X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=sha1_file.c;h=4304fe9bbc2b8e796e944fa7ddb2ea2791000adf;hb=40250af411f33afa0c39a5d461829b676453ce3b;hp=6d0a72ed093d353a672129f7e460d0c1015212d7;hpb=6b4318e604ca729d5d7508a744f0155555094fae;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index 6d0a72ed0..4304fe9bb 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -349,6 +349,7 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
 static void read_info_alternates(const char * relative_base, int depth)
 {
 	char *map;
+	size_t mapsz;
 	struct stat st;
 	char path[PATH_MAX];
 	int fd;
@@ -361,12 +362,13 @@ static void read_info_alternates(const char * relative_base, int depth)
 		close(fd);
 		return;
 	}
-	map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	mapsz = xsize_t(st.st_size);
+	map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);
 
-	link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
+	link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
 
-	munmap(map, st.st_size);
+	munmap(map, mapsz);
 }
 
 void prepare_alt_odb(void)
@@ -430,48 +432,50 @@ void pack_report()
 		pack_mapped, peak_pack_mapped);
 }
 
-static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
-				void **idx_map_)
+static int check_packed_git_idx(const char *path,  struct packed_git *p)
 {
 	void *idx_map;
-	uint32_t *index;
-	unsigned long idx_size;
-	int nr, i;
+	struct pack_idx_header *hdr;
+	size_t idx_size;
+	uint32_t nr, i, *index;
 	int fd = open(path, O_RDONLY);
 	struct stat st;
+
 	if (fd < 0)
 		return -1;
 	if (fstat(fd, &st)) {
 		close(fd);
 		return -1;
 	}
-	idx_size = st.st_size;
+	idx_size = xsize_t(st.st_size);
+	if (idx_size < 4 * 256 + 20 + 20) {
+		close(fd);
+		return error("index file %s is too small", path);
+	}
 	idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);
 
-	index = idx_map;
-	*idx_map_ = idx_map;
-	*idx_size_ = idx_size;
-
-	/* check index map */
-	if (idx_size < 4*256 + 20 + 20)
-		return error("index file %s is too small", path);
-
 	/* a future index format would start with this, as older git
 	 * binaries would fail the non-monotonic index check below.
 	 * give a nicer warning to the user if we can.
 	 */
-	if (index[0] == htonl(PACK_IDX_SIGNATURE))
+	hdr = idx_map;
+	if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
+		munmap(idx_map, idx_size);
 		return error("index file %s is a newer version"
 			" and is not supported by this binary"
 			" (try upgrading GIT to a newer version)",
 			path);
+	}
 
 	nr = 0;
+	index = idx_map;
 	for (i = 0; i < 256; i++) {
-		unsigned int n = ntohl(index[i]);
-		if (n < nr)
+		uint32_t n = ntohl(index[i]);
+		if (n < nr) {
+			munmap(idx_map, idx_size);
 			return error("non-monotonic index %s", path);
+		}
 		nr = n;
 	}
 
@@ -482,9 +486,14 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
 	 *  - 20-byte SHA1 of the packfile
 	 *  - 20-byte SHA1 file checksum
 	 */
-	if (idx_size != 4*256 + nr * 24 + 20 + 20)
+	if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+		munmap(idx_map, idx_size);
 		return error("wrong index file size in %s", path);
+	}
 
+	p->index_version = 1;
+	p->index_data = idx_map;
+	p->index_size = idx_size;
 	return 0;
 }
 
@@ -605,7 +614,7 @@ static int open_packed_git_1(struct packed_git *p)
 		return error("end of packfile %s is unavailable", p->pack_name);
 	if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
 		return error("packfile %s signature is unavailable", p->pack_name);
-	idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
+	idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
 	if (hashcmp(sha1, idx_sha1))
 		return error("packfile %s does not match index", p->pack_name);
 	return 0;
@@ -622,7 +631,7 @@ static int open_packed_git(struct packed_git *p)
 	return -1;
 }
 
