git/builtin-notes.c

/*
 * Builtin "git notes"
 *
 * Copyright (c) 2010 Johan Herland <johan@herland.net>
 *
 * Based on git-notes.sh by Johannes Schindelin,
 * and builtin-tag.c by Kristian Høgsberg and Carlos Rica.
 */

#include "cache.h"
#include "builtin.h"
#include "notes.h"
#include "blob.h"
#include "commit.h"
#include "refs.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "parse-options.h"

static const char * const git_notes_usage[] = {
	"git notes [list [<object>]]",
	"git notes add [-f] [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
	"git notes copy [-f] <from-object> <to-object>",
	"git notes append [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
	"git notes edit [<object>]",
	"git notes show [<object>]",
	"git notes remove [<object>]",
	"git notes prune",
	NULL
};

static const char note_template[] =
	"\n"
	"#\n"
	"# Write/edit the notes for the following object:\n"
	"#\n";

struct msg_arg {
	int given;
	int use_editor;
	struct strbuf buf;
};

static int list_each_note(const unsigned char *object_sha1,
		const unsigned char *note_sha1, char *note_path,
		void *cb_data)
{
	printf("%s %s\n", sha1_to_hex(note_sha1), sha1_to_hex(object_sha1));
	return 0;
}

static void write_note_data(int fd, const unsigned char *sha1)
{
	unsigned long size;
	enum object_type type;
	char *buf = read_sha1_file(sha1, &type, &size);
	if (buf) {
		if (size)
			write_or_die(fd, buf, size);
		free(buf);
	}
}

static void write_commented_object(int fd, const unsigned char *object)
{
	const char *show_args[5] =
		{"show", "--stat", "--no-notes", sha1_to_hex(object), NULL};
	struct child_process show;
	struct strbuf buf = STRBUF_INIT;
	FILE *show_out;

	/* Invoke "git show --stat --no-notes $object" */
	memset(&show, 0, sizeof(show));
	show.argv = show_args;
	show.no_stdin = 1;
	show.out = -1;
	show.err = 0;
	show.git_cmd = 1;
	if (start_command(&show))
		die("unable to start 'show' for object '%s'",
		    sha1_to_hex(object));

	/* Open the output as FILE* so strbuf_getline() can be used. */
	show_out = xfdopen(show.out, "r");
	if (show_out == NULL)
		die_errno("can't fdopen 'show' output fd");

	/* Prepend "# " to each output line and write result to 'fd' */
	while (strbuf_getline(&buf, show_out, '\n') != EOF) {
		write_or_die(fd, "# ", 2);
		write_or_die(fd, buf.buf, buf.len);
		write_or_die(fd, "\n", 1);
	}
	strbuf_release(&buf);
	if (fclose(show_out))
		die_errno("failed to close pipe to 'show' for object '%s'",
			  sha1_to_hex(object));
	if (finish_command(&show))
		die("failed to finish 'show' for object '%s'",
		    sha1_to_hex(object));
}

static void create_note(const unsigned char *object, struct msg_arg *msg,
			int append_only, const unsigned char *prev,
			unsigned char *result)
{
	char *path = NULL;

	if (msg->use_editor || !msg->given) {
		int fd;

		/* write the template message before editing: */
		path = git_pathdup("NOTES_EDITMSG");
		fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
		if (fd < 0)
			die_errno("could not create file '%s'", path);

		if (msg->given)
			write_or_die(fd, msg->buf.buf, msg->buf.len);
		else if (prev && !append_only)
			write_note_data(fd, prev);
		write_or_die(fd, note_template, strlen(note_template));

		write_commented_object(fd, object);

		close(fd);
		strbuf_reset(&(msg->buf));

		if (launch_editor(path, &(msg->buf), NULL)) {
			die("Please supply the note contents using either -m" \
			    " or -F option");
		}
		stripspace(&(msg->buf), 1);
	}

	if (prev && append_only) {
		/* Append buf to previous note contents */
		unsigned long size;
		enum object_type type;
		char *prev_buf = read_sha1_file(prev, &type, &size);

		strbuf_grow(&(msg->buf), size + 1);
		if (msg->buf.len && prev_buf && size)
			strbuf_insert(&(msg->buf), 0, "\n", 1);
		if (prev_buf && size)
			strbuf_insert(&(msg->buf), 0, prev_buf, size);
		free(prev_buf);
	}

	if (!msg->buf.len) {
		fprintf(stderr, "Removing note for object %s\n",
			sha1_to_hex(object));
		hashclr(result);
	} else {
		if (write_sha1_file(msg->buf.buf, msg->buf.len, blob_type, result)) {
			error("unable to write note object");
			if (path)
				error("The note contents has been left in %s",
				      path);
			exit(128);
		}
	}

