X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_file.c;h=aea0f40d57a134a2a853136cd0815e5c743a115d;hb=7612a1efdb0c0806b43db10ce784707aae874340;hp=8d3a65f5f8ff59041cf1d4e07d0e43c9402e0c38;hpb=5da5c8f4cf4fb4e1cbccca4e7cebe70b77cf0b00;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index 8d3a65f5..aea0f40d 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -6,11 +6,13 @@
  * This handles basic git sha1 object files - packing, unpacking,
  * creation etc.
  */
-#include <sys/types.h>
-#include <dirent.h>
 #include "cache.h"
 #include "delta.h"
 #include "pack.h"
+#include "blob.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -20,6 +22,8 @@
 #endif
 #endif
 
+const unsigned char null_sha1[20] = { 0, };
+
 static unsigned int sha1_file_open_flag = O_NOATIME;
 
 static unsigned hexval(char c)
@@ -46,121 +50,68 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
-static int get_sha1_file(const char *path, unsigned char *result)
+int adjust_shared_perm(const char *path)
 {
-	char buffer[60];
-	int fd = open(path, O_RDONLY);
-	int len;
+	struct stat st;
+	int mode;
 
-	if (fd < 0)
-		return -1;
-	len = read(fd, buffer, sizeof(buffer));
-	close(fd);
-	if (len < 40)
+	if (!shared_repository)
+		return 0;
+	if (lstat(path, &st) < 0)
 		return -1;
-	return get_sha1_hex(buffer, result);
-}
-
-static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,
-	*git_graft_file;
-static void setup_git_env(void)
-{
-	git_dir = gitenv(GIT_DIR_ENVIRONMENT);
-	if (!git_dir)
-		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
-	git_object_dir = gitenv(DB_ENVIRONMENT);
-	if (!git_object_dir) {
-		git_object_dir = xmalloc(strlen(git_dir) + 9);
-		sprintf(git_object_dir, "%s/objects", git_dir);
-	}
-	git_refs_dir = xmalloc(strlen(git_dir) + 6);
-	sprintf(git_refs_dir, "%s/refs", git_dir);
-	git_index_file = gitenv(INDEX_ENVIRONMENT);
-	if (!git_index_file) {
-		git_index_file = xmalloc(strlen(git_dir) + 7);
-		sprintf(git_index_file, "%s/index", git_dir);
-	}
-	git_graft_file = gitenv(GRAFT_ENVIRONMENT);
-	if (!git_graft_file)
-		git_graft_file = strdup(git_path("info/grafts"));
-}
-
-char *get_object_directory(void)
-{
-	if (!git_object_dir)
-		setup_git_env();
-	return git_object_dir;
-}
-
-char *get_refs_directory(void)
-{
-	if (!git_refs_dir)
-		setup_git_env();
-	return git_refs_dir;
-}
-
-char *get_index_file(void)
-{
-	if (!git_index_file)
-		setup_git_env();
-	return git_index_file;
-}
-
-char *get_graft_file(void)
-{
-	if (!git_graft_file)
-		setup_git_env();
-	return git_graft_file;
+	mode = st.st_mode;
+	if (mode & S_IRUSR)
+		mode |= S_IRGRP;
+	if (mode & S_IWUSR)
+		mode |= S_IWGRP;
+	if (mode & S_IXUSR)
+		mode |= S_IXGRP;
+	if (S_ISDIR(mode))
+		mode |= S_ISGID;
+	if (chmod(path, mode) < 0)
+		return -2;
+	return 0;
 }
 
 int safe_create_leading_directories(char *path)
 {
 	char *pos = path;
+	struct stat st;
+
+	if (*pos == '/')
+		pos++;
 
 	while (pos) {
 		pos = strchr(pos, '/');
 		if (!pos)
 			break;
 		*pos = 0;
-		if (mkdir(path, 0777) < 0)
-			if (errno != EEXIST) {
+		if (!stat(path, &st)) {
+			/* path exists */
+			if (!S_ISDIR(st.st_mode)) {
 				*pos = '/';
-				return -1;
+				return -3;
 			}
+		}
+		else if (mkdir(path, 0777)) {
+			*pos = '/';
+			return -1;
+		}
+		else if (adjust_shared_perm(path)) {
+			*pos = '/';
+			return -2;
+		}
 		*pos++ = '/';
 	}
 	return 0;
 }
 
-int get_sha1(const char *str, unsigned char *sha1)
-{
-	static const char *prefix[] = {
-		"",
-		"refs",
-		"refs/tags",
-		"refs/heads",
-		"refs/snap",
-		NULL
-	};
-	const char **p;
-
-	if (!get_sha1_hex(str, sha1))
-		return 0;
-
-	for (p = prefix; *p; p++) {
-		char * pathname = git_path("%s/%s", *p, str);
-		if (!get_sha1_file(pathname, sha1))
-			return 0;
-	}
-
-	return -1;
-}
-
 char * sha1_to_hex(const unsigned char *sha1)
 {
-	static char buffer[50];
+	static int bufno;
+	static char hexbuffer[4][50];
 	static const char hex[] = "0123456789abcdef";
-	char *buf = buffer;
+	char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
 	int i;
 
 	for (i = 0; i < 20; i++) {
@@ -168,6 +119,8 @@ char * sha1_to_hex(const unsigned char *sha1)
 		*buf++ = hex[val >> 4];
 		*buf++ = hex[val & 0xf];
 	}
+	*buf = '\0';
+
 	return buffer;
 }
 
