terom@0: #include "cache.h"
terom@4: #include "shared/util.h"
terom@6: #include "shared/log.h" // only LOG_DEBUG
terom@17: #include "error.h"
terom@0: 
terom@1: #include <stdlib.h>
terom@177: #include <string.h>
terom@1: #include <unistd.h>
terom@1: #include <sys/types.h>
terom@1: #include <sys/stat.h>
terom@1: #include <fcntl.h>
terom@1: #include <sys/mman.h>
terom@2: #include <errno.h>
terom@6: #include <assert.h>
terom@1: 
terom@1: 
terom@9: int pt_cache_new (struct pt_cache **cache_ptr, const char *path, int mode)
terom@0: {
terom@0:     struct pt_cache *cache;
terom@17:     int err;
terom@0: 
terom@1:     // alloc
terom@0:     if ((cache = calloc(1, sizeof(*cache))) == NULL)
terom@17:         RETURN_ERROR(PT_ERR_MEM);
terom@0: 
terom@1:     if ((cache->path = strdup(path)) == NULL)
terom@17:         JUMP_SET_ERROR(err, PT_ERR_MEM);
terom@1: 
terom@1:     // init
terom@1:     cache->fd = -1;
terom@3:     cache->mode = mode;
terom@1: 
terom@1:     // ok
terom@1:     *cache_ptr = cache;
terom@1: 
terom@1:     return 0;
terom@1: 
terom@1: error:
terom@1:     // cleanup
terom@1:     if (cache)
terom@1:         pt_cache_destroy(cache);
terom@1: 
terom@17:     return err;
terom@1: }
terom@1: 
terom@56: /**
terom@59:  * Force-clean pt_cache, warn on errors
terom@59:  */
terom@59: static void pt_cache_abort (struct pt_cache *cache)
terom@59: {
terom@59:     if (cache->file != NULL) {
terom@59:         if (munmap(cache->file, sizeof(struct pt_cache_file) + cache->file->header.data_size))
terom@59:             log_warn_errno("munmap: %p, %zu", cache->file, sizeof(struct pt_cache_file) + cache->file->header.data_size);
terom@59: 
terom@59:         cache->file = NULL;
terom@59:     }
terom@59: 
terom@59:     if (cache->fd >= 0) {
terom@59:         if (close(cache->fd))
terom@59:             log_warn_errno("close: %d", cache->fd);
terom@59: 
terom@59:         cache->fd = -1;
terom@59:     }
terom@59: }
terom@59: 
terom@59: /**
terom@56:  * Open the cache file as an fd for reading
terom@56:  */
terom@56: static int pt_cache_open_read_fd (struct pt_cache *cache, int *fd_ptr)
terom@56: {
terom@56:     int fd;
terom@56:     
terom@56:     // actual open()
terom@56:     if ((fd = open(cache->path, O_RDONLY)) < 0)
terom@56:         RETURN_ERROR_ERRNO(PT_ERR_OPEN_MODE, EACCES);
terom@56: 
terom@56:     // ok
terom@56:     *fd_ptr = fd;
terom@56: 
terom@56:     return 0;
terom@56: }
terom@56: 
terom@56: /**
terom@56:  * Read in the cache header from the open file
terom@56:  */
terom@56: static int pt_cache_read_header (int fd, struct pt_cache_header *header)
terom@56: {
terom@56:     size_t len = sizeof(*header);
terom@56:     char *buf = (char *) header;
terom@56: 
terom@56:     // seek to start
terom@56:     if (lseek(fd, 0, SEEK_SET) != 0)
terom@56:         RETURN_ERROR(PT_ERR_CACHE_SEEK);
terom@56: 
terom@56:     // write out full header
terom@56:     while (len) {
terom@56:         ssize_t ret;
terom@56:         
terom@56:         // try and write out the header
terom@56:         if ((ret = read(fd, buf, len)) <= 0)
terom@56:             RETURN_ERROR(PT_ERR_CACHE_READ);
terom@56: 
terom@56:         // update offset
terom@56:         buf += ret;
terom@56:         len -= ret;
terom@56:     }
terom@56: 
terom@56:     // done
terom@56:     return 0;
terom@56: }
terom@56: 
terom@56: /**
terom@56:  * Read and return the version number from the cache file, temporarily opening it if needed
terom@56:  */
terom@56: static int pt_cache_version (struct pt_cache *cache)
terom@56: {
terom@56:     int fd;
terom@56:     struct pt_cache_header header;
terom@56:     int ret;
terom@56: 
terom@56:     // already open?
