builtin/cat-file.c - jrn/git - Git at Google

 /*
  * GIT - The information manager from hell
  *
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "cache.h"
 #include "exec_cmd.h"
 #include "tag.h"
 #include "tree.h"
 #include "builtin.h"
 #include "parse-options.h"
 #include "diff.h"
 #include "userdiff.h"
 #include "streaming.h"

 static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
 {
 	unsigned char sha1[20];
 	enum object_type type;
 	char *buf;
 	unsigned long size;
 	struct object_context obj_context;

 	if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
 		die("Not a valid object name %s", obj_name);

 	buf = NULL;
 	switch (opt) {
 	case 't':
 		type = sha1_object_info(sha1, NULL);
 		if (type > 0) {
 			printf("%s\n", typename(type));
 			return 0;
 		}
 		break;

 	case 's':
 		type = sha1_object_info(sha1, &size);
 		if (type > 0) {
 			printf("%lu\n", size);
 			return 0;
 		}
 		break;

 	case 'e':
 		return !has_sha1_file(sha1);

 	case 'p':
 		type = sha1_object_info(sha1, NULL);
 		if (type < 0)
 			die("Not a valid object name %s", obj_name);

 		/* custom pretty-print here */
 		if (type == OBJ_TREE) {
 			const char *ls_args[3] = { NULL };
 			ls_args[0] =  "ls-tree";
 			ls_args[1] =  obj_name;
 			return cmd_ls_tree(2, ls_args, NULL);
 		}

 		if (type == OBJ_BLOB)
 			return stream_blob_to_fd(1, sha1, NULL, 0);
 		buf = read_sha1_file(sha1, &type, &size);
 		if (!buf)
 			die("Cannot read object %s", obj_name);

 		/* otherwise just spit out the data */
 		break;

 	case 'c':
 		if (!obj_context.path[0])
 			die("git cat-file --textconv %s: <object> must be <sha1:path>",
 			    obj_name);

 		if (!textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
 			die("git cat-file --textconv: unable to run textconv on %s",
 			    obj_name);
 		break;

 	case 0:
 		if (type_from_string(exp_type) == OBJ_BLOB) {
 			unsigned char blob_sha1[20];
 			if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
 				enum object_type type;
 				unsigned long size;
 				char *buffer = read_sha1_file(sha1, &type, &size);
 				if (memcmp(buffer, "object ", 7) ||
 				    get_sha1_hex(buffer + 7, blob_sha1))
 					die("%s not a valid tag", sha1_to_hex(sha1));
 				free(buffer);
 			} else
 				hashcpy(blob_sha1, sha1);

 			if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
 				return stream_blob_to_fd(1, blob_sha1, NULL, 0);
 			/*
 			 * we attempted to dereference a tag to a blob
 			 * and failed; there may be new dereference
 			 * mechanisms this code is not aware of.
 			 * fall-back to the usual case.
 			 */
 		}
 		buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 		break;

 	default:
 		die("git cat-file: unknown option: %s", exp_type);
 	}

 	if (!buf)
 		die("git cat-file %s: bad file", obj_name);

 	write_or_die(1, buf, size);
 	return 0;
 }

 struct expand_data {
 	unsigned char sha1[20];
 	enum object_type type;
 	unsigned long size;
 	unsigned long disk_size;

 	/*
 	 * If mark_query is true, we do not expand anything, but rather
 	 * just mark the object_info with items we wish to query.
 	 */
 	int mark_query;

 	/*
 	 * After a mark_query run, this object_info is set up to be
 	 * passed to sha1_object_info_extended. It will point to the data
 	 * elements above, so you can retrieve the response from there.
 	 */
 	struct object_info info;
 };

 static int is_atom(const char *atom, const char *s, int slen)
 {
 	int alen = strlen(atom);
 	return alen == slen && !memcmp(atom, s, alen);
 }