@@ -211,84 +164,234 @@ char *sha1_file_name(const unsigned char *sha1)
 	return base;
 }
 
-struct alternate_object_database *alt_odb;
+char *sha1_pack_name(const unsigned char *sha1)
+{
+	static const char hex[] = "0123456789abcdef";
+	static char *name, *base, *buf;
+	int i;
+
+	if (!base) {
+		const char *sha1_file_directory = get_object_directory();
+		int len = strlen(sha1_file_directory);
+		base = xmalloc(len + 60);
+		sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
+		name = base + len + 11;
+	}
+
+	buf = name;
+
+	for (i = 0; i < 20; i++) {
+		unsigned int val = *sha1++;
+		*buf++ = hex[val >> 4];
+		*buf++ = hex[val & 0xf];
+	}
+	
+	return base;
+}
+
+char *sha1_pack_index_name(const unsigned char *sha1)
+{
+	static const char hex[] = "0123456789abcdef";
+	static char *name, *base, *buf;
+	int i;
+
+	if (!base) {
+		const char *sha1_file_directory = get_object_directory();
+		int len = strlen(sha1_file_directory);
+		base = xmalloc(len + 60);
+		sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
+		name = base + len + 11;
+	}
+
+	buf = name;
+
+	for (i = 0; i < 20; i++) {
+		unsigned int val = *sha1++;
+		*buf++ = hex[val >> 4];
+		*buf++ = hex[val & 0xf];
+	}
+	
+	return base;
+}
+
+struct alternate_object_database *alt_odb_list;
+static struct alternate_object_database **alt_odb_tail;
+
+static void read_info_alternates(const char * alternates, int depth);
 
 /*
  * Prepare alternate object database registry.
- * alt_odb points at an array of struct alternate_object_database.
- * This array is terminated with an element that has both its base
- * and name set to NULL.  alt_odb[n] comes from n'th non-empty
- * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
- * variable, and its base points at a statically allocated buffer
- * that contains "/the/directory/corresponding/to/.git/objects/...",
- * while its name points just after the slash at the end of
- * ".git/objects/" in the example above, and has enough space to hold
- * 40-byte hex SHA1, an extra slash for the first level indirection,
- * and the terminating NUL.
- * This function allocates the alt_odb array and all the strings
- * pointed by base fields of the array elements with one xmalloc();
- * the string pool immediately follows the array.
+ *
+ * The variable alt_odb_list points at the list of struct
+ * alternate_object_database.  The elements on this list come from
+ * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
+ * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
+ * whose contents is similar to that environment variable but can be
+ * LF separated.  Its base points at a statically allocated buffer that
+ * contains "/the/directory/corresponding/to/.git/objects/...", while
+ * its name points just after the slash at the end of ".git/objects/"
+ * in the example above, and has enough space to hold 40-byte hex
+ * SHA1, an extra slash for the first level indirection, and the
+ * terminating NUL.
  */
-void prepare_alt_odb(void)
+static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
+{
+	struct stat st;
+	const char *objdir = get_object_directory();
+	struct alternate_object_database *ent;
+	struct alternate_object_database *alt;
+	/* 43 = 40-byte + 2 '/' + terminating NUL */
+	int pfxlen = len;
+	int entlen = pfxlen + 43;
+	int base_len = -1;
+
+	if (*entry != '/' && relative_base) {
+		/* Relative alt-odb */
+		if (base_len < 0)
+			base_len = strlen(relative_base) + 1;
+		entlen += base_len;
+		pfxlen += base_len;
+	}
+	ent = xmalloc(sizeof(*ent) + entlen);
+
+	if (*entry != '/' && relative_base) {
+		memcpy(ent->base, relative_base, base_len - 1);
+		ent->base[base_len - 1] = '/';
+		memcpy(ent->base + base_len, entry, len);
+	}
+	else
+		memcpy(ent->base, entry, pfxlen);
+
+	ent->name = ent->base + pfxlen + 1;
+	ent->base[pfxlen + 3] = '/';
+	ent->base[pfxlen] = ent->base[entlen-1] = 0;
+
+	/* Detect cases where alternate disappeared */
+	if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
+		error("object directory %s does not exist; "
+		      "check .git/objects/info/alternates.",
+		      ent->base);
+		free(ent);
+		return -1;
+	}
+
+	/* Prevent the common mistake of listing the same
+	 * thing twice, or object directory itself.
+	 */
+	for (alt = alt_odb_list; alt; alt = alt->next) {
+		if (!memcmp(ent->base, alt->base, pfxlen)) {
+			free(ent);
+			return -1;
+		}
+	}
+	if (!memcmp(ent->base, objdir, pfxlen)) {
+		free(ent);
+		return -1;
+	}
+
+	/* add the alternate entry */
+	*alt_odb_tail = ent;
+	alt_odb_tail = &(ent->next);
+	ent->next = NULL;
+
+	/* recursively add alternates */
+	read_info_alternates(ent->base, depth + 1);
+
+	ent->base[pfxlen] = '/';
+
+	return 0;
+}
+
+static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
+				 const char *relative_base, int depth)
 {
-	int pass, totlen, i;
 	const char *cp, *last;
-	char *op = NULL;
-	const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
 