-static int in_window(struct pack_window *win, unsigned long offset)
+static int in_window(struct pack_window *win, off_t offset)
 {
 	/* We must promise at least 20 bytes (one hash) after the
 	 * offset is available from this window, otherwise the offset
@@ -637,7 +646,7 @@ static int in_window(struct pack_window *win, unsigned long offset)
 
 unsigned char* use_pack(struct packed_git *p,
 		struct pack_window **w_cursor,
-		unsigned long offset,
+		off_t offset,
 		unsigned int *left)
 {
 	struct pack_window *win = *w_cursor;
@@ -662,11 +671,13 @@ unsigned char* use_pack(struct packed_git *p,
 		}
 		if (!win) {
 			size_t window_align = packed_git_window_size / 2;
+			off_t len;
 			win = xcalloc(1, sizeof(*win));
 			win->offset = (offset / window_align) * window_align;
-			win->len = p->pack_size - win->offset;
-			if (win->len > packed_git_window_size)
-				win->len = packed_git_window_size;
+			len = p->pack_size - win->offset;
+			if (len > packed_git_window_size)
+				len = packed_git_window_size;
+			win->len = (size_t)len;
 			pack_mapped += win->len;
 			while (packed_git_limit < pack_mapped
 				&& unuse_one_window(p))
@@ -695,41 +706,41 @@ unsigned char* use_pack(struct packed_git *p,
 	}
 	offset -= win->offset;
 	if (left)
-		*left = win->len - offset;
+		*left = win->len - xsize_t(offset);
 	return win->base + offset;
 }
 
-struct packed_git *add_packed_git(char *path, int path_len, int local)
+struct packed_git *add_packed_git(const char *path, int path_len, int local)
 {
 	struct stat st;
-	struct packed_git *p;
-	unsigned long idx_size;
-	void *idx_map;
-	unsigned char sha1[20];
+	struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
 
-	if (check_packed_git_idx(path, &idx_size, &idx_map))
+	/*
+	 * Make sure a corresponding .pack file exists and that
+	 * the index looks sane.
+	 */
+	path_len -= strlen(".idx");
+	if (path_len < 1)
 		return NULL;
-
-	/* do we have a corresponding .pack file? */
-	strcpy(path + path_len - 4, ".pack");
-	if (stat(path, &st) || !S_ISREG(st.st_mode)) {
-		munmap(idx_map, idx_size);
+	memcpy(p->pack_name, path, path_len);
+	strcpy(p->pack_name + path_len, ".pack");
+	if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode) ||
+	    check_packed_git_idx(path, p)) {
+		free(p);
 		return NULL;
 	}
+
 	/* ok, it looks sane as far as we can check without
 	 * actually mapping the pack file.
 	 */
-	p = xmalloc(sizeof(*p) + path_len + 2);
-	strcpy(p->pack_name, path);
-	p->index_size = idx_size;
 	p->pack_size = st.st_size;
-	p->index_base = idx_map;
 	p->next = NULL;
 	p->windows = NULL;
 	p->pack_fd = -1;
 	p->pack_local = local;
-	if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
-		hashcpy(p->sha1, sha1);
+	p->mtime = st.st_mtime;
+	if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
+		hashclr(p->sha1);
 	return p;
 }
 
@@ -739,23 +750,19 @@ struct packed_git *parse_pack_index(unsigned char *sha1)
 	return parse_pack_index_file(sha1, path);
 }
 
-struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
+struct packed_git *parse_pack_index_file(const unsigned char *sha1,
+					 const char *idx_path)
 {
-	struct packed_git *p;
-	unsigned long idx_size;
-	void *idx_map;
-	char *path;
+	const char *path = sha1_pack_name(sha1);
+	struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
 
-	if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
+	if (check_packed_git_idx(idx_path, p)) {
+		free(p);
 		return NULL;
+	}
 
-	path = sha1_pack_name(sha1);
-
-	p = xmalloc(sizeof(*p) + strlen(path) + 2);
 	strcpy(p->pack_name, path);
-	p->index_size = idx_size;
 	p->pack_size = 0;
-	p->index_base = idx_map;
 	p->next = NULL;
 	p->windows = NULL;
 	p->pack_fd = -1;
@@ -812,6 +819,60 @@ static void prepare_packed_git_one(char *objdir, int local)
 	closedir(dir);
 }
 
