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-rw-r--r--builtin-pack-objects.c69
1 files changed, 54 insertions, 15 deletions
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 17627b34e8..9f035ba8e6 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -36,6 +36,7 @@ struct object_entry {
struct object_entry *delta_sibling; /* other deltified objects who
* uses the same base as me
*/
+ void *delta_data; /* cached delta (uncompressed) */
unsigned long delta_size; /* delta data size (uncompressed) */
enum object_type type;
enum object_type in_pack_type; /* could be delta */
@@ -76,6 +77,9 @@ static struct progress progress_state;
static int pack_compression_level = Z_DEFAULT_COMPRESSION;
static int pack_compression_seen;
+static unsigned long delta_cache_size = 0;
+static unsigned long max_delta_cache_size = 0;
+
/*
* The object names in objects array are hashed with this hashtable,
* to help looking up the entry by object name.
@@ -405,24 +409,31 @@ static unsigned long write_object(struct sha1file *f,
z_stream stream;
unsigned long maxsize;
void *out;
- buf = read_sha1_file(entry->sha1, &type, &size);
- if (!buf)
- die("unable to read %s", sha1_to_hex(entry->sha1));
- if (size != entry->size)
- die("object %s size inconsistency (%lu vs %lu)",
- sha1_to_hex(entry->sha1), size, entry->size);
- if (usable_delta) {
- buf = delta_against(buf, size, entry);
+ if (entry->delta_data && usable_delta) {
+ buf = entry->delta_data;
size = entry->delta_size;
obj_type = (allow_ofs_delta && entry->delta->offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
} else {
- /*
- * recover real object type in case
- * check_object() wanted to re-use a delta,
- * but we couldn't since base was in previous split pack
- */
- obj_type = type;
+ buf = read_sha1_file(entry->sha1, &type, &size);
+ if (!buf)
+ die("unable to read %s", sha1_to_hex(entry->sha1));
+ if (size != entry->size)
+ die("object %s size inconsistency (%lu vs %lu)",
+ sha1_to_hex(entry->sha1), size, entry->size);
+ if (usable_delta) {
+ buf = delta_against(buf, size, entry);
+ size = entry->delta_size;
+ obj_type = (allow_ofs_delta && entry->delta->offset) ?
+ OBJ_OFS_DELTA : OBJ_REF_DELTA;
+ } else {
+ /*
+ * recover real object type in case
+ * check_object() wanted to re-use a delta,
+ * but we couldn't since base was in previous split pack
+ */
+ obj_type = type;
+ }
}
/* compress the data to store and put compressed length in datalen */
memset(&stream, 0, sizeof(stream));
@@ -1385,6 +1396,20 @@ struct unpacked {
struct delta_index *index;
};
+static int delta_cacheable(struct unpacked *trg, struct unpacked *src,
+ unsigned long src_size, unsigned long trg_size,
+ unsigned long delta_size)
+{
+ if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
+ return 0;
+
+ /* cache delta, if objects are large enough compared to delta size */
+ if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
+ return 1;
+
+ return 0;
+}
+
/*
* We search for deltas _backwards_ in a list sorted by type and
* by size, so that we see progressively smaller and smaller files.
@@ -1466,10 +1491,20 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
if (!delta_buf)
return 0;
+ if (trg_entry->delta_data) {
+ delta_cache_size -= trg_entry->delta_size;
+ free(trg_entry->delta_data);
+ }
+ trg_entry->delta_data = 0;
trg_entry->delta = src_entry;
trg_entry->delta_size = delta_size;
trg_entry->depth = src_entry->depth + 1;
- free(delta_buf);
+
+ if (delta_cacheable(src, trg, src_size, trg_size, delta_size)) {
+ trg_entry->delta_data = xrealloc(delta_buf, delta_size);
+ delta_cache_size += trg_entry->delta_size;
+ } else
+ free(delta_buf);
return 1;
}
@@ -1615,6 +1650,10 @@ static int git_pack_config(const char *k, const char *v)
pack_compression_seen = 1;
return 0;
}
+ if (!strcmp(k, "pack.deltacachesize")) {
+ max_delta_cache_size = git_config_int(k, v);
+ return 0;
+ }
return git_default_config(k, v);
}