-	if (alt_odb)
+	if (depth > 5) {
+		error("%s: ignoring alternate object stores, nesting too deep.",
+				relative_base);
 		return;
-	/* The first pass counts how large an area to allocate to
-	 * hold the entire alt_odb structure, including array of
-	 * structs and path buffers for them.  The second pass fills
-	 * the structure and prepares the path buffers for use by
-	 * fill_sha1_path().
-	 */
-	for (totlen = pass = 0; pass < 2; pass++) {
-		last = alt;
-		i = 0;
-		do {
-			cp = strchr(last, ':') ? : last + strlen(last);
-			if (last != cp) {
-				/* 43 = 40-byte + 2 '/' + terminating NUL */
-				int pfxlen = cp - last;
-				int entlen = pfxlen + 43;
-				if (pass == 0)
-					totlen += entlen;
-				else {
-					alt_odb[i].base = op;
-					alt_odb[i].name = op + pfxlen + 1;
-					memcpy(op, last, pfxlen);
-					op[pfxlen] = op[pfxlen + 3] = '/';
-					op[entlen-1] = 0;
-					op += entlen;
-				}
-				i++;
-			}
-			while (*cp && *cp == ':')
+	}
+
+	last = alt;
+	while (last < ep) {
+		cp = last;
+		if (cp < ep && *cp == '#') {
+			while (cp < ep && *cp != sep)
 				cp++;
-			last = cp;
-		} while (*cp);
-		if (pass)
-			break;
-		alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
-		alt_odb[i].base = alt_odb[i].name = NULL;
-		op = (char*)(&alt_odb[i+1]);
+			last = cp + 1;
+			continue;
+		}
+		while (cp < ep && *cp != sep)
+			cp++;
+		if (last != cp) {
+			if ((*last != '/') && depth) {
+				error("%s: ignoring relative alternate object store %s",
+						relative_base, last);
+			} else {
+				link_alt_odb_entry(last, cp - last,
+						relative_base, depth);
+			}
+		}
+		while (cp < ep && *cp == sep)
+			cp++;
+		last = cp;
+	}
+}
+
+static void read_info_alternates(const char * relative_base, int depth)
+{
+	char *map;
+	struct stat st;
+	char path[PATH_MAX];
+	int fd;
+
+	sprintf(path, "%s/info/alternates", relative_base);
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return;
+	if (fstat(fd, &st) || (st.st_size == 0)) {
+		close(fd);
+		return;
 	}
+	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if (map == MAP_FAILED)
+		return;
+
+	link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
+
+	munmap(map, st.st_size);
+}
+
+void prepare_alt_odb(void)
+{
+	char *alt;
+
+	alt = getenv(ALTERNATE_DB_ENVIRONMENT);
+	if (!alt) alt = "";
+
+	if (alt_odb_tail)
+		return;
+	alt_odb_tail = &alt_odb_list;
+	link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
+
+	read_info_alternates(get_object_directory(), 0);
 }
 
 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 {
-	int i;
 	char *name = sha1_file_name(sha1);
+	struct alternate_object_database *alt;
 
 	if (!stat(name, st))
 		return name;
 	prepare_alt_odb();
-	for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
+	for (alt = alt_odb_list; alt; alt = alt->next) {
+		name = alt->name;
 		fill_sha1_path(name, sha1);
-		if (!stat(alt_odb[i].base, st))
-			return alt_odb[i].base;
+		if (!stat(alt->base, st))
+			return alt->base;
 	}
 	return NULL;
 }
@@ -371,6 +474,14 @@ void unuse_packed_git(struct packed_git *p)
 
 int use_packed_git(struct packed_git *p)
 {
+	if (!p->pack_size) {
+		struct stat st;
+		// We created the struct before we had the pack
+		stat(p->pack_name, &st);
+		if (!S_ISREG(st.st_mode))
+			die("packfile %s not a regular file", p->pack_name);
+		p->pack_size = st.st_size;
+	}
 	if (!p->pack_base) {
 		int fd;
 		struct stat st;
@@ -398,20 +509,23 @@ int use_packed_git(struct packed_git *p)
 		 * this is cheap.
 		 */
 		if (memcmp((char*)(p->index_base) + p->index_size - 40,
-			   p->pack_base + p->pack_size - 20, 20))
+			   p->pack_base + p->pack_size - 20, 20)) {
+			      
 			die("packfile %s does not match index.", p->pack_name);
+		}
 	}
 	p->pack_last_used = pack_used_ctr++;
 	p->pack_use_cnt++;
 	return 0;
 }
 
