From a601fb8d1922ddd8e7fbb39f8ae2c6137b3a12a5 Mon Sep 17 00:00:00 2001
From: Jens Arnold <amiconn@rockbox.org>
Date: Sat, 17 Dec 2005 12:17:11 +0000
Subject: More compact & straight-forward headbytes handling.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8255 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/common/file.c | 45 +++++++++++----------------------------------
 1 file changed, 11 insertions(+), 34 deletions(-)

diff --git a/firmware/common/file.c b/firmware/common/file.c
index 7f36ecf..90fab6d 100644
--- a/firmware/common/file.c
+++ b/firmware/common/file.c
@@ -24,6 +24,7 @@
 #include "dir.h"
 #include "debug.h"
 #include "dircache.h"
+#include "system.h"
 
 /*
   These functions provide a roughly POSIX-compatible file IO API.
@@ -439,53 +440,29 @@ static int readwrite(int fd, void* buf, long count, bool write)
 
     /* any head bytes? */
     if ( file->cacheoffset != -1 ) {
-        int headbytes;
         int offs = file->cacheoffset;
-        if ( count <= SECTOR_SIZE - file->cacheoffset ) {
-            headbytes = count;
-            file->cacheoffset += count;
-            if ( file->cacheoffset >= SECTOR_SIZE )
-            {
-                /* Flush the cache first if it's dirty. */
-                if (file->dirty)
-                {
-                    rc = flush_cache(fd);
-                    if ( rc < 0 ) {
-                        errno = EIO;
-                        return rc * 10 - 9;
-                    }
-                }
-                file->cacheoffset = -1;
-            }
+        int headbytes = MIN(count, SECTOR_SIZE - offs);
+
+        if (write) {
+            memcpy( file->cache + offs, buf, headbytes );
+            file->dirty = true;
         }
         else {
-            headbytes = SECTOR_SIZE - file->cacheoffset;
-            if (file->dirty)
-            {
-                rc = flush_cache(fd);
-                if ( rc < 0 ) {
-                    errno = EIO;
-                    return rc * 10 - 9;
-                }
-            }
-            file->cacheoffset = -1;
+            memcpy( buf, file->cache + offs, headbytes );
         }
 
-        if (write) {
-            memcpy( file->cache + offs, buf, headbytes );
-            if (offs+headbytes == SECTOR_SIZE) {
+        if (offs + headbytes == SECTOR_SIZE) {
+            if (file->dirty) {
                 int rc = flush_cache(fd);
                 if ( rc < 0 ) {
                     errno = EIO;
                     return rc * 10 - 2;
                 }
-                file->cacheoffset = -1;
             }
-            else
-                file->dirty = true;
+            file->cacheoffset = -1;
         }
         else {
-            memcpy( buf, file->cache + offs, headbytes );
+            file->cacheoffset += headbytes;
         }
 
         nread = headbytes;
-- 
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