X-Git-Url: http://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fbuffer.c;fp=src%2Fbuffer.c;h=fc4fac0f3629570f3097d65c54337db857b56f8e;hb=f431fcb35f400be388a905ae0f7f50c1f5c4cd5d;hp=0000000000000000000000000000000000000000;hpb=3794e551c7db9aa81405f65f7b04a9951c4120b2;p=tinc

diff --git a/src/buffer.c b/src/buffer.c
new file mode 100644
index 00000000..fc4fac0f
--- /dev/null
+++ b/src/buffer.c
@@ -0,0 +1,99 @@
+/*
+    buffer.c -- buffer management
+    Copyright (C) 2011 Guus Sliepen <guus@tinc-vpn.org>,
+
+    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.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "system.h"
+
+#include "buffer.h"
+#include "xalloc.h"
+
+// Make sure we can add size bytes to the buffer, and return a pointer to the start of those bytes.
+
+char *buffer_prepare(buffer_t *buffer, int size) {
+	if(!buffer->data) {
+		buffer->maxlen = size;
+		buffer->data = xmalloc(size);
+	} else {
+		if(buffer->offset && buffer->len + size > buffer->maxlen) {
+			memmove(buffer->data, buffer->data + buffer->offset, buffer->len - buffer->offset);
+			buffer->len -= buffer->offset;
+			buffer->offset = 0;
+		}
+
+		if(buffer->len + size > buffer->maxlen) {
+			buffer->maxlen = buffer->len + size;
+			buffer->data = xrealloc(buffer->data, buffer->maxlen);
+		}
+	}
+
+	buffer->len += size;
+	return buffer->data + buffer->offset;
+}
+
+// Copy data into the buffer.
+			
+char *buffer_add(buffer_t *buffer, const char *data, int size) {
+	memcpy(buffer_prepare(buffer, size), data, size);
+}
+
+// Remove given number of bytes from the buffer, return a pointer to the start of them.
+
+static char *buffer_consume(buffer_t *buffer, int size) {
+	char *start = buffer->data + buffer->offset;
+
+	buffer->offset += size;
+
+	if(buffer->offset >= buffer->len) {
+		buffer->offset = 0;
+		buffer->len = 0;
+	} else {
+		buffer->offset += size;
+	}
+
+	return start;
+}
+
+// Check if there is a complete line in the buffer, and if so, return it NULL-terminated.
+
+char *buffer_readline(buffer_t *buffer) {
+	char *newline = memchr(buffer->data + buffer->offset, '\n', buffer->len - buffer->offset);
+
+	if(!newline)
+		return NULL;
+
+	int len = newline + 1 - buffer->data + buffer->offset;
+	*newline = 0;
+	return buffer_consume(buffer, len);
+}
+
+// Check if we have enough bytes in the buffer, and if so, return a pointer to the start of them.
+
+char *buffer_read(buffer_t *buffer, int size) {
+	if(buffer->len - buffer->offset < size)
+		return NULL;
+
+	return buffer_consume(buffer, size);
+}
+
+void buffer_clear(buffer_t *buffer) {
+	free(buffer->data);
+	buffer->data = 0;
+	buffer->maxlen = 0;
+	buffer->len = 0;
+	buffer->offset = 0;
+}