-struct packed_git *add_packed_git(char *path, int path_len)
+struct packed_git *add_packed_git(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];
 
 	if (check_packed_git_idx(path, &idx_size, &idx_map))
 		return NULL;
@@ -434,10 +548,50 @@ struct packed_git *add_packed_git(char *path, int path_len)
 	p->pack_base = NULL;
 	p->pack_last_used = 0;
 	p->pack_use_cnt = 0;
+	p->pack_local = local;
+	if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
+		memcpy(p->sha1, sha1, 20);
+	return p;
+}
+
+struct packed_git *parse_pack_index(unsigned char *sha1)
+{
+	char *path = sha1_pack_index_name(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 *p;
+	unsigned long idx_size;
+	void *idx_map;
+	char *path;
+
+	if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
+		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->pack_base = NULL;
+	p->pack_last_used = 0;
+	p->pack_use_cnt = 0;
+	memcpy(p->sha1, sha1, 20);
 	return p;
 }
 
-static void prepare_packed_git_one(char *objdir)
+void install_packed_git(struct packed_git *pack)
+{
+	pack->next = packed_git;
+	packed_git = pack;
+}
+
+static void prepare_packed_git_one(char *objdir, int local)
 {
 	char path[PATH_MAX];
 	int len;
@@ -447,8 +601,12 @@ static void prepare_packed_git_one(char *objdir)
 	sprintf(path, "%s/pack", objdir);
 	len = strlen(path);
 	dir = opendir(path);
-	if (!dir)
+	if (!dir) {
+		if (errno != ENOENT)
+			error("unable to open object pack directory: %s: %s",
+			      path, strerror(errno));
 		return;
+	}
 	path[len++] = '/';
 	while ((de = readdir(dir)) != NULL) {
 		int namelen = strlen(de->d_name);
@@ -459,7 +617,13 @@ static void prepare_packed_git_one(char *objdir)
 
 		/* we have .idx.  Is it a file we can map? */
 		strcpy(path + len, de->d_name);
-		p = add_packed_git(path, len + namelen);
+		for (p = packed_git; p; p = p->next) {
+			if (!memcmp(path, p->pack_name, len + namelen - 4))
+				break;
+		}
+		if (p)
+			continue;
+		p = add_packed_git(path, len + namelen, local);
 		if (!p)
 			continue;
 		p->next = packed_git;
@@ -468,20 +632,27 @@ static void prepare_packed_git_one(char *objdir)
 	closedir(dir);
 }
 
+static int prepare_packed_git_run_once = 0;
 void prepare_packed_git(void)
 {
-	int i;
-	static int run_once = 0;
+	struct alternate_object_database *alt;
 
-	if (run_once++)
+	if (prepare_packed_git_run_once)
 		return;
-
-	prepare_packed_git_one(get_object_directory());
+	prepare_packed_git_one(get_object_directory(), 1);
 	prepare_alt_odb();
-	for (i = 0; alt_odb[i].base != NULL; i++) {
-		alt_odb[i].name[0] = 0;
-		prepare_packed_git_one(alt_odb[i].base);
+	for (alt = alt_odb_list; alt; alt = alt->next) {
+		alt->name[-1] = 0;
+		prepare_packed_git_one(alt->base, 0);
+		alt->name[-1] = '/';
 	}
+	prepare_packed_git_run_once = 1;
+}
+
+static void reprepare_packed_git(void)
+{
+	prepare_packed_git_run_once = 0;
+	prepare_packed_git();
 }
 
 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
@@ -684,10 +855,12 @@ static int packed_delta_info(unsigned char *base_sha1,
 		 * the result size.
 		 */
 		data = delta_head;
-		get_delta_hdr_size(&data); /* ignore base size */
+
+		/* ignore base size */
+		get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
 
 		/* Read the result size */
-		result_size = get_delta_hdr_size(&data);
+		result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
 		*sizep = result_size;
 	}
 	return 0;
@@ -721,25 +894,46 @@ static unsigned long unpack_object_header(struct packed_git *p, unsigned long of
 	return offset;
 }
 
+int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
+			   unsigned char *base, unsigned long *sizep,
+			   enum object_type *kindp)
+{
+	unsigned long ptr;
+	int status = -1;
+
+	use_packed_git(p);
+	ptr = offset;
+	ptr = unpack_object_header(p, ptr, kindp, sizep);
+	if (*kindp != OBJ_DELTA)
+		goto done;
+	memcpy(base, p->pack_base + ptr, 20);
+	status = 0;
+ done:
+	unuse_packed_git(p);
+	return status;
+}
+
 void packed_object_info_detail(struct pack_entry *e,
 			       char *type,
 			       unsigned long *size,
 			       unsigned long *store_size,
-			       int *delta_chain_length,
+			       unsigned int *delta_chain_length,
 			       unsigned char *base_sha1)
 {
 	struct packed_git *p = e->p;
-	unsigned long offset, left;
+	unsigned long offset;
 	unsigned char *pack;
 	enum object_type kind;
 
