wutdevoptab: Rename all files to *fsa*.cpp

libraries/wutdevoptab/devoptab_fsa_seek.cpp

@@ -0,0 +1,79 @@
+#include "devoptab_fsa.h"
+
+off_t
+__wut_fs_seek(struct _reent *r,
+              void *fd,
+              off_t pos,
+              int whence)
+{
+   FSStatus status;
+   FSCmdBlock cmd;
+   FSStat fsStat;
+   uint64_t offset;
+   __wut_fs_file_t *file;
+
+   if (!fd) {
+      r->_errno = EINVAL;
+      return -1;
+   }
+
+   FSInitCmdBlock(&cmd);
+   file = (__wut_fs_file_t *)fd;
+
+   // Find the offset to see from
+   switch(whence) {
+   // Set absolute position; start offset is 0
+   case SEEK_SET:
+      offset = 0;
+      break;
+
+   // Set position relative to the current position
+   case SEEK_CUR:
+      offset = file->offset;
+      break;
+
+   // Set position relative to the end of the file
+   case SEEK_END: {
+      status = FSGetStatFile(__wut_devoptab_fs_client, &cmd, file->fd, &fsStat,
+                             FS_ERROR_FLAG_ALL);
+      if (status < 0) {
+         r->_errno = __wut_fs_translate_error(status);
+         return -1;
+      }
+      offset = fsStat.size;
+      break;
+   }
+   // An invalid option was provided
+   default:
+      r->_errno = EINVAL;
+      return -1;
+   }
+
+   if(pos < 0 && offset < -pos) {
+      // Don't allow seek to before the beginning of the file
+      r->_errno = EINVAL;
+      return -1;
+   } else if (offset + pos > UINT32_MAX) {
+      // Check for overflow
+      r->_errno = EINVAL;
+      return -1;
+   }
+   
+   if((uint32_t) (offset + pos) == file->offset) {
+      return file->offset;
+   }
+
+   uint32_t old_offset = file->offset;
+   file->offset = offset + pos;
+
+   status = FSSetPosFile(__wut_devoptab_fs_client, &cmd, file->fd, file->offset,
+                         FS_ERROR_FLAG_ALL);
+   if (status < 0) {
+      // revert offset update on error.
+      file->offset = old_offset;
+      r->_errno = __wut_fs_translate_error(status);
+      return -1;
+   }
+
+   return file->offset;
+}