 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 			void *vdata)
 {
 	struct expand_data *data = vdata;

 	if (is_atom("objectname", atom, len)) {
 		if (!data->mark_query)
 			strbuf_addstr(sb, sha1_to_hex(data->sha1));
 	} else if (is_atom("objecttype", atom, len)) {
 		if (data->mark_query)
 			data->info.typep = &data->type;
 		else
 			strbuf_addstr(sb, typename(data->type));
 	} else if (is_atom("objectsize", atom, len)) {
 		if (data->mark_query)
 			data->info.sizep = &data->size;
 		else
 			strbuf_addf(sb, "%lu", data->size);
 	} else if (is_atom("objectsize:disk", atom, len)) {
 		if (data->mark_query)
 			data->info.disk_sizep = &data->disk_size;
 		else
 			strbuf_addf(sb, "%lu", data->disk_size);
 	} else
 		die("unknown format element: %.*s", len, atom);
 }

 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 {
 	const char *end;

 	if (*start != '(')
 		return 0;
 	end = strchr(start + 1, ')');
 	if (!end)
 		die("format element '%s' does not end in ')'", start);

 	expand_atom(sb, start + 1, end - start - 1, data);

 	return end - start + 1;
 }

 static void print_object_or_die(int fd, const unsigned char *sha1,
 				enum object_type type, unsigned long size)
 {
 	if (type == OBJ_BLOB) {
 		if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 			die("unable to stream %s to stdout", sha1_to_hex(sha1));
 	}
 	else {
 		enum object_type rtype;
 		unsigned long rsize;
 		void *contents;

 		contents = read_sha1_file(sha1, &rtype, &rsize);
 		if (!contents)
 			die("object %s disappeared", sha1_to_hex(sha1));
 		if (rtype != type)
 			die("object %s changed type!?", sha1_to_hex(sha1));
 		if (rsize != size)
 			die("object %s change size!?", sha1_to_hex(sha1));

 		write_or_die(fd, contents, size);
 		free(contents);
 	}
 }

 struct batch_options {
 	int enabled;
 	int print_contents;
 	const char *format;
 };

 static int batch_one_object(const char *obj_name, struct batch_options *opt,
 			    struct expand_data *data)
 {
 	struct strbuf buf = STRBUF_INIT;

 	if (!obj_name)
 	   return 1;

 	if (get_sha1(obj_name, data->sha1)) {
 		printf("%s missing\n", obj_name);
 		fflush(stdout);
 		return 0;
 	}

 	if (sha1_object_info_extended(data->sha1, &data->info) < 0) {
 		printf("%s missing\n", obj_name);
 		fflush(stdout);
 		return 0;
 	}

 	strbuf_expand(&buf, opt->format, expand_format, data);
 	strbuf_addch(&buf, '\n');
 	write_or_die(1, buf.buf, buf.len);
 	strbuf_release(&buf);

 	if (opt->print_contents) {
 		print_object_or_die(1, data->sha1, data->type, data->size);
 		write_or_die(1, "\n", 1);
 	}
 	return 0;
 }

 static int batch_objects(struct batch_options *opt)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct expand_data data;

 	if (!opt->format)
 		opt->format = "%(objectname) %(objecttype) %(objectsize)";

 	/*
 	 * Expand once with our special mark_query flag, which will prime the
 	 * object_info to be handed to sha1_object_info_extended for each
 	 * object.
 	 */
 	memset(&data, 0, sizeof(data));
 	data.mark_query = 1;
 	strbuf_expand(&buf, opt->format, expand_format, &data);
 	data.mark_query = 0;

 	/*
 	 * We are going to call get_sha1 on a potentially very large number of
 	 * objects. In most large cases, these will be actual object sha1s. The
 	 * cost to double-check that each one is not also a ref (just so we can
 	 * warn) ends up dwarfing the actual cost of the object lookups
 	 * themselves. We can work around it by just turning off the warning.
 	 */
 	warn_on_object_refname_ambiguity = 0;

 	while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 		int error = batch_one_object(buf.buf, opt, &data);
 		if (error)
 			return error;
 	}

 	return 0;
 }

 static const char * const cat_file_usage[] = {
 	N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
 	N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
 	NULL
 };

 static int git_cat_file_config(const char *var, const char *value, void *cb)
 {
 	if (userdiff_config(var, value) < 0)
 		return -1;