 	offset = unpack_object_header(p, e->offset, &kind, size);
 	pack = p->pack_base + offset;
-	left = p->pack_size - offset;
 	if (kind != OBJ_DELTA)
 		*delta_chain_length = 0;
 	else {
-		int chain_length = 0;
+		unsigned int chain_length = 0;
+		if (p->pack_size <= offset + 20)
+			die("pack file %s records an incomplete delta base",
+			    p->pack_name);
 		memcpy(base_sha1, pack, 20);
 		do {
 			struct pack_entry base_ent;
@@ -755,19 +949,20 @@ void packed_object_info_detail(struct pack_entry *e,
 	}
 	switch (kind) {
 	case OBJ_COMMIT:
-		strcpy(type, "commit");
+		strcpy(type, commit_type);
 		break;
 	case OBJ_TREE:
-		strcpy(type, "tree");
+		strcpy(type, tree_type);
 		break;
 	case OBJ_BLOB:
-		strcpy(type, "blob");
+		strcpy(type, blob_type);
 		break;
 	case OBJ_TAG:
-		strcpy(type, "tag");
+		strcpy(type, tag_type);
 		break;
 	default:
-		die("corrupted pack file");
+		die("corrupted pack file %s containing object of kind %d",
+		    p->pack_name, kind);
 	}
 	*store_size = 0; /* notyet */
 }
@@ -794,19 +989,20 @@ static int packed_object_info(struct pack_entry *entry,
 		unuse_packed_git(p);
 		return retval;
 	case OBJ_COMMIT:
-		strcpy(type, "commit");
+		strcpy(type, commit_type);
 		break;
 	case OBJ_TREE:
-		strcpy(type, "tree");
+		strcpy(type, tree_type);
 		break;
 	case OBJ_BLOB:
-		strcpy(type, "blob");
+		strcpy(type, blob_type);
 		break;
 	case OBJ_TAG:
-		strcpy(type, "tag");
+		strcpy(type, tag_type);
 		break;
 	default:
-		die("corrupted pack file");
+		die("corrupted pack file %s containing object of kind %d",
+		    p->pack_name, kind);
 	}
 	if (sizep)
 		*sizep = size;
@@ -832,6 +1028,16 @@ static void *unpack_delta_entry(unsigned char *base_sha1,
 
 	if (left < 20)
 		die("truncated pack file");
+
+	/* The base entry _must_ be in the same pack */
+	if (!find_pack_entry_one(base_sha1, &base_ent, p))
+		die("failed to find delta-pack base object %s",
+		    sha1_to_hex(base_sha1));
+	base = unpack_entry_gently(&base_ent, type, &base_size);
+	if (!base)
+		die("failed to read delta-pack base object %s",
+		    sha1_to_hex(base_sha1));
+
 	data = base_sha1 + 20;
 	data_size = left - 20;
 	delta_data = xmalloc(delta_size);
@@ -849,14 +1055,6 @@ static void *unpack_delta_entry(unsigned char *base_sha1,
 	if ((st != Z_STREAM_END) || stream.total_out != delta_size)
 		die("delta data unpack failed");
 
-	/* The base entry _must_ be in the same pack */
-	if (!find_pack_entry_one(base_sha1, &base_ent, p))
-		die("failed to find delta-pack base object %s",
-		    sha1_to_hex(base_sha1));
-	base = unpack_entry_gently(&base_ent, type, &base_size);
-	if (!base)
-		die("failed to read delta-pack base object %s",
-		    sha1_to_hex(base_sha1));
 	result = patch_delta(base, base_size,
 			     delta_data, delta_size,
 			     &result_size);
@@ -906,7 +1104,7 @@ static void *unpack_entry(struct pack_entry *entry,
 	retval = unpack_entry_gently(entry, type, sizep);
 	unuse_packed_git(p);
 	if (!retval)
-		die("corrupted pack file");
+		die("corrupted pack file %s", p->pack_name);
 	return retval;
 }
 
@@ -928,16 +1126,16 @@ void *unpack_entry_gently(struct pack_entry *entry,
 		retval = unpack_delta_entry(pack, size, left, type, sizep, p);
 		return retval;
 	case OBJ_COMMIT:
-		strcpy(type, "commit");
+		strcpy(type, commit_type);
 		break;
 	case OBJ_TREE:
-		strcpy(type, "tree");
+		strcpy(type, tree_type);
 		break;
 	case OBJ_BLOB:
-		strcpy(type, "blob");
+		strcpy(type, blob_type);
 		break;
 	case OBJ_TAG:
-		strcpy(type, "tag");
+		strcpy(type, tag_type);
 		break;
 	default:
 		return NULL;
@@ -975,7 +1173,7 @@ int find_pack_entry_one(const unsigned char *sha1,
 		int mi = (lo + hi) / 2;
 		int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
 		if (!cmp) {
-			e->offset = ntohl(*((int*)(index + 24 * mi)));
+			e->offset = ntohl(*((unsigned int *)(index + 24 * mi)));
 			memcpy(e->sha1, sha1, 20);
 			e->p = p;
 			return 1;
@@ -1000,6 +1198,20 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 	return 0;
 }
 
+struct packed_git *find_sha1_pack(const unsigned char *sha1, 
+				  struct packed_git *packs)
+{
+	struct packed_git *p;
+	struct pack_entry e;
+
+	for (p = packs; p; p = p->next) {
+		if (find_pack_entry_one(sha1, &e, p))
+			return p;
+	}
+	return NULL;
+	
+}
+
 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
 {
 	int status;
@@ -1012,9 +1224,12 @@ int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep
 	if (!map) {
 		struct pack_entry e;
 
