}
static void buffer_exit(struct buffer *buf) {
- free(buf->data);
+ if(!buf->external) {
+ free(buf->data);
+ }
+
memset(buf, 0, sizeof(*buf));
}
}
}
-void utcp_set_sndbuf(struct utcp_connection *c, size_t size) {
- if(!c) {
- return;
+static void buffer_transfer(struct buffer *buf, char *newdata, size_t newsize) {
+ if(buffer_wraps(buf)) {
+ // Old situation:
+ // [345......012]
+ // New situation:
+ // [012345......]
+ uint32_t tailsize = buf->size - buf->offset;
+ memcpy(newdata, buf->data + buf->offset, tailsize);
+ memcpy(newdata + tailsize, buf->data, buf->used - buf->offset);
+ } else {
+ // Old situation:
+ // [....012345..]
+ // New situation:
+ // [012345......]
+ memcpy(newdata, buf->data + buf->offset, buf->used);
+ }
+
+ buf->offset = 0;
+ buf->size = newsize;
+}
+
+static void set_buffer_storage(struct buffer *buf, char *data, size_t size) {
+ if(size > UINT32_MAX) {
+ size = UINT32_MAX;
}
- c->sndbuf.maxsize = size;
+ buf->maxsize = size;
- if(c->sndbuf.maxsize != size) {
- c->sndbuf.maxsize = -1;
+ if(data) {
+ if(buf->external) {
+ // Don't allow resizing an external buffer
+ abort();
+ }
+
+ if(size < buf->used) {
+ // Ignore requests for an external buffer if we are already using more than it can store
+ return;
+ }
+
+ // Transition from internal to external buffer
+ buffer_transfer(buf, data, size);
+ free(buf->data);
+ buf->data = data;
+ 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);
+
+ if(!data) {
+ // Cannot handle this
+ abort();
+ }
+
+ buffer_transfer(buf, data, minsize);
+ buf->data = data;
+ buf->external = false;
}
+}
+
+void utcp_set_sndbuf(struct utcp_connection *c, void *data, size_t size) {
+ if(!c) {
+ return;
+ }
+
+ set_buffer_storage(&c->sndbuf, data, size);
c->do_poll = is_reliable(c) && buffer_free(&c->sndbuf);
}
}
}
-void utcp_set_rcvbuf(struct utcp_connection *c, size_t size) {
+void utcp_set_rcvbuf(struct utcp_connection *c, void *data, size_t size) {
if(!c) {
return;
}
- c->rcvbuf.maxsize = size;
-
- if(c->rcvbuf.maxsize != size) {
- c->rcvbuf.maxsize = -1;
- }
+ set_buffer_storage(&c->rcvbuf, data, size);
}
size_t utcp_get_sendq(struct utcp_connection *c) {