[PATCH v2 1/3] cli: refactor "notmuch tag" data structures for tagging operations

[Jani Nikula]

To simplify code, keep all tagging operations in a single array
instead of separate add and remove arrays. Apply tag changes in the
order specified on the command line, instead of first removing and
then adding the tags.

This results in a minor functional change: If a tag is both added and
removed, the last specified operation is now used. Previously the tag
was always added.

Signed-off-by: Jani Nikula <jani at nikula.org>
---
 notmuch-tag.c |   79 +++++++++++++++++++++++++-------------------------------
 1 files changed, 35 insertions(+), 44 deletions(-)

diff --git a/notmuch-tag.c b/notmuch-tag.c
index 36b9b09..c39b235 100644
--- a/notmuch-tag.c
+++ b/notmuch-tag.c
@@ -53,10 +53,14 @@ _escape_tag (char *buf, const char *tag)
     return buf;
 }
 
+typedef struct {
+    const char *tag;
+    notmuch_bool_t remove;
+} tag_operation_t;
+
 static char *
-_optimize_tag_query (void *ctx, const char *orig_query_string, char *argv[],
-		     int *add_tags, int add_tags_count,
-		     int *remove_tags, int remove_tags_count)
+_optimize_tag_query (void *ctx, const char *orig_query_string,
+		     const tag_operation_t *tag_ops)
 {
     /* This is subtler than it looks.  Xapian ignores the '-' operator
      * at the beginning both queries and parenthesized groups and,
@@ -74,12 +78,9 @@ _optimize_tag_query (void *ctx, const char *orig_query_string, char *argv[],
     /* Allocate a buffer for escaping tags.  This is large enough to
      * hold a fully escaped tag with every character doubled plus
      * enclosing quotes and a NUL. */
-    for (i = 0; i < add_tags_count; i++)
-	if (strlen (argv[add_tags[i]] + 1) > max_tag_len)
-	    max_tag_len = strlen (argv[add_tags[i]] + 1);
-    for (i = 0; i < remove_tags_count; i++)
-	if (strlen (argv[remove_tags[i]] + 1) > max_tag_len)
-	    max_tag_len = strlen (argv[remove_tags[i]] + 1);
+    for (i = 0; tag_ops[i].tag; i++)
+	if (strlen (tag_ops[i].tag) > max_tag_len)
+	    max_tag_len = strlen (tag_ops[i].tag);
     escaped = talloc_array(ctx, char, max_tag_len * 2 + 3);
     if (!escaped)
 	return NULL;
@@ -90,16 +91,11 @@ _optimize_tag_query (void *ctx, const char *orig_query_string, char *argv[],
     else
 	query_string = talloc_asprintf (ctx, "( %s ) and (", orig_query_string);
 
-    for (i = 0; i < add_tags_count && query_string; i++) {
-	query_string = talloc_asprintf_append_buffer (
-	    query_string, "%snot tag:%s", join,
-	    _escape_tag (escaped, argv[add_tags[i]] + 1));
-	join = " or ";
-    }
-    for (i = 0; i < remove_tags_count && query_string; i++) {
+    for (i = 0; tag_ops[i].tag && query_string; i++) {
 	query_string = talloc_asprintf_append_buffer (
-	    query_string, "%stag:%s", join,
-	    _escape_tag (escaped, argv[remove_tags[i]] + 1));
+	    query_string, "%s%stag:%s", join,
+	    tag_ops[i].remove ? "" : "not ",
+	    _escape_tag (escaped, tag_ops[i].tag));
 	join = " or ";
     }
 
@@ -113,9 +109,8 @@ _optimize_tag_query (void *ctx, const char *orig_query_string, char *argv[],
 int
 notmuch_tag_command (void *ctx, int argc, char *argv[])
 {
-    int *add_tags, *remove_tags;
-    int add_tags_count = 0;
-    int remove_tags_count = 0;
+    tag_operation_t *tag_ops;
+    int tag_ops_count = 0;
     char *query_string;
     notmuch_config_t *config;
     notmuch_database_t *notmuch;
@@ -133,35 +128,33 @@ notmuch_tag_command (void *ctx, int argc, char *argv[])
     action.sa_flags = SA_RESTART;
     sigaction (SIGINT, &action, NULL);
 
-    add_tags = talloc_size (ctx, argc * sizeof (int));
-    if (add_tags == NULL) {
-	fprintf (stderr, "Out of memory.\n");
-	return 1;
-    }
+    argc--; argv++; /* skip subcommand argument */
 
-    remove_tags = talloc_size (ctx, argc * sizeof (int));
-    if (remove_tags == NULL) {
+    /* Array of tagging operations (add or remove), terminated with an
+     * empty element. */
+    tag_ops = talloc_array (ctx, tag_operation_t, argc + 1);
+    if (tag_ops == NULL) {
 	fprintf (stderr, "Out of memory.\n");
 	return 1;
     }
 
-    argc--; argv++; /* skip subcommand argument */
-
     for (i = 0; i < argc; i++) {
 	if (strcmp (argv[i], "--") == 0) {
 	    i++;
 	    break;
 	}
-	if (argv[i][0] == '+') {
-	    add_tags[add_tags_count++] = i;
-	} else if (argv[i][0] == '-') {
-	    remove_tags[remove_tags_count++] = i;
+	if (argv[i][0] == '+' || argv[i][0] == '-') {
+	    tag_ops[tag_ops_count].tag = argv[i] + 1;
+	    tag_ops[tag_ops_count].remove = argv[i][0] == '-';
+	    tag_ops_count++;
 	} else {
 	    break;
 	}
     }
 
-    if (add_tags_count == 0 && remove_tags_count == 0) {
+    tag_ops[tag_ops_count].tag = NULL;
+
+    if (tag_ops_count == 0) {
 	fprintf (stderr, "Error: 'notmuch tag' requires at least one tag to add or remove.\n");
 	return 1;
     }
@@ -175,9 +168,7 @@ notmuch_tag_command (void *ctx, int argc, char *argv[])
 
     /* Optimize the query so it excludes messages that already have
      * the specified set of tags. */
-    query_string = _optimize_tag_query (ctx, query_string, argv,
-					add_tags, add_tags_count,
-					remove_tags, remove_tags_count);
+    query_string = _optimize_tag_query (ctx, query_string, tag_ops);
     if (query_string == NULL) {
 	fprintf (stderr, "Out of memory.\n");
 	return 1;
@@ -211,12 +202,12 @@ notmuch_tag_command (void *ctx, int argc, char *argv[])
 
 	notmuch_message_freeze (message);
 
-	for (i = 0; i < remove_tags_count; i++)
-	    notmuch_message_remove_tag (message,
-					argv[remove_tags[i]] + 1);
-
-	for (i = 0; i < add_tags_count; i++)
-	    notmuch_message_add_tag (message, argv[add_tags[i]] + 1);
+	for (i = 0; tag_ops[i].tag; i++) {
+	    if (tag_ops[i].remove)
+		notmuch_message_remove_tag (message, tag_ops[i].tag);
+	    else
+		notmuch_message_add_tag (message, tag_ops[i].tag);
+	}
 
 	notmuch_message_thaw (message);
 
-- 
1.7.5.4