-		if (!find_pack_entry(sha1, &e))
-			return error("unable to find %s", sha1_to_hex(sha1));
-		return packed_object_info(&e, type, sizep);
+		if (find_pack_entry(sha1, &e))
+			return packed_object_info(&e, type, sizep);
+		reprepare_packed_git();
+		if (find_pack_entry(sha1, &e))
+			return packed_object_info(&e, type, sizep);
+		return error("unable to find %s", sha1_to_hex(sha1));
 	}
 	if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
 		status = error("unable to unpack %s header",
@@ -1056,6 +1271,9 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
 		munmap(map, mapsize);
 		return buf;
 	}
+	reprepare_packed_git();
+	if (find_pack_entry(sha1, &e))
+		return read_packed_sha1(sha1, type, size);
 	return NULL;
 }
 
@@ -1084,9 +1302,9 @@ void *read_object_with_reference(const unsigned char *sha1,
 			return buffer;
 		}
 		/* Handle references */
-		else if (!strcmp(type, "commit"))
+		else if (!strcmp(type, commit_type))
 			ref_type = "tree ";
-		else if (!strcmp(type, "tag"))
+		else if (!strcmp(type, tag_type))
 			ref_type = "object ";
 		else {
 			free(buffer);
@@ -1099,6 +1317,7 @@ void *read_object_with_reference(const unsigned char *sha1,
 			free(buffer);
 			return NULL;
 		}
+		free(buffer);
 		/* Now we have the ID of the referred-to object in
 		 * actual_sha1.  Check again. */
 	}
@@ -1125,6 +1344,98 @@ char *write_sha1_file_prepare(void *buf,
 	return sha1_file_name(sha1);
 }
 
+/*
+ * Link the tempfile to the final place, possibly creating the
+ * last directory level as you do so.
+ *
+ * Returns the errno on failure, 0 on success.
+ */
+static int link_temp_to_file(const char *tmpfile, char *filename)
+{
+	int ret;
+
+	if (!link(tmpfile, filename))
+		return 0;
+
+	/*
+	 * Try to mkdir the last path component if that failed
+	 * with an ENOENT.
+	 *
+	 * Re-try the "link()" regardless of whether the mkdir
+	 * succeeds, since a race might mean that somebody
+	 * else succeeded.
+	 */
+	ret = errno;
+	if (ret == ENOENT) {
+		char *dir = strrchr(filename, '/');
+		if (dir) {
+			*dir = 0;
+			mkdir(filename, 0777);
+			if (adjust_shared_perm(filename))
+				return -2;
+			*dir = '/';
+			if (!link(tmpfile, filename))
+				return 0;
+			ret = errno;
+		}
+	}
+	return ret;
+}
+
+/*
+ * Move the just written object into its final resting place
+ */
+int move_temp_to_file(const char *tmpfile, char *filename)
+{
+	int ret = link_temp_to_file(tmpfile, filename);
+
+	/*
+	 * Coda hack - coda doesn't like cross-directory links,
+	 * so we fall back to a rename, which will mean that it
+	 * won't be able to check collisions, but that's not a
+	 * big deal.
+	 *
+	 * The same holds for FAT formatted media.
+	 *
+	 * When this succeeds, we just return 0. We have nothing
+	 * left to unlink.
+	 */
+	if (ret && ret != EEXIST) {
+		if (!rename(tmpfile, filename))
+			return 0;
+		ret = errno;
+	}
+	unlink(tmpfile);
+	if (ret) {
+		if (ret != EEXIST) {
+			fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
+			return -1;
+		}
+		/* FIXME!!! Collision check here ? */
+	}
+
+	return 0;
+}
+
+static int write_buffer(int fd, const void *buf, size_t len)
+{
+	while (len) {
+		ssize_t size;
+
+		size = write(fd, buf, len);
+		if (!size)
+			return error("file write: disk full");
+		if (size < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return error("file write error (%s)", strerror(errno));
+		}
+		len -= size;
+		buf += size;
+	}
+	return 0;
+}
+
 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
 	int size;
@@ -1134,7 +1445,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 	char *filename;
 	static char tmpfile[PATH_MAX];
 	unsigned char hdr[50];
-	int fd, hdrlen, ret;
+	int fd, hdrlen;
 
 	/* Normally if we have it in the pack then we do not bother writing
 	 * it out into .git/objects/??/?{38} file.
@@ -1155,7 +1466,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 	}
 
 	if (errno != ENOENT) {
-		fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
+		fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
 		return -1;
 	}
 
@@ -1163,7 +1474,7 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 
 	fd = mkstemp(tmpfile);
 	if (fd < 0) {
-		fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
+		fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
 		return -1;
 	}
 
@@ -1191,115 +1502,98 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 	deflateEnd(&stream);
 	size = stream.total_out;
 
-	if (write(fd, compressed, size) != size)
-		die("unable to write file");
+	if (write_buffer(fd, compressed, size) < 0)
+		die("unable to write sha1 file");
 	fchmod(fd, 0444);
 	close(fd);
 	free(compressed);
 
-	ret = link(tmpfile, filename);
-	if (ret < 0) {
-		ret = errno;
+	return move_temp_to_file(tmpfile, filename);
+}
 
