/**
* Invoked when a client connection is ready to be written to.
*/
static void handle_client_writebuf(ev_loop *lp, ev_io *watcher, int ready_events) {
// Get the associated connection struct
conn_info *conn = watcher->data;
// Build the IO vectors to perform the write
struct iovec vectors[2];
int num_vectors;
circbuf_setup_writev_iovec(&conn->output, (struct iovec*)&vectors, &num_vectors);
// Issue the write
ssize_t write_bytes = writev(watcher->fd, (struct iovec*)&vectors, num_vectors);
if (write_bytes > 0) {
// Update the cursor
circbuf_advance_read(&conn->output, write_bytes);
// Check if we should reset the use_write_buf.
// This is done when the buffer size is 0.
if (conn->output.read_cursor == conn->output.write_cursor) {
conn->use_write_buf = 0;
ev_io_stop(lp, &conn->write_client);
}
}
// Handle any errors
if (write_bytes <= 0 && (errno != EAGAIN && errno != EINTR)) {
syslog(LOG_ERR, "Failed to write() to connection [%d]! %s.",
conn->client.fd, strerror(errno));
close_client_connection(conn);
return;
}
}
/**
* This method is used to read and consume the input buffer
* @arg conn The client connection
* @arg bytes The number of bytes to read
* @arg buf Output parameter, sets the start of the buffer.
* @arg should_free Output parameter, should the buffer be freed by the caller.
* @return 0 on success, -1 if there is insufficient data.
*/
int read_client_bytes(statsite_conn_info *conn, int bytes, char** buf, int* should_free) {
if (unlikely(bytes > circbuf_used_buf(&conn->input))) return -1;
// Handle the wrap around case
if (unlikely(conn->input.write_cursor < conn->input.read_cursor)) {
// Check if we can use a contiguous chunk
int end_size = conn->input.buf_size - conn->input.read_cursor;
if (end_size >= bytes) {
*buf = conn->input.buffer + conn->input.read_cursor;
*should_free = 0;
// Otherwise, allocate a dynamic slab, and copy
} else {
*buf = malloc(bytes);
memcpy(*buf, conn->input.buffer + conn->input.read_cursor, end_size);
memcpy(*buf + end_size, conn->input.buffer, bytes - end_size);
*should_free = 1;
}
// Handle the contiguous case
} else {
*buf = conn->input.buffer + conn->input.read_cursor;
*should_free = 0;
}
// Advance the read cursor
circbuf_advance_read(&conn->input, bytes);
return 0;
}
/**
* Invoked when a client connection is ready to be written to.
*/
static int handle_client_writebuf(ev_io *watch, worker_ev_userdata* data) {
// Get the associated connection struct
conn_info *conn = watch->data;
// Build the IO vectors to perform the write
struct iovec vectors[2];
int num_vectors;
circbuf_setup_writev_iovec(&conn->output, (struct iovec*)&vectors, &num_vectors);
// Issue the write
ssize_t write_bytes = writev(watch->fd, (struct iovec*)&vectors, num_vectors);
int reschedule = 0;
if (write_bytes > 0) {
// Update the cursor
circbuf_advance_read(&conn->output, write_bytes);
// Check if we should reset the use_write_buf.
// This is done when the buffer size is 0.
if (conn->output.read_cursor == conn->output.write_cursor) {
conn->use_write_buf = 0;
} else {
reschedule = 1;
}
}
// Handle any errors
if (write_bytes <= 0 && (errno != EAGAIN && errno != EINTR)) {
syslog(LOG_ERR, "Failed to write() to connection [%d]! %s.",
conn->client.fd, strerror(errno));
close_client_connection(conn);
decref_client_connection(conn);
return 1;
}
// Check if we should reschedule or end
if (reschedule) {
schedule_async(data->netconf, SCHEDULE_WATCHER, &conn->write_client);
} else {
decref_client_connection(conn);
}
return 0;
}
/**
* This method is used to seek the input buffer without
* consuming input. It can be used in conjunction with
* peek_client_bytes to conditionally seek.
* @arg conn The client connection
* @arg bytes The number of bytes to seek
* @return 0 on success, -1 if there is insufficient data.
*/
int seek_client_bytes(statsite_conn_info *conn, int bytes) {
if (unlikely(bytes > circbuf_used_buf(&conn->input))) return -1;
circbuf_advance_read(&conn->input, bytes);
return 0;
}
