Added file config structure and lfs_file_opencfg

The optional config structure options up the possibility of adding
file-level configuration in a backwards compatible manner.

Also adds possibility to open multiple files with LFS_NO_MALLOC
enabled thanks to dpgeorge

Also bumped minor version to v1.5

1 files changed, 28 insertions, 6 deletions

diff --git a/lfs.h b/lfs.h
index 1b1be19..cb7222c 100644
--- a/lfs.h
+++ b/lfs.h
@@ -21,7 +21,7 @@ extern "C"
 // Software library version
 // Major (top-nibble), incremented on backwards incompatible changes
 // Minor (bottom-nibble), incremented on feature additions
-#define LFS_VERSION 0x00010004
+#define LFS_VERSION 0x00010005
 #define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
 #define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >>  0))
 
@@ -167,6 +167,12 @@ struct lfs_config {
     void *file_buffer;
 };
 
+// Optional configuration provided during lfs_file_opencfg
+struct lfs_file_config {
+    // Optional, statically allocated buffer for files. Must be program sized.
+    // If NULL, malloc will be used by default.
+    void *buffer;
+};
 
 // File info structure
 struct lfs_info {
@@ -214,6 +220,7 @@ typedef struct lfs_file {
     lfs_block_t head;
     lfs_size_t size;
 
+    const struct lfs_file_config *cfg;
     uint32_t flags;
     lfs_off_t pos;
     lfs_block_t block;
@@ -281,7 +288,8 @@ typedef struct lfs {
 // Format a block device with the littlefs
 //
 // Requires a littlefs object and config struct. This clobbers the littlefs
-// object, and does not leave the filesystem mounted.
+// object, and does not leave the filesystem mounted. The config struct must
+// be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
 int lfs_format(lfs_t *lfs, const struct lfs_config *config);
@@ -290,7 +298,8 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *config);
 //
 // Requires a littlefs object and config struct. Multiple filesystems
 // may be mounted simultaneously with multiple littlefs objects. Both
-// lfs and config must be allocated while mounted.
+// lfs and config must be allocated while mounted. The config struct must
+// be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
 int lfs_mount(lfs_t *lfs, const struct lfs_config *config);
@@ -328,14 +337,27 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
 
 // Open a file
 //
-// The mode that the file is opened in is determined
-// by the flags, which are values from the enum lfs_open_flags
-// that are bitwise-ored together.
+// The mode that the file is opened in is determined by the flags, which
+// are values from the enum lfs_open_flags that are bitwise-ored together.
 //
 // Returns a negative error code on failure.
 int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags);
 
+// Open a file with extra configuration
+//
+// The mode that the file is opened in is determined by the flags, which
+// are values from the enum lfs_open_flags that are bitwise-ored together.
+//
+// The config struct provides additional config options per file as described
+// above. The config struct must be allocated while the file is open, and the
+// config struct must be zeroed for defaults and backwards compatibility.
+//
+// Returns a negative error code on failure.
+int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
+        const char *path, int flags,
+        const struct lfs_file_config *config);
+
 // Close a file
 //
 // Any pending writes are written out to storage as though