Reduce UTCP memory usage.

[meshlink] / src / utcp.c

diff --git a/src/utcp.c b/src/utcp.c
index 46d7fd35f065473f0baa1a27fe307ee8795eeebc..c21e7067b89610c17182eae3dce57b58a9dfa274 100644 (file)
--- a/src/utcp.c
+++ b/src/utcp.c
@@ -196,6 +196,16 @@ static bool buffer_wraps(struct buffer *buf) {
 }
 
 static bool buffer_resize(struct buffer *buf, uint32_t newsize) {
+       assert(!buf->external);
+
+       if(!newsize) {
+               free(buf->data);
+               buf->data = NULL;
+               buf->size = 0;
+               buf->offset = 0;
+               return true;
+       }
+
        char *newdata = realloc(buf->data, newsize);
 
        if(!newdata) {
@@ -441,17 +451,40 @@ static void set_buffer_storage(struct buffer *buf, char *data, size_t size) {
                buf->external = true;
        } else if(buf->external) {
                // Transition from external to internal buf
-               size_t minsize = buf->used < DEFAULT_SNDBUFSIZE ? DEFAULT_SNDBUFSIZE : buf->used;
-               data = malloc(minsize);
+               size_t minsize = buf->used <= DEFAULT_SNDBUFSIZE ? DEFAULT_SNDBUFSIZE : buf->used;
 
-               if(!data) {
-                       // Cannot handle this
-                       abort();
+               if(minsize) {
+                       data = malloc(minsize);
+
+                       if(!data) {
+                               // Cannot handle this
+                               abort();
+                       }
+
+                       buffer_transfer(buf, data, minsize);
+                       buf->data = data;
+               } else {
+                       buf->data = NULL;
+                       buf->size = 0;
                }
 
-               buffer_transfer(buf, data, minsize);
-               buf->data = data;
                buf->external = false;
+       } else {
+               // Realloc internal storage
+               size_t minsize = buf->used <= DEFAULT_SNDBUFSIZE ? DEFAULT_SNDBUFSIZE : buf->used;
+
+               if(minsize) {
+                       data = realloc(buf->data, minsize);
+
+                       if(data) {
+                               buf->data = data;
+                               buf->size = minsize;
+                       }
+               } else {
+                       free(buf->data);
+                       buf->data = NULL;
+                       buf->size = 0;
+               }
        }
 }
 
@@ -2075,13 +2108,8 @@ static bool reset_connection(struct utcp_connection *c) {
 }
 
 static void set_reapable(struct utcp_connection *c) {
-       if(c->sndbuf.external) {
-               set_buffer_storage(&c->sndbuf, NULL, DEFAULT_MTU);
-       }
-
-       if(c->rcvbuf.external) {
-               set_buffer_storage(&c->rcvbuf, NULL, DEFAULT_MTU);
-       }
+       set_buffer_storage(&c->sndbuf, NULL, DEFAULT_MTU);
+       set_buffer_storage(&c->rcvbuf, NULL, DEFAULT_MTU);
 
        c->recv = NULL;
        c->poll = NULL;