convert object type handling from a string to a number

We currently have two parallel notation for dealing with object types
in the code: a string and a numerical value.  One of them is obviously
redundent, and the most used one requires more stack space and a bunch
of strcmp() all over the place.

This is an initial step for the removal of the version using a char array
found in object reading code paths.  The patch is unfortunately large but
there is no sane way to split it in smaller parts without breaking the
system.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

archive-tar.c

@@ -262,7 +262,7 @@ static int write_tar_entry(const unsigned char *sha1,
 	static struct strbuf path;
 	int filenamelen = strlen(filename);
 	void *buffer;
-	char type[20];
+	enum object_type type;
 	unsigned long size;
 
 	if (!path.alloc) {
@@ -283,7 +283,7 @@ static int write_tar_entry(const unsigned char *sha1,
 		buffer = NULL;
 		size = 0;
 	} else {
-		buffer = read_sha1_file(sha1, type, &size);
+		buffer = read_sha1_file(sha1, &type, &size);
 		if (!buffer)
 			die("cannot read %s", sha1_to_hex(sha1));
 	}

archive-zip.c

@@ -167,7 +167,7 @@ static int write_zip_entry(const unsigned char *sha1,
 	int pathlen;
 	unsigned char *out;
 	char *path;
-	char type[20];
+	enum object_type type;
 	void *buffer = NULL;
 	void *deflated = NULL;
 
@@ -195,7 +195,7 @@ static int write_zip_entry(const unsigned char *sha1,
 		if (S_ISREG(mode) && zlib_compression_level != 0)
 			method = 8;
 		result = 0;
-		buffer = read_sha1_file(sha1, type, &size);
+		buffer = read_sha1_file(sha1, &type, &size);
 		if (!buffer)
 			die("cannot read %s", sha1_to_hex(sha1));
 		crc = crc32(crc, buffer, size);

blob.c

@@ -30,18 +30,18 @@ int parse_blob_buffer(struct blob *item, void *buffer, unsigned long size)
 
 int parse_blob(struct blob *item)
 {
-        char type[20];
+        enum object_type type;
         void *buffer;
         unsigned long size;
 	int ret;
 
         if (item->object.parsed)
                 return 0;
-        buffer = read_sha1_file(item->object.sha1, type, &size);
+        buffer = read_sha1_file(item->object.sha1, &type, &size);
         if (!buffer)
                 return error("Could not read %s",
                              sha1_to_hex(item->object.sha1));
-        if (strcmp(type, blob_type))
+        if (type != OBJ_BLOB)
                 return error("Object %s not a blob",
                              sha1_to_hex(item->object.sha1));
 	ret = parse_blob_buffer(item, buffer, size);

builtin-apply.c

@@ -1912,11 +1912,11 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
 
 	if (has_sha1_file(sha1)) {
 		/* We already have the postimage */
-		char type[10];
+		enum object_type type;
 		unsigned long size;
 
 		free(desc->buffer);
-		desc->buffer = read_sha1_file(sha1, type, &size);
+		desc->buffer = read_sha1_file(sha1, &type, &size);
 		if (!desc->buffer)
 			return error("the necessary postimage %s for "
 				     "'%s' cannot be read",
@@ -1972,8 +1972,8 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
 	buf = NULL;
 	if (cached) {
 		if (ce) {
-			char type[20];
-			buf = read_sha1_file(ce->sha1, type, &size);
+			enum object_type type;
+			buf = read_sha1_file(ce->sha1, &type, &size);
 			if (!buf)
 				return error("read of %s failed",
 					     patch->old_name);

builtin-blame.c

@@ -87,9 +87,9 @@ struct origin {
 static char *fill_origin_blob(struct origin *o, mmfile_t *file)
 {
 	if (!o->file.ptr) {
-		char type[10];
+		enum object_type type;
 		num_read_blob++;
-		file->ptr = read_sha1_file(o->blob_sha1, type,
+		file->ptr = read_sha1_file(o->blob_sha1, &type,
 					   (unsigned long *)(&(file->size)));
 		o->file = *file;
 	}
@@ -263,16 +263,14 @@ static struct origin *get_origin(struct scoreboard *sb,
 static int fill_blob_sha1(struct origin *origin)
 {
 	unsigned mode;
-	char type[10];
 
 	if (!is_null_sha1(origin->blob_sha1))
 		return 0;
 	if (get_tree_entry(origin->commit->object.sha1,
 			   origin->path,
 			   origin->blob_sha1, &mode))
 		goto error_out;
-	if (sha1_object_info(origin->blob_sha1, type, NULL) ||
-	    strcmp(type, blob_type))
+	if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 		goto error_out;
 	return 0;
  error_out:
@@ -1322,10 +1320,10 @@ static void get_commit_info(struct commit *commit,
 	 * we now need to populate them for output.
 	 */
 	if (!commit->buffer) {
-		char type[20];
+		enum object_type type;
 		unsigned long size;
 		commit->buffer =
-			read_sha1_file(commit->object.sha1, type, &size);
+			read_sha1_file(commit->object.sha1, &type, &size);
 	}
 	ret->author = author_buf;
 	get_ac_line(commit->buffer, "\nauthor ",
@@ -2006,7 +2004,7 @@ static struct commit *fake_working_tree_commit(const char *path, const char *con
 	buf[fin_size] = 0;
 	origin->file.ptr = buf;
 	origin->file.size = fin_size;
-	pretend_sha1_file(buf, fin_size, blob_type, origin->blob_sha1);
+	pretend_sha1_file(buf, fin_size, OBJ_BLOB, origin->blob_sha1);
 	commit->util = origin;
 
