X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=sha1_file.c;h=4304fe9bbc2b8e796e944fa7ddb2ea2791000adf;hb=40250af411f33afa0c39a5d461829b676453ce3b;hp=110d696213323407616c3ed2417ebf7448a623c1;hpb=5bb44a51038a18f4f940968aed84e6cc26afcebe;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index 110d69621..4304fe9bb 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1030,14 +1030,27 @@ static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size
 		n = size;
 	memcpy(buf, (char *) buffer + bytes, n);
 	bytes = n;
-	if (bytes < size) {
+	if (bytes <= size) {
+		/*
+		 * The above condition must be (bytes <= size), not
+		 * (bytes < size).  In other words, even though we
+		 * expect no more output and set avail_out to zer0,
+		 * the input zlib stream may have bytes that express
+		 * "this concludes the stream", and we *do* want to
+		 * eat that input.
+		 *
+		 * Otherwise we would not be able to test that we
+		 * consumed all the input to reach the expected size;
+		 * we also want to check that zlib tells us that all
+		 * went well with status == Z_STREAM_END at the end.
+		 */
 		stream->next_out = buf + bytes;
 		stream->avail_out = size - bytes;
 		while (status == Z_OK)
 			status = inflate(stream, Z_FINISH);
 	}
 	buf[size] = 0;
-	if ((status == Z_OK || status == Z_STREAM_END) && !stream->avail_in) {
+	if (status == Z_STREAM_END && !stream->avail_in) {
 		inflateEnd(stream);
 		return buf;
 	}
@@ -1352,6 +1365,110 @@ static void *unpack_compressed_entry(struct packed_git *p,
 	return buffer;
 }
 
+#define MAX_DELTA_CACHE (256)
+
+static size_t delta_base_cached;
+
+static struct delta_base_cache_lru_list {
+	struct delta_base_cache_lru_list *prev;
+	struct delta_base_cache_lru_list *next;
+} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
+
+static struct delta_base_cache_entry {
+	struct delta_base_cache_lru_list lru;
+	void *data;
+	struct packed_git *p;
+	off_t base_offset;
+	unsigned long size;
+	enum object_type type;
+} delta_base_cache[MAX_DELTA_CACHE];
+
+static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
+{
+	unsigned long hash;
+
+	hash = (unsigned long)p + (unsigned long)base_offset;
+	hash += (hash >> 8) + (hash >> 16);
+	return hash % MAX_DELTA_CACHE;
+}
+
+static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
+	unsigned long *base_size, enum object_type *type, int keep_cache)
+{
+	void *ret;
+	unsigned long hash = pack_entry_hash(p, base_offset);
+	struct delta_base_cache_entry *ent = delta_base_cache + hash;
+
+	ret = ent->data;
+	if (ret && ent->p == p && ent->base_offset == base_offset)
+		goto found_cache_entry;
+	return unpack_entry(p, base_offset, type, base_size);
+
+found_cache_entry:
+	if (!keep_cache) {
+		ent->data = NULL;
+		ent->lru.next->prev = ent->lru.prev;
+		ent->lru.prev->next = ent->lru.next;
+		delta_base_cached -= ent->size;
+	}
+	else {
+		ret = xmalloc(ent->size + 1);
+		memcpy(ret, ent->data, ent->size);
+		((char *)ret)[ent->size] = 0;
+	}
+	*type = ent->type;
+	*base_size = ent->size;
+	return ret;
+}
+
+static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
+{
+	if (ent->data) {
+		free(ent->data);
+		ent->data = NULL;
+		ent->lru.next->prev = ent->lru.prev;
+		ent->lru.prev->next = ent->lru.next;
+		delta_base_cached -= ent->size;
+	}
+}
+
+static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
+	void *base, unsigned long base_size, enum object_type type)
+{
+	unsigned long hash = pack_entry_hash(p, base_offset);
+	struct delta_base_cache_entry *ent = delta_base_cache + hash;
+	struct delta_base_cache_lru_list *lru;
+
+	release_delta_base_cache(ent);
+	delta_base_cached += base_size;
+
+	for (lru = delta_base_cache_lru.next;
+	     delta_base_cached > delta_base_cache_limit
+	     && lru != &delta_base_cache_lru;
+	     lru = lru->next) {
+		struct delta_base_cache_entry *f = (void *)lru;
+		if (f->type == OBJ_BLOB)
+			release_delta_base_cache(f);
+	}
+	for (lru = delta_base_cache_lru.next;
+	     delta_base_cached > delta_base_cache_limit
+	     && lru != &delta_base_cache_lru;
+	     lru = lru->next) {
+		struct delta_base_cache_entry *f = (void *)lru;
+		release_delta_base_cache(f);
+	}
+
+	ent->p = p;
+	ent->base_offset = base_offset;
+	ent->type = type;
+	ent->data = base;
+	ent->size = base_size;
+	ent->lru.next = &delta_base_cache_lru;
+	ent->lru.prev = delta_base_cache_lru.prev;
+	delta_base_cache_lru.prev->next = &ent->lru;
+	delta_base_cache_lru.prev = &ent->lru;
+}
+
 static void *unpack_delta_entry(struct packed_git *p,
 				struct pack_window **w_curs,
 				off_t curpos,
@@ -1365,7 +1482,7 @@ static void *unpack_delta_entry(struct packed_git *p,
 	off_t base_offset;
 
