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authorJunio C Hamano <gitster@pobox.com>2011-08-05 14:54:57 -0700
committerJunio C Hamano <gitster@pobox.com>2011-08-05 14:54:57 -0700
commit96790ca02935791b302cd65a4d092f4cdf5cd21e (patch)
tree450e39507c2024160acf6d85fc965c7cfa1f21f6
parent5d2fc9135a35284176e99708b9b6f32c9e6eb7a2 (diff)
parent1b4bb16b9ec331c91e28d2e3e7dee5070534b6a2 (diff)
downloadgit-96790ca02935791b302cd65a4d092f4cdf5cd21e.tar.gz
Merge branch 'jc/pack-order-tweak'
* jc/pack-order-tweak: pack-objects: optimize "recency order" core: log offset pack data accesses happened
-rw-r--r--builtin/pack-objects.c138
-rw-r--r--cache.h3
-rw-r--r--config.c3
-rw-r--r--environment.c1
-rw-r--r--sha1_file.c21
5 files changed, 165 insertions, 1 deletions
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 84e6dafb12..27f24d3aaf 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -51,6 +51,8 @@ struct object_entry {
* objects against.
*/
unsigned char no_try_delta;
+ unsigned char tagged; /* near the very tip of refs */
+ unsigned char filled; /* assigned write-order */
};
/*
@@ -96,6 +98,7 @@ static unsigned long window_memory_limit = 0;
*/
static int *object_ix;
static int object_ix_hashsz;
+static struct object_entry *locate_object_entry(const unsigned char *sha1);
/*
* stats
@@ -200,6 +203,7 @@ static void copy_pack_data(struct sha1file *f,
}
}
+/* Return 0 if we will bust the pack-size limit */
static unsigned long write_object(struct sha1file *f,
struct object_entry *entry,
off_t write_offset)
@@ -434,6 +438,134 @@ static int write_one(struct sha1file *f,
return 1;
}
+static int mark_tagged(const char *path, const unsigned char *sha1, int flag,
+ void *cb_data)
+{
+ unsigned char peeled[20];
+ struct object_entry *entry = locate_object_entry(sha1);
+
+ if (entry)
+ entry->tagged = 1;
+ if (!peel_ref(path, peeled)) {
+ entry = locate_object_entry(peeled);
+ if (entry)
+ entry->tagged = 1;
+ }
+ return 0;
+}
+
+static void add_to_write_order(struct object_entry **wo,
+ int *endp,
+ struct object_entry *e)
+{
+ if (e->filled)
+ return;
+ wo[(*endp)++] = e;
+ e->filled = 1;
+}
+
+static void add_descendants_to_write_order(struct object_entry **wo,
+ int *endp,
+ struct object_entry *e)
+{
+ struct object_entry *child;
+
+ for (child = e->delta_child; child; child = child->delta_sibling)
+ add_to_write_order(wo, endp, child);
+ for (child = e->delta_child; child; child = child->delta_sibling)
+ add_descendants_to_write_order(wo, endp, child);
+}
+
+static void add_family_to_write_order(struct object_entry **wo,
+ int *endp,
+ struct object_entry *e)
+{
+ struct object_entry *root;
+
+ for (root = e; root->delta; root = root->delta)
+ ; /* nothing */
+ add_to_write_order(wo, endp, root);
+ add_descendants_to_write_order(wo, endp, root);
+}
+
+static struct object_entry **compute_write_order(void)
+{
+ int i, wo_end;
+
+ struct object_entry **wo = xmalloc(nr_objects * sizeof(*wo));
+
+ for (i = 0; i < nr_objects; i++) {
+ objects[i].tagged = 0;
+ objects[i].filled = 0;
+ objects[i].delta_child = NULL;
+ objects[i].delta_sibling = NULL;
+ }
+
+ /*
+ * Fully connect delta_child/delta_sibling network.
+ * Make sure delta_sibling is sorted in the original
+ * recency order.
+ */
+ for (i = nr_objects - 1; 0 <= i; i--) {
+ struct object_entry *e = &objects[i];
+ if (!e->delta)
+ continue;
+ /* Mark me as the first child */
+ e->delta_sibling = e->delta->delta_child;
+ e->delta->delta_child = e;
+ }
+
+ /*
+ * Mark objects that are at the tip of tags.
+ */
+ for_each_tag_ref(mark_tagged, NULL);
+
+ /*
+ * Give the commits in the original recency order until
+ * we see a tagged tip.
+ */
+ for (i = wo_end = 0; i < nr_objects; i++) {
+ if (objects[i].tagged)
+ break;
+ add_to_write_order(wo, &wo_end, &objects[i]);
+ }
+
+ /*
+ * Then fill all the tagged tips.
