builtin-fast-export.c - git - Git at Google

 /*
  * "git fast-export" builtin command
  *
  * Copyright (C) 2007 Johannes E. Schindelin
  */
 #include "builtin.h"
 #include "cache.h"
 #include "commit.h"
 #include "object.h"
 #include "tag.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "log-tree.h"
 #include "revision.h"
 #include "decorate.h"
 #include "path-list.h"
 #include "utf8.h"
 #include "parse-options.h"

 static const char *fast_export_usage[] = {
 	"git-fast-export [rev-list-opts]",
 	NULL
 };

 static int progress;
 static enum { VERBATIM, WARN, STRIP, ABORT } signed_tag_mode = ABORT;

 static int parse_opt_signed_tag_mode(const struct option *opt,
 				     const char *arg, int unset)
 {
 	if (unset || !strcmp(arg, "abort"))
 		signed_tag_mode = ABORT;
 	else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
 		signed_tag_mode = VERBATIM;
 	else if (!strcmp(arg, "warn"))
 		signed_tag_mode = WARN;
 	else if (!strcmp(arg, "strip"))
 		signed_tag_mode = STRIP;
 	else
 		return error("Unknown signed-tag mode: %s", arg);
 	return 0;
 }

 static struct decoration idnums;
 static uint32_t last_idnum;

 static int has_unshown_parent(struct commit *commit)
 {
 	struct commit_list *parent;

 	for (parent = commit->parents; parent; parent = parent->next)
 		if (!(parent->item->object.flags & SHOWN) &&
 		    !(parent->item->object.flags & UNINTERESTING))
 			return 1;
 	return 0;
 }

 /* Since intptr_t is C99, we do not use it here */
 static void mark_object(struct object *object)
 {
 	last_idnum++;
 	add_decoration(&idnums, object, ((uint32_t *)NULL) + last_idnum);
 }

 static int get_object_mark(struct object *object)
 {
 	void *decoration = lookup_decoration(&idnums, object);
 	if (!decoration)
 		return 0;
 	return (uint32_t *)decoration - (uint32_t *)NULL;
 }

 static void show_progress(void)
 {
 	static int counter = 0;
 	if (!progress)
 		return;
 	if ((++counter % progress) == 0)
 		printf("progress %d objects\n", counter);
 }

 static void handle_object(const unsigned char *sha1)
 {
 	unsigned long size;
 	enum object_type type;
 	char *buf;
 	struct object *object;

 	if (is_null_sha1(sha1))
 		return;

 	object = parse_object(sha1);
 	if (!object)
 		die ("Could not read blob %s", sha1_to_hex(sha1));

 	if (object->flags & SHOWN)
 		return;

 	buf = read_sha1_file(sha1, &type, &size);
 	if (!buf)
 		die ("Could not read blob %s", sha1_to_hex(sha1));

 	mark_object(object);

 	printf("blob\nmark :%d\ndata %lu\n", last_idnum, size);
 	if (size && fwrite(buf, size, 1, stdout) != 1)
 		die ("Could not write blob %s", sha1_to_hex(sha1));
 	printf("\n");

 	show_progress();

 	object->flags |= SHOWN;
 	free(buf);
 }

 static void show_filemodify(struct diff_queue_struct *q,
 			    struct diff_options *options, void *data)
 {
 	int i;
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filespec *spec = q->queue[i]->two;
 		if (is_null_sha1(spec->sha1))
 			printf("D %s\n", spec->path);
 		else {
 			struct object *object = lookup_object(spec->sha1);
 			printf("M %06o :%d %s\n", spec->mode,
 			       get_object_mark(object), spec->path);
 		}
 	}
 }

 static const char *find_encoding(const char *begin, const char *end)
 {
 	const char *needle = "\nencoding ";
 	char *bol, *eol;

 	bol = memmem(begin, end ? end - begin : strlen(begin),
 		     needle, strlen(needle));
 	if (!bol)
 		return git_commit_encoding;
 	bol += strlen(needle);
 	eol = strchrnul(bol, '\n');
 	*eol = '\0';
 	return bol;
 }

