1 files changed, 107 insertions, 0 deletions
diff --git a/src/cbuffer.c b/src/cbuffer.c
new file mode 100644
index 0000000..1242496
--- /dev/null
+++ b/src/cbuffer.c
@@ -0,0 +1,107 @@
+/*
+ * Venus GPS Server
+ *
+ * Copyright (C) 2010 by Multi-Tech Systems
+ *
+ * Author: James Maki <jmaki@multitech.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+#include "log.h"
+#include "cbuffer.h"
+#include "utils.h"
+#include <errno.h>
+
+int buffered_write(int fd, struct cbuffer *buf) {
+	int i;
+	int len;
+	int count = buffer_used(buf);
+	int total = 0;
+
+	i = buf->read_index;
+	if(i + count > buffer_size(buf)) {
+		len = full_write(fd, buf->buffer + i, buffer_size(buf) - i);
+		if(len <= 0) {
+			log_error("full_write failed errno: %d", errno);
+			return len;
+		}
+
+		total += len;
+		count -= len;
+
+		if(len < buffer_size(buf) - i) {
+			buf->read_index = i + len;
+			return total;
+		}
+
+		i = 0;
+	}
+
+	len = full_write(fd, buf->buffer + i, count);
+	if(len <= 0) {
+		if(total) {
+			return total;
+		} else {
+			log_error("full_write failed errno: %d", errno);
+			return len;
+		}
+	}
+	buf->read_index = i + len;
+	total += len;
+
+	return total;
+}
+
+int buffered_read(int fd, struct cbuffer *buf) {
+	int i;
+	int len;
+	int count = buffer_free(buf);
+	int total = 0;
+
+	i = buf->write_index;
+	if(i + count > buffer_size(buf)) {
+		len = safe_read(fd, buf->buffer + i, buffer_size(buf) - i);
+		if(len <= 0) {
+			log_warning("safe_read failed errno: %d", errno);
+			return len;
+		}
+
+		total += len;
+		count -= len;
+
+		if(len < buffer_size(buf) - i) {
+			buf->write_index = i + len;
+			return total;
+		}
+
+		i = 0;
+	}
+
+	len = safe_read(fd, buf->buffer + i, count);
+	if(len <= 0) {
+		if(total) {
+			return total;
+		} else {
+			log_warning("safe_read failed errno: %d", errno);
+			return len;
+		}
+	}
+	buf->write_index = i + len;
+	total += len;
+
+	return total;
+}
+