	if (path) {
		unlink_or_warn(path);
		free(path);
	}
}

static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
{
	struct msg_arg *msg = opt->value;

	if (!arg)
		return -1;

	strbuf_grow(&(msg->buf), strlen(arg) + 2);
	if (msg->buf.len)
		strbuf_addstr(&(msg->buf), "\n");
	strbuf_addstr(&(msg->buf), arg);
	stripspace(&(msg->buf), 0);

	msg->given = 1;
	return 0;
}

static int parse_file_arg(const struct option *opt, const char *arg, int unset)
{
	struct msg_arg *msg = opt->value;

	if (!arg)
		return -1;

	if (msg->buf.len)
		strbuf_addstr(&(msg->buf), "\n");
	if (!strcmp(arg, "-")) {
		if (strbuf_read(&(msg->buf), 0, 1024) < 0)
			die_errno("cannot read '%s'", arg);
	} else if (strbuf_read_file(&(msg->buf), arg, 1024) < 0)
		die_errno("could not open or read '%s'", arg);
	stripspace(&(msg->buf), 0);

	msg->given = 1;
	return 0;
}

static int parse_reuse_arg(const struct option *opt, const char *arg, int unset)
{
	struct msg_arg *msg = opt->value;
	char *buf;
	unsigned char object[20];
	enum object_type type;
	unsigned long len;

	if (!arg)
		return -1;

	if (msg->buf.len)
		strbuf_addstr(&(msg->buf), "\n");

	if (get_sha1(arg, object))
		die("Failed to resolve '%s' as a valid ref.", arg);
	if (!(buf = read_sha1_file(object, &type, &len)) || !len) {
		free(buf);
		die("Failed to read object '%s'.", arg);;
	}
	strbuf_add(&(msg->buf), buf, len);
	free(buf);

	msg->given = 1;
	return 0;
}

static int parse_reedit_arg(const struct option *opt, const char *arg, int unset)
{
	struct msg_arg *msg = opt->value;
	msg->use_editor = 1;
	return parse_reuse_arg(opt, arg, unset);
}

int commit_notes(struct notes_tree *t, const char *msg)
{
	struct commit_list *parent;
	unsigned char tree_sha1[20], prev_commit[20], new_commit[20];
	struct strbuf buf = STRBUF_INIT;

	if (!t)
		t = &default_notes_tree;
	if (!t->initialized || !t->ref || !*t->ref)
		die("Cannot commit uninitialized/unreferenced notes tree");

	/* Prepare commit message and reflog message */
	strbuf_addstr(&buf, "notes: "); /* commit message starts at index 7 */
	strbuf_addstr(&buf, msg);
	if (buf.buf[buf.len - 1] != '\n')
		strbuf_addch(&buf, '\n'); /* Make sure msg ends with newline */

	/* Convert notes tree to tree object */
	if (write_notes_tree(t, tree_sha1))
		die("Failed to write current notes tree to database");

	/* Create new commit for the tree object */
	if (!read_ref(t->ref, prev_commit)) { /* retrieve parent commit */
		parent = xmalloc(sizeof(*parent));
		parent->item = lookup_commit(prev_commit);
		parent->next = NULL;
	} else {
		hashclr(prev_commit);
		parent = NULL;
	}
	if (commit_tree(buf.buf + 7, tree_sha1, parent, new_commit, NULL))
		die("Failed to commit notes tree to database");

	/* Update notes ref with new commit */
	update_ref(buf.buf, t->ref, new_commit, prev_commit, 0, DIE_ON_ERR);

	strbuf_release(&buf);
	return 0;
}

int cmd_notes(int argc, const char **argv, const char *prefix)
{
	struct notes_tree *t;
	unsigned char object[20], from_obj[20], new_note[20];
	const unsigned char *note;
	const char *object_ref;
	char logmsg[100];

	int list = 0, add = 0, copy = 0, append = 0, edit = 0, show = 0,
	    remove = 0, prune = 0, force = 0;
	int given_object = 0, i = 1, retval = 0;
	struct msg_arg msg = { 0, 0, STRBUF_INIT };
	struct option options[] = {
		OPT_GROUP("Notes options"),
		OPT_CALLBACK('m', "message", &msg, "MSG",
			     "note contents as a string", parse_msg_arg),
		OPT_CALLBACK('F', "file", &msg, "FILE",
			     "note contents in a file", parse_file_arg),
		OPT_CALLBACK('c', "reedit-message", &msg, "OBJECT",
			   "reuse and edit specified note object", parse_reedit_arg),
		OPT_CALLBACK('C', "reuse-message", &msg, "OBJECT",
			   "reuse specified note object", parse_reuse_arg),
		OPT_BOOLEAN('f', "force", &force, "replace existing notes"),
		OPT_END()
	};

	git_config(git_default_config, NULL);