 	return git_default_config(var, value, cb);
 }

 static int batch_option_callback(const struct option *opt,
 				 const char *arg,
 				 int unset)
 {
 	struct batch_options *bo = opt->value;

 	if (unset) {
 		memset(bo, 0, sizeof(*bo));
 		return 0;
 	}

 	bo->enabled = 1;
 	bo->print_contents = !strcmp(opt->long_name, "batch");
 	bo->format = arg;

 	return 0;
 }

 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 {
 	int opt = 0;
 	const char *exp_type = NULL, *obj_name = NULL;
 	struct batch_options batch = {0};

 	const struct option options[] = {
 		OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 		OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
 		OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
 		OPT_SET_INT('e', NULL, &opt,
 			    N_("exit with zero when there's no error"), 'e'),
 		OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 		OPT_SET_INT(0, "textconv", &opt,
 			    N_("for blob objects, run textconv on object's content"), 'c'),
 		{ OPTION_CALLBACK, 0, "batch", &batch, "format",
 			N_("show info and content of objects fed from the standard input"),
 			PARSE_OPT_OPTARG, batch_option_callback },
 		{ OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 			N_("show info about objects fed from the standard input"),
 			PARSE_OPT_OPTARG, batch_option_callback },
 		OPT_END()
 	};

 	git_config(git_cat_file_config, NULL);

 	if (argc != 3 && argc != 2)
 		usage_with_options(cat_file_usage, options);

 	argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);

 	if (opt) {
 		if (argc == 1)
 			obj_name = argv[0];
 		else
 			usage_with_options(cat_file_usage, options);
 	}
 	if (!opt && !batch.enabled) {
 		if (argc == 2) {
 			exp_type = argv[0];
 			obj_name = argv[1];
 		} else
 			usage_with_options(cat_file_usage, options);
 	}
 	if (batch.enabled && (opt || argc)) {
 		usage_with_options(cat_file_usage, options);
 	}

 	if (batch.enabled)
 		return batch_objects(&batch);

 	return cat_one_file(opt, exp_type, obj_name);
 }
	/*
	* GIT - The information manager from hell
	*
	* Copyright (C) Linus Torvalds, 2005
	*/
	#include "cache.h"
	#include "exec_cmd.h"
	#include "tag.h"
	#include "tree.h"
	#include "builtin.h"
	#include "parse-options.h"
	#include "diff.h"
	#include "userdiff.h"
	#include "streaming.h"

	static int cat_one_file(int opt, const char exp_type, const char obj_name)
	{
	unsigned char sha1[20];
	enum object_type type;
	char *buf;
	unsigned long size;
	struct object_context obj_context;

	if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
	die("Not a valid object name %s", obj_name);

	buf = NULL;
	switch (opt) {
	case 't':
	type = sha1_object_info(sha1, NULL);
	if (type > 0) {
	printf("%s\n", typename(type));
	return 0;
	}
	break;

	case 's':
	type = sha1_object_info(sha1, &size);
	if (type > 0) {
	printf("%lu\n", size);
	return 0;
	}
	break;

	case 'e':
	return !has_sha1_file(sha1);

	case 'p':
	type = sha1_object_info(sha1, NULL);
	if (type < 0)
	die("Not a valid object name %s", obj_name);

	/* custom pretty-print here */
	if (type == OBJ_TREE) {
	const char *ls_args[3] = { NULL };
	ls_args[0] = "ls-tree";
	ls_args[1] = obj_name;
	return cmd_ls_tree(2, ls_args, NULL);
	}

	if (type == OBJ_BLOB)
	return stream_blob_to_fd(1, sha1, NULL, 0);
	buf = read_sha1_file(sha1, &type, &size);
	if (!buf)
	die("Cannot read object %s", obj_name);

