/*
* Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
* Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "fmacros.h"
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include "async.h"
#include "net.h"
#include "dict.c"
#include "sds.h"
#define _EL_ADD_READ(ctx) do { \
if ((ctx)->ev.addRead) (ctx)->ev.addRead((ctx)->ev.data); \
} while(0)
#define _EL_DEL_READ(ctx) do { \
if ((ctx)->ev.delRead) (ctx)->ev.delRead((ctx)->ev.data); \
} while(0)
#define _EL_ADD_WRITE(ctx) do { \
if ((ctx)->ev.addWrite) (ctx)->ev.addWrite((ctx)->ev.data); \
} while(0)
#define _EL_DEL_WRITE(ctx) do { \
if ((ctx)->ev.delWrite) (ctx)->ev.delWrite((ctx)->ev.data); \
} while(0)
#define _EL_CLEANUP(ctx) do { \
if ((ctx)->ev.cleanup) (ctx)->ev.cleanup((ctx)->ev.data); \
} while(0);
/* Forward declaration of function in hiredis.c */
void __redisAppendCommand(redisContext *c, char *cmd, size_t len);
/* Functions managing dictionary of callbacks for pub/sub. */
static unsigned int callbackHash(const void *key) {
return dictGenHashFunction((unsigned char*)key,sdslen((char*)key));
}
static void *callbackValDup(void *privdata, const void *src) {
((void) privdata);
redisCallback *dup = malloc(sizeof(*dup));
memcpy(dup,src,sizeof(*dup));
return dup;
}
static int callbackKeyCompare(void *privdata, const void *key1, const void *key2) {
int l1, l2;
((void) privdata);
l1 = sdslen((sds)key1);
l2 = sdslen((sds)key2);
if (l1 != l2) return 0;
return memcmp(key1,key2,l1) == 0;
}
static void callbackKeyDestructor(void *privdata, void *key) {
((void) privdata);
sdsfree((sds)key);
}
static void callbackValDestructor(void *privdata, void *val) {
((void) privdata);
free(val);
}
static dictType callbackDict = {
callbackHash,
NULL,
callbackValDup,
callbackKeyCompare,
callbackKeyDestructor,
callbackValDestructor
};
static redisAsyncContext *redisAsyncInitialize(redisContext *c) {
redisAsyncContext *ac = realloc(c,sizeof(redisAsyncContext));
c = &(ac->c);
/* The regular connect functions will always set the flag REDIS_CONNECTED.
* For the async API, we want to wait until the first write event is
* received up before setting this flag, so reset it here. */
c->flags &= ~REDIS_CONNECTED;
ac->err = 0;
ac->errstr = NULL;
ac->data = NULL;
ac->ev.data = NULL;
ac->ev.addRead = NULL;
ac->ev.delRead = NULL;
ac->ev.addWrite = NULL;
ac->ev.delWrite = NULL;
ac->ev.cleanup = NULL;
ac->onConnect = NULL;
ac->onDisconnect = NULL;
ac->replies.head = NULL;
ac->replies.tail = NULL;
ac->sub.invalid.head = NULL;
ac->sub.invalid.tail = NULL;
ac->sub.channels = dictCreate(&callbackDict,NULL);
ac->sub.patterns = dictCreate(&callbackDict,NULL);
return ac;
}
/* We want the error field to be accessible directly instead of requiring
* an indirection to the redisContext struct. */
static void __redisAsyncCopyError(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
ac->err = c->err;
ac->errstr = c->errstr;
}
redisAsyncContext *redisAsyncConnect(const char *ip, int port) {
redisContext *c = redisConnectNonBlock(ip,port);
redisAsyncContext *ac = redisAsyncInitialize(c);
__redisAsyncCopyError(ac);
return ac;
}
redisAsyncContext *redisAsyncConnectUnix(const char *path) {
redisContext *c = redisConnectUnixNonBlock(path);
redisAsyncContext *ac = redisAsyncInitialize(c);
__redisAsyncCopyError(ac);
return ac;
}
int redisAsyncSetConnectCallback(redisAsyncContext *ac, redisConnectCallback *fn) {
if (ac->onConnect == NULL) {
ac->onConnect = fn;
/* The common way to detect an established connection is to wait for
* the first write event to be fired. This assumes the related event
* library functions are already set. */
_EL_ADD_WRITE(ac);
return REDIS_OK;
}
return REDIS_ERR;
}
int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn) {
if (ac->onDisconnect == NULL) {
ac->onDisconnect = fn;
return REDIS_OK;
}
return REDIS_ERR;
}
/* Helper functions to push/shift callbacks */
static int __redisPushCallback(redisCallbackList *list, redisCallback *source) {
redisCallback *cb;
/* Copy callback from stack to heap */
cb = malloc(sizeof(*cb));
if (source != NULL) {
memcpy(cb,source,sizeof(*cb));
cb->next = NULL;
}
/* Store callback in list */
if (list->head == NULL)
list->head = cb;
