Quoth Jani Nikula on Nov 09 at 8:46 am: > > FWIW, I reviewed this and didn't find any obvious problems. A few > nitpicks below, though. > > BR, > Jani. > > On Mon, 7 Nov 2011 22:55:23 -0500, Austin Clements <amdragon@MIT.EDU> wrote: > > This optimizes the user's tagging query to exclude messages that won't > > be affected by the tagging operation, saving computation and IO for > > redundant tagging operations. > > > > For example, > > notmuch tag +notmuch to:notmuch@notmuchmail.org > > will now use the query > > ( to:notmuch@notmuchmail.org ) and (not tag:"notmuch") > > > > In the past, we've often suggested that people do this exact > > transformation by hand for slow tagging operations. This makes that > > unnecessary. > > --- > > I was about to implement this optimization in my initial tagging > > script, but then I figured, why not just do it in notmuch so we can > > stop telling people to do this by hand? > > > > NEWS | 9 ++++++ > > notmuch-tag.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 85 insertions(+), 0 deletions(-) > > > > diff --git a/NEWS b/NEWS > > index e00452a..9ca5e0c 100644 > > --- a/NEWS > > +++ b/NEWS > > @@ -16,6 +16,15 @@ Add search terms to "notmuch dump" > > search/show/tag. The output file argument of dump is deprecated in > > favour of using stdout. > > > > +Optimizations > > +------------- > > + > > +Automatic tag query optimization > > + > > + "notmuch tag" now automatically optimizes the user's query to > > + exclude messages whose tags won't change. In the past, we've > > + suggested that people do this by hand; this is no longer necessary. > > + > > Notmuch 0.9 (2011-10-01) > > ======================== > > > > diff --git a/notmuch-tag.c b/notmuch-tag.c > > index dded39e..62c4bf1 100644 > > --- a/notmuch-tag.c > > +++ b/notmuch-tag.c > > @@ -30,6 +30,76 @@ handle_sigint (unused (int sig)) > > interrupted = 1; > > } > > > > +static char * > > +_escape_tag (char *buf, const char *tag) > > +{ > > + const char *in = tag; > > + char *out = buf; > > + /* Boolean terms surrounded by double quotes can contain any > > + * character. Double quotes are quoted by doubling them. */ > > + *(out++) = '"'; > > + while (*in) { > > + if (*in == '"') > > + *(out++) = '"'; > > + *(out++) = *(in++); > > + } > > + *(out++) = '"'; > > The parenthesis are unnecessary for *p++. Removed. I put these in out of paranoia, but I suppose it wouldn't be an lvalue if it parsed differently. > > + *out = 0; > > + return buf; > > +} > > + > > +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) > > +{ > > + /* This is subtler than it looks. Xapian ignores the '-' operator > > + * at the beginning both queries and parenthesized groups and, > > + * furthermore, the presence of a '-' operator at the beginning of > > + * a group can inhibit parsing of the previous operator. Hence, > > + * the user-provided query MUST appear first, but it is safe to > > + * parenthesize and the exclusion part of the query must not use > > + * the '-' operator (though the NOT operator is fine). */ > > + > > + char *escaped, *query_string; > > + const char *join = ""; > > + int i; > > + unsigned int max_tag_len = 0; > > + > > + /* Allocate a buffer for escaping tags. */ > > + 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); > > + escaped = talloc_array(ctx, char, max_tag_len * 2 + 3); > > Perhaps a comment here or above _escape_tag() explaining the worst case > memory consumption of strlen(tag) * 2 + 3 for a tag of "s would be in > order. Definitely. Done. > It's unrelated, but looking at the above also made me check something > I've suspected before: notmuch allows you to have empty or zero length > tags "", which is probably not intentional. > > There's no check for talloc failures here or below. But then there are > few checks for that in the cli in general. *shrug*. It's unfortunate that error handling obscures C code so much. But there's no sense in not handling errors, so I fixed this. > > + > > + /* Build the new query string */ > > + if (strcmp (orig_query_string, "*") == 0) > > + query_string = talloc_strdup (ctx, "("); > > + else > > + query_string = talloc_asprintf (ctx, "( %s ) and (", orig_query_string); > > + > > + for (i = 0; i < add_tags_count; 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; i++) { > > + query_string = talloc_asprintf_append_buffer ( > > + query_string, "%stag:%s", join, > > + _escape_tag (escaped, argv[remove_tags[i]] + 1)); > > + join = " or "; > > + } > > + > > + query_string = talloc_strdup_append_buffer (query_string, ")"); > > + > > + talloc_free (escaped); > > + return query_string; > > +} > > + > > int > > notmuch_tag_command (void *ctx, unused (int argc), unused (char *argv[])) > > { > > @@ -93,6 +163,12 @@ notmuch_tag_command (void *ctx, unused (int argc), unused (char *argv[])) > > return 1; > > } > > > > + /* 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); > > + > > config = notmuch_config_open (ctx, NULL, NULL); > > if (config == NULL) > > return 1;