	/* otherwise just spit out the data */
	break;

	case 'c':
	if (!obj_context.path[0])
	die("git cat-file --textconv %s: <object> must be <sha1:path>",
	obj_name);

	if (!textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
	die("git cat-file --textconv: unable to run textconv on %s",
	obj_name);
	break;

	case 0:
	if (type_from_string(exp_type) == OBJ_BLOB) {
	unsigned char blob_sha1[20];
	if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
	enum object_type type;
	unsigned long size;
	char *buffer = read_sha1_file(sha1, &type, &size);
	if (memcmp(buffer, "object ", 7) \|\|
	get_sha1_hex(buffer + 7, blob_sha1))
	die("%s not a valid tag", sha1_to_hex(sha1));
	free(buffer);
	} else
	hashcpy(blob_sha1, sha1);

	if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
	return stream_blob_to_fd(1, blob_sha1, NULL, 0);
	/*
	* we attempted to dereference a tag to a blob
	* and failed; there may be new dereference
	* mechanisms this code is not aware of.
	* fall-back to the usual case.
	*/
	}
	buf = read_object_with_reference(sha1, exp_type, &size, NULL);
	break;

	default:
	die("git cat-file: unknown option: %s", exp_type);
	}

	if (!buf)
	die("git cat-file %s: bad file", obj_name);

	write_or_die(1, buf, size);
	return 0;
	}

	struct expand_data {
	unsigned char sha1[20];
	enum object_type type;
	unsigned long size;
	unsigned long disk_size;

	/*
	* If mark_query is true, we do not expand anything, but rather
	* just mark the object_info with items we wish to query.
	*/
	int mark_query;

	/*
	* After a mark_query run, this object_info is set up to be
	* passed to sha1_object_info_extended. It will point to the data
	* elements above, so you can retrieve the response from there.
	*/
	struct object_info info;
	};

	static int is_atom(const char atom, const char s, int slen)
	{
	int alen = strlen(atom);
	return alen == slen && !memcmp(atom, s, alen);
	}

	static void expand_atom(struct strbuf sb, const char atom, int len,
	void *vdata)
	{
	struct expand_data *data = vdata;

	if (is_atom("objectname", atom, len)) {
	if (!data->mark_query)
	strbuf_addstr(sb, sha1_to_hex(data->sha1));
	} else if (is_atom("objecttype", atom, len)) {
	if (data->mark_query)
	data->info.typep = &data->type;
	else
	strbuf_addstr(sb, typename(data->type));
	} else if (is_atom("objectsize", atom, len)) {
	if (data->mark_query)
	data->info.sizep = &data->size;
	else
	strbuf_addf(sb, "%lu", data->size);
	} else if (is_atom("objectsize:disk", atom, len)) {
	if (data->mark_query)
	data->info.disk_sizep = &data->disk_size;
	else
	strbuf_addf(sb, "%lu", data->disk_size);
	} else
	die("unknown format element: %.*s", len, atom);
	}

	static size_t expand_format(struct strbuf sb, const char start, void *data)
	{
	const char *end;

	if (*start != '(')
	return 0;
	end = strchr(start + 1, ')');
	if (!end)
	die("format element '%s' does not end in ')'", start);

	expand_atom(sb, start + 1, end - start - 1, data);

	return end - start + 1;
	}

	static void print_object_or_die(int fd, const unsigned char *sha1,
	enum object_type type, unsigned long size)
	{
	if (type == OBJ_BLOB) {
	if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
	die("unable to stream %s to stdout", sha1_to_hex(sha1));
	}
	else {
	enum object_type rtype;
	unsigned long rsize;
	void *contents;

	contents = read_sha1_file(sha1, &rtype, &rsize);
	if (!contents)
	die("object %s disappeared", sha1_to_hex(sha1));
	if (rtype != type)
	die("object %s changed type!?", sha1_to_hex(sha1));
	if (rsize != size)
	die("object %s change size!?", sha1_to_hex(sha1));

	write_or_die(fd, contents, size);
	free(contents);
	}
	}

	struct batch_options {
	int enabled;
	int print_contents;
	const char *format;
	};

	static int batch_one_object(const char obj_name, struct batch_options opt,
	struct expand_data *data)
	{
	struct strbuf buf = STRBUF_INIT;

	if (!obj_name)
	return 1;

	if (get_sha1(obj_name, data->sha1)) {
	printf("%s missing\n", obj_name);
	fflush(stdout);
	return 0;
	}

