.gitignore
README.md
module.c
| *.xo | |
| *.so | |
| *.o |
Assumes:
- Redis unstable in ..
- hiredis in .., already made
| SHOBJ_CFLAGS ?= -W -Wall -fno-common -g -ggdb -std=c99 -O2 -pthread | |
| SHOBJ_LDFLAGS ?= -shared -lpthread | |
| REDIS_PATH = ../redis | |
| HIREDIS_PATH = ../hiredis | |
| .SUFFIXES: .c .so .xo .o | |
| all: cron.so | |
| .c.xo: | |
| $(CC) -I. -I$(REDIS_PATH)/src -I$(HIREDIS_PATH) $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@ | |
| module.xo: $(REDIS_PATH)/src/redismodule.h $(HIREDIS_PATH)/hiredis.h | |
| cron.so: module.xo | |
| $(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc | |
| clean: | |
| rm -rf *.xo *.so |
| #include <redismodule.h> | |
| #include <hiredis.h> | |
| #include <unistd.h> | |
| #include <pthread.h> | |
| typedef struct { | |
| pthread_t tid; | |
| redisContext *rc; | |
| } cron_t; | |
| // global cron stuff | |
| cron_t cron = { | |
| .tid = 0, | |
| .rc = NULL | |
| }; | |
| // Main cron thread event loop | |
| void *Cron_ThreadMain(void *argv) | |
| { | |
| REDISMODULE_NOT_USED(argv); | |
| // TODO: persist the connection, reconnect on disconnect | |
| while(1) { | |
| sleep(1); | |
| // TODO: discover local settings or use arguments | |
| cron.rc = redisConnect("127.0.0.1", 6379); | |
| if (cron.rc == NULL || cron.rc->err) { | |
| if (cron.rc) { | |
| printf("cron thread error: %s\n", cron.rc->errstr); | |
| // handle error | |
| goto cleanup; | |
| } else { | |
| printf("cron thread can't allocate redis context\n"); | |
| goto cleanup; | |
| } | |
| return NULL; | |
| } | |
| redisReply *reply = redisCommand(cron.rc, "PING"); | |
| if (!reply) { | |
| printf("cron thread PING reply missing\n"); | |
| goto cleanup; | |
| //handle error | |
| } | |
| if (reply->type != REDIS_REPLY_STATUS) { | |
| printf("cron thread PING reply is wrong\n"); | |
| goto cleanup; | |
| // handle error | |
| } | |
| printf("cron thread: %s\n", reply->str); | |
| freeReplyObject(reply); | |
| redisFree(cron.rc); | |
| } | |
| cleanup: | |
| printf("cron thread exited abnormally\n"); | |
| cron.tid = 0; | |
| return NULL; | |
| } | |
| // Starts the cron thread | |
| int RedisCommand_CronStart(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) | |
| { | |
| REDISMODULE_NOT_USED(argv); | |
| if (argc != 1) | |
| return RedisModule_WrongArity(ctx); | |
| if (cron.tid) { | |
| RedisModule_ReplyWithError(ctx, "cron thread already running"); | |
| return REDISMODULE_ERR; | |
| } | |
| // TODO: prettier error reporting | |
| if (pthread_create(&cron.tid, NULL, Cron_ThreadMain, NULL)) { | |
| return RedisModule_ReplyWithError(ctx, "could not start cron thread"); | |
| return REDISMODULE_ERR; | |
| } | |
| RedisModule_ReplyWithSimpleString(ctx, "OK"); | |
| return REDISMODULE_OK; | |
| } | |
| // Stops the cron thread | |
| int RedisCommand_CronStop(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) | |
| { | |
| REDISMODULE_NOT_USED(argv); | |
| if (argc != 1) | |
| return RedisModule_WrongArity(ctx); | |
| if (!cron.tid) { | |
| RedisModule_ReplyWithError(ctx, "cron not running"); | |
| return REDISMODULE_ERR; | |
| } | |
| // TODO: prettier error reporting | |
| if (pthread_cancel(cron.tid)) { | |
| return RedisModule_ReplyWithError(ctx, "could not cancel cron thread"); | |
| return REDISMODULE_ERR; | |
| } | |
| cron.tid = 0; | |
| RedisModule_ReplyWithSimpleString(ctx, "OK"); | |
| return REDISMODULE_OK; | |
| } | |
| int RedisModule_OnLoad(RedisModuleCtx *ctx) | |
| { | |
| if (RedisModule_Init(ctx, "cron", 1, REDISMODULE_APIVER_1) == REDISMODULE_ERR) | |
| return REDISMODULE_ERR; | |
| if (RedisModule_CreateCommand(ctx, "cron.start", RedisCommand_CronStart, "readonly", 0, 0, 0) == REDISMODULE_ERR) | |
| return REDISMODULE_ERR; | |
| if (RedisModule_CreateCommand(ctx, "cron.stop", RedisCommand_CronStop, "readonly", 0, 0, 0) == REDISMODULE_ERR) | |
| return REDISMODULE_ERR; | |
| return REDISMODULE_OK; | |
| } | |