-/*
- Basic socket buffered IO
-*/
+/* LibMemcached
+ * Copyright (C) 2006-2009 Brian Aker
+ * All rights reserved.
+ *
+ * Use and distribution licensed under the BSD license. See
+ * the COPYING file in the parent directory for full text.
+ *
+ * Summary: Server IO, Not public!
+ *
+ */
+
#include "common.h"
#include "memcached_io.h"
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 ssize_t io_flush(memcached_server_st *ptr, memcached_return_t *error);
static void increment_udp_message_id(memcached_server_st *ptr);
-static memcached_return io_wait(memcached_server_st *ptr,
- memc_read_or_write read_or_write)
+static memcached_return_t 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
- ** on write if we haven't read anything from our input buffer..
- ** Try to purge the input buffer if we don't do any flow control in the
- ** application layer (just sending a lot of data etc)
- ** The test is moved down in the purge function to avoid duplication of
- ** the test.
- */
+ ** We are going to block on write, but at least on Solaris we might block
+ ** on write if we haven't read anything from our input buffer..
+ ** Try to purge the input buffer if we don't do any flow control in the
+ ** application layer (just sending a lot of data etc)
+ ** The test is moved down in the purge function to avoid duplication of
+ ** the test.
+ */
if (read_or_write == MEM_WRITE)
{
- memcached_return rc=memcached_purge(ptr);
+ memcached_return_t 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.no_block == false)
+ 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.use_udp == false)
+ {
+ /*
+ * 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_t 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
}
#endif
-memcached_return memcached_io_read(memcached_server_st *ptr,
- void *buffer, size_t length, ssize_t *nread)
+memcached_return_t memcached_io_read(memcached_server_st *ptr,
+ void *buffer, size_t length, ssize_t *nread)
{
char *buffer_ptr;
else if (data_read == -1)
{
ptr->cached_errno= errno;
- memcached_return rc= MEMCACHED_UNKNOWN_READ_FAILURE;
+ memcached_return_t rc= MEMCACHED_UNKNOWN_READ_FAILURE;
switch (errno)
{
case EAGAIN:
case EINTR:
if ((rc= io_wait(ptr, MEM_READ)) == MEMCACHED_SUCCESS)
continue;
- /* fall through */
+ /* fall through */
default:
{
}
ptr->io_bytes_sent = 0;
- ptr->read_data_length= data_read;
- ptr->read_buffer_length= data_read;
+ ptr->read_data_length= (size_t) data_read;
+ ptr->read_buffer_length= (size_t) data_read;
ptr->read_ptr= ptr->read_buffer;
}
}
ptr->server_failure_counter= 0;
- *nread = (size_t)(buffer_ptr - (char*)buffer);
+ *nread = (ssize_t)(buffer_ptr - (char*)buffer);
return MEMCACHED_SUCCESS;
}
if (ptr->write_buffer_offset == buffer_end && ptr->type != MEMCACHED_CONNECTION_UDP)
{
- memcached_return rc;
+ memcached_return_t rc;
ssize_t sent_length;
WATCHPOINT_ASSERT(ptr->fd != -1);
if (with_flush)
{
- memcached_return rc;
+ memcached_return_t rc;
WATCHPOINT_ASSERT(ptr->fd != -1);
if (io_flush(ptr, &rc) == -1)
return -1;
}
- return original_length;
+ return (ssize_t) original_length;
}
-memcached_return memcached_io_close(memcached_server_st *ptr)
+memcached_return_t memcached_io_close(memcached_server_st *ptr)
{
int r;
}
static ssize_t io_flush(memcached_server_st *ptr,
- memcached_return *error)
+ memcached_return_t *error)
{
/*
- ** We might want to purge the input buffer if we haven't consumed
- ** any output yet... The test for the limits is the purge is inline
- ** in the purge function to avoid duplicating the logic..
- */
+ ** We might want to purge the input buffer if we haven't consumed
+ ** any output yet... The test for the limits is the purge is inline
+ ** in the purge function to avoid duplicating the logic..
