Merge branch 'nd/stream-more'

Use API to read blob data in smaller chunks in more places to reduce the
memory footprint.

By Nguyễn Thái Ngọc Duy (6) and Junio C Hamano (1)
* nd/stream-more:
  update-server-info: respect core.bigfilethreshold
  fsck: use streaming API for writing lost-found blobs
  show: use streaming API for showing blobs
  parse_object: avoid putting whole blob in core
  cat-file: use streaming API to print blobs
  Add more large blob test cases
  streaming: make streaming-write-entry to be more reusable

1 files changed, 40 insertions, 2 deletions

diff --git a/sha1_file.c b/sha1_file.c
index 4f06a0e450..ad314f08b9 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -19,6 +19,7 @@
 #include "pack-revindex.h"
 #include "sha1-lookup.h"
 #include "bulk-checkin.h"
+#include "streaming.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -1146,10 +1147,47 @@ static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
 	return NULL;
 }
 
-int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
+/*
+ * With an in-core object data in "map", rehash it to make sure the
+ * object name actually matches "sha1" to detect object corruption.
+ * With "map" == NULL, try reading the object named with "sha1" using
+ * the streaming interface and rehash it to do the same.
+ */
+int check_sha1_signature(const unsigned char *sha1, void *map,
+			 unsigned long size, const char *type)
 {
 	unsigned char real_sha1[20];
-	hash_sha1_file(map, size, type, real_sha1);
+	enum object_type obj_type;
+	struct git_istream *st;
+	git_SHA_CTX c;
+	char hdr[32];
+	int hdrlen;
+
+	if (map) {
+		hash_sha1_file(map, size, type, real_sha1);
+		return hashcmp(sha1, real_sha1) ? -1 : 0;
+	}
+
+	st = open_istream(sha1, &obj_type, &size, NULL);
+	if (!st)
+		return -1;
+
+	/* Generate the header */
+	hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
+
+	/* Sha1.. */
+	git_SHA1_Init(&c);
+	git_SHA1_Update(&c, hdr, hdrlen);
+	for (;;) {
+		char buf[1024 * 16];
+		ssize_t readlen = read_istream(st, buf, sizeof(buf));
+
+		if (!readlen)
+			break;
+		git_SHA1_Update(&c, buf, readlen);
+	}
+	git_SHA1_Final(real_sha1, &c);
+	close_istream(st);
 	return hashcmp(sha1, real_sha1) ? -1 : 0;
 }