From 8fe2104a1e5771ac8079a438fa21e00f946be8b3 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Mon, 4 Sep 2006 13:59:58 -0700 Subject: [PATCH] Leave cache files mapped permanently. Without reference counting on cache objects, there's no way to know when an application is finished using objects pulled from the cache. Until some kinf of cache reference counting can be done, leave all cache objects mapped for the life of the library (until FcFini is called). To mitigate the cost of this, ensure that each instance of a cache file is mapped only once. --- src/fccache.c | 143 +++++++++++++++++++++++++++++++++++++++----------- src/fcinit.c | 1 + src/fcint.h | 3 ++ 3 files changed, 116 insertions(+), 31 deletions(-) diff --git a/src/fccache.c b/src/fccache.c index aa03990..a3a758e 100644 --- a/src/fccache.c +++ b/src/fccache.c @@ -134,7 +134,7 @@ FcDirCacheOpenFile (const FcChar8 *cache_file, struct stat *file_stat) */ static FcBool FcDirCacheProcess (FcConfig *config, const FcChar8 *dir, - FcBool (*callback) (int fd, off_t size, void *closure), + FcBool (*callback) (int fd, struct stat *stat, void *closure), void *closure, FcChar8 **cache_file_ret) { int fd = -1; @@ -162,7 +162,7 @@ FcDirCacheProcess (FcConfig *config, const FcChar8 *dir, if (fd >= 0) { if (dir_stat.st_mtime <= file_stat.st_mtime) { - ret = (*callback) (fd, file_stat.st_size, closure); + ret = (*callback) (fd, &file_stat, closure); if (ret) { if (cache_file_ret) @@ -182,26 +182,120 @@ FcDirCacheProcess (FcConfig *config, const FcChar8 *dir, return ret; } +static void +FcDirCacheDispose (FcCache *cache) +{ + switch (cache->magic) { + case FC_CACHE_MAGIC_ALLOC: + free (cache); + break; + case FC_CACHE_MAGIC_MMAP: +#if defined(HAVE_MMAP) || defined(__CYGWIN__) + munmap (cache, cache->size); +#elif defined(_WIN32) + UnmapViewOfFile (cache); +#endif + break; + } +} + #define FC_CACHE_MIN_MMAP 1024 +#define FC_CACHE_HASH_SIZE 67 + +typedef struct _FcCacheBucket FcCacheBucket; + +struct _FcCacheBucket { + FcCacheBucket *next; + FcCache *cache; + dev_t cache_dev; + ino_t cache_ino; + time_t cache_mtime; +}; + +static FcCacheBucket *FcCacheBuckets[FC_CACHE_HASH_SIZE]; + +static uint32_t +FcCacheStatHash (struct stat *cache_stat) +{ + return ((uint32_t) cache_stat->st_dev ^ + (uint32_t) cache_stat->st_ino ^ + (uint32_t) cache_stat->st_mtime); +} + +static FcCache * +FcCacheLookup (struct stat *cache_stat) +{ + uint32_t hash = FcCacheStatHash(cache_stat); + FcCacheBucket **bucket = &FcCacheBuckets[hash % FC_CACHE_HASH_SIZE]; + FcCacheBucket *b; + + for (b = *bucket; b; b = b->next) + if (b->cache_dev == cache_stat->st_dev && + b->cache_ino == cache_stat->st_ino && + b->cache_mtime == cache_stat->st_mtime) + return b->cache; + return NULL; +} + +static FcBool +FcCacheRecord (FcCache *cache, struct stat *cache_stat) +{ + uint32_t hash = FcCacheStatHash(cache_stat); + FcCacheBucket **bucket = &FcCacheBuckets[hash % FC_CACHE_HASH_SIZE]; + FcCacheBucket *b; + + b = malloc (sizeof (FcCacheBucket)); + if (!b) + return FcFalse; + b->next = *bucket; + b->cache = cache; + b->cache_dev = cache_stat->st_dev; + b->cache_ino = cache_stat->st_ino; + b->cache_mtime = cache_stat->st_mtime; + *bucket = b; + return FcTrue; +} + +void +FcCacheFini (void) +{ + int i; + FcCacheBucket *b, *next; + + for (i = 0; i < FC_CACHE_HASH_SIZE; i++) + { + for (b = FcCacheBuckets[i]; b; b = next) + { + next = b->next; + FcDirCacheDispose (b->cache); + free (b); + } + FcCacheBuckets[i] = NULL; + } +} + /* * Map a cache file into memory */ static FcCache * -FcDirCacheMapFd (int fd, off_t size) +FcDirCacheMapFd (int