-		/*
-		 * Coda hack - coda doesn't like cross-directory links,
-		 * so we fall back to a rename, which will mean that it
-		 * won't be able to check collisions, but that's not a
-		 * big deal.
-		 *
-		 * When this succeeds, we just return 0. We have nothing
-		 * left to unlink.
-		 */
-		if (ret == EXDEV && !rename(tmpfile, filename))
-			return 0;
-	}
-	unlink(tmpfile);
-	if (ret) {
-		if (ret != EEXIST) {
-			fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
-			return -1;
-		}
-		/* FIXME!!! Collision check here ? */
-	}
+/*
+ * We need to unpack and recompress the object for writing
+ * it out to a different file.
+ */
+static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
+{
+	size_t size;
+	z_stream stream;
+	unsigned char *unpacked;
+	unsigned long len;
+	char type[20];
+	char hdr[50];
+	int hdrlen;
+	void *buf;
 
-	return 0;
+	// need to unpack and recompress it by itself
+	unpacked = read_packed_sha1(sha1, type, &len);
+
+	hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
+
+	/* Set it up */
+	memset(&stream, 0, sizeof(stream));
+	deflateInit(&stream, Z_BEST_COMPRESSION);
+	size = deflateBound(&stream, len + hdrlen);
+	buf = xmalloc(size);
+
+	/* Compress it */
+	stream.next_out = buf;
+	stream.avail_out = size;
+
+	/* First header.. */
+	stream.next_in = (void *)hdr;
+	stream.avail_in = hdrlen;
+	while (deflate(&stream, 0) == Z_OK)
+		/* nothing */;
+
+	/* Then the data itself.. */
+	stream.next_in = unpacked;
+	stream.avail_in = len;
+	while (deflate(&stream, Z_FINISH) == Z_OK)
+		/* nothing */;
+	deflateEnd(&stream);
+	free(unpacked);
+
+	*objsize = stream.total_out;
+	return buf;
 }
 
 int write_sha1_to_fd(int fd, const unsigned char *sha1)
 {
-	ssize_t size;
+	int retval;
 	unsigned long objsize;
-	int posn = 0;
 	void *buf = map_sha1_file_internal(sha1, &objsize);
-	z_stream stream;
-	if (!buf) {
-		unsigned char *unpacked;
-		unsigned long len;
-		char type[20];
-		char hdr[50];
-		int hdrlen;
-		// need to unpack and recompress it by itself
-		unpacked = read_packed_sha1(sha1, type, &len);
-
-		hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
-
-		/* Set it up */
-		memset(&stream, 0, sizeof(stream));
-		deflateInit(&stream, Z_BEST_COMPRESSION);
-		size = deflateBound(&stream, len + hdrlen);
-		buf = xmalloc(size);
-
-		/* Compress it */
-		stream.next_out = buf;
-		stream.avail_out = size;
-		
-		/* First header.. */
-		stream.next_in = (void *)hdr;
-		stream.avail_in = hdrlen;
-		while (deflate(&stream, 0) == Z_OK)
-			/* nothing */;
 
-		/* Then the data itself.. */
-		stream.next_in = unpacked;
-		stream.avail_in = len;
-		while (deflate(&stream, Z_FINISH) == Z_OK)
-			/* nothing */;
-		deflateEnd(&stream);
-		
-		objsize = stream.total_out;
+	if (buf) {
+		retval = write_buffer(fd, buf, objsize);
+		munmap(buf, objsize);
+		return retval;
 	}
 
-	do {
-		size = write(fd, buf + posn, objsize - posn);
-		if (size <= 0) {
-			if (!size) {
-				fprintf(stderr, "write closed");
-			} else {
-				perror("write ");
-			}
-			return -1;
-		}
-		posn += size;
-	} while (posn < objsize);
-	return 0;
+	buf = repack_object(sha1, &objsize);
+	retval = write_buffer(fd, buf, objsize);
+	free(buf);
+	return retval;
 }
 
-int write_sha1_from_fd(const unsigned char *sha1, int fd)
+int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
+		       size_t bufsize, size_t *bufposn)
 {
-	char *filename = sha1_file_name(sha1);
-
+	char tmpfile[PATH_MAX];
 	int local;
 	z_stream stream;
 	unsigned char real_sha1[20];
-	unsigned char buf[4096];
 	unsigned char discard[4096];
 	int ret;
 	SHA_CTX c;
 
-	local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+	snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
 
+	local = mkstemp(tmpfile);
 	if (local < 0)
-		return error("Couldn't open %s\n", filename);
+		return error("Couldn't open %s for %s",
+			     tmpfile, sha1_to_hex(sha1));
 
 	memset(&stream, 0, sizeof(stream));
 
