#ifndef _IMAGE_H_ #define _IMAGE_H_ #include "../config.h" #include "globals.h" extern dnbd3_image_t *_images[SERVER_MAX_IMAGES]; extern int _num_images; extern pthread_spinlock_t _images_lock; int image_is_complete(dnbd3_image_t *image); void image_update_cachemap(dnbd3_image_t *image, uint64_t start, uint64_t end, const int set); int image_save_cache_map(dnbd3_image_t *image); dnbd3_image_t* image_get(char *name, uint16_t revision); void image_release(dnbd3_image_t *image); dnbd3_image_t* image_free(dnbd3_image_t *image); int image_load_all(char *path); int image_create(char *image, int revision, uint64_t size); int image_generate_crc_file(char *image); // 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 // this would be the case whenever the image file size is not a // multiple of 32kib (= the number of blocks is not divisible by 8) // ie: if the image is 49152 bytes and you do 49152 >> 15 you get 1, // but you actually need 2 bytes to have a complete cache map #define IMGSIZE_TO_MAPBYTES(bytes) ((int)(((bytes) + (1 << 15) - 1) >> 15)) // calculate number of hash blocks in file. One hash block is 16MiB #define HASH_BLOCK_SIZE ((int64_t)(1 << 24)) #define IMGSIZE_TO_HASHBLOCKS(bytes) ((int)(((bytes) + HASH_BLOCK_SIZE - 1) / HASH_BLOCK_SIZE)) #endif