+static int sort_pack(const void *a_, const void *b_)
+{
+	struct packed_git *a = *((struct packed_git **)a_);
+	struct packed_git *b = *((struct packed_git **)b_);
+	int st;
+
+	/*
+	 * Local packs tend to contain objects specific to our
+	 * variant of the project than remote ones.  In addition,
+	 * remote ones could be on a network mounted filesystem.
+	 * Favor local ones for these reasons.
+	 */
+	st = a->pack_local - b->pack_local;
+	if (st)
+		return -st;
+
+	/*
+	 * Younger packs tend to contain more recent objects,
+	 * and more recent objects tend to get accessed more
+	 * often.
+	 */
+	if (a->mtime < b->mtime)
+		return 1;
+	else if (a->mtime == b->mtime)
+		return 0;
+	return -1;
+}
+
+static void rearrange_packed_git(void)
+{
+	struct packed_git **ary, *p;
+	int i, n;
+
+	for (n = 0, p = packed_git; p; p = p->next)
+		n++;
+	if (n < 2)
+		return;
+
+	/* prepare an array of packed_git for easier sorting */
+	ary = xcalloc(n, sizeof(struct packed_git *));
+	for (n = 0, p = packed_git; p; p = p->next)
+		ary[n++] = p;
+
+	qsort(ary, n, sizeof(struct packed_git *), sort_pack);
+
+	/* link them back again */
+	for (i = 0; i < n - 1; i++)
+		ary[i]->next = ary[i + 1];
+	ary[n - 1]->next = NULL;
+	packed_git = ary[0];
+
+	free(ary);
+}
+
 static int prepare_packed_git_run_once = 0;
 void prepare_packed_git(void)
 {
@@ -826,6 +887,7 @@ void prepare_packed_git(void)
 		prepare_packed_git_one(alt->base, 0);
 		alt->name[-1] = '/';
 	}
+	rearrange_packed_git();
 	prepare_packed_git_run_once = 1;
 }
 
@@ -871,9 +933,9 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 		 */
 		sha1_file_open_flag = 0;
 	}
-	map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	*size = xsize_t(st.st_size);
+	map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);
-	*size = st.st_size;
 	return map;
 }
 
@@ -956,26 +1018,50 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
 	return 0;
 }
 
-static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
+static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
 {
 	int bytes = strlen(buffer) + 1;
 	unsigned char *buf = xmalloc(1+size);
 	unsigned long n;
+	int status = Z_OK;
 
 	n = stream->total_out - bytes;
 	if (n > 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 (inflate(stream, Z_FINISH) == Z_OK)
-			/* nothing */;
+		while (status == Z_OK)
+			status = inflate(stream, Z_FINISH);
 	}
 	buf[size] = 0;
-	inflateEnd(stream);
-	return buf;
+	if (status == Z_STREAM_END && !stream->avail_in) {
+		inflateEnd(stream);
+		return buf;
+	}
+
+	if (status < 0)
+		error("corrupt loose object '%s'", sha1_to_hex(sha1));
+	else if (stream->avail_in)
+		error("garbage at end of loose object '%s'",
+		      sha1_to_hex(sha1));
+	free(buf);
+	return NULL;
 }
 
 /*
@@ -1029,7 +1115,7 @@ static int parse_sha1_header(const char *hdr, unsigned long *sizep)
 	return *hdr ? -1 : type_from_string(type);
 }
 
-void * unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size)
+static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
 {
 	int ret;
 	z_stream stream;
@@ -1039,17 +1125,17 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type
 	if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
 		return NULL;
 
-	return unpack_sha1_rest(&stream, hdr, *size);
+	return unpack_sha1_rest(&stream, hdr, *size, sha1);
 }
 
-static unsigned long get_delta_base(struct packed_git *p,
+static off_t get_delta_base(struct packed_git *p,
 				    struct pack_window **w_curs,
-				    unsigned long *curpos,
+				    off_t *curpos,
 				    enum object_type type,
-				    unsigned long delta_obj_offset)
+				    off_t delta_obj_offset)
 {
 	unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
-	unsigned long base_offset;
+	off_t base_offset;
 
