static void write_cb(uv_write_t *req, int status)
{
lcb_luv_socket_t sock = (lcb_luv_socket_t)req->data;
struct lcb_luv_evstate_st *evstate;
if (!sock) {
fprintf(stderr, "Got write callback (req=%p) without socket\n",
(void *)req);
return;
}
evstate = EVSTATE_FIND(sock, WRITE);
if (status) {
evstate->err =
lcb_luv_errno_map((uv_last_error(sock->parent->loop)).code);
}
log_write_debug("Flush done. Flushed %d bytes", sock->write.buf.len);
sock->write.pos = 0;
sock->write.nb = 0;
evstate->flags |= LCB_LUV_EVf_PENDING;
evstate->flags &= ~(LCB_LUV_EVf_FLUSHING);
if (SOCK_EV_ENABLED(sock, WRITE)) {
sock->event->lcb_cb(sock->idx, LCB_WRITE_EVENT, sock->event->lcb_arg);
if (sock->write.nb) {
evstate->flags &= ~(LCB_LUV_EVf_PENDING);
lcb_luv_flush(sock);
}
}
lcb_luv_socket_unref(sock);
}
/**
* Flush the write buffers
*/
void lcb_luv_flush(lcb_luv_socket_t sock)
{
int status;
struct lcb_luv_evstate_st *evstate;
if (sock->write.nb == 0) {
return;
}
evstate = EVSTATE_FIND(sock, WRITE);
if (EVSTATE_IS(evstate, FLUSHING)) {
log_write_info("Not flushing because we are in the middle of a flush");
return;
}
sock->write.buf.base = sock->write.data;
sock->write.buf.len = sock->write.nb;
log_write_debug("Will flush");
status = uv_write(&sock->u_req.write,
(uv_stream_t *)&sock->tcp,
&sock->write.buf, 1, write_cb);
lcb_luv_socket_ref(sock);
if (status) {
evstate->err =
lcb_luv_errno_map((uv_last_error(sock->parent->loop)).code);
}
evstate->flags |= LCB_LUV_EVf_FLUSHING;
}
/**
* Deliver an asynchronous 'write-ready' notification to libcouchbase.
* This will invoke the normal callback chains..
*
* So how this works is rather complicated. It is used primarily for
* write-readiness (i.e. to let libcouchbase put data into our socket buffer).
*
* If requested from within the callback (i.e. async_cb itself), then we need
* to heuristically decide what exactly lcb will do.
*
* If it's a simple write event (i.e. actually copying the data between buffers)
* then our buffer will eventually become full and this function will fail
* to set the async_redo flag.
*
* The case is different in connect though: while a connect-readiness
* notification is a write event, it doesn't actually fill the socket with
* anything, so there is the possibility of recursion.
*
* Furthermore, connect-'readiness' is an actual event in uv, so there is no
* need for this readiness emulation.
*/
void
lcb_luv_send_async_write_ready(lcb_luv_socket_t sock)
{
if (sock->async_entered) {
/**
* Doing extra checks here to ensure we don't end up inside a busy
* loop.
*/
struct lcb_luv_evstate_st *wev = EVSTATE_FIND(sock, WRITE);
struct lcb_luv_evstate_st *cev = EVSTATE_FIND(sock, CONNECT);
if (!EVSTATE_IS(cev, CONNECTED)) {
log_loop_debug("Not iterating again for phony write event");
return;
}
if (EVSTATE_IS(wev, FLUSHING)) {
log_loop_debug("Not requesting second iteration. "
"Already inside a flush");
return;
}
if (sock->write.nb >= sizeof(sock->write.data)) {
log_loop_debug("Not enough space to write..");
return;
}
sock->async_redo = 1;
return;
}
if (sock->async_active) {
log_loop_trace("prep_active is true");
return;
}
log_loop_debug("Will try and schedule prepare callback for %d", sock->idx);
lcb_luv_socket_ref(sock);
uv_async_send(&sock->async);
sock->async_active = 1;
}
static lcb_ssize_t write_common(lcb_luv_socket_t sock,
const void *buf,
size_t len,
int *errno_out)
{
lcb_ssize_t ret;
struct lcb_luv_evstate_st *evstate = EVSTATE_FIND(sock, WRITE);
log_write_debug("%d: Requested to write %d bytes from %p",
sock->idx, len, buf);
if (evstate->err) {
log_write_warn("Socket has pending error %d", evstate->err);
*errno_out = evstate->err;
evstate->err = 0;
return -1;
}
if (EVSTATE_IS(evstate, FLUSHING)) {
log_write_info("Will not write because we are inside a flush");
*errno_out = EWOULDBLOCK;
return -1;
}
ret = MINIMUM(len, sizeof(sock->write.data) - sock->write.nb);
if (ret == 0) {
log_write_info("We have no more space inside the buffer");
*errno_out = EWOULDBLOCK;
return -1;
}
memcpy(sock->write.data + sock->write.pos, buf, ret);
// lcb_luv_hexdump(sock->write.data + sock->write.pos, ret);
sock->write.pos += ret;
sock->write.nb += ret;
log_write_trace("Returning %d", ret);
return ret;
}