From 85e36aab1258d8d9ec7b61ce013f167ef8e03ae0 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Thu, 5 Mar 2020 22:38:15 +0100 Subject: Change the signature of sqfs_compressor_create to return an error code Make sure the function has a way of telling the caller *why* it failed. This way, the function can convey whether it had an internal error, an allocation failure, whether the arguments are totaly nonsensical, or simply that the compressor *or specific configuration* is not supported. Signed-off-by: David Oberhollenzer --- include/common.h | 3 ++- include/sqfs/compressor.h | 14 ++++++++++---- 2 files changed, 12 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/common.h b/include/common.h index bbdf81d..2ecea42 100644 --- a/include/common.h +++ b/include/common.h @@ -148,7 +148,8 @@ void print_version(const char *progname); XXX: This must be in libcommon instead of libsquashfs for legal reasons. */ -sqfs_compressor_t *lzo_compressor_create(const sqfs_compressor_config_t *cfg); +int lzo_compressor_create(const sqfs_compressor_config_t *cfg, + sqfs_compressor_t **out); /* Parse a number optionally followed by a KMG suffix (case insensitive). Prints diff --git a/include/sqfs/compressor.h b/include/sqfs/compressor.h index fd5d7e8..1a36c82 100644 --- a/include/sqfs/compressor.h +++ b/include/sqfs/compressor.h @@ -351,13 +351,19 @@ SQFS_API bool sqfs_compressor_exists(SQFS_COMPRESSOR id); /** * @brief Create an instance of a compressor implementation. * + * If this function returns @ref SQFS_ERROR_UNSUPPORTED, it can mean that + * either the compressor is not supported at all by the version of libsquashfs + * you are using, or that the specific configuration that has been requested + * is not supported (e.g. unknown flags, or the local version can only + * uncompress, but not compress). + * * @param cfg A pointer to a compressor configuration. + * @param out Returns a pointer to the compressor on success. * - * @return A pointer to a compressor object on success, NULL on allocation - * failure or if initializing the compressor failed. + * @return Zero on success, an SQFS_ERROR code on failure. */ -SQFS_API -sqfs_compressor_t *sqfs_compressor_create(const sqfs_compressor_config_t *cfg); +SQFS_API int sqfs_compressor_create(const sqfs_compressor_config_t *cfg, + sqfs_compressor_t **out); /** * @brief Get the name of a compressor backend from its ID. -- cgit v1.2.3