 	/* use_pack() assured us we have [base_info, base_info + 20)
 	 * as a range that we can look at without walking off the
@@ -1085,17 +1171,17 @@ static unsigned long get_delta_base(struct packed_git *p,
 }
 
 /* forward declaration for a mutually recursive function */
-static int packed_object_info(struct packed_git *p, unsigned long offset,
+static int packed_object_info(struct packed_git *p, off_t offset,
 			      unsigned long *sizep);
 
 static int packed_delta_info(struct packed_git *p,
 			     struct pack_window **w_curs,
-			     unsigned long curpos,
+			     off_t curpos,
 			     enum object_type type,
-			     unsigned long obj_offset,
+			     off_t obj_offset,
 			     unsigned long *sizep)
 {
-	unsigned long base_offset;
+	off_t base_offset;
 
 	base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
 	type = packed_object_info(p, base_offset, NULL);
@@ -1145,7 +1231,7 @@ static int packed_delta_info(struct packed_git *p,
 
 static int unpack_object_header(struct packed_git *p,
 				struct pack_window **w_curs,
-				unsigned long *curpos,
+				off_t *curpos,
 				unsigned long *sizep)
 {
 	unsigned char *base;
@@ -1169,14 +1255,15 @@ static int unpack_object_header(struct packed_git *p,
 }
 
 const char *packed_object_info_detail(struct packed_git *p,
-				      unsigned long obj_offset,
+				      off_t obj_offset,
 				      unsigned long *size,
 				      unsigned long *store_size,
 				      unsigned int *delta_chain_length,
 				      unsigned char *base_sha1)
 {
 	struct pack_window *w_curs = NULL;
-	unsigned long curpos, dummy;
+	off_t curpos;
+	unsigned long dummy;
 	unsigned char *next_sha1;
 	enum object_type type;
 
@@ -1200,6 +1287,7 @@ const char *packed_object_info_detail(struct packed_git *p,
 			obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
 			if (*delta_chain_length == 0) {
 				/* TODO: find base_sha1 as pointed by curpos */
+				hashclr(base_sha1);
 			}
 			break;
 		case OBJ_REF_DELTA:
@@ -1215,11 +1303,12 @@ const char *packed_object_info_detail(struct packed_git *p,
 	}
 }
 
-static int packed_object_info(struct packed_git *p, unsigned long obj_offset,
+static int packed_object_info(struct packed_git *p, off_t obj_offset,
 			      unsigned long *sizep)
 {
 	struct pack_window *w_curs = NULL;
-	unsigned long size, curpos = obj_offset;
+	unsigned long size;
+	off_t curpos = obj_offset;
 	enum object_type type;
 
 	type = unpack_object_header(p, &w_curs, &curpos, &size);
@@ -1247,7 +1336,7 @@ static int packed_object_info(struct packed_git *p, unsigned long obj_offset,
 
 static void *unpack_compressed_entry(struct packed_git *p,
 				    struct pack_window **w_curs,
-				    unsigned long curpos,
+				    off_t curpos,
 				    unsigned long size)
 {
 	int st;
@@ -1276,22 +1365,128 @@ 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,
-				unsigned long curpos,
+				off_t curpos,
 				unsigned long delta_size,
-				unsigned long obj_offset,
+				off_t obj_offset,
 				enum object_type *type,
 				unsigned long *sizep)
 {
 	void *delta_data, *result, *base;
-	unsigned long base_size, base_offset;
+	unsigned long base_size;
+	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 %lu from %s",
-		    base_offset, p->pack_name);
+		die("failed to read delta base object"
+		    " at %"PRIuMAX" from %s",
+		    (uintmax_t)base_offset, p->pack_name);
 
 	delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
 	result = patch_delta(base, base_size,
@@ -1300,15 +1495,15 @@ 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;
 }
 
-void *unpack_entry(struct packed_git *p, unsigned long obj_offset,
+void *unpack_entry(struct packed_git *p, off_t obj_offset,
 		   enum object_type *type, unsigned long *sizep)
 {
 	struct pack_window *w_curs = NULL;
-	unsigned long curpos = obj_offset;
+	off_t curpos = obj_offset;
 	void *data;
 