	if (sha1_object_info_extended(data->sha1, &data->info) < 0) {
	printf("%s missing\n", obj_name);
	fflush(stdout);
	return 0;
	}

	strbuf_expand(&buf, opt->format, expand_format, data);
	strbuf_addch(&buf, '\n');
	write_or_die(1, buf.buf, buf.len);
	strbuf_release(&buf);

	if (opt->print_contents) {
	print_object_or_die(1, data->sha1, data->type, data->size);
	write_or_die(1, "\n", 1);
	}
	return 0;
	}

	static int batch_objects(struct batch_options *opt)
	{
	struct strbuf buf = STRBUF_INIT;
	struct expand_data data;

	if (!opt->format)
	opt->format = "%(objectname) %(objecttype) %(objectsize)";

	/*
	* Expand once with our special mark_query flag, which will prime the
	* object_info to be handed to sha1_object_info_extended for each
	* object.
	*/
	memset(&data, 0, sizeof(data));
	data.mark_query = 1;
	strbuf_expand(&buf, opt->format, expand_format, &data);
	data.mark_query = 0;

	/*
	* We are going to call get_sha1 on a potentially very large number of
	* objects. In most large cases, these will be actual object sha1s. The
	* cost to double-check that each one is not also a ref (just so we can
	* warn) ends up dwarfing the actual cost of the object lookups
	* themselves. We can work around it by just turning off the warning.
	*/
	warn_on_object_refname_ambiguity = 0;

	while (strbuf_getline(&buf, stdin, '\n') != EOF) {
	int error = batch_one_object(buf.buf, opt, &data);
	if (error)
	return error;
	}

	return 0;
	}

	static const char * const cat_file_usage[] = {
	N_("git cat-file (-t\|-s\|-e\|-p\|<type>\|--textconv) <object>"),
	N_("git cat-file (--batch\|--batch-check) < <list_of_objects>"),
	NULL
	};

	static int git_cat_file_config(const char var, const char value, void *cb)
	{
	if (userdiff_config(var, value) < 0)
	return -1;

	return git_default_config(var, value, cb);
	}

	static int batch_option_callback(const struct option *opt,
	const char *arg,
	int unset)
	{
	struct batch_options *bo = opt->value;

	if (unset) {
	memset(bo, 0, sizeof(*bo));
	return 0;
	}

	bo->enabled = 1;
	bo->print_contents = !strcmp(opt->long_name, "batch");
	bo->format = arg;

	return 0;
	}

	int cmd_cat_file(int argc, const char *argv, const char prefix)
	{
	int opt = 0;
	const char exp_type = NULL, obj_name = NULL;
	struct batch_options batch = {0};

	const struct option options[] = {
	OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
	OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
	OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
	OPT_SET_INT('e', NULL, &opt,
	N_("exit with zero when there's no error"), 'e'),
	OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
	OPT_SET_INT(0, "textconv", &opt,
	N_("for blob objects, run textconv on object's content"), 'c'),
	{ OPTION_CALLBACK, 0, "batch", &batch, "format",
	N_("show info and content of objects fed from the standard input"),
	PARSE_OPT_OPTARG, batch_option_callback },
	{ OPTION_CALLBACK, 0, "batch-check", &batch, "format",
	N_("show info about objects fed from the standard input"),
	PARSE_OPT_OPTARG, batch_option_callback },
	OPT_END()
	};

	git_config(git_cat_file_config, NULL);

	if (argc != 3 && argc != 2)
	usage_with_options(cat_file_usage, options);

	argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);

	if (opt) {
	if (argc == 1)
	obj_name = argv[0];
	else
	usage_with_options(cat_file_usage, options);
	}
	if (!opt && !batch.enabled) {
	if (argc == 2) {
	exp_type = argv[0];
	obj_name = argv[1];
	} else
	usage_with_options(cat_file_usage, options);
	}
	if (batch.enabled && (opt \|\| argc)) {
	usage_with_options(cat_file_usage, options);
	}

	if (batch.enabled)
	return batch_objects(&batch);

	return cat_one_file(opt, exp_type, obj_name);
	}