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Diffstat (limited to 'deps/hiredis/examples/example-push.c')
| -rw-r--r-- | deps/hiredis/examples/example-push.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/deps/hiredis/examples/example-push.c b/deps/hiredis/examples/example-push.c new file mode 100644 index 0000000..6bc1205 --- /dev/null +++ b/deps/hiredis/examples/example-push.c @@ -0,0 +1,159 @@ +/* + * Copyright (c) 2020, Michael Grunder <michael dot grunder 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 <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <hiredis.h> + +#define KEY_COUNT 5 + +#define panicAbort(fmt, ...) \ + do { \ + fprintf(stderr, "%s:%d:%s(): " fmt, __FILE__, __LINE__, __func__, __VA_ARGS__); \ + exit(-1); \ + } while (0) + +static void assertReplyAndFree(redisContext *context, redisReply *reply, int type) { + if (reply == NULL) + panicAbort("NULL reply from server (error: %s)", context->errstr); + + if (reply->type != type) { + if (reply->type == REDIS_REPLY_ERROR) + fprintf(stderr, "Redis Error: %s\n", reply->str); + + panicAbort("Expected reply type %d but got type %d", type, reply->type); + } + + freeReplyObject(reply); +} + +/* Switch to the RESP3 protocol and enable client tracking */ +static void enableClientTracking(redisContext *c) { + redisReply *reply = redisCommand(c, "HELLO 3"); + if (reply == NULL || c->err) { + panicAbort("NULL reply or server error (error: %s)", c->errstr); + } + + if (reply->type != REDIS_REPLY_MAP) { + fprintf(stderr, "Error: Can't send HELLO 3 command. Are you sure you're "); + fprintf(stderr, "connected to redis-server >= 6.0.0?\nRedis error: %s\n", + reply->type == REDIS_REPLY_ERROR ? reply->str : "(unknown)"); + exit(-1); + } + + freeReplyObject(reply); + + /* Enable client tracking */ + reply = redisCommand(c, "CLIENT TRACKING ON"); + assertReplyAndFree(c, reply, REDIS_REPLY_STATUS); +} + +void pushReplyHandler(void *privdata, void *r) { + redisReply *reply = r; + int *invalidations = privdata; + + /* Sanity check on the invalidation reply */ + if (reply->type != REDIS_REPLY_PUSH || reply->elements != 2 || + reply->element[1]->type != REDIS_REPLY_ARRAY || + reply->element[1]->element[0]->type != REDIS_REPLY_STRING) + { + panicAbort("%s", "Can't parse PUSH message!"); + } + + /* Increment our invalidation count */ + *invalidations += 1; + + printf("pushReplyHandler(): INVALIDATE '%s' (invalidation count: %d)\n", + reply->element[1]->element[0]->str, *invalidations); + + freeReplyObject(reply); +} + +/* We aren't actually freeing anything here, but it is included to show that we can + * have hiredis call our data destructor when freeing the context */ +void privdata_dtor(void *privdata) { + unsigned int *icount = privdata; + printf("privdata_dtor(): In context privdata dtor (invalidations: %u)\n", *icount); +} + +int main(int argc, char **argv) { + unsigned int j, invalidations = 0; + redisContext *c; + redisReply *reply; + + const char *hostname = (argc > 1) ? argv[1] : "127.0.0.1"; + int port = (argc > 2) ? atoi(argv[2]) : 6379; + + redisOptions o = {0}; + REDIS_OPTIONS_SET_TCP(&o, hostname, port); + + /* Set our context privdata to the address of our invalidation counter. Each + * time our PUSH handler is called, hiredis will pass the privdata for context. + * + * This could also be done after we create the context like so: + * + * c->privdata = &invalidations; + * c->free_privdata = privdata_dtor; + */ + REDIS_OPTIONS_SET_PRIVDATA(&o, &invalidations, privdata_dtor); + + /* Set our custom PUSH message handler */ + o.push_cb = pushReplyHandler; + + c = redisConnectWithOptions(&o); + if (c == NULL || c->err) + panicAbort("Connection error: %s", c ? c->errstr : "OOM"); + + /* Enable RESP3 and turn on client tracking */ + enableClientTracking(c); + + /* Set some keys and then read them back. Once we do that, Redis will deliver + * invalidation push messages whenever the key is modified */ + for (j = 0; j < KEY_COUNT; j++) { + reply = redisCommand(c, "SET key:%d initial:%d", j, j); + assertReplyAndFree(c, reply, REDIS_REPLY_STATUS); + + reply = redisCommand(c, "GET key:%d", j); + assertReplyAndFree(c, reply, REDIS_REPLY_STRING); + } + + /* Trigger invalidation messages by updating keys we just read */ + for (j = 0; j < KEY_COUNT; j++) { + printf(" main(): SET key:%d update:%d\n", j, j); + reply = redisCommand(c, "SET key:%d update:%d", j, j); + assertReplyAndFree(c, reply, REDIS_REPLY_STATUS); + printf(" main(): SET REPLY OK\n"); + } + + printf("\nTotal detected invalidations: %d, expected: %d\n", invalidations, KEY_COUNT); + + /* PING server */ + redisFree(c); +} |