1 files changed, 62 insertions, 3 deletions

diff --git a/fast-import.c b/fast-import.c
index 45b4edf36b..a523b171e2 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -275,6 +275,8 @@ struct recent_command
 static unsigned long max_depth = 10;
 static off_t max_packsize = (1LL << 32) - 1;
 static int force_update;
+static int pack_compression_level = Z_DEFAULT_COMPRESSION;
+static int pack_compression_seen;
 
 /* Stats and misc. counters */
 static uintmax_t alloc_count;
@@ -1038,7 +1040,7 @@ static int store_object(
 		delta = NULL;
 
 	memset(&s, 0, sizeof(s));
-	deflateInit(&s, zlib_compression_level);
+	deflateInit(&s, pack_compression_level);
 	if (delta) {
 		s.next_in = delta;
 		s.avail_in = deltalen;
@@ -1066,7 +1068,7 @@ static int store_object(
 			delta = NULL;
 
 			memset(&s, 0, sizeof(s));
-			deflateInit(&s, zlib_compression_level);
+			deflateInit(&s, pack_compression_level);
 			s.next_in = (void *)dat->buf;
 			s.avail_in = dat->len;
 			s.avail_out = deflateBound(&s, s.avail_in);
@@ -1123,6 +1125,24 @@ static int store_object(
 	return 0;
 }
 
+/* All calls must be guarded by find_object() or find_mark() to
+ * ensure the 'struct object_entry' passed was written by this
+ * process instance.  We unpack the entry by the offset, avoiding
+ * the need for the corresponding .idx file.  This unpacking rule
+ * works because we only use OBJ_REF_DELTA within the packfiles
+ * created by fast-import.
+ *
+ * oe must not be NULL.  Such an oe usually comes from giving
+ * an unknown SHA-1 to find_object() or an undefined mark to
+ * find_mark().  Callers must test for this condition and use
+ * the standard read_sha1_file() when it happens.
+ *
+ * oe->pack_id must not be MAX_PACK_ID.  Such an oe is usually from
+ * find_mark(), where the mark was reloaded from an existing marks
+ * file and is referencing an object that this fast-import process
+ * instance did not write out to a packfile.  Callers must test for
+ * this condition and use read_sha1_file() instead.
+ */
 static void *gfi_unpack_entry(
 	struct object_entry *oe,
 	unsigned long *sizep)
@@ -1130,7 +1150,22 @@ static void *gfi_unpack_entry(
 	enum object_type type;
 	struct packed_git *p = all_packs[oe->pack_id];
 	if (p == pack_data && p->pack_size < (pack_size + 20)) {
+		/* The object is stored in the packfile we are writing to
+		 * and we have modified it since the last time we scanned
+		 * back to read a previously written object.  If an old
+		 * window covered [p->pack_size, p->pack_size + 20) its
+		 * data is stale and is not valid.  Closing all windows
+		 * and updating the packfile length ensures we can read
+		 * the newly written data.
+		 */
 		close_pack_windows(p);
+
+		/* We have to offer 20 bytes additional on the end of
+		 * the packfile as the core unpacker code assumes the
+		 * footer is present at the file end and must promise
+		 * at least 20 bytes within any window it maps.  But
+		 * we don't actually create the footer here.
+		 */
 		p->pack_size = pack_size + 20;
 	}
 	return unpack_entry(p, oe->offset, &type, sizep);
@@ -2282,6 +2317,27 @@ static void import_marks(const char *input_file)
 	fclose(f);
 }
 
+static int git_pack_config(const char *k, const char *v)
+{
+	if (!strcmp(k, "pack.depth")) {
+		max_depth = git_config_int(k, v);
+		if (max_depth > MAX_DEPTH)
+			max_depth = MAX_DEPTH;
+		return 0;
+	}
+	if (!strcmp(k, "pack.compression")) {
+		int level = git_config_int(k, v);
+		if (level == -1)
+			level = Z_DEFAULT_COMPRESSION;
+		else if (level < 0 || level > Z_BEST_COMPRESSION)
+			die("bad pack compression level %d", level);
+		pack_compression_level = level;
+		pack_compression_seen = 1;
+		return 0;
+	}
+	return git_default_config(k, v);
+}
+
 static const char fast_import_usage[] =
 "git-fast-import [--date-format=f] [--max-pack-size=n] [--depth=n] [--active-branches=n] [--export-marks=marks.file]";
 
@@ -2289,7 +2345,10 @@ int main(int argc, const char **argv)
 {
 	unsigned int i, show_stats = 1;
 
-	git_config(git_default_config);
+	git_config(git_pack_config);
+	if (!pack_compression_seen && core_compression_seen)
+		pack_compression_level = core_compression_level;
+
 	alloc_objects(object_entry_alloc);
 	strbuf_init(&command_buf, 0);
 	atom_table = xcalloc(atom_table_sz, sizeof(struct atom_str*));