 static void handle_commit(struct commit *commit, struct rev_info *rev)
 {
 	int saved_output_format = rev->diffopt.output_format;
 	const char *author, *author_end, *committer, *committer_end;
 	const char *encoding, *message;
 	char *reencoded = NULL;
 	struct commit_list *p;
 	int i;

 	rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;

 	parse_commit(commit);
 	author = strstr(commit->buffer, "\nauthor ");
 	if (!author)
 		die ("Could not find author in commit %s",
 		     sha1_to_hex(commit->object.sha1));
 	author++;
 	author_end = strchrnul(author, '\n');
 	committer = strstr(author_end, "\ncommitter ");
 	if (!committer)
 		die ("Could not find committer in commit %s",
 		     sha1_to_hex(commit->object.sha1));
 	committer++;
 	committer_end = strchrnul(committer, '\n');
 	message = strstr(committer_end, "\n\n");
 	encoding = find_encoding(committer_end, message);
 	if (message)
 		message += 2;

 	if (commit->parents) {
 		parse_commit(commit->parents->item);
 		diff_tree_sha1(commit->parents->item->tree->object.sha1,
 			       commit->tree->object.sha1, "", &rev->diffopt);
 	}
 	else
 		diff_root_tree_sha1(commit->tree->object.sha1,
 				    "", &rev->diffopt);

 	for (i = 0; i < diff_queued_diff.nr; i++)
 		handle_object(diff_queued_diff.queue[i]->two->sha1);

 	mark_object(&commit->object);
 	if (!is_encoding_utf8(encoding))
 		reencoded = reencode_string(message, "UTF-8", encoding);
 	if (!commit->parents)
 		printf("reset %s\n", (const char*)commit->util);
 	printf("commit %s\nmark :%d\n%.*s\n%.*s\ndata %u\n%s",
 	       (const char *)commit->util, last_idnum,
 	       (int)(author_end - author), author,
 	       (int)(committer_end - committer), committer,
 	       (unsigned)(reencoded
 			  ? strlen(reencoded) : message
 			  ? strlen(message) : 0),
 	       reencoded ? reencoded : message ? message : "");
 	free(reencoded);

 	for (i = 0, p = commit->parents; p; p = p->next) {
 		int mark = get_object_mark(&p->item->object);
 		if (!mark)
 			continue;
 		if (i == 0)
 			printf("from :%d\n", mark);
 		else
 			printf("merge :%d\n", mark);
 		i++;
 	}

 	log_tree_diff_flush(rev);
 	rev->diffopt.output_format = saved_output_format;

 	printf("\n");

 	show_progress();
 }

 static void handle_tail(struct object_array *commits, struct rev_info *revs)
 {
 	struct commit *commit;
 	while (commits->nr) {
 		commit = (struct commit *)commits->objects[commits->nr - 1].item;
 		if (has_unshown_parent(commit))
 			return;
 		handle_commit(commit, revs);
 		commits->nr--;
 	}
 }

 static void handle_tag(const char *name, struct tag *tag)
 {
 	unsigned long size;
 	enum object_type type;
 	char *buf;
 	const char *tagger, *tagger_end, *message;
 	size_t message_size = 0;

 	buf = read_sha1_file(tag->object.sha1, &type, &size);
 	if (!buf)
 		die ("Could not read tag %s", sha1_to_hex(tag->object.sha1));
 	message = memmem(buf, size, "\n\n", 2);
 	if (message) {
 		message += 2;
 		message_size = strlen(message);
 	}
 	tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 	if (!tagger)
 		die ("No tagger for tag %s", sha1_to_hex(tag->object.sha1));
 	tagger++;
 	tagger_end = strchrnul(tagger, '\n');

