
+ struct patch_id bucket[BUCKET_SIZE];
+};
+
+int init_patch_ids(struct patch_ids *ids)
+{
+ memset(ids, 0, sizeof(*ids));
+ diff_setup(&ids->diffopts);
+ ids->diffopts.recursive = 1;
+ if (diff_setup_done(&ids->diffopts) < 0)
+ return error("diff_setup_done failed");
+ return 0;
+}
+
+int free_patch_ids(struct patch_ids *ids)
+{
+ struct patch_id_bucket *next, *patches;
+
+ free(ids->table);
+ for (patches = ids->patches; patches; patches = next) {
+ next = patches->next;
+ free(patches);
+ }
+ return 0;
+}
+
+static struct patch_id *add_commit(struct commit *commit,
+ struct patch_ids *ids,
+ int no_add)
+{
+ struct patch_id_bucket *bucket;
+ struct patch_id *ent;
+ unsigned char sha1[20];
+ int pos;
+
+ if (commit_patch_id(commit, &ids->diffopts, sha1))
+ return NULL;
+ pos = patch_pos(ids->table, ids->nr, sha1);
+ if (0 <= pos)
+ return ids->table[pos];
+ if (no_add)
+ return NULL;
+
+ pos = -1 - pos;
+
+ bucket = ids->patches;
+ if (!bucket || (BUCKET_SIZE <= bucket->nr)) {
+ bucket = xcalloc(1, sizeof(*bucket));
+ bucket->next = ids->patches;
+ ids->patches = bucket;
+ }
+ ent = &bucket->bucket[bucket->nr++];
+ hashcpy(ent->patch_id, sha1);
+
+ if (ids->alloc <= ids->nr) {
+ ids->alloc = alloc_nr(ids->nr);
+ ids->table = xrealloc(ids->table, sizeof(ent) * ids->alloc);
+ }
+ if (pos < ids->nr)
+ memmove(ids->table + pos + 1, ids->table + pos,
+ sizeof(ent) * (ids->nr - pos));
+ ids->nr++;
+ ids->table[pos] = ent;
+ return ids->table[pos];
+}
+
+struct patch_id *has_commit_patch_id(struct commit *commit,
+ struct patch_ids *ids)
+{
+ return add_commit(commit, ids, 1);
+}
+
+struct patch_id *add_commit_patch_id(struct commit *commit,
+ struct patch_ids *ids)
+{
+ return add_commit(commit, ids, 0);
+}
diff --git a/patch-ids.h b/patch-ids.h
new file mode 100644
index 0000000..c8c7ca1
--- /dev/null
+++ b/patch-ids.h
@@ -0,0 +1,21 @@
+#ifndef PATCH_IDS_H
+#define PATCH_IDS_H
+
+struct patch_id {
+ unsigned char patch_id[20];
+ char seen;
+};
+
+struct patch_ids {
+ struct diff_options diffopts;
+ int nr, alloc;
+ struct patch_id **table;
+ struct patch_id_bucket *patches;
+};
+
+int init_patch_ids(struct patch_ids *);
+int free_patch_ids(struct patch_ids *);
+struct patch_id *add_commit_patch_id(struct commit *, struct patch_ids *);
+struct patch_id *has_commit_patch_id(struct commit *, struct patch_ids *);
+
+#endif /* PATCH_IDS_H */
--
1.5.1.777.gd14d3
