Builtin-ify git-notes

The builtin-ification includes some minor behavioural changes to the
command-line interface: It is no longer allowed to mix the -m and -F
arguments, and it is not allowed to use multiple -F options.

As part of the builtin-ification, we add the commit_notes() function
to the builtin API. This function (together with the notes.h API) can
be easily used from other builtins to manipulate the notes tree.

Also includes needed changes to t3301.

This patch has been improved by the following contributions:
- Stephen Boyd: Use die() instead of fprintf(stderr, ...) followed by exit(1)

Cc: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 280 insertions, 0 deletions

diff --git a/builtin-notes.c b/builtin-notes.c
new file mode 100644
index 0000000000..89aa6e072e
--- /dev/null
+++ b/builtin-notes.c
@@ -0,0 +1,280 @@
+/*
+ * 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 edit [-m <msg> | -F <file>] [<object>]",
+	"git notes show [<object>]",
+	NULL
+};
+
+static const char note_template[] =
+	"\n"
+	"#\n"
+	"# Write/edit the notes for the following object:\n"
+	"#\n";
+
+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 strbuf *buf,
+			int skip_editor,
+			const unsigned char *prev,
+			unsigned char *result)
+{
+	char *path = NULL;
+
+	if (!skip_editor) {
+		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 (prev)
+			write_note_data(fd, prev);
+		write_or_die(fd, note_template, strlen(note_template));
+
+		write_commented_object(fd, object);
+
+		close(fd);
+
+		if (launch_editor(path, buf, NULL)) {
+			die("Please supply the note contents using either -m" \
+			    " or -F option");
+		}
+	}
+
+	stripspace(buf, 1);
+
+	if (!skip_editor && !buf->len) {
+		fprintf(stderr, "Removing note for object %s\n",
+			sha1_to_hex(object));
+		hashclr(result);
+	} else {
+		if (write_sha1_file(buf->buf, 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);
+	}
+}
+
+struct msg_arg {
+	int given;
+	struct strbuf buf;
+};
+
+static int parse_msg_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\n");
+	strbuf_addstr(&(msg->buf), arg);
+	msg->given = 1;
+	return 0;
+}
+
+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 strbuf buf = STRBUF_INIT;
+	struct notes_tree *t;
+	unsigned char object[20], new_note[20];
+	const unsigned char *note;
+	const char *object_ref;
+	int edit = 0, show = 0;
+	const char *msgfile = NULL;
+	struct msg_arg msg = { 0, STRBUF_INIT };
+	struct option options[] = {
+		OPT_GROUP("Notes edit options"),
+		OPT_CALLBACK('m', NULL, &msg, "msg",
+			     "note contents as a string", parse_msg_arg),
+		OPT_FILENAME('F', NULL, &msgfile, "note contents in a file"),
+		OPT_END()
+	};
+
+	git_config(git_default_config, NULL);
+
+	argc = parse_options(argc, argv, prefix, options, git_notes_usage, 0);
+
+	if (argc && !strcmp(argv[0], "edit"))
+		edit = 1;
+	else if (argc && !strcmp(argv[0], "show"))
+		show = 1;
+
+	if (edit + show != 1)
+		usage_with_options(git_notes_usage, options);
+
+	object_ref = argc == 2 ? argv[1] : "HEAD";
+	if (argc > 2) {
+		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/)",
+		    edit ? "edit" : "show", t->ref);
+
+	note = get_note(t, object);
+
+	/* show command */
+
+	if (show && !note) {
+		error("No note found for object %s.", sha1_to_hex(object));
+		return 1;
+	} else if (show) {
+		const char *show_args[3] = {"show", sha1_to_hex(note), NULL};
+		return execv_git_cmd(show_args);
+	}
+
+	/* edit command */
+
+	if (msg.given || msgfile) {
+		if (msg.given && msgfile) {
+			error("mixing -m and -F options is not allowed.");
+			usage_with_options(git_notes_usage, options);
+		}
+		if (msg.given)
+			strbuf_addbuf(&buf, &(msg.buf));
+		else {
+			if (!strcmp(msgfile, "-")) {
+				if (strbuf_read(&buf, 0, 1024) < 0)
+					die_errno("cannot read '%s'", msgfile);
+			} else {
+				if (strbuf_read_file(&buf, msgfile, 1024) < 0)
+					die_errno("could not open or read '%s'",
+						msgfile);
+			}
+		}
+	}
+
+	create_note(object, &buf, msg.given || msgfile, note, new_note);
+	add_note(t, object, new_note, combine_notes_overwrite);
+	commit_notes(t, "Note added by 'git notes edit'");
+
+	free_notes(t);
+	strbuf_release(&buf);
+	return 0;
+}