Implement readahead buffering for non-raw files. This drastically improves

the efficiency of byte-by-byte read operations on filesystems not already
supported by the block cache (especially NFS).

This should be a welcome change for users booting via PXE, as the loader
now reads its startup files almost instantly, instead of taking tens of
seconds.

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/libstand/stand.h b/lib/libstand/stand.h
index aa8e65f..e48565a 100644
--- a/lib/libstand/stand.h
+++ b/lib/libstand/stand.h
@@ -159,7 +159,11 @@ struct open_file {
     void		*f_devdata;	/* device specific data */
     struct fs_ops	*f_ops;		/* pointer to file system operations */
     void		*f_fsdata;	/* file system specific data */
-    off_t		f_offset;	/* current file offset (F_RAW) */
+    off_t		f_offset;	/* current file offset */
+    char		*f_rabuf;	/* readahead buffer pointer */
+    size_t		f_ralen;	/* valid data in readahead buffer */
+    off_t		f_raoffset;	/* consumer offset in readahead buffer */
+#define SOPEN_RASIZE	512
 };
 
 #define	SOPEN_MAX	8