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/* The thread entry point that actually executes the blocking part
* of the command HELLO.KEYS.
*
* Note: this implementation is very simple on purpose, so no duplicated
* keys (returned by SCAN) are filtered. However adding such a functionality
* would be trivial just using any data structure implementing a dictionary
* in order to filter the duplicated items. */
void *HelloKeys_ThreadMain(void *arg) {
RedisModuleBlockedClient *bc = arg;
RedisModuleCtx *ctx = RedisModule_GetThreadSafeContext(bc);
long long cursor = 0;
size_t replylen = 0;
RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
do {
RedisModule_ThreadSafeContextLock(ctx);
RedisModuleCallReply *reply = RedisModule_Call(ctx,
"SCAN","l",(long long)cursor);
RedisModule_ThreadSafeContextUnlock(ctx);
RedisModuleCallReply *cr_cursor =
RedisModule_CallReplyArrayElement(reply,0);
RedisModuleCallReply *cr_keys =
RedisModule_CallReplyArrayElement(reply,1);
RedisModuleString *s = RedisModule_CreateStringFromCallReply(cr_cursor);
RedisModule_StringToLongLong(s,&cursor);
RedisModule_FreeString(ctx,s);
size_t items = RedisModule_CallReplyLength(cr_keys);
for (size_t j = 0; j < items; j++) {
RedisModuleCallReply *ele =
RedisModule_CallReplyArrayElement(cr_keys,j);
RedisModule_ReplyWithCallReply(ctx,ele);
replylen++;
}
RedisModule_FreeCallReply(reply);
} while (cursor != 0);
RedisModule_ReplySetArrayLength(ctx,replylen);
RedisModule_FreeThreadSafeContext(ctx);
RedisModule_UnblockClient(bc,NULL);
return NULL;
}
/* HELLO.KEYS -- Return all the keys in the current database without blocking
* the server. The keys do not represent a point-in-time state so only the keys
* that were in the database from the start to the end are guaranteed to be
* there. */
int HelloKeys_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
REDISMODULE_NOT_USED(argv);
if (argc != 1) return RedisModule_WrongArity(ctx);
pthread_t tid;
/* Note that when blocking the client we do not set any callback: no
* timeout is possible since we passed '0', nor we need a reply callback
* because we'll use the thread safe context to accumulate a reply. */
RedisModuleBlockedClient *bc = RedisModule_BlockClient(ctx,NULL,NULL,NULL,0);
/* Now that we setup a blocking client, we need to pass the control
* to the thread. However we need to pass arguments to the thread:
* the reference to the blocked client handle. */
if (pthread_create(&tid,NULL,HelloKeys_ThreadMain,bc) != 0) {
RedisModule_AbortBlock(bc);
return RedisModule_ReplyWithError(ctx,"-ERR Can't start thread");
}
return REDISMODULE_OK;
}
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