Optimize thread search using matched docid sets.

This reduces thread search's 1+2t Xapian queries (where t is the
number of matched threads) to 1+t queries and constructs exactly one
notmuch_message_t for each message instead of 2 to 3.
notmuch_query_search_threads eagerly fetches the docids of all
messages matching the user query instead of lazily constructing
message objects and fetching thread ID's from term lists.
_notmuch_thread_create takes a seed docid and the set of all matched
docids and uses a single Xapian query to expand this docid to its
containing thread, using the matched docid set to determine which
messages in the thread match the user query instead of using a second
Xapian query.

This reduces the amount of time required to load my inbox from 4.523
seconds to 3.025 seconds (1.5X faster).
This commit is contained in:
Austin Clements 2010-11-17 14:28:26 -05:00 committed by Carl Worth
parent e255654232
commit b3caef1f06
4 changed files with 155 additions and 113 deletions

View file

@ -254,6 +254,12 @@ _notmuch_message_create_for_message_id (notmuch_database_t *notmuch,
return message;
}
unsigned int
_notmuch_message_get_doc_id (notmuch_message_t *message)
{
return message->doc_id;
}
const char *
notmuch_message_get_message_id (notmuch_message_t *message)
{

View file

@ -156,6 +156,8 @@ typedef enum _notmuch_private_status {
: \
(notmuch_status_t) private_status)
typedef struct _notmuch_doc_id_set notmuch_doc_id_set_t;
/* database.cc */
/* Lookup a prefix value by name.
@ -222,8 +224,8 @@ _notmuch_directory_get_document_id (notmuch_directory_t *directory);
notmuch_thread_t *
_notmuch_thread_create (void *ctx,
notmuch_database_t *notmuch,
const char *thread_id,
const char *query_string,
unsigned int seed_doc_id,
notmuch_doc_id_set_t *match_set,
notmuch_sort_t sort);
/* message.cc */
@ -239,6 +241,9 @@ _notmuch_message_create_for_message_id (notmuch_database_t *notmuch,
const char *message_id,
notmuch_private_status_t *status);
unsigned int
_notmuch_message_get_doc_id (notmuch_message_t *message);
const char *
_notmuch_message_get_in_reply_to (notmuch_message_t *message);
@ -426,6 +431,14 @@ _notmuch_mset_messages_get (notmuch_messages_t *messages);
void
_notmuch_mset_messages_move_to_next (notmuch_messages_t *messages);
notmuch_bool_t
_notmuch_doc_id_set_contains (notmuch_doc_id_set_t *doc_ids,
unsigned int doc_id);
void
_notmuch_doc_id_set_remove (notmuch_doc_id_set_t *doc_ids,
unsigned int doc_id);
/* message.cc */
void

