-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;
- }
-
- buf->maxsize = size;
-
- 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;
- }
-}
-