1 files changed, 415 insertions, 0 deletions

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
new file mode 100644
index 0000000000..f8d81291b9
--- /dev/null
+++ b/builtin/cat-file.c
@@ -0,0 +1,415 @@
+/*
+ * 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 '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))
+			break;
+
+	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 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);
+				const char *target;
+				if (!skip_prefix(buffer, "object ", &target) ||
+				    get_sha1_hex(target, 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;
+	const char *rest;
+	unsigned char delta_base_sha1[20];
+
+	/*
+	 * 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;
+
+	/*
+	 * Whether to split the input on whitespace before feeding it to
+	 * get_sha1; this is decided during the mark_query phase based on
+	 * whether we have a %(rest) token in our format.
+	 */
+	int split_on_whitespace;
+
+	/*
+	 * 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 if (is_atom("rest", atom, len)) {
+		if (data->mark_query)
+			data->split_on_whitespace = 1;
+		else if (data->rest)
+			strbuf_addstr(sb, data->rest);
+	} else if (is_atom("deltabase", atom, len)) {
+		if (data->mark_query)
+			data->info.delta_base_sha1 = data->delta_base_sha1;
+		else
+			strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
+	} 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, struct expand_data *data)
+{
+	const unsigned char *sha1 = data->sha1;
+
+	assert(data->info.typep);
+
+	if (data->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 type;
+		unsigned long size;
+		void *contents;
+
+		contents = read_sha1_file(sha1, &type, &size);
+		if (!contents)
+			die("object %s disappeared", sha1_to_hex(sha1));
+		if (type != data->type)
+			die("object %s changed type!?", sha1_to_hex(sha1));
+		if (data->info.sizep && size != data->size)
+			die("object %s changed 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, LOOKUP_REPLACE_OBJECT) < 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);
+		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;
+	int save_warning;
+	int retval = 0;
+
+	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;
+
+	/*
+	 * If we are printing out the object, then always fill in the type,
+	 * since we will want to decide whether or not to stream.
+	 */
+	if (opt->print_contents)
+		data.info.typep = &data.type;
+
+	/*
+	 * 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.
+	 */
+	save_warning = warn_on_object_refname_ambiguity;
+	warn_on_object_refname_ambiguity = 0;
+
+	while (strbuf_getline(&buf, stdin, '\n') != EOF) {
+		if (data.split_on_whitespace) {
+			/*
+			 * Split at first whitespace, tying off the beginning
+			 * of the string and saving the remainder (or NULL) in
+			 * data.rest.
+			 */
+			char *p = strpbrk(buf.buf, " \t");
+			if (p) {
+				while (*p && strchr(" \t", *p))
+					*p++ = '\0';
+			}
+			data.rest = p;
+		}
+
+		retval = batch_one_object(buf.buf, opt, &data);
+		if (retval)
+			break;
+	}
+
+	strbuf_release(&buf);
+	warn_on_object_refname_ambiguity = save_warning;
+	return retval;
+}
+
+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);
+}