View file

@ -36,13 +36,21 @@ typedef struct _notmuch_mset_messages {
Xapian::MSetIterator iterator_end;
} notmuch_mset_messages_t;
struct _notmuch_doc_id_set {
unsigned int *bitmap;
unsigned int bound;
};
struct _notmuch_threads {
notmuch_query_t *query;
GHashTable *threads;
notmuch_messages_t *messages;
/* This thread ID is our iterator state. */
const char *thread_id;
/* The ordered list of doc ids matched by the query. */
GArray *doc_ids;
/* Our iterator's current position in doc_ids. */
unsigned int doc_id_pos;
/* The set of matched docid's that have not been assigned to a
* thread. Initially, this contains every docid in doc_ids. */
notmuch_doc_id_set_t match_set;
};
notmuch_query_t *
@ -195,6 +203,19 @@ _notmuch_mset_messages_valid (notmuch_messages_t *messages)
return (mset_messages->iterator != mset_messages->iterator_end);
}
static Xapian::docid
_notmuch_mset_messages_get_doc_id (notmuch_messages_t *messages)
{
notmuch_mset_messages_t *mset_messages;
mset_messages = (notmuch_mset_messages_t *) messages;
if (! _notmuch_mset_messages_valid (&mset_messages->base))
return 0;
return *mset_messages->iterator;
}
notmuch_message_t *
_notmuch_mset_messages_get (notmuch_messages_t *messages)
{
@ -233,6 +254,49 @@ _notmuch_mset_messages_move_to_next (notmuch_messages_t *messages)
mset_messages->iterator++;
}
static notmuch_bool_t
_notmuch_doc_id_set_init (void *ctx,
notmuch_doc_id_set_t *doc_ids,
GArray *arr, unsigned int bound)
{
size_t count = (bound + sizeof (doc_ids->bitmap[0]) - 1) /
sizeof (doc_ids->bitmap[0]);
unsigned int *bitmap = talloc_zero_array (ctx, unsigned int, count);
if (bitmap == NULL)
return FALSE;
doc_ids->bitmap = bitmap;
doc_ids->bound = bound;
for (unsigned int i = 0; i < arr->len; i++) {
unsigned int doc_id = g_array_index(arr, unsigned int, i);
bitmap[doc_id / sizeof (bitmap[0])] |=
1 << (doc_id % sizeof (bitmap[0]));
}
return TRUE;
}
notmuch_bool_t
_notmuch_doc_id_set_contains (notmuch_doc_id_set_t *doc_ids,
unsigned int doc_id)
{
if (doc_id >= doc_ids->bound)
return FALSE;
return (doc_ids->bitmap[doc_id / sizeof (doc_ids->bitmap[0])] &
(1 << (doc_id % sizeof (doc_ids->bitmap[0])))) != 0;
}
void
_notmuch_doc_id_set_remove (notmuch_doc_id_set_t *doc_ids,
unsigned int doc_id)
{
if (doc_id < doc_ids->bound)
doc_ids->bitmap[doc_id / sizeof (doc_ids->bitmap[0])] &=
~(1 << (doc_id % sizeof (doc_ids->bitmap[0])));
}
/* Glib objects force use to use a talloc destructor as well, (but not
* nearly as ugly as the for messages due to C++ objects). At
* this point, I'd really like to have some talloc-friendly
@ -240,7 +304,8 @@ _notmuch_mset_messages_move_to_next (notmuch_messages_t *messages)
static int
_notmuch_threads_destructor (notmuch_threads_t *threads)
{
g_hash_table_unref (threads->threads);
if (threads->doc_ids)
g_array_unref (threads->doc_ids);
return 0;
}
@ -249,24 +314,39 @@ notmuch_threads_t *
notmuch_query_search_threads (notmuch_query_t *query)
{
notmuch_threads_t *threads;
notmuch_messages_t *messages;
Xapian::docid max_doc_id = 0;
threads = talloc (query, notmuch_threads_t);
if (threads == NULL)
return NULL;
threads->doc_ids = NULL;
talloc_set_destructor (threads, _notmuch_threads_destructor);
threads->query = query;
threads->threads = g_hash_table_new_full (g_str_hash, g_str_equal,
free, NULL);
threads->messages = notmuch_query_search_messages (query);
if (threads->messages == NULL) {
messages = notmuch_query_search_messages (query);
if (messages == NULL) {
talloc_free (threads);
return NULL;
}
threads->thread_id = NULL;
threads->doc_ids = g_array_new (FALSE, FALSE, sizeof (unsigned int));
while (notmuch_messages_valid (messages)) {
unsigned int doc_id = _notmuch_mset_messages_get_doc_id (messages);
g_array_append_val (threads->doc_ids, doc_id);
max_doc_id = MAX (max_doc_id, doc_id);
notmuch_messages_move_to_next (messages);
}
threads->doc_id_pos = 0;
talloc_set_destructor (threads, _notmuch_threads_destructor);
talloc_free (messages);
if (! _notmuch_doc_id_set_init (threads, &threads->match_set,
threads->doc_ids, max_doc_id + 1)) {
talloc_free (threads);
return NULL;
}
return threads;
}
@ -280,51 +360,41 @@ notmuch_query_destroy (notmuch_query_t *query)
notmuch_bool_t
notmuch_threads_valid (notmuch_threads_t *threads)
{
notmuch_message_t *message;
unsigned int doc_id;
if (threads->thread_id)
return TRUE;
while (threads->doc_id_pos < threads->doc_ids->len) {
doc_id = g_array_index (threads->doc_ids, unsigned int,
threads->doc_id_pos);
if (_notmuch_doc_id_set_contains (&threads->match_set, doc_id))
break;
while (notmuch_messages_valid (threads->messages))
{
message = notmuch_messages_get (threads->messages);
threads->thread_id = notmuch_message_get_thread_id (message);
if (! g_hash_table_lookup_extended (threads->threads,
threads->thread_id,
NULL, NULL))
{
g_hash_table_insert (threads->threads,
xstrdup (threads->thread_id), NULL);
notmuch_messages_move_to_next (threads->messages);
return TRUE;
}
notmuch_messages_move_to_next (threads->messages);
threads->doc_id_pos++;
}
threads->thread_id = NULL;
return FALSE;
return threads->doc_id_pos < threads->doc_ids->len;
}
notmuch_thread_t *
notmuch_threads_get (notmuch_threads_t *threads)
{
unsigned int doc_id;
if (! notmuch_threads_valid (threads))
return NULL;
doc_id = g_array_index (threads->doc_ids, unsigned int,
threads->doc_id_pos);
return _notmuch_thread_create (threads->query,
threads->query->notmuch,
threads->thread_id,
threads->query->query_string,
doc_id,
&threads->match_set,
threads->query->sort);
}
void
notmuch_threads_move_to_next (notmuch_threads_t *threads)
{
threads->thread_id = NULL;
threads->doc_id_pos++;
}
void

View file

@ -371,16 +371,17 @@ _resolve_thread_relationships (unused (notmuch_thread_t *thread))
*/
}
/* Create a new notmuch_thread_t object for the given thread ID,
* treating any messages matching 'query_string' as "matched".
/* Create a new notmuch_thread_t object by finding the thread
* containing the message with the given doc ID, treating any messages
* contained in match_set as "matched". Remove all messages in the
* thread from match_set.
*
* Creating the thread will trigger two database searches. The first
* is for all messages belonging to the thread, (to get the first
* subject line, the total count of messages, and all authors). The
* second search is for all messages that are in the thread and that
* also match the given query_string. This is to allow for a separate
* count of matched messages, and to allow a viewer to display these
* messages differently.
* Creating the thread will perform a database search to get all
* messages belonging to the thread and will get the first subject
* line, the total count of messages, and all authors in the thread.
* Each message in the thread is checked against match_set to allow
* for a separate count of matched messages, and to allow a viewer to
* display these messages differently.
*
* Here, 'ctx' is talloc context for the resulting thread object.
*
@ -389,53 +390,28 @@ _resolve_thread_relationships (unused (notmuch_thread_t *thread))
notmuch_thread_t *
_notmuch_thread_create (void *ctx,
notmuch_database_t *notmuch,
const char *thread_id,
const char *query_string,
unsigned int seed_doc_id,
notmuch_doc_id_set_t *match_set,
notmuch_sort_t sort)
{
notmuch_thread_t *thread;
notmuch_message_t *seed_message;
const char *thread_id;
const char *thread_id_query_string;
notmuch_query_t *thread_id_query;
notmuch_messages_t *messages;
notmuch_message_t *message;
notmuch_bool_t matched_is_subset_of_thread;
seed_message = _notmuch_message_create (ctx, notmuch, seed_doc_id, NULL);
if (! seed_message)
INTERNAL_ERROR ("Thread seed message %u does not exist", seed_doc_id);
thread_id = notmuch_message_get_thread_id (seed_message);
thread_id_query_string = talloc_asprintf (ctx, "thread:%s", thread_id);
if (unlikely (query_string == NULL))
if (unlikely (thread_id_query_string == NULL))
return NULL;
/* Under normal circumstances we need to do two database
* queries. One is for the thread itself (thread_id_query_string)
* and the second is to determine which messages in that thread
* match the original query (matched_query_string).
*
* But under two circumstances, we use only the
* thread_id_query_string:
*
* 1. If the original query_string *is* just the thread
* specification.
*
* 2. If the original query_string matches all messages ("" or
* "*").
*
* In either of these cases, we can be more efficient by running
* just the thread_id query (since we know all messages in the
* thread will match the query_string).
*
* Beyond the performance advantage, in the second case, it's
* important to not try to create a concatenated query because our
* parser handles "" and "*" as special cases and will not do the
* right thing with a query string of "* and thread:<foo>".
**/
matched_is_subset_of_thread = 1;
if (strcmp (query_string, thread_id_query_string) == 0 ||
strcmp (query_string, "") == 0 ||
strcmp (query_string, "*") == 0)
{
matched_is_subset_of_thread = 0;
}
thread_id_query = notmuch_query_create (notmuch, thread_id_query_string);
if (unlikely (thread_id_query == NULL))
return NULL;
@ -482,48 +458,25 @@ _notmuch_thread_create (void *ctx,
notmuch_messages_valid (messages);
notmuch_messages_move_to_next (messages))
{
unsigned int doc_id;
message = notmuch_messages_get (messages);
doc_id = _notmuch_message_get_doc_id (message);
if (doc_id == seed_doc_id)
message = seed_message;
_thread_add_message (thread, message);
if (! matched_is_subset_of_thread)
if ( _notmuch_doc_id_set_contains (match_set, doc_id)) {
_notmuch_doc_id_set_remove (match_set, doc_id);
_thread_add_matched_message (thread, message, sort);
}
_notmuch_message_close (message);
}
notmuch_query_destroy (thread_id_query);
if (matched_is_subset_of_thread)
{
const char *matched_query_string;
notmuch_query_t *matched_query;
matched_query_string = talloc_asprintf (ctx, "%s AND (%s)",
thread_id_query_string,
query_string);
if (unlikely (matched_query_string == NULL))
return NULL;
matched_query = notmuch_query_create (notmuch, matched_query_string);
if (unlikely (matched_query == NULL))
return NULL;
/* As above, we use oldest-first order unconditionally here. */
notmuch_query_set_sort (matched_query, NOTMUCH_SORT_OLDEST_FIRST);
for (messages = notmuch_query_search_messages (matched_query);
notmuch_messages_valid (messages);
notmuch_messages_move_to_next (messages))
{
message = notmuch_messages_get (messages);
_thread_add_matched_message (thread, message, sort);
_notmuch_message_close (message);
}
notmuch_query_destroy (matched_query);
}
_resolve_thread_authors_string (thread);
_resolve_thread_relationships (thread);