Avoid allocating packet buffers unnecessarily.

[meshlink] / src / buffer.c

diff --git a/src/buffer.c b/src/buffer.c
index 3d4c32975b9a56e0e1d23a544c5384ee7985f01f..c6c3495411f08fcb7c0df4f6a198cf3c8ca811fa 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1,6 +1,6 @@
 /*
     buffer.c -- buffer management
-    Copyright (C) 2011 Guus Sliepen <guus@tinc-vpn.org>,
+    Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
 
     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
@@ -22,7 +22,7 @@
 #include "buffer.h"
 #include "xalloc.h"
 
-void buffer_compact(buffer_t *buffer, int maxsize) {
+void buffer_compact(buffer_t *buffer, size_t maxsize) {
        if(buffer->len >= maxsize || buffer->offset / 7 > buffer->len / 8) {
                memmove(buffer->data, buffer->data + buffer->offset, buffer->len - buffer->offset);
                buffer->len -= buffer->offset;
@@ -32,8 +32,10 @@ void buffer_compact(buffer_t *buffer, int maxsize) {
 
 // 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) {
+char *buffer_prepare(buffer_t *buffer, size_t size) {
        if(!buffer->data) {
+               assert(!buffer->maxlen);
+
                buffer->maxlen = size;
                buffer->data = xmalloc(size);
        } else {
@@ -57,14 +59,20 @@ char *buffer_prepare(buffer_t *buffer, int size) {
 }
 
 // Copy data into the buffer.
-                       
-void buffer_add(buffer_t *buffer, const char *data, int size) {
+
+void buffer_add(buffer_t *buffer, const char *data, size_t size) {
+       assert(data);
+       assert(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) {
+static char *buffer_consume(buffer_t *buffer, size_t size) {
+       assert(size);
+       assert(buffer->len - buffer->offset >= size);
+
        char *start = buffer->data + buffer->offset;
 
        buffer->offset += size;
@@ -82,24 +90,30 @@ static char *buffer_consume(buffer_t *buffer, int size) {
 char *buffer_readline(buffer_t *buffer) {
        char *newline = memchr(buffer->data + buffer->offset, '\n', buffer->len - buffer->offset);
 
-       if(!newline)
+       if(!newline) {
                return NULL;
+       }
 
-       int len = newline + 1 - (buffer->data + buffer->offset);
+       size_t 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)
+char *buffer_read(buffer_t *buffer, size_t size) {
+       assert(size);
+
+       if(buffer->len - buffer->offset < size) {
                return NULL;
+       }
 
        return buffer_consume(buffer, size);
 }
 
 void buffer_clear(buffer_t *buffer) {
+       assert(!buffer->data == !buffer->maxlen);
+
        free(buffer->data);
        buffer->data = NULL;
        buffer->maxlen = 0;