terom@0: #ifndef PNGTILE_CACHE_H
terom@0: #define PNGTILE_CACHE_H
terom@0: 
terom@0: /**
terom@0:  * @file
terom@0:  *
terom@0:  * Internal image cache implementation
terom@0:  */
terom@0: #include "image.h"
terom@0: 
terom@1: #include <stdint.h>
terom@1: #include <stdbool.h>
terom@1: 
terom@1: #include <png.h>
terom@1: 
terom@0: /**
terom@0:  * State for cache access
terom@0:  */
terom@0: struct pt_cache {
terom@1:     /** Filesystem path to cache file */
terom@1:     char *path;
terom@0: 
terom@1:     /** The mode we are operating in, bitmask of PT_IMG_* */
terom@1:     int mode;
terom@1:     
terom@1:     /** Opened file */
terom@1:     int fd;
terom@1: 
terom@1:     /** Memory-mapped file data, from the second page on */
terom@1:     uint8_t *mmap;
terom@1: 
terom@1:     /** Size of the mmap'd segment in bytes */
terom@1:     size_t size;
terom@0: };
terom@0: 
terom@0: /**
terom@1:  * Size of a cache file page in bytes
terom@1:  */
terom@1: #define PT_CACHE_PAGE 4096
terom@1: 
terom@1: /**
terom@0:  * On-disk header
terom@0:  */
terom@0: struct pt_cache_header {
terom@0:     /** Pixel dimensions of image */
terom@0:     uint32_t width, height;
terom@0:     
terom@0:     /** Pixel format */
terom@0:     uint8_t bit_depth, color_type;
terom@0: 
terom@0:     /** Convenience field for number of bytes per row */
terom@0:     uint32_t row_bytes;
terom@0: };
terom@0: 
terom@0: /**
terom@0:  * Construct the image cache info object associated with the given image.
terom@0:  */
terom@1: int pt_cache_open (struct pt_cache **cache_ptr, const char *path, int mode);
terom@0: 
terom@0: /**
terom@1:  * Verify if the cached data has become stale compared to the given original file.
terom@0:  */
terom@1: int pt_cache_stale (struct pt_cache *cache, const char *orig_path);
terom@0: 
terom@0: /**
terom@0:  * Update the cache data from the given PNG image.
terom@0:  */
terom@0: int pt_cache_update_png (struct pt_cache *cache, png_structp png, png_infop info);
terom@0: 
terom@1: /**
terom@1:  * Release all resources associated with the given cache object without any cleanup.
terom@1:  */
terom@1: void pt_cache_destroy (struct pt_cache *cache);
terom@1: 
terom@0: #endif