if (list->tail != NULL)
list->tail->next = cb;
list->tail = cb;
return REDIS_OK;
}
static int __redisShiftCallback(redisCallbackList *list, redisCallback *target) {
redisCallback *cb = list->head;
if (cb != NULL) {
list->head = cb->next;
if (cb == list->tail)
list->tail = NULL;
/* Copy callback from heap to stack */
if (target != NULL)
memcpy(target,cb,sizeof(*cb));
free(cb);
return REDIS_OK;
}
return REDIS_ERR;
}
static void __redisRunCallback(redisAsyncContext *ac, redisCallback *cb, redisReply *reply) {
redisContext *c = &(ac->c);
if (cb->fn != NULL) {
c->flags |= REDIS_IN_CALLBACK;
cb->fn(ac,reply,cb->privdata);
c->flags &= ~REDIS_IN_CALLBACK;
}
}
/* Helper function to free the context. */
static void __redisAsyncFree(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
redisCallback cb;
dictIterator *it;
dictEntry *de;
/* Execute pending callbacks with NULL reply. */
while (__redisShiftCallback(&ac->replies,&cb) == REDIS_OK)
__redisRunCallback(ac,&cb,NULL);
/* Execute callbacks for invalid commands */
while (__redisShiftCallback(&ac->sub.invalid,&cb) == REDIS_OK)
__redisRunCallback(ac,&cb,NULL);
/* Run subscription callbacks callbacks with NULL reply */
it = dictGetIterator(ac->sub.channels);
while ((de = dictNext(it)) != NULL)
__redisRunCallback(ac,dictGetEntryVal(de),NULL);
dictReleaseIterator(it);
dictRelease(ac->sub.channels);
it = dictGetIterator(ac->sub.patterns);
while ((de = dictNext(it)) != NULL)
__redisRunCallback(ac,dictGetEntryVal(de),NULL);
dictReleaseIterator(it);
dictRelease(ac->sub.patterns);
/* Signal event lib to clean up */
_EL_CLEANUP(ac);
/* Execute disconnect callback. When redisAsyncFree() initiated destroying
* this context, the status will always be REDIS_OK. */
if (ac->onDisconnect && (c->flags & REDIS_CONNECTED)) {
if (c->flags & REDIS_FREEING) {
ac->onDisconnect(ac,REDIS_OK);
} else {
ac->onDisconnect(ac,(ac->err == 0) ? REDIS_OK : REDIS_ERR);
}
}
/* Cleanup self */
redisFree(c);
}
/* Free the async context. When this function is called from a callback,
* control needs to be returned to redisProcessCallbacks() before actual
* free'ing. To do so, a flag is set on the context which is picked up by
* redisProcessCallbacks(). Otherwise, the context is immediately free'd. */
void redisAsyncFree(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
c->flags |= REDIS_FREEING;
if (!(c->flags & REDIS_IN_CALLBACK))
__redisAsyncFree(ac);
}
/* Helper function to make the disconnect happen and clean up. */
static void __redisAsyncDisconnect(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
/* Make sure error is accessible if there is any */
__redisAsyncCopyError(ac);
if (ac->err == 0) {
/* For clean disconnects, there should be no pending callbacks. */
assert(__redisShiftCallback(&ac->replies,NULL) == REDIS_ERR);
} else {
/* Disconnection is caused by an error, make sure that pending
* callbacks cannot call new commands. */
c->flags |= REDIS_DISCONNECTING;
}
/* For non-clean disconnects, __redisAsyncFree() will execute pending
* callbacks with a NULL-reply. */
__redisAsyncFree(ac);
}
/* Tries to do a clean disconnect from Redis, meaning it stops new commands
* from being issued, but tries to flush the output buffer and execute
* callbacks for all remaining replies. When this function is called from a
* callback, there might be more replies and we can safely defer disconnecting
* to redisProcessCallbacks(). Otherwise, we can only disconnect immediately
* when there are no pending callbacks. */
void redisAsyncDisconnect(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
c->flags |= REDIS_DISCONNECTING;
if (!(c->flags & REDIS_IN_CALLBACK) && ac->replies.head == NULL)
__redisAsyncDisconnect(ac);
}
static int __redisGetSubscribeCallback(redisAsyncContext *ac, redisReply *reply, redisCallback *dstcb) {
redisContext *c = &(ac->c);
dict *callbacks;
dictEntry *de;
int pvariant;
char *stype;
sds sname;
/* Custom reply functions are not supported for pub/sub. This will fail
* very hard when they are used... */
if (reply->type == REDIS_REPLY_ARRAY) {
assert(reply->elements >= 2);
assert(reply->element[0]->type == REDIS_REPLY_STRING);
stype = reply->element[0]->str;
pvariant = (tolower(stype[0]) == 'p') ? 1 : 0;
