diff options
Diffstat (limited to 'examples')
| -rw-r--r-- | examples/CMakeLists.txt | 3 | ||||
| -rw-r--r-- | examples/example-push.c | 118 |
2 files changed, 121 insertions, 0 deletions
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt index dd3a313..1d5bc56 100644 --- a/examples/CMakeLists.txt +++ b/examples/CMakeLists.txt @@ -44,3 +44,6 @@ ENDIF() ADD_EXECUTABLE(example example.c) TARGET_LINK_LIBRARIES(example hiredis) + +ADD_EXECUTABLE(example-push example-push.c) +TARGET_LINK_LIBRARIES(example-push hiredis) diff --git a/examples/example-push.c b/examples/example-push.c new file mode 100644 index 0000000..d8b41f9 --- /dev/null +++ b/examples/example-push.c @@ -0,0 +1,118 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <hiredis.h> +#include <win32.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); +} + +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 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 our context privdata to the address of our invalidation counter. Each + * time our PUSH handler is called, hiredis will pass the privdata for context */ + c->privdata = &invalidations; + + /* 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); +} |