terom@56:     if (cache->file)
terom@56:         return cache->file->header.version;
terom@56: 
terom@56:     // temp. open
terom@56:     if ((ret = pt_cache_open_read_fd(cache, &fd)))
terom@56:         return ret;
terom@56: 
terom@56:     // read header
terom@56:     if ((ret = pt_cache_read_header(fd, &header)))
terom@56:         JUMP_ERROR(ret);
terom@56: 
terom@56:     // ok
terom@56:     ret = header.version;
terom@56:     
terom@56: error:
terom@56:     // close
terom@56:     close(fd);
terom@56:     
terom@56:     return ret;
terom@56: }
terom@56: 
terom@8: int pt_cache_status (struct pt_cache *cache, const char *img_path)
terom@0: {
terom@2:     struct stat st_img, st_cache;
terom@56:     int ver;
terom@2:     
terom@2:     // test original file
terom@2:     if (stat(img_path, &st_img) < 0)
terom@17:         RETURN_ERROR(PT_ERR_IMG_STAT);
terom@2:     
terom@2:     // test cache file
terom@2:     if (stat(cache->path, &st_cache) < 0) {
terom@2:         // always stale if it doesn't exist yet
terom@2:         if (errno == ENOENT)
terom@8:             return PT_CACHE_NONE;
terom@2:         else
terom@17:             RETURN_ERROR(PT_ERR_CACHE_STAT);
terom@2:     }
terom@2: 
terom@2:     // compare mtime
terom@8:     if (st_img.st_mtime > st_cache.st_mtime)
terom@8:         return PT_CACHE_STALE;
terom@56:     
terom@56:     // read version
terom@56:     if ((ver = pt_cache_version(cache)) < 0)
terom@56:         // fail
terom@56:         return ver;
terom@8: 
terom@56:     // compare version
terom@56:     if (ver != PT_CACHE_VERSION)
terom@56:         return PT_CACHE_INCOMPAT;
terom@56:     
terom@56:     // ok, should be in order
terom@56:     return PT_CACHE_FRESH;
terom@0: }
terom@0: 
terom@56: void pt_cache_info (struct pt_cache *cache, struct pt_image_info *info)
terom@10: {
terom@54:     struct stat st;
terom@17: 
terom@56:     if (cache->file)
terom@56:         // img info
terom@56:         pt_png_info(&cache->file->header.png, info);
terom@10: 
terom@54:     // stat
terom@54:     if (stat(cache->path, &st) < 0) {
terom@54:         // unknown
terom@54:         info->cache_mtime = 0;
terom@54:         info->cache_bytes = 0;
terom@54:         info->cache_blocks = 0;
terom@54: 
terom@54:     } else {
terom@54:         // store
terom@56:         info->cache_version = pt_cache_version(cache);
terom@54:         info->cache_mtime = st.st_mtime;
terom@54:         info->cache_bytes = st.st_size;
terom@54:         info->cache_blocks = st.st_blocks;
terom@54:     }
terom@10: }
terom@10: 
terom@76: static int pt_cache_tmp_name (struct pt_cache *cache, char tmp_path[], size_t tmp_len)
terom@66: {
terom@66:     // get .tmp path
terom@76:     if (path_with_fext(cache->path, tmp_path, tmp_len, ".tmp"))
terom@66:         RETURN_ERROR(PT_ERR_PATH);
terom@66: 
terom@66:     return 0;
terom@66: }
terom@66: 
terom@0: /**
terom@71:  * Compute and return the full size of the .cache file
terom@71:  */
terom@71: static size_t pt_cache_size (size_t data_size)
terom@71: {
terom@71:     assert(sizeof(struct pt_cache_file) == PT_CACHE_HEADER_SIZE);
terom@71: 
terom@71:     return sizeof(struct pt_cache_file) + data_size;
terom@71: }
terom@71: 
terom@71: /**
terom@4:  * Open the .tmp cache file as an fd for writing
terom@4:  */
terom@6: static int pt_cache_open_tmp_fd (struct pt_cache *cache, int *fd_ptr)
terom@4: {
terom@4:     int fd;
terom@4:     char tmp_path[1024];
terom@66:     int err;
terom@66: 
terom@4:     // get .tmp path
terom@76:     if ((err = pt_cache_tmp_name(cache, tmp_path, sizeof(tmp_path))))
terom@66:         return err;
terom@4: 
terom@66:     // open for write, create, fail if someone else already opened it for update
terom@66:     if ((fd = open(tmp_path, O_RDWR | O_CREAT | O_EXCL, 0644)) < 0)
terom@17:         RETURN_ERROR(PT_ERR_CACHE_OPEN_TMP);
terom@4: 
terom@4:     // ok
terom@4:     *fd_ptr = fd;
terom@4: 
terom@4:     return 0;
terom@4: }
terom@4: 
terom@4: 
terom@4: /**
terom@71:  * Mmap the pt_cache_file using pt_cache_size(data_size)