 	/* handle signed tags */
 	if (message) {
 		const char *signature = strstr(message,
 					       "\n-----BEGIN PGP SIGNATURE-----\n");
 		if (signature)
 			switch(signed_tag_mode) {
 			case ABORT:
 				die ("Encountered signed tag %s; use "
 				     "--signed-tag=<mode> to handle it.",
 				     sha1_to_hex(tag->object.sha1));
 			case WARN:
 				warning ("Exporting signed tag %s",
 					 sha1_to_hex(tag->object.sha1));
 				/* fallthru */
 			case VERBATIM:
 				break;
 			case STRIP:
 				message_size = signature + 1 - message;
 				break;
 			}
 	}

 	if (!prefixcmp(name, "refs/tags/"))
 		name += 10;
 	printf("tag %s\nfrom :%d\n%.*s\ndata %d\n%.*s\n",
 	       name, get_object_mark(tag->tagged),
 	       (int)(tagger_end - tagger), tagger,
 	       (int)message_size, (int)message_size, message ? message : "");
 }

 static void get_tags_and_duplicates(struct object_array *pending,
 				    struct path_list *extra_refs)
 {
 	struct tag *tag;
 	int i;

 	for (i = 0; i < pending->nr; i++) {
 		struct object_array_entry *e = pending->objects + i;
 		unsigned char sha1[20];
 		struct commit *commit = commit;
 		char *full_name;

 		if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
 			continue;

 		switch (e->item->type) {
 		case OBJ_COMMIT:
 			commit = (struct commit *)e->item;
 			break;
 		case OBJ_TAG:
 			tag = (struct tag *)e->item;
 			while (tag && tag->object.type == OBJ_TAG) {
 				path_list_insert(full_name, extra_refs)->util = tag;
 				tag = (struct tag *)tag->tagged;
 			}
 			if (!tag)
 				die ("Tag %s points nowhere?", e->name);
 			switch(tag->object.type) {
 			case OBJ_COMMIT:
 				commit = (struct commit *)tag;
 				break;
 			case OBJ_BLOB:
 				handle_object(tag->object.sha1);
 				continue;
 			}
 			break;
 		default:
 			die ("Unexpected object of type %s",
 			     typename(e->item->type));
 		}
 		if (commit->util)
 			/* more than one name for the same object */
 			path_list_insert(full_name, extra_refs)->util = commit;
 		else
 			commit->util = full_name;
 	}
 }

 static void handle_tags_and_duplicates(struct path_list *extra_refs)
 {
 	struct commit *commit;
 	int i;

 	for (i = extra_refs->nr - 1; i >= 0; i--) {
 		const char *name = extra_refs->items[i].path;
 		struct object *object = extra_refs->items[i].util;
 		switch (object->type) {
 		case OBJ_TAG:
 			handle_tag(name, (struct tag *)object);
 			break;
 		case OBJ_COMMIT:
 			/* create refs pointing to already seen commits */
 			commit = (struct commit *)object;
 			printf("reset %s\nfrom :%d\n\n", name,
 			       get_object_mark(&commit->object));
 			show_progress();
 			break;
 		}
 	}
 }

 int cmd_fast_export(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
 	struct object_array commits = { 0, 0, NULL };
 	struct path_list extra_refs = { NULL, 0, 0, 0 };
 	struct commit *commit;
 	struct option options[] = {
 		OPT_INTEGER(0, "progress", &progress,
 			    "show progress after <n> objects"),
 		OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, "mode",
 			     "select handling of signed tags",
 			     parse_opt_signed_tag_mode),
 		OPT_END()
 	};

 	/* we handle encodings */
 	git_config(git_default_config, NULL);

 	init_revisions(&revs, prefix);
 	argc = setup_revisions(argc, argv, &revs, NULL);
 	argc = parse_options(argc, argv, options, fast_export_usage, 0);
 	if (argc > 1)
 		usage_with_options (fast_export_usage, options);

 	get_tags_and_duplicates(&revs.pending, &extra_refs);