 	*type = unpack_object_header(p, &w_curs, &curpos, sizep);
@@ -1331,33 +1526,35 @@ void *unpack_entry(struct packed_git *p, unsigned long obj_offset,
 	return data;
 }
 
-int num_packed_objects(const struct packed_git *p)
+uint32_t num_packed_objects(const struct packed_git *p)
 {
 	/* See check_packed_git_idx() */
-	return (p->index_size - 20 - 20 - 4*256) / 24;
+	return (uint32_t)((p->index_size - 20 - 20 - 4*256) / 24);
 }
 
-int nth_packed_object_sha1(const struct packed_git *p, int n,
-			   unsigned char* sha1)
+const unsigned char *nth_packed_object_sha1(const struct packed_git *p,
+					    uint32_t n)
 {
-	void *index = p->index_base + 256;
-	if (n < 0 || num_packed_objects(p) <= n)
-		return -1;
-	hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
-	return 0;
+	const unsigned char *index = p->index_data;
+	index += 4 * 256;
+	if (num_packed_objects(p) <= n)
+		return NULL;
+	return index + 24 * n + 4;
 }
 
-unsigned long find_pack_entry_one(const unsigned char *sha1,
+off_t find_pack_entry_one(const unsigned char *sha1,
 				  struct packed_git *p)
 {
-	uint32_t *level1_ofs = p->index_base;
+	const uint32_t *level1_ofs = p->index_data;
 	int hi = ntohl(level1_ofs[*sha1]);
 	int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
-	void *index = p->index_base + 256;
+	const unsigned char *index = p->index_data;
+
+	index += 4 * 256;
 
 	do {
 		int mi = (lo + hi) / 2;
-		int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
+		int cmp = hashcmp(index + 24 * mi + 4, sha1);
 		if (!cmp)
 			return ntohl(*((uint32_t *)((char *)index + (24 * mi))));
 		if (cmp > 0)
@@ -1389,7 +1586,7 @@ static int matches_pack_name(struct packed_git *p, const char *ig)
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
 {
 	struct packed_git *p;
-	unsigned long offset;
+	off_t offset;
 
 	prepare_packed_git();
 
@@ -1481,7 +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);
 }
 
 /*
@@ -1555,7 +1752,7 @@ void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
 		return buf;
 	map = map_sha1_file(sha1, &mapsize);
 	if (map) {
-		buf = unpack_sha1_file(map, mapsize, type, size);
+		buf = unpack_sha1_file(map, mapsize, type, size, sha1);
 		munmap(map, mapsize);
 		return buf;
 	}
@@ -1610,7 +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)
 {
@@ -1738,7 +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];
@@ -1749,7 +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];
@@ -1781,7 +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) {
@@ -1809,15 +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);
@@ -1902,7 +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) {
@@ -1951,7 +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);
@@ -2056,11 +2261,10 @@ int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
 	     enum object_type type, const char *path)
 {
-	unsigned long size = st->st_size;
-	void *buf;
+	size_t size = xsize_t(st->st_size);
+	void *buf = NULL;
 	int ret, re_allocated = 0;
 
-	buf = "";
 	if (size)
 		buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);
@@ -2100,6 +2304,7 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
 {
 	int fd;
 	char *target;
+	size_t len;
 
 	switch (st->st_mode & S_IFMT) {
 	case S_IFREG:
@@ -2112,16 +2317,17 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
 				     path);
 		break;
 	case S_IFLNK:
-		target = xmalloc(st->st_size+1);
-		if (readlink(path, target, st->st_size+1) != st->st_size) {
+		len = xsize_t(st->st_size);
+		target = xmalloc(len + 1);
+		if (readlink(path, target, len + 1) != st->st_size) {
 			char *errstr = strerror(errno);
 			free(target);
 			return error("readlink(\"%s\"): %s", path,
 			             errstr);
 		}
 		if (!write_object)
-			hash_sha1_file(target, st->st_size, blob_type, sha1);
-		else if (write_sha1_file(target, st->st_size, blob_type, sha1))
+			hash_sha1_file(target, len, blob_type, sha1);
+		else if (write_sha1_file(target, len, blob_type, sha1))
 			return error("%s: failed to insert into database",
 				     path);
 		free(target);