/* * Copyright (c) 2009-2010, Salvatore Sanfilippo * Copyright (c) 2010, Pieter Noordhuis * * 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 #include #include #include "async.h" #include "sds.h" #include "util.h" /* 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 redisAsyncSetReplyObjectFunctions(redisAsyncContext *ac, redisReplyObjectFunctions *fn) { redisContext *c = &(ac->c); return redisSetReplyObjectFunctions(c,fn); } 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. */ if (ac->ev.addWrite) ac->ev.addWrite(ac->ev.data); 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 (!cb) redisOOM(); 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 */ if (ac->ev.cleanup) ac->ev.cleanup(ac->ev.data); /* 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+pvariant]->type == REDIS_REPLY_INTEGER); if (reply->element[2+pvariant]->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; } /* 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) { /* No more regular callbacks, the context *must* be subscribed. */ assert(c->flags & REDIS_SUBSCRIBED); __redisGetSubscribeCallback(ac,reply,&cb); } if (cb.fn != NULL) { __redisRunCallback(ac,&cb,reply); c->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->fn->freeObject(reply); } } /* Disconnect when there was an error reading the reply */ if (status != REDIS_OK) __redisAsyncDisconnect(ac); } /* 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 (redisBufferRead(c) == REDIS_ERR) { __redisAsyncDisconnect(ac); } else { /* Always re-schedule reads */ if (ac->ev.addRead) ac->ev.addRead(ac->ev.data); redisProcessCallbacks(ac); } } void redisAsyncHandleWrite(redisAsyncContext *ac) { redisContext *c = &(ac->c); int done = 0; if (redisBufferWrite(c,&done) == REDIS_ERR) { __redisAsyncDisconnect(ac); } else { /* Continue writing when not done, stop writing otherwise */ if (!done) { if (ac->ev.addWrite) ac->ev.addWrite(ac->ev.data); } else { if (ac->ev.delWrite) ac->ev.delWrite(ac->ev.data); } /* Always schedule reads after writes */ if (ac->ev.addRead) ac->ev.addRead(ac->ev.data); /* Fire onConnect when this is the first write event. */ if (!(c->flags & REDIS_CONNECTED)) { c->flags |= REDIS_CONNECTED; if (ac->onConnect) ac->onConnect(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 (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 */ if (ac->ev.addWrite) ac->ev.addWrite(ac->ev.data); 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; }