typedef enum {
MEM_READ,
- MEM_WRITE,
+ MEM_WRITE
} memc_read_or_write;
static ssize_t io_flush(memcached_server_st *ptr, memcached_return *error);
static memcached_return io_wait(memcached_server_st *ptr,
memc_read_or_write read_or_write)
{
- struct pollfd fds[1];
- short flags= 0;
+ struct pollfd fds= {
+ .fd= ptr->fd,
+ .events = POLLIN
+ };
int error;
- if (read_or_write == MEM_WRITE) /* write */
- flags= POLLOUT;
- else
- flags= POLLIN;
-
- memset(&fds, 0, sizeof(struct pollfd));
- fds[0].fd= ptr->fd;
- fds[0].events= flags;
+ unlikely (read_or_write == MEM_WRITE) /* write */
+ fds.events= POLLOUT;
/*
** We are going to block on write, but at least on Solaris we might block
*/
if (read_or_write == MEM_WRITE)
{
- memcached_return rc=memcached_purge(ptr);
+ memcached_return rc= memcached_purge(ptr);
if (rc != MEMCACHED_SUCCESS && rc != MEMCACHED_STORED)
- return MEMCACHED_FAILURE;
+ return MEMCACHED_FAILURE;
}
- error= poll(fds, 1, ptr->root->poll_timeout);
+ int timeout= ptr->root->poll_timeout;
+ if ((ptr->root->flags & MEM_NO_BLOCK) == 0)
+ timeout= -1;
+
+ error= poll(&fds, 1, timeout);
if (error == 1)
return MEMCACHED_SUCCESS;
else if (error == 0)
- {
return MEMCACHED_TIMEOUT;
- }
/* Imposssible for anything other then -1 */
WATCHPOINT_ASSERT(error == -1);
memcached_quit_server(ptr, 1);
return MEMCACHED_FAILURE;
+}
+
+/**
+ * Try to fill the input buffer for a server with as much
+ * data as possible.
+ *
+ * @param ptr the server to pack
+ */
+static bool repack_input_buffer(memcached_server_st *ptr)
+{
+ if (ptr->read_ptr != ptr->read_buffer)
+ {
+ /* Move all of the data to the beginning of the buffer so
+ ** that we can fit more data into the buffer...
+ */
+ memmove(ptr->read_buffer, ptr->read_ptr, ptr->read_buffer_length);
+ ptr->read_ptr= ptr->read_buffer;
+ ptr->read_data_length= ptr->read_buffer_length;
+ }
+
+ /* There is room in the buffer, try to fill it! */
+ if (ptr->read_buffer_length != MEMCACHED_MAX_BUFFER)
+ {
+ /* Just try a single read to grab what's available */
+ ssize_t nr= read(ptr->fd,
+ ptr->read_ptr + ptr->read_data_length,
+ MEMCACHED_MAX_BUFFER - ptr->read_data_length);
+ if (nr > 0)
+ {
+ ptr->read_data_length+= (size_t)nr;
+ ptr->read_buffer_length+= (size_t)nr;
+ return true;
+ }
+ }
+ return false;
+}
+
+/**
+ * If the we have callbacks connected to this server structure
+ * we may start process the input queue and fire the callbacks
+ * for the incomming messages. This function is _only_ called
+ * when the input buffer is full, so that we _know_ that we have
+ * at least _one_ message to process.
+ *
+ * @param ptr the server to star processing iput messages for
+ * @return true if we processed anything, false otherwise
+ */
+static bool process_input_buffer(memcached_server_st *ptr)
+{
+ /*
+ ** We might be able to process some of the response messages if we
+ ** have a callback set up
+ */
+ if (ptr->root->callbacks != NULL && (ptr->root->flags & MEM_USE_UDP) == 0)
+ {
+ /*
+ * We might have responses... try to read them out and fire
+ * callbacks
+ */
+ memcached_callback_st cb= *ptr->root->callbacks;
+
+ char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
+ memcached_return error;
+ error= memcached_response(ptr, buffer, sizeof(buffer),
+ &ptr->root->result);
+ if (error == MEMCACHED_SUCCESS)
+ {
+ for (unsigned int x= 0; x < cb.number_of_callback; x++)
+ {
+ error= (*cb.callback[x])(ptr->root, &ptr->root->result, cb.context);
+ if (error != MEMCACHED_SUCCESS)
+ break;
+ }
+
+ /* @todo what should I do with the error message??? */
+ }
+ /* @todo what should I do with other error messages?? */
+ return true;
+ }
+
+ return false;
}
#ifdef UNUSED
continue;
case EAGAIN:
{
+ /*
+ * We may be blocked on write because the input buffer
+ * is full. Let's check if we have room in our input
+ * buffer for more data and retry the write before
+ * waiting..
+ */
+ if (repack_input_buffer(ptr) ||
+ process_input_buffer(ptr))
+ continue;
+
memcached_return rc;
rc= io_wait(ptr, MEM_WRITE);
return (ssize_t) return_length;
}
-/*
+/*
Eventually we will just kill off the server with the problem.
*/
void memcached_io_reset(memcached_server_st *ptr)
/**
* Read a given number of bytes from the server and place it into a specific
- * buffer. Reset the IO channel on this server if an error occurs.
+ * buffer. Reset the IO channel on this server if an error occurs.
*/
memcached_return memcached_safe_read(memcached_server_st *ptr,
void *dta,
uint16_t cur_req= get_udp_datagram_request_id(header);
int msg_num= get_msg_num_from_request_id(cur_req);
int thread_id= get_thread_id_from_request_id(cur_req);
-
+
if (((++msg_num) & UDP_REQUEST_ID_THREAD_MASK) != 0)
msg_num= 0;
projects / m6w6 / libmemcached / blobdiff