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

	if (argc && !strcmp(argv[0], "list"))
		list = 1;
	else if (argc && !strcmp(argv[0], "add"))
		add = 1;
	else if (argc && !strcmp(argv[0], "copy"))
		copy = 1;
	else if (argc && !strcmp(argv[0], "append"))
		append = 1;
	else if (argc && !strcmp(argv[0], "edit"))
		edit = 1;
	else if (argc && !strcmp(argv[0], "show"))
		show = 1;
	else if (argc && !strcmp(argv[0], "remove"))
		remove = 1;
	else if (argc && !strcmp(argv[0], "prune"))
		prune = 1;
	else if (!argc) {
		list = 1; /* Default to 'list' if no other subcommand given */
		i = 0;
	}

	if (list + add + copy + append + edit + show + remove + prune != 1)
		usage_with_options(git_notes_usage, options);

	if (msg.given && !(add || append || edit)) {
		error("cannot use -m/-F/-c/-C options with %s subcommand.",
		      argv[0]);
		usage_with_options(git_notes_usage, options);
	}

	if (msg.given && edit) {
		fprintf(stderr, "The -m/-F/-c/-C options have been deprecated "
			"for the 'edit' subcommand.\n"
			"Please use 'git notes add -f -m/-F/-c/-C' instead.\n");
	}

	if (force && !(add || copy)) {
		error("cannot use -f option with %s subcommand.", argv[0]);
		usage_with_options(git_notes_usage, options);
	}

	if (copy) {
		const char *from_ref;
		if (argc < 3) {
			error("too few parameters");
			usage_with_options(git_notes_usage, options);
		}
		from_ref = argv[i++];
		if (get_sha1(from_ref, from_obj))
			die("Failed to resolve '%s' as a valid ref.", from_ref);
	}

	given_object = argc > i;
	object_ref = given_object ? argv[i++] : "HEAD";

	if (argc > i || (prune && given_object)) {
		error("too many parameters");
		usage_with_options(git_notes_usage, options);
	}

	if (get_sha1(object_ref, object))
		die("Failed to resolve '%s' as a valid ref.", object_ref);

	init_notes(NULL, NULL, NULL, 0);
	t = &default_notes_tree;

	if (prefixcmp(t->ref, "refs/notes/"))
		die("Refusing to %s notes in %s (outside of refs/notes/)",
		    argv[0], t->ref);

	note = get_note(t, object);

	/* list command */

	if (list) {
		if (given_object) {
			if (note) {
				puts(sha1_to_hex(note));
				goto end;
			}
		} else {
			retval = for_each_note(t, 0, list_each_note, NULL);
			goto end;
		}
	}

	/* show command */

	if ((list || show) && !note) {
		error("No note found for object %s.", sha1_to_hex(object));
		retval = 1;
		goto end;
	} else if (show) {
		const char *show_args[3] = {"show", sha1_to_hex(note), NULL};
		retval = execv_git_cmd(show_args);
		goto end;
	}

	/* add/append/edit/remove/prune command */

	if ((add || copy) && note) {
		if (!force) {
			error("Cannot %s notes. Found existing notes for object"
			      " %s. Use '-f' to overwrite existing notes",
			      argv[0], sha1_to_hex(object));
			retval = 1;
			goto end;
		}
		fprintf(stderr, "Overwriting existing notes for object %s\n",
			sha1_to_hex(object));
	}

	if (remove) {
		msg.given = 1;
		msg.use_editor = 0;
		strbuf_reset(&(msg.buf));
	}

	if (prune) {
		hashclr(new_note);
		prune_notes(t);
		goto commit;
	} else if (copy) {
		const unsigned char *from_note = get_note(t, from_obj);
		if (!from_note) {
			error("Missing notes on source object %s. Cannot copy.",
			      sha1_to_hex(from_obj));
			retval = 1;
			goto end;
		}
		hashcpy(new_note, from_note);
	} else
		create_note(object, &msg, append, note, new_note);

	if (is_null_sha1(new_note))
		remove_note(t, object);
	else
		add_note(t, object, new_note, combine_notes_overwrite);

commit:
	snprintf(logmsg, sizeof(logmsg), "Notes %s by 'git notes %s'",
		 is_null_sha1(new_note) ? "removed" : "added", argv[0]);
	commit_notes(t, logmsg);

end:
	free_notes(t);
	strbuf_release(&(msg.buf));
	return retval;
}