[PATCH 16/29] Staging: yaffs2: yaffs_nameval: Add files

[Tracey Dent <tdent48227@gmail.com>]

Adding files to yaffs2 directory.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
---
 drivers/staging/yaffs2/yaffs_nameval.c |  197 ++++++++++++++++++++++++++++++++
 drivers/staging/yaffs2/yaffs_nameval.h |   26 ++++
 2 files changed, 223 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/yaffs2/yaffs_nameval.c
 create mode 100644 drivers/staging/yaffs2/yaffs_nameval.h

diff --git a/drivers/staging/yaffs2/yaffs_nameval.c b/drivers/staging/yaffs2/yaffs_nameval.c
new file mode 100644
index 0000000..a4ed297
--- /dev/null
+++ b/drivers/staging/yaffs2/yaffs_nameval.c
@@ -0,0 +1,197 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This simple implementation of a name-value store assumes a small number of values and fits
+ * into a small finite buffer.
+ *
+ * Each attribute is stored as a record:
+ *  sizeof(int) bytes   record size.
+ *  strnlen+1 bytes name null terminated.
+ *  nbytes    value.
+ *  ----------
+ *  total size  stored in record size 
+ *
+ * This code has not been tested with unicode yet.
+ */
+
+
+#include "yaffs_nameval.h"
+
+#include "yportenv.h"
+ 
+static int nval_find(const char *xb, int xb_size, const YCHAR *name,
+		int *exist_size)
+{
+	int pos=0;
+	int size;
+
+	memcpy(&size,xb,sizeof(int));
+	while(size > 0 && (size < xb_size) && (pos + size < xb_size)){
+		if(yaffs_strncmp((YCHAR *)(xb+pos+sizeof(int)),name,size) == 0){
+			if(exist_size)
+				*exist_size = size;
+			return pos;
+		}
+		pos += size;
+		if(pos < xb_size -sizeof(int))
+			memcpy(&size,xb + pos,sizeof(int));
+		else
+			size = 0;
+	}
+	if(exist_size)
+		*exist_size = 0;
+	return -1;
+}
+
+static int nval_used(const char *xb, int xb_size)
+{
+	int pos=0;
+	int size;
+
+	memcpy(&size,xb + pos,sizeof(int));
+	while(size > 0 && (size < xb_size) && (pos + size < xb_size)){
+		pos += size;
+		if(pos < xb_size -sizeof(int))
+			memcpy(&size,xb + pos,sizeof(int));
+		else
+			size = 0;
+	}
+	return pos;
+}
+
+int nval_del(char *xb, int xb_size, const YCHAR *name)
+{
+	int pos  = nval_find(xb, xb_size, name, NULL);
+	int size;
+	
+	if(pos >= 0 && pos < xb_size){
+		/* Find size, shift rest over this record, then zero out the rest of buffer */
+		memcpy(&size,xb+pos,sizeof(int));
+		memcpy(xb + pos, xb + pos + size, xb_size - (pos + size));
+		memset(xb + (xb_size - size),0,size);
+		return 0;
+	} else
+		return -ENODATA;
+}
+
+int nval_set(char *xb, int xb_size, const YCHAR *name, const char *buf, int bsize, int flags)
+{
+	int pos;
+	int namelen = yaffs_strnlen(name,xb_size);
+	int reclen;
+	int size_exist = 0;
+	int space;
+	int start;
+
+	pos = nval_find(xb,xb_size,name, &size_exist);
+
+	if(flags & XATTR_CREATE && pos >= 0)
+		return -EEXIST;
+	if(flags & XATTR_REPLACE && pos < 0)
+		return -ENODATA;
+
+	start = nval_used(xb,xb_size);
+	space = xb_size - start + size_exist;
+
+	reclen = (sizeof(int) + namelen + 1 + bsize);
+
+	if(reclen > space)
+		return -ENOSPC;
+
+	if(pos >= 0){
+		nval_del(xb,xb_size,name);
+		start = nval_used(xb, xb_size);
+	}
+
+	pos = start;
+
+	memcpy(xb + pos,&reclen,sizeof(int));
+	pos +=sizeof(int);
+	yaffs_strncpy((YCHAR *)(xb + pos), name, reclen);
+	pos+= (namelen+1);
+	memcpy(xb + pos,buf,bsize);
+	return 0;
+}
+
+int nval_get(const char *xb, int xb_size, const YCHAR *name, char *buf, int bsize)
+{
+	int pos = nval_find(xb,xb_size,name,NULL);
+	int size;
+	
+	if(pos >= 0 && pos< xb_size){
+		
+		memcpy(&size,xb +pos,sizeof(int));
+		pos+=sizeof(int); /* advance past record length */
+		size -= sizeof(int);
+
+		/* Advance over name string */
+		while(xb[pos] && size > 0 && pos < xb_size){
+			pos++;
+			size--;
+		}
+		/*Advance over NUL */
+		pos++;
+		size--;
+
+		if(size <= bsize){
+			memcpy(buf,xb + pos,size);
+			return size;
+		}
+		
+	}
+	if(pos >= 0)
+		return -ERANGE;
+	else
+		return -ENODATA;
+}
+
+int nval_list(const char *xb, int xb_size, char *buf, int bsize)
+{
+	int pos = 0;
+	int size;
+	int name_len;
+	int ncopied = 0;
+	int filled = 0;
+
+	memcpy(&size,xb + pos,sizeof(int));
+	while(size > sizeof(int) && size <= xb_size && (pos + size) < xb_size && !filled){
+		pos+= sizeof(int);
+		size-=sizeof(int);
+		name_len = yaffs_strnlen((YCHAR *)(xb + pos), size);
+		if(ncopied + name_len + 1 < bsize){
+			memcpy(buf,xb+pos,name_len * sizeof(YCHAR));
+			buf+= name_len;
+			*buf = '\0';
+			buf++;
+			if(sizeof(YCHAR) > 1){
+				*buf = '\0';
+				buf++;
+			}
+			ncopied += (name_len+1);
+		} else
+			filled = 1;
+		pos+=size;
+		if(pos < xb_size -sizeof(int))
+			memcpy(&size,xb + pos,sizeof(int));
+		else
+			size = 0;
+	}
+	return ncopied;
+}
+
+
+int nval_hasvalues(const char *xb, int xb_size)
+{
+	return nval_used(xb, xb_size) > 0;
+}
diff --git a/drivers/staging/yaffs2/yaffs_nameval.h b/drivers/staging/yaffs2/yaffs_nameval.h
new file mode 100644
index 0000000..bd80859
--- /dev/null
+++ b/drivers/staging/yaffs2/yaffs_nameval.h
@@ -0,0 +1,26 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __NAMEVAL_H__
+#define __NAMEVAL_H__
+
+#include "yportenv.h"
+
+int nval_del(char *xb, int xb_size, const YCHAR *name);
+int nval_set(char *xb, int xb_size, const YCHAR *name, const char *buf, int bsize, int flags);
+int nval_get(const char *xb, int xb_size, const YCHAR *name, char *buf, int bsize);
+int nval_list(const char *xb, int xb_size, char *buf, int bsize);
+int nval_hasvalues(const char *xb, int xb_size);
+#endif
-- 
1.7.3.2.146.gca209