terom@1:  */
terom@60: static int pt_cache_open_mmap (struct pt_cache *cache, struct pt_cache_file **file_ptr, size_t data_size, bool readonly)
terom@1: {
terom@1:     int prot = 0;
terom@1:     void *addr;
terom@1: 
terom@1:     // determine prot
terom@6:     prot |= PROT_READ;
terom@1: 
terom@9:     if (!readonly) {
terom@11:         assert(cache->mode & PT_OPEN_UPDATE);
terom@9: 
terom@1:         prot |= PROT_WRITE;
terom@9:     }
terom@1: 
terom@53:     // mmap() the full file including header
terom@71:     if ((addr = mmap(NULL, pt_cache_size(data_size), prot, MAP_SHARED, cache->fd, 0)) == MAP_FAILED)
terom@17:         RETURN_ERROR(PT_ERR_CACHE_MMAP);
terom@1: 
terom@1:     // ok
terom@60:     *file_ptr = addr;
terom@1: 
terom@1:     return 0;
terom@1: }
terom@1: 
terom@56: int pt_cache_open (struct pt_cache *cache)
terom@9: {
terom@56:     struct pt_cache_header header;
terom@56:     int err;
terom@9: 
terom@56:     // ignore if already open
terom@56:     if (cache->file)
terom@56:         return 0;
terom@9: 
terom@56:     // open the .cache in readonly mode
terom@56:     if ((err = pt_cache_open_read_fd(cache, &cache->fd)))
terom@56:         return err;
terom@56: 
terom@56:     // read in header
terom@56:     if ((err = pt_cache_read_header(cache->fd, &header)))
terom@56:         JUMP_ERROR(err);
terom@56: 
terom@56:     // check version
terom@56:     if (header.version != PT_CACHE_VERSION)
terom@56:         JUMP_SET_ERROR(err, PT_ERR_CACHE_VERSION);
terom@56: 
terom@56:     // mmap the header + data
terom@60:     if ((err = pt_cache_open_mmap(cache, &cache->file, header.data_size, true)))
terom@56:         JUMP_ERROR(err);
terom@9: 
terom@9:     // done
terom@9:     return 0;
terom@56: 
terom@56: error:
terom@56:     // cleanup
terom@56:     pt_cache_abort(cache);
terom@56: 
terom@56:     return err;
terom@9: }
terom@9: 
terom@9: /**
terom@1:  * Write out the cache header into the opened file
terom@1:  */
terom@1: static int pt_cache_write_header (struct pt_cache *cache, const struct pt_cache_header *header)
terom@1: {
terom@1:     size_t len = sizeof(*header);
terom@1:     const char *buf = (const char *) header;
terom@1: 
terom@1:     // seek to start
terom@1:     if (lseek(cache->fd, 0, SEEK_SET) != 0)
terom@17:         RETURN_ERROR(PT_ERR_CACHE_SEEK);
terom@1: 
terom@1:     // write out full header
terom@1:     while (len) {
terom@1:         ssize_t ret;
terom@1:         
terom@1:         // try and write out the header
terom@17:         if ((ret = write(cache->fd, buf, len)) <= 0)
terom@17:             RETURN_ERROR(PT_ERR_CACHE_WRITE);
terom@1: 
terom@1:         // update offset
terom@1:         buf += ret;
terom@1:         len -= ret;
terom@1:     }
terom@1: 
terom@1:     // done
terom@1:     return 0;
terom@1: }
terom@1: 
terom@1: /**
terom@4:  * Create a new .tmp cache file, open it, and write out the header.
terom@0:  */
terom@11: static int pt_cache_create (struct pt_cache *cache, struct pt_cache_header *header)
terom@0: {
terom@17:     int err;
terom@7: 
terom@66:     assert(cache->mode & PT_OPEN_UPDATE);
terom@2: 
terom@4:     // open as .tmp
terom@17:     if ((err = pt_cache_open_tmp_fd(cache, &cache->fd)))
terom@17:         return err;
terom@1: 
terom@56:     // write header
terom@56:     if ((err = pt_cache_write_header(cache, header)))
terom@56:         JUMP_ERROR(err);
terom@1: 
terom@1:     // grow file
terom@71:     if (ftruncate(cache->fd, pt_cache_size(header->data_size)) < 0)
terom@17:         JUMP_SET_ERROR(err, PT_ERR_CACHE_TRUNC);
terom@1: 
terom@7:     // mmap header and data
terom@60:     if ((err = pt_cache_open_mmap(cache, &cache->file, header->data_size, false)))
terom@17:         JUMP_ERROR(err);
terom@1: 
terom@1:     // done
terom@1:     return 0;
terom@1: 
terom@1: error:
terom@1:     // cleanup
terom@1:     pt_cache_abort(cache);
terom@1: 
terom@17:     return err;
terom@0: }
terom@0: 
terom@4: /**
terom@4:  * Rename the opened .tmp to .cache
terom@4:  */
