From 868fec1f8eca7c344fc9ac057b7418331299d9ce Mon Sep 17 00:00:00 2001
From: Lars Müller
Date: Sat, 1 Mar 2008 18:30:38 +0000
Subject: Import dnbd* from the former openslx-contrib repo as of revision 92.

openslx-contrib is currently read only and will get removed in some
days.


git-svn-id: http://svn.openslx.org/svn/openslx/contrib/dnbd/trunk@1592 95ad53e4-c205-0410-b2fa-d234c58c8868
---
 server/filer.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 server/filer.c

(limited to 'server/filer.c')

diff --git a/server/filer.c b/server/filer.c
new file mode 100644
index 0000000..b8412b7
--- /dev/null
+++ b/server/filer.c
@@ -0,0 +1,120 @@
+/*
+ * filer.c - open, seeks in and reads from a file 
+ * 
+ * Copyright (C) 2006 Thorsten Zitterell <thorsten@zitterell.de>
+ */
+ 
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include "filer.h"
+
+/* 
+ * function filer_getcapacity()
+ * returns: size/capacity of file/device 
+ */
+unsigned long long filer_getcapacity(filer_info_t * filer_info)
+{
+	return filer_info->size;
+}
+
+/* 
+ * function filer_seekblock(): seek to position in file/block device 
+ * returns: 1 on success, otherwise 0
+ */
+static inline int filer_seekblock(filer_info_t * filer_info, off_t newpos)
+{
+	if (lseek(filer_info->fd, newpos, SEEK_SET) == (off_t) -1) {
+		return 0;
+	}
+	filer_info->pos = newpos;
+	return 1;
+}
+
+/* 
+ * function filer_readblock(): read bytes at specific position 
+ * returns: 1 on success, otherwise 0
+ */
+inline int filer_readblock(filer_info_t * filer_info, void *buf, size_t size,
+		     off_t pos)
+{
+	size_t remain = size;
+	int result = 0;
+	int numblocks = 0;
+	
+	if (!filer_seekblock(filer_info, pos)) goto leave;		
+	
+	while (remain > 0) {
+		if ((numblocks = read(filer_info->fd, buf, remain)) <= 0) {
+			if (errno == EINTR)
+				continue;
+			goto leave;
+		}
+		
+		if (numblocks == 0) {
+			goto leave;
+		}
+		remain -= numblocks;
+		buf += numblocks;
+	}
+	result = 1;
+      leave:
+	filer_info->pos += (size - remain);
+	return result;
+}
+
+/* 
+ * function filer_init(): open file to be served
+ * returns: data structure with file information 
+ */
+filer_info_t *filer_init(const char *filename)
+{
+	filer_info_t *filer_info;
+	struct stat64 stbuf;
+
+	filer_info = (filer_info_t *) malloc(sizeof(filer_info_t));
+	if (!filer_info)
+		return NULL;
+
+	filer_info->filename = strdup(filename);
+	if ((filer_info->fd = open(filename, O_RDONLY | O_LARGEFILE)) < 0) {
+		fprintf(stderr, "ERROR: Cannot open filename \"%s\"\n",
+			filename);
+		goto out_free;
+	}
+
+	stbuf.st_size = 0;
+	
+	if (fstat64(filer_info->fd, &stbuf) < 0) {
+		fprintf(stderr, "ERROR: Cannot stat file \"%s\"\n",
+			filename);
+		goto out_free;
+	}
+
+	/* get file/device size */
+	if ((filer_info->size = stbuf.st_size) == 0) {
+		filer_info->size = lseek64(filer_info->fd, (off_t) 0, SEEK_END);
+	}
+
+	if (filer_info->size == 0) {
+	    fprintf(stderr, "ERROR: File/device has zero size\n");
+		goto out_free;
+	}
+
+	goto out;
+
+      out_free:
+	if (filer_info)
+		free(filer_info);
+
+	filer_info = NULL;
+      out:
+	return filer_info;
+}
-- 
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