+ */
+ for (; i < nr_objects; i++) {
+ if (objects[i].tagged)
+ add_to_write_order(wo, &wo_end, &objects[i]);
+ }
+
+ /*
+ * And then all remaining commits and tags.
+ */
+ for (i = 0; i < nr_objects; i++) {
+ if (objects[i].type != OBJ_COMMIT &&
+ objects[i].type != OBJ_TAG)
+ continue;
+ add_to_write_order(wo, &wo_end, &objects[i]);
+ }
+
+ /*
+ * And then all the trees.
+ */
+ for (i = 0; i < nr_objects; i++) {
+ if (objects[i].type != OBJ_TREE)
+ continue;
+ add_to_write_order(wo, &wo_end, &objects[i]);
+ }
+
+ /*
+ * Finally all the rest in really tight order
+ */
+ for (i = 0; i < nr_objects; i++)
+ add_family_to_write_order(wo, &wo_end, &objects[i]);
+
+ return wo;
+}
+
static void write_pack_file(void)
{
uint32_t i = 0, j;
@@ -442,10 +574,12 @@ static void write_pack_file(void)
struct pack_header hdr;
uint32_t nr_remaining = nr_result;
time_t last_mtime = 0;
+ struct object_entry **write_order;
if (progress > pack_to_stdout)
progress_state = start_progress("Writing objects", nr_result);
written_list = xmalloc(nr_objects * sizeof(*written_list));
+ write_order = compute_write_order();
do {
unsigned char sha1[20];
@@ -469,7 +603,8 @@ static void write_pack_file(void)
offset = sizeof(hdr);
nr_written = 0;
for (; i < nr_objects; i++) {
- if (!write_one(f, objects + i, &offset))
+ struct object_entry *e = write_order[i];
+ if (!write_one(f, e, &offset))
break;
display_progress(progress_state, written);
}
@@ -546,6 +681,7 @@ static void write_pack_file(void)
} while (nr_remaining && i < nr_objects);
free(written_list);
+ free(write_order);
stop_progress(&progress_state);
if (written != nr_result)
die("wrote %"PRIu32" objects while expecting %"PRIu32,
diff --git a/cache.h b/cache.h
index 9e12d55470..f49eaf9263 100644
--- a/cache.h
+++ b/cache.h
@@ -773,6 +773,9 @@ extern int parse_sha1_header(const char *hdr, unsigned long *sizep);
/* global flag to enable extra checks when accessing packed objects */
extern int do_check_packed_object_crc;
+/* for development: log offset of pack access */
+extern const char *log_pack_access;
+
extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
extern int move_temp_to_file(const char *tmpfile, const char *filename);
diff --git a/config.c b/config.c
index e42c59b190..4183f80262 100644
--- a/config.c
+++ b/config.c
@@ -576,6 +576,9 @@ static int git_default_core_config(const char *var, const char *value)
return 0;
}
+ if (!strcmp(var, "core.logpackaccess"))
+ return git_config_string(&log_pack_access, var, value);
+
if (!strcmp(var, "core.autocrlf")) {
if (value && !strcasecmp(value, "input")) {
if (core_eol == EOL_CRLF)
diff --git a/environment.c b/environment.c
index 94d58fd244..19351024f5 100644
--- a/environment.c
+++ b/environment.c
@@ -36,6 +36,7 @@ size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
size_t delta_base_cache_limit = 16 * 1024 * 1024;
unsigned long big_file_threshold = 512 * 1024 * 1024;
+const char *log_pack_access;
const char *pager_program;
int pager_use_color = 1;
const char *editor_program;
diff --git a/sha1_file.c b/sha1_file.c
index 89d7e5eb57..d5616dca08 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1797,6 +1797,24 @@ static void *unpack_delta_entry(struct packed_git *p,
return result;
}
+static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
+{
+ static FILE *log_file;
+
+ if (!log_file) {
+ log_file = fopen(log_pack_access, "w");
+ if (!log_file) {
+ error("cannot open pack access log '%s' for writing: %s",
+ log_pack_access, strerror(errno));
+ log_pack_access = NULL;
+ return;
+ }
+ }
+ fprintf(log_file, "%s %"PRIuMAX"\n",
+ p->pack_name, (uintmax_t)obj_offset);
+ fflush(log_file);
+}
+
int do_check_packed_object_crc;
void *unpack_entry(struct packed_git *p, off_t obj_offset,
@@ -1806,6 +1824,9 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
off_t curpos = obj_offset;
void *data;
+ if (log_pack_access)
+ write_pack_access_log(p, obj_offset);
+
if (do_check_packed_object_crc && p->index_version > 1) {
struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
unsigned long len = revidx[1].offset - obj_offset;