Adding upstream version 1:2.3.21+dfsg1.upstream/1%2.3.21+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/src/lib/file-cache.h b/src/lib/file-cache.h
new file mode 100644
index 0000000..afffbd4
--- /dev/null
+++ b/src/lib/file-cache.h
@@ -0,0 +1,37 @@
+#ifndef FILE_CACHE_H
+#define FILE_CACHE_H
+
+/* Create a new file cache. It works very much like file-backed mmap()ed
+   memory, but it works more nicely with remote filesystems (no SIGBUS). */
+struct file_cache *file_cache_new(int fd);
+struct file_cache *file_cache_new_path(int fd, const char *path);
+/* Destroy the cache and set cache pointer to NULL. */
+void file_cache_free(struct file_cache **cache);
+
+/* Change cached file descriptor. Invalidates the whole cache. */
+void file_cache_set_fd(struct file_cache *cache, int fd);
+
+/* Change the memory allocated for the cache. This can be used to immediately
+   set the maximum size so there's no need to grow the memory area with
+   possibly slow copying. */
+int file_cache_set_size(struct file_cache *cache, uoff_t size);
+
+/* Read data from file, returns how many bytes was actually read or -1 if
+   error occurred. */
+ssize_t file_cache_read(struct file_cache *cache, uoff_t offset, size_t size);
+
+/* Returns pointer to beginning of cached file. Only parts of the returned
+   memory that are valid are the ones that have been file_cache_read().
+   Note that the pointer may become invalid after calling file_cache_read(). */
+const void *file_cache_get_map(struct file_cache *cache, size_t *size_r);
+
+/* Update cached memory area. Mark fully written pages as cached. */
+void file_cache_write(struct file_cache *cache, const void *data, size_t size,
+		      uoff_t offset);
+
+/* Invalidate cached memory area. It will be read again next time it's tried
+   to be accessed. */
+void file_cache_invalidate(struct file_cache *cache,
+			   uoff_t offset, uoff_t size);
+
+#endif