 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");
 	revs.diffopt.format_callback = show_filemodify;
 	DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
 	while ((commit = get_revision(&revs))) {
 		if (has_unshown_parent(commit)) {
 			struct commit_list *parent = commit->parents;
 			add_object_array(&commit->object, NULL, &commits);
 			for (; parent; parent = parent->next)
 				if (!parent->item->util)
 					parent->item->util = commit->util;
 		}
 		else {
 			handle_commit(commit, &revs);
 			handle_tail(&commits, &revs);
 		}
 	}

 	handle_tags_and_duplicates(&extra_refs);

 	return 0;
 }
	/*
	* "git fast-export" builtin command
	*
	* Copyright (C) 2007 Johannes E. Schindelin
	*/
	#include "builtin.h"
	#include "cache.h"
	#include "commit.h"
	#include "object.h"
	#include "tag.h"
	#include "diff.h"
	#include "diffcore.h"
	#include "log-tree.h"
	#include "revision.h"
	#include "decorate.h"
	#include "path-list.h"
	#include "utf8.h"
	#include "parse-options.h"

	static const char *fast_export_usage[] = {
	"git-fast-export [rev-list-opts]",
	NULL
	};

	static int progress;
	static enum { VERBATIM, WARN, STRIP, ABORT } signed_tag_mode = ABORT;

	static int parse_opt_signed_tag_mode(const struct option *opt,
	const char *arg, int unset)
	{
	if (unset \|\| !strcmp(arg, "abort"))
	signed_tag_mode = ABORT;
	else if (!strcmp(arg, "verbatim") \|\| !strcmp(arg, "ignore"))
	signed_tag_mode = VERBATIM;
	else if (!strcmp(arg, "warn"))
	signed_tag_mode = WARN;
	else if (!strcmp(arg, "strip"))
	signed_tag_mode = STRIP;
	else
	return error("Unknown signed-tag mode: %s", arg);
	return 0;
	}

	static struct decoration idnums;
	static uint32_t last_idnum;

	static int has_unshown_parent(struct commit *commit)
	{
	struct commit_list *parent;

	for (parent = commit->parents; parent; parent = parent->next)
	if (!(parent->item->object.flags & SHOWN) &&
	!(parent->item->object.flags & UNINTERESTING))
	return 1;
	return 0;
	}

	/* Since intptr_t is C99, we do not use it here */
	static void mark_object(struct object *object)
	{
	last_idnum++;
	add_decoration(&idnums, object, ((uint32_t *)NULL) + last_idnum);
	}

	static int get_object_mark(struct object *object)
	{
	void *decoration = lookup_decoration(&idnums, object);
	if (!decoration)
	return 0;
	return (uint32_t )decoration - (uint32_t )NULL;
	}

	static void show_progress(void)
	{
	static int counter = 0;
	if (!progress)
	return;
	if ((++counter % progress) == 0)
	printf("progress %d objects\n", counter);
	}

	static void handle_object(const unsigned char *sha1)
	{
	unsigned long size;
	enum object_type type;
	char *buf;
	struct object *object;

	if (is_null_sha1(sha1))
	return;

	object = parse_object(sha1);
	if (!object)
	die ("Could not read blob %s", sha1_to_hex(sha1));

	if (object->flags & SHOWN)
	return;

	buf = read_sha1_file(sha1, &type, &size);
	if (!buf)
	die ("Could not read blob %s", sha1_to_hex(sha1));

	mark_object(object);

	printf("blob\nmark :%d\ndata %lu\n", last_idnum, size);
	if (size && fwrite(buf, size, 1, stdout) != 1)
	die ("Could not write blob %s", sha1_to_hex(sha1));
	printf("\n");

	show_progress();

	object->flags \|= SHOWN;
	free(buf);
	}

	static void show_filemodify(struct diff_queue_struct *q,
	struct diff_options options, void data)
	{
	int i;
	for (i = 0; i < q->nr; i++) {
	struct diff_filespec *spec = q->queue[i]->two;
	if (is_null_sha1(spec->sha1))
	printf("D %s\n", spec->path);
	else {
	struct object *object = lookup_object(spec->sha1);
	printf("M %06o :%d %s\n", spec->mode,
	get_object_mark(object), spec->path);
	}
	}
	}

	static const char find_encoding(const char begin, const char *end)
	{
	const char *needle = "\nencoding ";
	char bol, eol;