+ */
{
- memcached_return rc;
- WATCHPOINT_ASSERT(ptr->fd != -1);
- rc= memcached_purge(ptr);
+ memcached_return_t rc;
+ WATCHPOINT_ASSERT(ptr->fd != -1);
+ rc= memcached_purge(ptr);
- if (rc != MEMCACHED_SUCCESS && rc != MEMCACHED_STORED)
- return -1;
+ if (rc != MEMCACHED_SUCCESS && rc != MEMCACHED_STORED)
+ return -1;
}
ssize_t sent_length;
size_t return_length;
return -1;
if (ptr->write_buffer_offset == 0 || (ptr->type == MEMCACHED_CONNECTION_UDP
- && ptr->write_buffer_offset == UDP_DATAGRAM_HEADER_LENGTH))
+ && ptr->write_buffer_offset == UDP_DATAGRAM_HEADER_LENGTH))
return 0;
/* Looking for memory overflows */
case ENOBUFS:
continue;
case EAGAIN:
- {
- memcached_return rc;
- rc= io_wait(ptr, MEM_WRITE);
+ {
+ /*
+ * 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;
- if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_TIMEOUT)
- continue;
+ memcached_return_t rc;
+ rc= io_wait(ptr, MEM_WRITE);
- memcached_quit_server(ptr, 1);
- return -1;
- }
+ if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_TIMEOUT)
+ continue;
+
+ memcached_quit_server(ptr, 1);
+ return -1;
+ }
default:
memcached_quit_server(ptr, 1);
*error= MEMCACHED_ERRNO;
return -1;
}
- ptr->io_bytes_sent += sent_length;
+ ptr->io_bytes_sent += (uint32_t) sent_length;
local_write_ptr+= sent_length;
- write_length-= sent_length;
- return_length+= sent_length;
+ write_length-= (uint32_t) sent_length;
+ return_length+= (uint32_t) sent_length;
}
WATCHPOINT_ASSERT(write_length == 0);
else
ptr->write_buffer_offset= 0;
- return return_length;
+ 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,
- size_t size)
+memcached_return_t memcached_safe_read(memcached_server_st *ptr,
+ void *dta,
+ size_t size)
{
size_t offset= 0;
char *data= dta;
while (offset < size)
{
ssize_t nread;
- memcached_return rc= memcached_io_read(ptr, data + offset, size - offset,
- &nread);
+ memcached_return_t rc= memcached_io_read(ptr, data + offset, size - offset,
+ &nread);
if (rc != MEMCACHED_SUCCESS)
return rc;
- offset+= nread;
+ offset+= (size_t) nread;
}
return MEMCACHED_SUCCESS;
}
-memcached_return memcached_io_readline(memcached_server_st *ptr,
- char *buffer_ptr,
- size_t size)
+memcached_return_t memcached_io_readline(memcached_server_st *ptr,
+ char *buffer_ptr,
+ size_t size)
{
bool line_complete= false;
size_t total_nr= 0;
* We don't have any data in the buffer, so let's fill the read
* buffer. Call the standard read function to avoid duplicating
* the logic.
- */
+ */
ssize_t nread;
- memcached_return rc= memcached_io_read(ptr, buffer_ptr, 1, &nread);
+ memcached_return_t rc= memcached_io_read(ptr, buffer_ptr, 1, &nread);
if (rc != MEMCACHED_SUCCESS)
return rc;
{
struct udp_datagram_header_st *header= (struct udp_datagram_header_st *)ptr->write_buffer;
uint16_t cur_req= get_udp_datagram_request_id(header);
- uint16_t msg_num= get_msg_num_from_request_id(cur_req);
- uint16_t thread_id= get_thread_id_from_request_id(cur_req);
-
+ 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;
- header->request_id= htons(thread_id | msg_num);
+ header->request_id= htons((uint16_t) (thread_id | msg_num));
}
-memcached_return memcached_io_init_udp_header(memcached_server_st *ptr, uint16_t thread_id)
+memcached_return_t memcached_io_init_udp_header(memcached_server_st *ptr, uint16_t thread_id)
{
if (thread_id > UDP_REQUEST_ID_MAX_THREAD_ID)
return MEMCACHED_FAILURE;
struct udp_datagram_header_st *header= (struct udp_datagram_header_st *)ptr->write_buffer;
- header->request_id= htons(generate_udp_request_thread_id(thread_id));
+ header->request_id= htons((uint16_t) (generate_udp_request_thread_id(thread_id)));
header->num_datagrams= htons(1);
header->sequence_number= htons(0);
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