+struct wim_lookup_table_entry;
+struct wimlib_unix_data;
+struct wim_dentry;
+struct apply_ctx;
+
+/* Path to extracted file, or "cookie" identifying the file (e.g. inode number).
+ * */
+typedef union {
+ const tchar *path;
+ u64 cookie;
+} file_spec_t;
+
+/*
+ * struct apply_operations - Callback functions for a specific extraction
+ * mode/backend. These are lower-level functions that are called by the generic
+ * code in extract.c.
+ *
+ * Unless otherwise specified, the callbacks in this structure are expected to
+ * return 0 on success or a WIMLIB_ERR_* value on failure as well as set errno.
+ * When possible, error messages should NOT be printed as they are handled by
+ * the generic code.
+ *
+ * Many callbacks are optional, but to extract the most data from the WIM
+ * format, as many as possible should be provided, and the corresponding
+ * features should be marked as supported in start_extract().
+ */
+struct apply_operations {
+
+ /* OPTIONAL: Name of this extraction mode. */
+ const tchar *name;
+
+ /* REQUIRED: Fill in ctx->supported_features with nonzero values for
+ * features supported by the extraction mode and volume. This callback
+ * can also be used to do any setup needed to access the volume. */
+ int (*start_extract)
+ (const tchar *path, struct apply_ctx *ctx);
+
+ /* OPTIONAL: If root_directory_is_special is set: provide this
+ * callback to determine whether the path corresponds to the root of the
+ * target volume (%true) or not (%false). */
+ bool (*target_is_root)
+ (const tchar *target);
+
+ /* REQUIRED: Create a file. */
+ int (*create_file)
+ (const tchar *path, struct apply_ctx *ctx, u64 *cookie_ret);
+
+ /* REQUIRED: Create a directory. */
+ int (*create_directory)
+ (const tchar *path, struct apply_ctx *ctx, u64 *cookie_ret);
+
+ /* OPTIONAL: Create a hard link. In start_extract(), set
+ * ctx->supported_features.hard_links if supported. */
+ int (*create_hardlink)
+ (const tchar *oldpath, const tchar *newpath,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Create a symbolic link. In start_extract(), set
+ * ctx->supported_features.symlink_reparse_points if supported. */
+ int (*create_symlink)
+ (const tchar *oldpath, const tchar *newpath,
+ struct apply_ctx *ctx);
+
+ /* REQUIRED: Extract unnamed data stream. */
+ int (*extract_unnamed_stream)
+ (file_spec_t file, struct wim_lookup_table_entry *lte,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Extracted named data stream. In start_extract(), set
+ * ctx->supported_features.alternate_data_streams if supported. */
+ int (*extract_named_stream)
+ (file_spec_t file, const utf16lechar *stream_name,
+ size_t stream_name_nchars, struct wim_lookup_table_entry *lte,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Extracted encrypted stream. In start_extract(), set
+ * ctx->supported_features.encrypted_files if supported. */
+ int (*extract_encrypted_stream)
+ (const tchar *path, struct wim_lookup_table_entry *lte,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Set file attributes. Calling code calls this if non-NULL.
+ */
+ int (*set_file_attributes)
+ (const tchar *path, u32 attributes, struct apply_ctx *ctx,
+ unsigned pass);
+
+ /* OPTIONAL: Set reparse data. In start_extract(), set
+ * ctx->supported_features.reparse_data if supported. */
+ int (*set_reparse_data)
+ (const tchar *path, const u8 *rpbuf, u16 rpbuflen,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Set short (DOS) filename. In start_extract(), set
+ * ctx->supported_features.short_name if supported. */
+ int (*set_short_name)
+ (const tchar *path, const utf16lechar *short_name,
+ size_t short_name_nchars, struct apply_ctx *ctx);
+
+ /* OPTIONAL: Set Windows NT security descriptor. In start_extract(),
+ * set ctx->supported_features.security_descriptors if supported. */
+ int (*set_security_descriptor)
+ (const tchar *path, const u8 *desc, size_t desc_size,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Set wimlib-specific UNIX data. In start_extract(), set
+ * ctx->supported_features.unix_data if supported. */
+ int (*set_unix_data)
+ (const tchar *path, const struct wimlib_unix_data *data,
+ struct apply_ctx *ctx);
+
+ /* OPTIONAL: Set timestamps. Calling code calls this if non-NULL. */
+ int (*set_timestamps)
+ (const tchar *path, u64 creation_time, u64 last_write_time,
+ u64 last_access_time, struct apply_ctx *ctx);
+
+ /* OPTIONAL: Called after the extraction operation has succeeded. */
+ int (*finish_extract)
+ (struct apply_ctx *ctx);
+
+ /* OPTIONAL: Called after the extraction operation has failed. */
+ int (*abort_extract)
+ (struct apply_ctx *ctx);
+
+ /* REQUIRED: Path separator character to use when building paths. */
+ tchar path_separator;
+
+ /* REQUIRED: Maximum path length, in tchars, including the
+ * null-terminator. */
+ unsigned path_max;
+
+ /* OPTIONAL: String to prefix every path with. */
+ const tchar *path_prefix;