 	/*
@@ -2068,7 +2066,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	int show_stats = 0;
 	const char *revs_file = NULL;
 	const char *final_commit_name = NULL;
-	char type[10];
+	enum object_type type;
 	const char *bottomtop = NULL;
 	const char *contents_from = NULL;
 
@@ -2302,7 +2300,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 		if (fill_blob_sha1(o))
 			die("no such path %s in %s", path, final_commit_name);
 
-		sb.final_buf = read_sha1_file(o->blob_sha1, type,
+		sb.final_buf = read_sha1_file(o->blob_sha1, &type,
 					      &sb.final_buf_size);
 	}
 	num_read_blob++;

builtin-cat-file.c

@@ -79,7 +79,7 @@ static void pprint_tag(const unsigned char *sha1, const char *buf, unsigned long
 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 {
 	unsigned char sha1[20];
-	char type[20];
+	enum object_type type;
 	void *buf;
 	unsigned long size;
 	int opt;
@@ -100,14 +100,16 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 	buf = NULL;
 	switch (opt) {
 	case 't':
-		if (!sha1_object_info(sha1, type, NULL)) {
-			printf("%s\n", type);
+		type = sha1_object_info(sha1, NULL);
+		if (type > 0) {
+			printf("%s\n", typename(type));
 			return 0;
 		}
 		break;
 
 	case 's':
-		if (!sha1_object_info(sha1, type, &size)) {
+		type = sha1_object_info(sha1, &size);
+		if (type > 0) {
 			printf("%lu\n", size);
 			return 0;
 		}
@@ -117,17 +119,18 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 		return !has_sha1_file(sha1);
 
 	case 'p':
-		if (sha1_object_info(sha1, type, NULL))
+		type = sha1_object_info(sha1, NULL);
+		if (type < 0)
 			die("Not a valid object name %s", argv[2]);
 
 		/* custom pretty-print here */
-		if (!strcmp(type, tree_type))
+		if (type == OBJ_TREE)
 			return cmd_ls_tree(2, argv + 1, NULL);
 
-		buf = read_sha1_file(sha1, type, &size);
+		buf = read_sha1_file(sha1, &type, &size);
 		if (!buf)
 			die("Cannot read object %s", argv[2]);
-		if (!strcmp(type, tag_type)) {
+		if (type == OBJ_TAG) {
 			pprint_tag(sha1, buf, size);
 			return 0;
 		}

builtin-commit-tree.c

@@ -47,11 +47,10 @@ static void add_buffer(char **bufp, unsigned int *sizep, const char *fmt, ...)
 
 static void check_valid(unsigned char *sha1, const char *expect)
 {
-	char type[20];
-
-	if (sha1_object_info(sha1, type, NULL))
+	enum object_type type = sha1_object_info(sha1, NULL);
+	if (type < 0)
 		die("%s is not a valid object", sha1_to_hex(sha1));
-	if (expect && strcmp(type, expect))
+	if (expect && type != type_from_string(expect))
 		die("%s is not a valid '%s' object", sha1_to_hex(sha1),
 		    expect);
 }

builtin-for-each-ref.c

@@ -173,8 +173,8 @@ static void verify_format(const char *format)
  */
 static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned long *sz, int *eaten)
 {
-	char type[20];
-	void *buf = read_sha1_file(sha1, type, sz);
+	enum object_type type;
+	void *buf = read_sha1_file(sha1, &type, sz);
 
 	if (buf)
 		*obj = parse_object_buffer(sha1, type, *sz, buf, eaten);

builtin-grep.c

@@ -84,11 +84,11 @@ static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char
 {
 	unsigned long size;
 	char *data;
-	char type[20];
+	enum object_type type;
 	char *to_free = NULL;
 	int hit;
 
