2 Basic socket buffered IO
6 #include "memcached_io.h"
7 #include <sys/select.h>
15 static ssize_t
io_flush(memcached_server_st
*ptr
, memcached_return
*error
);
17 static memcached_return
io_wait(memcached_server_st
*ptr
,
18 memc_read_or_write read_or_write
)
24 if (read_or_write
== MEM_WRITE
) /* write */
25 flags
= POLLOUT
| POLLERR
;
27 flags
= POLLIN
| POLLERR
;
29 memset(&fds
, 0, sizeof(struct pollfd
));
33 error
= poll(fds
, 1, ptr
->root
->poll_timeout
);
36 return MEMCACHED_SUCCESS
;
39 return MEMCACHED_TIMEOUT
;
42 /* Imposssible for anything other then -1 */
43 WATCHPOINT_ASSERT(error
== -1);
44 memcached_quit_server(ptr
, 1);
46 return MEMCACHED_FAILURE
;
51 void memcached_io_preread(memcached_st
*ptr
)
57 for (x
= 0; x
< ptr
->number_of_hosts
; x
++)
59 if (memcached_server_response_count(ptr
, x
) &&
60 ptr
->hosts
[x
].read_data_length
< MEMCACHED_MAX_BUFFER
)
64 data_read
= read(ptr
->hosts
[x
].fd
,
65 ptr
->hosts
[x
].read_ptr
+ ptr
->hosts
[x
].read_data_length
,
66 MEMCACHED_MAX_BUFFER
- ptr
->hosts
[x
].read_data_length
);
70 ptr
->hosts
[x
].read_buffer_length
+= data_read
;
71 ptr
->hosts
[x
].read_data_length
+= data_read
;
77 ssize_t
memcached_io_read(memcached_server_st
*ptr
,
78 char *buffer
, size_t length
)
87 if (!ptr
->read_buffer_length
)
93 data_read
= read(ptr
->fd
,
95 MEMCACHED_MAX_BUFFER
);
98 else if (data_read
== -1)
100 ptr
->cached_errno
= errno
;
107 rc
= io_wait(ptr
, MEM_READ
);
109 if (rc
== MEMCACHED_SUCCESS
)
115 memcached_quit_server(ptr
, 1);
122 WATCHPOINT_ASSERT(0);
128 ptr
->read_data_length
= data_read
;
129 ptr
->read_buffer_length
= data_read
;
130 ptr
->read_ptr
= ptr
->read_buffer
;
137 difference
= (length
> ptr
->read_buffer_length
) ? ptr
->read_buffer_length
: length
;
139 memcpy(buffer_ptr
, ptr
->read_ptr
, difference
);
140 length
-= difference
;
141 ptr
->read_ptr
+= difference
;
142 ptr
->read_buffer_length
-= difference
;
143 buffer_ptr
+= difference
;
147 *buffer_ptr
= *ptr
->read_ptr
;
149 ptr
->read_buffer_length
--;
158 return (size_t)(buffer_ptr
- buffer
);
161 ssize_t
memcached_io_write(memcached_server_st
*ptr
,
162 char *buffer
, size_t length
, char with_flush
)
164 size_t original_length
;
167 original_length
= length
;
175 should_write
= MEMCACHED_MAX_BUFFER
- ptr
->write_buffer_offset
;
176 write_ptr
= ptr
->write_buffer
+ ptr
->write_buffer_offset
;
178 should_write
= (should_write
< length
) ? should_write
: length
;
180 memcpy(write_ptr
, buffer_ptr
, should_write
);
181 ptr
->write_buffer_offset
+= should_write
;
182 buffer_ptr
+= should_write
;
183 length
-= should_write
;
185 if (ptr
->write_buffer_offset
== MEMCACHED_MAX_BUFFER
)
190 sent_length
= io_flush(ptr
, &rc
);
191 if (sent_length
== -1)
194 WATCHPOINT_ASSERT(sent_length
== MEMCACHED_MAX_BUFFER
);
201 if (io_flush(ptr
, &rc
) == -1)
205 return original_length
;
208 memcached_return
memcached_io_close(memcached_server_st
*ptr
)
212 return MEMCACHED_SUCCESS
;
215 static ssize_t
io_flush(memcached_server_st
*ptr
,
216 memcached_return
*error
)
219 size_t return_length
;
220 char *local_write_ptr
= ptr
->write_buffer
;
221 size_t write_length
= ptr
->write_buffer_offset
;
223 *error
= MEMCACHED_SUCCESS
;
225 if (ptr
->write_buffer_offset
== 0)
228 /* Looking for memory overflows */
229 if (write_length
== MEMCACHED_MAX_BUFFER
)
230 WATCHPOINT_ASSERT(ptr
->write_buffer
== local_write_ptr
);
231 WATCHPOINT_ASSERT((ptr
->write_buffer
+ MEMCACHED_MAX_BUFFER
) >= (local_write_ptr
+ write_length
));
236 WATCHPOINT_ASSERT(write_length
> 0);
238 if (ptr
->type
== MEMCACHED_CONNECTION_UDP
)
242 ai
= ptr
->address_info
;
244 /* Crappy test code */
245 char buffer
[HUGE_STRING_LEN
+ 8];
246 memset(buffer
, 0, HUGE_STRING_LEN
+ 8);
247 memcpy (buffer
+8, local_write_ptr
, write_length
);
256 sent_length
= sendto(ptr
->fd
, buffer
, write_length
+ 8, 0,
257 (struct sockaddr
*)ai
->ai_addr
,
259 if (sent_length
== -1)
261 WATCHPOINT_ERRNO(errno
);
262 WATCHPOINT_ASSERT(0);
264 sent_length
-= 8; /* We remove the header */
268 if ((ssize_t
)(sent_length
= write(ptr
->fd
, local_write_ptr
,
269 write_length
)) == -1)
278 rc
= io_wait(ptr
, MEM_WRITE
);
280 if (rc
== MEMCACHED_SUCCESS
)
283 memcached_quit_server(ptr
, 1);
287 memcached_quit_server(ptr
, 1);
288 ptr
->cached_errno
= errno
;
289 *error
= MEMCACHED_ERRNO
;
295 local_write_ptr
+= sent_length
;
296 write_length
-= sent_length
;
297 return_length
+= sent_length
;
300 WATCHPOINT_ASSERT(write_length
== 0);
301 WATCHPOINT_ASSERT(return_length
== ptr
->write_buffer_offset
);
302 ptr
->write_buffer_offset
= 0;
304 return return_length
;
308 Eventually we will just kill off the server with the problem.
310 void memcached_io_reset(memcached_server_st
*ptr
)
312 memcached_quit_server(ptr
, 0);