	bol = memmem(begin, end ? end - begin : strlen(begin),
	needle, strlen(needle));
	if (!bol)
	return git_commit_encoding;
	bol += strlen(needle);
	eol = strchrnul(bol, '\n');
	*eol = '\0';
	return bol;
	}

	static void handle_commit(struct commit commit, struct rev_info rev)
	{
	int saved_output_format = rev->diffopt.output_format;
	const char author, author_end, committer, committer_end;
	const char encoding, message;
	char *reencoded = NULL;
	struct commit_list *p;
	int i;

	rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;

	parse_commit(commit);
	author = strstr(commit->buffer, "\nauthor ");
	if (!author)
	die ("Could not find author in commit %s",
	sha1_to_hex(commit->object.sha1));
	author++;
	author_end = strchrnul(author, '\n');
	committer = strstr(author_end, "\ncommitter ");
	if (!committer)
	die ("Could not find committer in commit %s",
	sha1_to_hex(commit->object.sha1));
	committer++;
	committer_end = strchrnul(committer, '\n');
	message = strstr(committer_end, "\n\n");
	encoding = find_encoding(committer_end, message);
	if (message)
	message += 2;

	if (commit->parents) {
	parse_commit(commit->parents->item);
	diff_tree_sha1(commit->parents->item->tree->object.sha1,
	commit->tree->object.sha1, "", &rev->diffopt);
	}
	else
	diff_root_tree_sha1(commit->tree->object.sha1,
	"", &rev->diffopt);

	for (i = 0; i < diff_queued_diff.nr; i++)
	handle_object(diff_queued_diff.queue[i]->two->sha1);

	mark_object(&commit->object);
	if (!is_encoding_utf8(encoding))
	reencoded = reencode_string(message, "UTF-8", encoding);
	if (!commit->parents)
	printf("reset %s\n", (const char*)commit->util);
	printf("commit %s\nmark :%d\n%.s\n%.s\ndata %u\n%s",
	(const char *)commit->util, last_idnum,
	(int)(author_end - author), author,
	(int)(committer_end - committer), committer,
	(unsigned)(reencoded
	? strlen(reencoded) : message
	? strlen(message) : 0),
	reencoded ? reencoded : message ? message : "");
	free(reencoded);

	for (i = 0, p = commit->parents; p; p = p->next) {
	int mark = get_object_mark(&p->item->object);
	if (!mark)
	continue;
	if (i == 0)
	printf("from :%d\n", mark);
	else
	printf("merge :%d\n", mark);
	i++;
	}

	log_tree_diff_flush(rev);
	rev->diffopt.output_format = saved_output_format;

	printf("\n");

	show_progress();
	}

	static void handle_tail(struct object_array commits, struct rev_info revs)
	{
	struct commit *commit;
	while (commits->nr) {
	commit = (struct commit *)commits->objects[commits->nr - 1].item;
	if (has_unshown_parent(commit))
	return;
	handle_commit(commit, revs);
	commits->nr--;
	}
	}

	static void handle_tag(const char name, struct tag tag)
	{
	unsigned long size;
	enum object_type type;
	char *buf;
	const char tagger, tagger_end, *message;
	size_t message_size = 0;

	buf = read_sha1_file(tag->object.sha1, &type, &size);
	if (!buf)
	die ("Could not read tag %s", sha1_to_hex(tag->object.sha1));
	message = memmem(buf, size, "\n\n", 2);
	if (message) {
	message += 2;
	message_size = strlen(message);
	}
	tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
	if (!tagger)
	die ("No tagger for tag %s", sha1_to_hex(tag->object.sha1));
	tagger++;
	tagger_end = strchrnul(tagger, '\n');