-	data = read_sha1_file(sha1, type, &size);
+	data = read_sha1_file(sha1, &type, &size);
 	if (!data) {
 		error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 		return 0;
@@ -380,10 +380,10 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
 		else if (S_ISREG(entry.mode))
 			hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
 		else if (S_ISDIR(entry.mode)) {
-			char type[20];
+			enum object_type type;
 			struct tree_desc sub;
 			void *data;
-			data = read_sha1_file(entry.sha1, type, &sub.size);
+			data = read_sha1_file(entry.sha1, &type, &sub.size);
 			if (!data)
 				die("unable to read tree (%s)",
 				    sha1_to_hex(entry.sha1));

builtin-log.c

@@ -89,8 +89,8 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 static int show_object(const unsigned char *sha1, int suppress_header)
 {
 	unsigned long size;
-	char type[20];
-	char *buf = read_sha1_file(sha1, type, &size);
+	enum object_type type;
+	char *buf = read_sha1_file(sha1, &type, &size);
 	int offset = 0;
 
 	if (!buf)

builtin-pack-objects.c

@@ -230,8 +230,8 @@ static unsigned char *find_packed_object_name(struct packed_git *p,
 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 {
 	unsigned long othersize, delta_size;
-	char type[10];
-	void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
+	enum object_type type;
+	void *otherbuf = read_sha1_file(entry->delta->sha1, &type, &othersize);
 	void *delta_buf;
 
 	if (!otherbuf)
@@ -375,7 +375,7 @@ static unsigned long write_object(struct sha1file *f,
 				  struct object_entry *entry)
 {
 	unsigned long size;
-	char type[10];
+	enum object_type type;
 	void *buf;
 	unsigned char header[10];
 	unsigned hdrlen, datalen;
@@ -416,7 +416,7 @@ static unsigned long write_object(struct sha1file *f,
 	}
 
 	if (!to_reuse) {
-		buf = read_sha1_file(entry->sha1, type, &size);
+		buf = read_sha1_file(entry->sha1, &type, &size);
 		if (!buf)
 			die("unable to read %s", sha1_to_hex(entry->sha1));
 		if (size != entry->size)
@@ -765,7 +765,7 @@ static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 	struct pbase_tree_cache *ent, *nent;
 	void *data;
 	unsigned long size;
-	char type[20];
+	enum object_type type;
 	int neigh;
 	int my_ix = pbase_tree_cache_ix(sha1);
 	int available_ix = -1;
@@ -792,10 +792,10 @@ static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 	/* Did not find one.  Either we got a bogus request or
 	 * we need to read and perhaps cache.
 	 */
-	data = read_sha1_file(sha1, type, &size);
+	data = read_sha1_file(sha1, &type, &size);
 	if (!data)
 		return NULL;
-	if (strcmp(type, tree_type)) {
+	if (type != OBJ_TREE) {
 		free(data);
 		return NULL;
 	}
@@ -854,19 +854,19 @@ static void add_pbase_object(struct tree_desc *tree,
 
 	while (tree_entry(tree,&entry)) {
 		unsigned long size;
-		char type[20];
+		enum object_type type;
 
 		if (entry.pathlen != cmplen ||
 		    memcmp(entry.path, name, cmplen) ||
 		    !has_sha1_file(entry.sha1) ||
-		    sha1_object_info(entry.sha1, type, &size))
+		    (type = sha1_object_info(entry.sha1, &size)) < 0)
 			continue;
 		if (name[cmplen] != '/') {
 			unsigned hash = name_hash(fullname);
 			add_object_entry(entry.sha1, hash, 1);
 			return;
 		}
-		if (!strcmp(type, tree_type)) {
+		if (type == OBJ_TREE) {
 			struct tree_desc sub;
 			struct pbase_tree_cache *tree;
 			const char *down = name+cmplen+1;
@@ -978,8 +978,6 @@ static void add_preferred_base(unsigned char *sha1)
 
 static void check_object(struct object_entry *entry)
 {
-	char type[20];
-
 	if (entry->in_pack && !entry->preferred_base) {
 		struct packed_git *p = entry->in_pack;
 		struct pack_window *w_curs = NULL;
@@ -1062,10 +1060,10 @@ static void check_object(struct object_entry *entry)
 		/* Otherwise we would do the usual */
 	}
 
-	if (sha1_object_info(entry->sha1, type, &entry->size))
+	entry->type = sha1_object_info(entry->sha1, &entry->size);
+	if (entry->type < 0)
 		die("unable to get type of object %s",
 		    sha1_to_hex(entry->sha1));
-	entry->type = type_from_string(type);
 }
 
 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
@@ -1195,7 +1193,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
 	struct object_entry *trg_entry = trg->entry;
 	struct object_entry *src_entry = src->entry;
 	unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
-	char type[10];
+	enum object_type type;
 	void *delta_buf;
 
 	/* Don't bother doing diffs between different types */
@@ -1246,13 +1244,13 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
 
 	/* Load data if not already done */
 	if (!trg->data) {
-		trg->data = read_sha1_file(trg_entry->sha1, type, &sz);
+		trg->data = read_sha1_file(trg_entry->sha1, &type, &sz);
 		if (sz != trg_size)
 			die("object %s inconsistent object length (%lu vs %lu)",
 			    sha1_to_hex(trg_entry->sha1), sz, trg_size);
 	}
 	if (!src->data) {
-		src->data = read_sha1_file(src_entry->sha1, type, &sz);
+		src->data = read_sha1_file(src_entry->sha1, &type, &sz);
 		if (sz != src_size)
 			die("object %s inconsistent object length (%lu vs %lu)",
 			    sha1_to_hex(src_entry->sha1), sz, src_size);