 	base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
-	base = unpack_entry(p, base_offset, type, &base_size);
+	base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
 	if (!base)
 		die("failed to read delta base object"
 		    " at %"PRIuMAX" from %s",
@@ -1378,7 +1495,7 @@ static void *unpack_delta_entry(struct packed_git *p,
 	if (!result)
 		die("failed to apply delta");
 	free(delta_data);
-	free(base);
+	add_delta_base_cache(p, base_offset, base, base_size, *type);
 	return result;
 }
 
@@ -1415,15 +1532,14 @@ uint32_t num_packed_objects(const struct packed_git *p)
 	return (uint32_t)((p->index_size - 20 - 20 - 4*256) / 24);
 }
 
-int nth_packed_object_sha1(const struct packed_git *p, uint32_t n,
-			   unsigned char* sha1)
+const unsigned char *nth_packed_object_sha1(const struct packed_git *p,
+					    uint32_t n)
 {
 	const unsigned char *index = p->index_data;
 	index += 4 * 256;
 	if (num_packed_objects(p) <= n)
-		return -1;
-	hashcpy(sha1, index + 24 * n + 4);
-	return 0;
+		return NULL;
+	return index + 24 * n + 4;
 }
 
 off_t find_pack_entry_one(const unsigned char *sha1,
@@ -1562,7 +1678,7 @@ static void *read_packed_sha1(const unsigned char *sha1,
 	if (!find_pack_entry(sha1, &e, NULL))
 		return NULL;
 	else
-		return unpack_entry(e.p, e.offset, type, size);
+		return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
 }
 
 /*
@@ -1691,7 +1807,7 @@ void *read_object_with_reference(const unsigned char *sha1,
 	}
 }
 
-static void write_sha1_file_prepare(void *buf, unsigned long len,
+static void write_sha1_file_prepare(const void *buf, unsigned long len,
                                     const char *type, unsigned char *sha1,
                                     char *hdr, int *hdrlen)
 {
@@ -1819,7 +1935,7 @@ static void setup_object_header(z_stream *stream, const char *type, unsigned lon
 	stream->avail_out -= hdrlen;
 }
 
-int hash_sha1_file(void *buf, unsigned long len, const char *type,
+int hash_sha1_file(const void *buf, unsigned long len, const char *type,
                    unsigned char *sha1)
 {
 	char hdr[32];
@@ -1830,7 +1946,7 @@ int hash_sha1_file(void *buf, unsigned long len, const char *type,
 
 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
-	int size;
+	int size, ret;
 	unsigned char *compressed;
 	z_stream stream;
 	unsigned char sha1[20];
@@ -1862,7 +1978,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 		return error("sha1 file %s: %s\n", filename, strerror(errno));
 	}
 
-	snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
+	snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
 
 	fd = mkstemp(tmpfile);
 	if (fd < 0) {
@@ -1890,15 +2006,21 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 	/* Then the data itself.. */
 	stream.next_in = buf;
 	stream.avail_in = len;
-	while (deflate(&stream, Z_FINISH) == Z_OK)
-		/* nothing */;
-	deflateEnd(&stream);
+	ret = deflate(&stream, Z_FINISH);
+	if (ret != Z_STREAM_END)
+		die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
+
+	ret = deflateEnd(&stream);
+	if (ret != Z_OK)
+		die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
+
 	size = stream.total_out;
 
 	if (write_buffer(fd, compressed, size) < 0)
 		die("unable to write sha1 file");
 	fchmod(fd, 0444);
-	close(fd);
+	if (close(fd))
+		die("unable to write sha1 file");
 	free(compressed);
 
 	return move_temp_to_file(tmpfile, filename);
@@ -1983,7 +2105,7 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 	int ret;
 	SHA_CTX c;
 
-	snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
+	snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
 
 	local = mkstemp(tmpfile);
 	if (local < 0) {
@@ -2032,7 +2154,9 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 	} while (1);
 	inflateEnd(&stream);
 
-	close(local);
+	fchmod(local, 0444);
+	if (close(local) != 0)
+		die("unable to write sha1 file");
 	SHA1_Final(real_sha1, &c);
 	if (ret != Z_STREAM_END) {
 		unlink(tmpfile);