terom@4: static int pt_cache_create_done (struct pt_cache *cache)
terom@4: {
terom@4:     char tmp_path[1024];
terom@66:     int err;
terom@4:     
terom@4:     // get .tmp path
terom@76:     if ((err = pt_cache_tmp_name(cache, tmp_path, sizeof(tmp_path))))
terom@66:         return err;
terom@4: 
terom@4:     // rename
terom@4:     if (rename(tmp_path, cache->path) < 0)
terom@17:         RETURN_ERROR(PT_ERR_CACHE_RENAME_TMP);
terom@4: 
terom@4:     // ok
terom@4:     return 0;
terom@4: }
terom@4: 
terom@66: /**
terom@66:  * Abort a failed cache update after cache_create
terom@66:  */
terom@66: static void pt_cache_create_abort (struct pt_cache *cache)
terom@66: {
terom@66:     char tmp_path[1024];
terom@66:     int err;
terom@66:     
terom@66:     // close open stuff
terom@66:     pt_cache_abort(cache);
terom@66: 
terom@66:     // get .tmp path
terom@76:     if ((err = pt_cache_tmp_name(cache, tmp_path, sizeof(tmp_path)))) {
terom@66:         log_warn_errno("pt_cache_tmp_name: %s: %s", cache->path, pt_strerror(err));
terom@66:         
terom@66:         return;
terom@66:     }
terom@66: 
terom@66:     // remove .tmp
terom@66:     if (unlink(tmp_path))
terom@66:         log_warn_errno("unlink: %s", tmp_path);
terom@66: }
terom@66: 
terom@56: int pt_cache_update (struct pt_cache *cache, struct pt_png_img *img, const struct pt_image_params *params)
terom@0: {
terom@0:     struct pt_cache_header header;
terom@17:     int err;
terom@66: 
terom@66:     // check mode
terom@66:     if (!(cache->mode & PT_OPEN_UPDATE))
terom@66:         RETURN_ERROR(PT_ERR_OPEN_MODE);
terom@66: 
terom@66:     // close if open
terom@66:     if ((err = pt_cache_close(cache)))
terom@66:         return err;
terom@56:     
terom@56:     // prep header
terom@56:     header.version = PT_CACHE_VERSION;
terom@56:     header.format = PT_IMG_PNG;
terom@1: 
terom@56:     // read img header
terom@56:     if ((err = pt_png_read_header(img, &header.png, &header.data_size)))
terom@56:         return err;
terom@6: 
terom@56:     // save any params
terom@52:     if (params)
terom@52:         header.params = *params;
terom@52: 
terom@56:     // create/open .tmp and write out header
terom@17:     if ((err = pt_cache_create(cache, &header)))
terom@17:         return err;
terom@56: 
terom@56:     // decode to disk
terom@56:     if ((err = pt_png_decode(img, &cache->file->header.png, &cache->file->header.params, cache->file->data)))
terom@66:         goto error;
terom@7: 
terom@56:     // done, commit .tmp
terom@17:     if ((err = pt_cache_create_done(cache)))
terom@66:         goto error;
terom@66:     
terom@66:     return 0;
terom@4: 
terom@66: error:
terom@66:     // cleanup .tmp
terom@66:     pt_cache_create_abort(cache);
terom@66: 
terom@66:     return err;
terom@12: }
terom@12: 
terom@56: int pt_cache_tile (struct pt_cache *cache, struct pt_tile *tile)
terom@34: {
terom@34:     int err;
terom@34: 
terom@34:     // ensure open
terom@34:     if ((err = pt_cache_open(cache)))
terom@34:         return err;
terom@34: 
terom@56:     // render
terom@56:     if ((err = pt_png_tile(&cache->file->header.png, cache->file->data, tile)))
terom@56:         return err;
terom@34: 
terom@9:     return 0;
terom@9: }
terom@9: 
terom@59: int pt_cache_close (struct pt_cache *cache)
terom@59: {
terom@59:     if (cache->file != NULL) {
terom@59:         if (munmap(cache->file, sizeof(struct pt_cache_file) + cache->file->header.data_size))
terom@59:             RETURN_ERROR(PT_ERR_CACHE_MUNMAP);
terom@59: 
terom@59:         cache->file = NULL;
terom@59:     }
terom@59: 
terom@59:     if (cache->fd >= 0) {
terom@59:         if (close(cache->fd))
terom@59:             RETURN_ERROR(PT_ERR_CACHE_CLOSE);
terom@59: 
terom@59:         cache->fd = -1;
terom@59:     }
terom@59: 
terom@59:     return 0;
terom@59: }
terom@59: 
terom@1: void pt_cache_destroy (struct pt_cache *cache)
terom@1: {
terom@59:     // cleanup
terom@1:     pt_cache_abort(cache);
terom@1: 
terom@59:     free(cache->path);
terom@1:     free(cache);
terom@1: }
terom@11: