diff options
Diffstat (limited to 'src/server/image.h')
-rw-r--r-- | src/server/image.h | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/src/server/image.h b/src/server/image.h index 4668eff..7b6583c 100644 --- a/src/server/image.h +++ b/src/server/image.h @@ -9,7 +9,7 @@ void image_serverStartup(); bool image_isComplete(dnbd3_image_t *image); -bool image_isHashBlockComplete(const uint8_t * const cacheMap, const uint64_t block, const uint64_t fileSize); +bool image_isHashBlockComplete(dnbd3_cache_map_t * const cache, const uint64_t block, const uint64_t fileSize); void image_updateCachemap(dnbd3_image_t *image, uint64_t start, uint64_t end, const bool set); @@ -17,7 +17,9 @@ void image_markComplete(dnbd3_image_t *image); bool image_ensureOpen(dnbd3_image_t *image); -dnbd3_image_t* image_get(char *name, uint16_t revision, bool checkIfWorking); +dnbd3_image_t* image_byId(int imgId); + +dnbd3_image_t* image_get(const char *name, uint16_t revision, bool checkIfWorking); bool image_reopenCacheFd(dnbd3_image_t *image, const bool force); @@ -47,6 +49,52 @@ void image_closeUnusedFd(); bool image_ensureDiskSpaceLocked(uint64_t size, bool force); +bool image_saveCacheMap(dnbd3_image_t *image); + +/** + * Check if given range is cached. Be careful when using this function because: + * 1) you need to hold a reference to the cache map + * 2) start and end are assumed to be 4k aligned + * 3) start and end are not checked to be in bounds (we don't know the image in this context) + */ +static inline bool image_isRangeCachedUnsafe(dnbd3_cache_map_t *cache, uint64_t start, uint64_t end) +{ + const uint64_t firstByteInMap = start >> 15; + const uint64_t lastByteInMap = (end - 1) >> 15; + const uint8_t fb = (uint8_t)(0xff << ((start >> 12) & 7)); + const uint8_t lb = (uint8_t)(~(0xff << ((((end - 1) >> 12) & 7) + 1))); + uint64_t pos; + uint8_t b; + bool isCached; + if ( firstByteInMap == lastByteInMap ) { // Single byte to check, much simpler + b = cache->map[firstByteInMap]; + isCached = ( b & ( fb & lb ) ) == ( fb & lb ); + } else { + isCached = true; + atomic_thread_fence( memory_order_acquire ); + // First byte + if ( isCached ) { + b = atomic_load_explicit( &cache->map[firstByteInMap], memory_order_relaxed ); + isCached = ( ( b & fb ) == fb ); + } + // Last byte + if ( isCached ) { + b = atomic_load_explicit( &cache->map[lastByteInMap], memory_order_relaxed ); + isCached = ( ( b & lb ) == lb ); + } + // Middle, must be all bits set (0xff) + if ( isCached ) { + for ( pos = firstByteInMap + 1; pos < lastByteInMap; ++pos ) { + if ( atomic_load_explicit( &cache->map[pos], memory_order_relaxed ) != 0xff ) { + isCached = false; + break; + } + } + } + } + return isCached; +} + // one byte in the map covers 8 4kib blocks, so 32kib per byte // "+ (1 << 15) - 1" is required to account for the last bit of // the image that is smaller than 32kib |