if (pvariant)
callbacks = ac->sub.patterns;
else
callbacks = ac->sub.channels;
/* Locate the right callback */
assert(reply->element[1]->type == REDIS_REPLY_STRING);
sname = sdsnewlen(reply->element[1]->str,reply->element[1]->len);
de = dictFind(callbacks,sname);
if (de != NULL) {
memcpy(dstcb,dictGetEntryVal(de),sizeof(*dstcb));
/* If this is an unsubscribe message, remove it. */
if (strcasecmp(stype+pvariant,"unsubscribe") == 0) {
dictDelete(callbacks,sname);
/* If this was the last unsubscribe message, revert to
* non-subscribe mode. */
assert(reply->element[2]->type == REDIS_REPLY_INTEGER);
if (reply->element[2]->integer == 0)
c->flags &= ~REDIS_SUBSCRIBED;
}
}
sdsfree(sname);
} else {
/* Shift callback for invalid commands. */
__redisShiftCallback(&ac->sub.invalid,dstcb);
}
return REDIS_OK;
}
void redisProcessCallbacks(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
redisCallback cb;
void *reply = NULL;
int status;
while((status = redisGetReply(c,&reply)) == REDIS_OK) {
if (reply == NULL) {
/* When the connection is being disconnected and there are
* no more replies, this is the cue to really disconnect. */
if (c->flags & REDIS_DISCONNECTING && sdslen(c->obuf) == 0) {
__redisAsyncDisconnect(ac);
return;
}
/* If monitor mode, repush callback */
if(c->flags & REDIS_MONITORING) {
__redisPushCallback(&ac->replies,&cb);
}
/* When the connection is not being disconnected, simply stop
* trying to get replies and wait for the next loop tick. */
break;
}
/* Even if the context is subscribed, pending regular callbacks will
* get a reply before pub/sub messages arrive. */
if (__redisShiftCallback(&ac->replies,&cb) != REDIS_OK) {
/*
* A spontaneous reply in a not-subscribed context can be the error
* reply that is sent when a new connection exceeds the maximum
* number of allowed connections on the server side.
*
* This is seen as an error instead of a regular reply because the
* server closes the connection after sending it.
*
* To prevent the error from being overwritten by an EOF error the
* connection is closed here. See issue #43.
*
* Another possibility is that the server is loading its dataset.
* In this case we also want to close the connection, and have the
* user wait until the server is ready to take our request.
*/
if (((redisReply*)reply)->type == REDIS_REPLY_ERROR) {
c->err = REDIS_ERR_OTHER;
snprintf(c->errstr,sizeof(c->errstr),"%s",((redisReply*)reply)->str);
__redisAsyncDisconnect(ac);
return;
}
/* No more regular callbacks and no errors, the context *must* be subscribed or monitoring. */
assert((c->flags & REDIS_SUBSCRIBED || c->flags & REDIS_MONITORING));
if(c->flags & REDIS_SUBSCRIBED)
__redisGetSubscribeCallback(ac,reply,&cb);
}
if (cb.fn != NULL) {
__redisRunCallback(ac,&cb,reply);
c->reader->fn->freeObject(reply);
/* Proceed with free'ing when redisAsyncFree() was called. */
if (c->flags & REDIS_FREEING) {
__redisAsyncFree(ac);
return;
}
} else {
/* No callback for this reply. This can either be a NULL callback,
* or there were no callbacks to begin with. Either way, don't
* abort with an error, but simply ignore it because the client
* doesn't know what the server will spit out over the wire. */
c->reader->fn->freeObject(reply);
}
}
/* Disconnect when there was an error reading the reply */
if (status != REDIS_OK)
__redisAsyncDisconnect(ac);
}
/* Internal helper function to detect socket status the first time a read or
* write event fires. When connecting was not succesful, the connect callback
* is called with a REDIS_ERR status and the context is free'd. */
static int __redisAsyncHandleConnect(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
if (redisCheckSocketError(c,c->fd) == REDIS_ERR) {
/* Try again later when connect(2) is still in progress. */
if (errno == EINPROGRESS)
return REDIS_OK;
if (ac->onConnect) ac->onConnect(ac,REDIS_ERR);
__redisAsyncDisconnect(ac);
return REDIS_ERR;
}
/* Mark context as connected. */
c->flags |= REDIS_CONNECTED;
if (ac->onConnect) ac->onConnect(ac,REDIS_OK);
return REDIS_OK;
}
/* This function should be called when the socket is readable.
* It processes all replies that can be read and executes their callbacks.