	/* handle signed tags */
	if (message) {
	const char *signature = strstr(message,
	"\n-----BEGIN PGP SIGNATURE-----\n");
	if (signature)
	switch(signed_tag_mode) {
	case ABORT:
	die ("Encountered signed tag %s; use "
	"--signed-tag=<mode> to handle it.",
	sha1_to_hex(tag->object.sha1));
	case WARN:
	warning ("Exporting signed tag %s",
	sha1_to_hex(tag->object.sha1));
	/* fallthru */
	case VERBATIM:
	break;
	case STRIP:
	message_size = signature + 1 - message;
	break;
	}
	}

	if (!prefixcmp(name, "refs/tags/"))
	name += 10;
	printf("tag %s\nfrom :%d\n%.s\ndata %d\n%.s\n",
	name, get_object_mark(tag->tagged),
	(int)(tagger_end - tagger), tagger,
	(int)message_size, (int)message_size, message ? message : "");
	}

	static void get_tags_and_duplicates(struct object_array *pending,
	struct path_list *extra_refs)
	{
	struct tag *tag;
	int i;

	for (i = 0; i < pending->nr; i++) {
	struct object_array_entry *e = pending->objects + i;
	unsigned char sha1[20];
	struct commit *commit = commit;
	char *full_name;

	if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
	continue;

	switch (e->item->type) {
	case OBJ_COMMIT:
	commit = (struct commit *)e->item;
	break;
	case OBJ_TAG:
	tag = (struct tag *)e->item;
	while (tag && tag->object.type == OBJ_TAG) {
	path_list_insert(full_name, extra_refs)->util = tag;
	tag = (struct tag *)tag->tagged;
	}
	if (!tag)
	die ("Tag %s points nowhere?", e->name);
	switch(tag->object.type) {
	case OBJ_COMMIT:
	commit = (struct commit *)tag;
	break;
	case OBJ_BLOB:
	handle_object(tag->object.sha1);
	continue;
	}
	break;
	default:
	die ("Unexpected object of type %s",
	typename(e->item->type));
	}
	if (commit->util)
	/* more than one name for the same object */
	path_list_insert(full_name, extra_refs)->util = commit;
	else
	commit->util = full_name;
	}
	}

	static void handle_tags_and_duplicates(struct path_list *extra_refs)
	{
	struct commit *commit;
	int i;

	for (i = extra_refs->nr - 1; i >= 0; i--) {
	const char *name = extra_refs->items[i].path;
	struct object *object = extra_refs->items[i].util;
	switch (object->type) {
	case OBJ_TAG:
	handle_tag(name, (struct tag *)object);
	break;
	case OBJ_COMMIT:
	/* create refs pointing to already seen commits */
	commit = (struct commit *)object;
	printf("reset %s\nfrom :%d\n\n", name,
	get_object_mark(&commit->object));
	show_progress();
	break;
	}
	}
	}

	int cmd_fast_export(int argc, const char *argv, const char prefix)
	{
	struct rev_info revs;
	struct object_array commits = { 0, 0, NULL };
	struct path_list extra_refs = { NULL, 0, 0, 0 };
	struct commit *commit;
	struct option options[] = {
	OPT_INTEGER(0, "progress", &progress,
	"show progress after <n> objects"),
	OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, "mode",
	"select handling of signed tags",
	parse_opt_signed_tag_mode),
	OPT_END()
	};

	/* we handle encodings */
	git_config(git_default_config, NULL);

	init_revisions(&revs, prefix);
	argc = setup_revisions(argc, argv, &revs, NULL);
	argc = parse_options(argc, argv, options, fast_export_usage, 0);
	if (argc > 1)
	usage_with_options (fast_export_usage, options);

	get_tags_and_duplicates(&revs.pending, &extra_refs);

	if (prepare_revision_walk(&revs))
	die("revision walk setup failed");
	revs.diffopt.format_callback = show_filemodify;
	DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
	while ((commit = get_revision(&revs))) {
	if (has_unshown_parent(commit)) {
	struct commit_list *parent = commit->parents;
	add_object_array(&commit->object, NULL, &commits);
	for (; parent; parent = parent->next)
	if (!parent->item->util)
	parent->item->util = commit->util;
	}
	else {
	handle_commit(commit, &revs);
	handle_tail(&commits, &revs);
	}
	}

	handle_tags_and_duplicates(&extra_refs);

	return 0;
	}