fd, struct stat *fd_stat) { - FcCache *cache = NULL; + FcCache *cache; FcBool allocated = FcFalse; - if (size < sizeof (FcCache)) + if (fd_stat->st_size < sizeof (FcCache)) return NULL; + cache = FcCacheLookup (fd_stat); + if (cache) + return cache; /* * For small cache files, just read them into memory */ - if (size >= FC_CACHE_MIN_MMAP) + if (fd_stat->st_size >= FC_CACHE_MIN_MMAP) { #if defined(HAVE_MMAP) || defined(__CYGWIN__) - cache = mmap (0, size, PROT_READ, MAP_SHARED, fd, 0); + cache = mmap (0, fd_stat->st_size, PROT_READ, MAP_SHARED, fd, 0); #elif defined(_WIN32) { HANDLE hFileMap; @@ -219,11 +313,11 @@ FcDirCacheMapFd (int fd, off_t size) } if (!cache) { - cache = malloc (size); + cache = malloc (fd_stat->st_size); if (!cache) return NULL; - if (read (fd, cache, size) != size) + if (read (fd, cache, fd_stat->st_size) != fd_stat->st_size) { free (cache); return NULL; @@ -232,14 +326,15 @@ FcDirCacheMapFd (int fd, off_t size) } if (cache->magic != FC_CACHE_MAGIC_MMAP || cache->version < FC_CACHE_CONTENT_VERSION || - cache->size != size) + cache->size != fd_stat->st_size || + !FcCacheRecord (cache, fd_stat)) { if (allocated) free (cache); else { #if defined(HAVE_MMAP) || defined(__CYGWIN__) - munmap (cache, size); + munmap (cache, fd_stat->st_size); #elif defined(_WIN32) UnmapViewOfFile (cache); #endif @@ -257,24 +352,13 @@ FcDirCacheMapFd (int fd, off_t size) void FcDirCacheUnload (FcCache *cache) { - switch (cache->magic) { - case FC_CACHE_MAGIC_ALLOC: - free (cache); - break; - case FC_CACHE_MAGIC_MMAP: -#if defined(HAVE_MMAP) || defined(__CYGWIN__) - munmap (cache, cache->size); -#elif defined(_WIN32) - UnmapViewOfFile (cache); -#endif - break; - } + /* Can't free or unmap the cache as apps may point into it */ } static FcBool -FcDirCacheMapHelper (int fd, off_t size, void *closure) +FcDirCacheMapHelper (int fd, struct stat *fd_stat, void *closure) { - FcCache *cache = FcDirCacheMapFd (fd, size); + FcCache *cache = FcDirCacheMapFd (fd, fd_stat); if (!cache) return FcFalse; @@ -303,7 +387,7 @@ FcDirCacheLoadFile (const FcChar8 *cache_file, struct stat *file_stat) fd = FcDirCacheOpenFile (cache_file, file_stat); if (fd < 0) return NULL; - cache = FcDirCacheMapFd (fd, file_stat->st_size); + cache = FcDirCacheMapFd (fd, file_stat); close (fd); return cache; } @@ -313,11 +397,10 @@ FcDirCacheLoadFile (const FcChar8 *cache_file, struct stat *file_stat) * the magic number and the size field */ static FcBool -FcDirCacheValidateHelper (int fd, off_t size, void *closure) +FcDirCacheValidateHelper (int fd, struct stat *fd_stat, void *closure) { FcBool ret = FcTrue; FcCache c; - struct stat file_stat; if (read (fd, &c, sizeof (FcCache)) != sizeof (FcCache)) ret = FcFalse; @@ -325,9 +408,7 @@ FcDirCacheValidateHelper (int fd, off_t size, void *closure) ret = FcFalse; else if (c.version < FC_CACHE_CONTENT_VERSION) ret = FcFalse; - else if (fstat (fd, &file_stat) < 0) - ret = FcFalse; - else if (file_stat.st_size != c.size) + else if (fd_stat->st_size != c.size) ret = FcFalse; return ret; } diff --git a/src/fcinit.c b/src/fcinit.c index 65702b4..f64c0f0 100644 --- a/src/fcinit.c +++ b/src/fcinit.c @@ -121,6 +121,7 @@ FcFini (void) FcConfigDestroy (_fcConfig); FcPatternFini (); + FcCacheFini (); } /* diff --git a/src/fcint.h b/src/fcint.h index 6cdb7cb..99ffe92 100644 --- a/src/fcint.h +++ b/src/fcint.h @@ -514,6 +514,9 @@ FcDirCacheBuild (FcFontSet *set, const FcChar8 *dir, FcStrSet *dirs); FcPrivate FcBool FcDirCacheWrite (FcCache *cache, FcConfig *config); +FcPrivate void +FcCacheFini (void); + /* fccfg.c */ FcPrivate FcBool -- 2.39.5