*/
void redisAsyncHandleRead(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
if (!(c->flags & REDIS_CONNECTED)) {
/* Abort connect was not successful. */
if (__redisAsyncHandleConnect(ac) != REDIS_OK)
return;
/* Try again later when the context is still not connected. */
if (!(c->flags & REDIS_CONNECTED))
return;
}
if (redisBufferRead(c) == REDIS_ERR) {
__redisAsyncDisconnect(ac);
} else {
/* Always re-schedule reads */
_EL_ADD_READ(ac);
redisProcessCallbacks(ac);
}
}
void redisAsyncHandleWrite(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
int done = 0;
if (!(c->flags & REDIS_CONNECTED)) {
/* Abort connect was not successful. */
if (__redisAsyncHandleConnect(ac) != REDIS_OK)
return;
/* Try again later when the context is still not connected. */
if (!(c->flags & REDIS_CONNECTED))
return;
}
if (redisBufferWrite(c,&done) == REDIS_ERR) {
__redisAsyncDisconnect(ac);
} else {
/* Continue writing when not done, stop writing otherwise */
if (!done)
_EL_ADD_WRITE(ac);
else
_EL_DEL_WRITE(ac);
/* Always schedule reads after writes */
_EL_ADD_READ(ac);
}
}
/* Sets a pointer to the first argument and its length starting at p. Returns
* the number of bytes to skip to get to the following argument. */
static char *nextArgument(char *start, char **str, size_t *len) {
char *p = start;
if (p[0] != '$') {
p = strchr(p,'$');
if (p == NULL) return NULL;
}
*len = (int)strtol(p+1,NULL,10);
p = strchr(p,'\r');
assert(p);
*str = p+2;
return p+2+(*len)+2;
}
/* Helper function for the redisAsyncCommand* family of functions. Writes a
* formatted command to the output buffer and registers the provided callback
* function with the context. */
static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, char *cmd, size_t len) {
redisContext *c = &(ac->c);
redisCallback cb;
int pvariant, hasnext;
char *cstr, *astr;
size_t clen, alen;
char *p;
sds sname;
/* Don't accept new commands when the connection is about to be closed. */
if (c->flags & (REDIS_DISCONNECTING | REDIS_FREEING)) return REDIS_ERR;
/* Setup callback */
cb.fn = fn;
cb.privdata = privdata;
/* Find out which command will be appended. */
p = nextArgument(cmd,&cstr,&clen);
assert(p != NULL);
hasnext = (p[0] == '$');
pvariant = (tolower(cstr[0]) == 'p') ? 1 : 0;
cstr += pvariant;
clen -= pvariant;
if (hasnext && strncasecmp(cstr,"subscribe\r\n",11) == 0) {
c->flags |= REDIS_SUBSCRIBED;
/* Add every channel/pattern to the list of subscription callbacks. */
while ((p = nextArgument(p,&astr,&alen)) != NULL) {
sname = sdsnewlen(astr,alen);
if (pvariant)
dictReplace(ac->sub.patterns,sname,&cb);
else
dictReplace(ac->sub.channels,sname,&cb);
}
} else if (strncasecmp(cstr,"unsubscribe\r\n",13) == 0) {
/* It is only useful to call (P)UNSUBSCRIBE when the context is
* subscribed to one or more channels or patterns. */
if (!(c->flags & REDIS_SUBSCRIBED)) return REDIS_ERR;
/* (P)UNSUBSCRIBE does not have its own response: every channel or
* pattern that is unsubscribed will receive a message. This means we
* should not append a callback function for this command. */
} else if(strncasecmp(cstr,"monitor\r\n",9) == 0) {
/* Set monitor flag and push callback */
c->flags |= REDIS_MONITORING;
__redisPushCallback(&ac->replies,&cb);
} else {
if (c->flags & REDIS_SUBSCRIBED)
/* This will likely result in an error reply, but it needs to be
* received and passed to the callback. */
__redisPushCallback(&ac->sub.invalid,&cb);
else
__redisPushCallback(&ac->replies,&cb);
}
__redisAppendCommand(c,cmd,len);
/* Always schedule a write when the write buffer is non-empty */
_EL_ADD_WRITE(ac);
return REDIS_OK;
}
int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, va_list ap) {
char *cmd;
int len;
int status;
len = redisvFormatCommand(&cmd,format,ap);
status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
free(cmd);
return status;
}
int redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, ...) {
va_list ap;
int status;
va_start(ap,format);
status = redisvAsyncCommand(ac,fn,privdata,format,ap);
va_end(ap);
return status;
}
int redisAsyncCommandArgv(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, int argc, const char **argv, const size_t *argvlen) {
char *cmd;
int len;
int status;
len = redisFormatCommandArgv(&cmd,argc,argv,argvlen);
status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
free(cmd);
return status;
}