# HG changeset patch # User Tero Marttila # Date 1262025389 -7200 # Node ID 49362b34116cd4107f8af43784a53f2b722a731b # Parent da7c6dcafb435edcad23fce1d889b6fca33f0832 open cache as .tmp, and rename to .cache when done diff -r da7c6dcafb43 -r 49362b34116c Makefile --- a/Makefile Mon Dec 28 19:58:51 2009 +0200 +++ b/Makefile Mon Dec 28 20:36:29 2009 +0200 @@ -16,7 +16,8 @@ all: depend lib/libpngtile.so bin/util lib/libpngtile.so : \ - build/obj/lib/image.o build/obj/lib/cache.o + build/obj/lib/image.o build/obj/lib/cache.o \ + build/obj/shared/util.o bin/util: \ lib/libpngtile.so \ diff -r da7c6dcafb43 -r 49362b34116c src/lib/cache.c --- a/src/lib/cache.c Mon Dec 28 19:58:51 2009 +0200 +++ b/src/lib/cache.c Mon Dec 28 20:36:29 2009 +0200 @@ -1,4 +1,5 @@ #include "cache.h" +#include "shared/util.h" #include #include @@ -92,25 +93,16 @@ } /** - * Open the cache file as an fd. + * Open the cache file as an fd for reading * * XXX: needs locking */ -static int pt_cache_open_fd (struct pt_cache *cache, int *fd_ptr) +static int pt_cache_open_read (struct pt_cache *cache, int *fd_ptr) { int fd; - int flags = 0; - - // determine open flags - // XXX: O_RDONLY | O_WRONLY == O_RDWR? - if (cache->mode & PT_IMG_READ) - flags |= O_RDONLY; - - if (cache->mode & PT_IMG_WRITE) - flags |= (O_WRONLY | O_CREAT); - + // actual open() - if ((fd = open(cache->path, flags)) < 0) + if ((fd = open(cache->path, O_RDONLY)) < 0) return -1; // ok @@ -120,6 +112,36 @@ } /** + * Open the .tmp cache file as an fd for writing + */ +static int pt_cache_open_tmp (struct pt_cache *cache, int *fd_ptr) +{ + int fd; + char tmp_path[1024]; + + // check mode + if (!(cache->mode & PT_IMG_WRITE)) { + errno = EPERM; + return -1; + } + + // get .tmp path + if (path_with_fext(cache->path, tmp_path, sizeof(tmp_path), ".tmp")) + return -1; + + // open for write, create + // XXX: locking? + if ((fd = open(tmp_path, O_RDWR | O_CREAT, 0644)) < 0) + return -1; + + // ok + *fd_ptr = fd; + + return 0; +} + + +/** * Mmap the opened cache file from offset PT_CACHE_PAGE, using the calculated size stored in cache->size */ static int pt_cache_open_mmap (struct pt_cache *cache, void **addr_ptr) @@ -174,7 +196,7 @@ } /** - * Create a new cache file, open it, and write out the header. + * Create a new .tmp cache file, open it, and write out the header. */ static int pt_cache_open_create (struct pt_cache *cache, struct pt_cache_header *header) { @@ -184,8 +206,8 @@ return -1; } - // open - if (pt_cache_open_fd(cache, &cache->fd)) + // open as .tmp + if (pt_cache_open_tmp(cache, &cache->fd)) return -1; // calculate data size @@ -213,6 +235,25 @@ return -1; } +/** + * Rename the opened .tmp to .cache + */ +static int pt_cache_create_done (struct pt_cache *cache) +{ + char tmp_path[1024]; + + // get .tmp path + if (path_with_fext(cache->path, tmp_path, sizeof(tmp_path), ".tmp")) + return -1; + + // rename + if (rename(tmp_path, cache->path) < 0) + return -1; + + // ok + return 0; +} + int pt_cache_update_png (struct pt_cache *cache, png_structp png, png_infop info) { struct pt_cache_header header; @@ -231,7 +272,7 @@ // fill in other info header.row_bytes = png_get_rowbytes(png, info); - // create and write out header + // create .tmp and write out header if (pt_cache_open_create(cache, &header)) return -1; @@ -243,6 +284,10 @@ png_read_row(png, cache->mmap + row * header.row_bytes, NULL); } + // move from .tmp to .cache + if (pt_cache_create_done(cache)) + return -1; + // done! return 0; } diff -r da7c6dcafb43 -r 49362b34116c src/lib/image.c --- a/src/lib/image.c Mon Dec 28 19:58:51 2009 +0200 +++ b/src/lib/image.c Mon Dec 28 20:36:29 2009 +0200 @@ -1,5 +1,6 @@ #include "image.h" #include "cache.h" +#include "shared/util.h" #include #include // for _POSIX_PATH_MAX @@ -137,22 +138,7 @@ */ static int pt_image_cache_path (struct pt_image *image, char *buf, size_t len) { - char *ext; - - // XXX: be more careful about buf len - - // copy filename - strncpy(buf, image->path, len); - - // find .ext - if ((ext = strrchr(buf, '.')) == NULL) - return -1; - - // change to .cache - strncpy(ext, ".cache", (buf + len) - ext); - - // hmmk - return 0; + return path_with_fext(image->path, buf, len, ".cache"); } int pt_image_open (struct pt_image **image_ptr, struct pt_ctx *ctx, const char *path, int cache_mode) diff -r da7c6dcafb43 -r 49362b34116c src/shared/util.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/shared/util.c Mon Dec 28 20:36:29 2009 +0200 @@ -0,0 +1,35 @@ +#include "util.h" + +#include + +int chfext (char *buf, size_t len, const char *newext) +{ + char *ext; + + // find .ext + if ((ext = strrchr(buf, '.')) == NULL) + return -1; + + // check length + if (ext + strlen(newext) >= buf + len) + return -1; + + // change to .foo + strcpy(ext, newext); + + // ok + return 0; +} + +int path_with_fext (const char *path, char *buf, size_t len, const char *newext) +{ + // verify length + if (strlen(path) > len) + return -1; + + // copy filename + strcpy(buf, path); + + // change fext + return chfext(buf, len, newext); +} diff -r da7c6dcafb43 -r 49362b34116c src/shared/util.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/shared/util.h Mon Dec 28 20:36:29 2009 +0200 @@ -0,0 +1,17 @@ +#ifndef SHARED_UTIL_H +#define SHARED_UTIL_H + +#include + +/** + * Replace the file extension in the given path buffer with the given extension, which should be of the form ".foo" + */ +int chfext (char *path, size_t len, const char *newext); + +/** + * Copy filesystem path with new file extension + */ +int path_with_fext (const char *path, char *buf, size_t len, const char *newext); + + +#endif