From c82544458231694c197b0c967f6e2844e8612bc6 Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Fri, 29 Aug 2008 09:39:08 +0200 Subject: tag: try not to reallocate tag.items in every add() call If many tag_items are added at once while the tag cache is being loaded, manage these items in a static fixed list, instead of reallocating the list with every newly created item. This reduces heap fragmentation. Massif results again: mk before: total 12,837,632; useful 10,626,383; extra 2,211,249 mk now: total 12,736,720; useful 10,626,383; extra 2,110,337 The "useful" value is the same since this patch only changes the way we allocate the same amount of memory, but heap fragmentation was reduced by 5%. --- src/song.c | 20 ++++++++++++++++---- src/tag.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- src/tag.h | 16 +++++++++++++++- 3 files changed, 91 insertions(+), 7 deletions(-) diff --git a/src/song.c b/src/song.c index deba96ada..063b0a7b6 100644 --- a/src/song.c +++ b/src/song.c @@ -239,9 +239,12 @@ void readSongInfoIntoList(FILE * fp, SongList * list, Directory * parentDir) while (myFgets(buffer, bufferSize, fp) && 0 != strcmp(SONG_END, buffer)) { if (0 == strncmp(SONG_KEY, buffer, strlen(SONG_KEY))) { - if (song) + if (song) { insertSongIntoList(list, &nextSongNode, song->url, song); + if (song->tag != NULL) + tag_end_add(song->tag); + } song = newNullSong(); song->url = xstrdup(buffer + strlen(SONG_KEY)); @@ -256,15 +259,21 @@ void readSongInfoIntoList(FILE * fp, SongList * list, Directory * parentDir) song->url = xstrdup(&(buffer[strlen(SONG_FILE)])); */ } else if (matchesAnMpdTagItemKey(buffer, &itemType)) { - if (!song->tag) + if (!song->tag) { song->tag = tag_new(); + tag_begin_add(song->tag); + } + tag_add_item(song->tag, itemType, &(buffer [strlen(mpdTagItemKeys[itemType]) + 2])); } else if (0 == strncmp(SONG_TIME, buffer, strlen(SONG_TIME))) { - if (!song->tag) + if (!song->tag) { song->tag = tag_new(); + tag_begin_add(song->tag); + } + song->tag->time = atoi(&(buffer[strlen(SONG_TIME)])); } else if (0 == strncmp(SONG_MTIME, buffer, strlen(SONG_MTIME))) { song->mtime = atoi(&(buffer[strlen(SONG_MTIME)])); @@ -273,8 +282,11 @@ void readSongInfoIntoList(FILE * fp, SongList * list, Directory * parentDir) FATAL("songinfo: unknown line in db: %s\n", buffer); } - if (song) + if (song) { insertSongIntoList(list, &nextSongNode, song->url, song); + if (song->tag != NULL) + tag_end_add(song->tag); + } while (nextSongNode) { nodeTemp = nextSongNode->nextNode; diff --git a/src/tag.c b/src/tag.c index e5d49df3e..b0e3e8618 100644 --- a/src/tag.c +++ b/src/tag.c @@ -361,6 +361,53 @@ static inline const char *fix_utf8(const char *str, size_t *length_r) { return temp; } +/** + * Maximum number of items managed in the bulk list; if it is + * exceeded, we switch back to "normal" reallocation. + */ +#define BULK_MAX 64 + +static struct { +#ifndef NDEBUG + int busy; +#endif + struct tag_item *items[BULK_MAX]; +} bulk; + +void tag_begin_add(struct mpd_tag *tag) +{ + assert(!bulk.busy); + assert(tag != NULL); + assert(tag->items == NULL); + assert(tag->numOfItems == 0); + +#ifndef NDEBUG + bulk.busy = 1; +#endif + tag->items = bulk.items; +} + +void tag_end_add(struct mpd_tag *tag) +{ + if (tag->items == bulk.items) { + assert(tag->numOfItems <= BULK_MAX); + + if (tag->numOfItems > 0) { + /* copy the tag items from the bulk list over + to a new list (which fits exactly) */ + tag->items = xmalloc(tag->numOfItems * + sizeof(tag->items[0])); + memcpy(tag->items, bulk.items, + tag->numOfItems * sizeof(tag->items[0])); + } else + tag->items = NULL; + } + +#ifndef NDEBUG + bulk.busy = 0; +#endif +} + static void appendToTagItems(struct mpd_tag *tag, enum tag_type type, const char *value, size_t len) { @@ -380,8 +427,19 @@ static void appendToTagItems(struct mpd_tag *tag, enum tag_type type, } tag->numOfItems++; - tag->items = xrealloc(tag->items, - tag->numOfItems * sizeof(*tag->items)); + + if (tag->items != bulk.items) + /* bulk mode disabled */ + tag->items = xrealloc(tag->items, + tag->numOfItems * sizeof(*tag->items)); + else if (tag->numOfItems >= BULK_MAX) { + /* bulk list already full - switch back to non-bulk */ + assert(bulk.busy); + + tag->items = xmalloc(tag->numOfItems * sizeof(tag->items[0])); + memcpy(tag->items, bulk.items, + (tag->numOfItems - 1) * sizeof(tag->items[0])); + } tag->items[i] = tag_pool_get_item(type, p, len); diff --git a/src/tag.h b/src/tag.h index 6ca48affa..44c680a98 100644 --- a/src/tag.h +++ b/src/tag.h @@ -61,8 +61,22 @@ void tag_clear_items_by_type(struct mpd_tag *tag, enum tag_type itemType); void tag_free(struct mpd_tag *tag); +/** + * Gives an optional hint to the tag library that we will now add + * several tag items; this is used by the library to optimize memory + * allocation. Only one tag may be in this state, and this tag must + * not have any items yet. You must call tag_end_add() when you are + * done. + */ +void tag_begin_add(struct mpd_tag *tag); + +/** + * Finishes the operation started with tag_begin_add(). + */ +void tag_end_add(struct mpd_tag *tag); + void tag_add_item_n(struct mpd_tag *tag, enum tag_type itemType, - const char *value, size_t len); + const char *value, size_t len); static inline void tag_add_item(struct mpd_tag *tag, enum tag_type itemType, const char *value) -- cgit v1.2.3