@@ -1309,41 +1603,65 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd)
 
 	do {
 		ssize_t size;
-		size = read(fd, buf, 4096);
+		if (*bufposn) {
+			stream.avail_in = *bufposn;
+			stream.next_in = (unsigned char *) buffer;
+			do {
+				stream.next_out = discard;
+				stream.avail_out = sizeof(discard);
+				ret = inflate(&stream, Z_SYNC_FLUSH);
+				SHA1_Update(&c, discard, sizeof(discard) -
+					    stream.avail_out);
+			} while (stream.avail_in && ret == Z_OK);
+			if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
+				die("unable to write sha1 file");
+			memmove(buffer, buffer + *bufposn - stream.avail_in,
+				stream.avail_in);
+			*bufposn = stream.avail_in;
+			if (ret != Z_OK)
+				break;
+		}
+		size = read(fd, buffer + *bufposn, bufsize - *bufposn);
 		if (size <= 0) {
 			close(local);
-			unlink(filename);
+			unlink(tmpfile);
 			if (!size)
 				return error("Connection closed?");
 			perror("Reading from connection");
 			return -1;
 		}
-		write(local, buf, size);
-		stream.avail_in = size;
-		stream.next_in = buf;
-		do {
-			stream.next_out = discard;
-			stream.avail_out = sizeof(discard);
-			ret = inflate(&stream, Z_SYNC_FLUSH);
-			SHA1_Update(&c, discard, sizeof(discard) -
-				    stream.avail_out);
-		} while (stream.avail_in && ret == Z_OK);
-		
-	} while (ret == Z_OK);
+		*bufposn += size;
+	} while (1);
 	inflateEnd(&stream);
 
 	close(local);
 	SHA1_Final(real_sha1, &c);
 	if (ret != Z_STREAM_END) {
-		unlink(filename);
+		unlink(tmpfile);
 		return error("File %s corrupted", sha1_to_hex(sha1));
 	}
 	if (memcmp(sha1, real_sha1, 20)) {
-		unlink(filename);
-		return error("File %s has bad hash\n", sha1_to_hex(sha1));
+		unlink(tmpfile);
+		return error("File %s has bad hash", sha1_to_hex(sha1));
 	}
-	
-	return 0;
+
+	return move_temp_to_file(tmpfile, sha1_file_name(sha1));
+}
+
+int has_pack_index(const unsigned char *sha1)
+{
+	struct stat st;
+	if (stat(sha1_pack_index_name(sha1), &st))
+		return 0;
+	return 1;
+}
+
+int has_pack_file(const unsigned char *sha1)
+{
+	struct stat st;
+	if (stat(sha1_pack_name(sha1), &st))
+		return 0;
+	return 1;
 }
 
 int has_sha1_pack(const unsigned char *sha1)
@@ -1362,6 +1680,66 @@ int has_sha1_file(const unsigned char *sha1)
 	return find_sha1_file(sha1, &st) ? 1 : 0;
 }
 
+/*
+ * reads from fd as long as possible into a supplied buffer of size bytes.
+ * If neccessary the buffer's size is increased using realloc()
+ *
+ * returns 0 if anything went fine and -1 otherwise
+ *
+ * NOTE: both buf and size may change, but even when -1 is returned
+ * you still have to free() it yourself.
+ */
+int read_pipe(int fd, char** return_buf, unsigned long* return_size)
+{
+	char* buf = *return_buf;
+	unsigned long size = *return_size;
+	int iret;
+	unsigned long off = 0;
+
+	do {
+		iret = xread(fd, buf + off, size - off);
+		if (iret > 0) {
+			off += iret;
+			if (off == size) {
+				size *= 2;
+				buf = realloc(buf, size);
+			}
+		}
+	} while (iret > 0);
+
+	*return_buf = buf;
+	*return_size = off;
+
+	if (iret < 0)
+		return -1;
+	return 0;
+}
+
+int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
+{
+	unsigned long size = 4096;
+	char *buf = malloc(size);
+	int ret;
+	unsigned char hdr[50];
+	int hdrlen;
+
+	if (read_pipe(fd, &buf, &size)) {
+		free(buf);
+		return -1;
+	}
+
+	if (!type)
+		type = blob_type;
+	if (write_object)
+		ret = write_sha1_file(buf, size, type, sha1);
+	else {
+		write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
+		ret = 0;
+	}
+	free(buf);
+	return ret;
+}
+
 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
 {
 	unsigned long size = st->st_size;
@@ -1378,7 +1756,7 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, con
 		return -1;
 
 	if (!type)
-		type = "blob";
+		type = blob_type;
 	if (write_object)
 		ret = write_sha1_file(buf, size, type, sha1);
 	else {
@@ -1389,3 +1767,42 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, con
 		munmap(buf, size);
 	return ret;
 }
+
+int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
+{
+	int fd;
+	char *target;
+
+	switch (st->st_mode & S_IFMT) {
+	case S_IFREG:
+		fd = open(path, O_RDONLY);
+		if (fd < 0)
+			return error("open(\"%s\"): %s", path,
+				     strerror(errno));
+		if (index_fd(sha1, fd, st, write_object, NULL) < 0)
+			return error("%s: failed to insert into database",
+				     path);
+		break;
+	case S_IFLNK:
+		target = xmalloc(st->st_size+1);
+		if (readlink(path, target, st->st_size+1) != st->st_size) {
+			char *errstr = strerror(errno);
+			free(target);
+			return error("readlink(\"%s\"): %s", path,
+			             errstr);
+		}
+		if (!write_object) {
+			unsigned char hdr[50];
+			int hdrlen;
+			write_sha1_file_prepare(target, st->st_size, blob_type,
+						sha1, hdr, &hdrlen);
+		} else if (write_sha1_file(target, st->st_size, blob_type, sha1))
+			return error("%s: failed to insert into database",
+				     path);
+		free(target);
+		break;
+	default:
+		return error("%s: unsupported file type", path);
+	}
+	return 0;
+}