zeek/src/storage/backend/redis/Redis.h

105 lines
3.2 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#pragma once
#include "zeek/iosource/IOSource.h"
#include "zeek/storage/Backend.h"
// Forward declare some types from hiredis to avoid including the header
struct redisAsyncContext;
struct redisReply;
struct redisPollEvents;
namespace zeek::storage::backend::redis {
class Redis : public Backend, public iosource::IOSource {
public:
Redis(std::string_view tag) : Backend(SupportedModes::ASYNC, tag), IOSource(true) {}
~Redis() override = default;
static BackendPtr Instantiate(std::string_view tag);
/**
* Returns a descriptive tag representing the source for debugging.
* This has to be overloaded for Redis because IOSource requires it.
*
* @return The debugging name.
*/
const char* Tag() override { return tag.c_str(); }
/**
* Called by the manager system to open the backend.
*/
OperationResult DoOpen(RecordValPtr options, OpenResultCallback* cb = nullptr) override;
/**
* Finalizes the backend when it's being closed.
*/
OperationResult DoClose(OperationResultCallback* cb = nullptr) override;
/**
* Returns whether the backend is opened.
*/
bool IsOpen() override { return connected; }
/**
* The workhorse method for Retrieve().
*/
OperationResult DoPut(ValPtr key, ValPtr value, bool overwrite = true, double expiration_time = 0,
OperationResultCallback* cb = nullptr) override;
/**
* The workhorse method for Get().
*/
OperationResult DoGet(ValPtr key, OperationResultCallback* cb = nullptr) override;
/**
* The workhorse method for Erase().
*/
OperationResult DoErase(ValPtr key, OperationResultCallback* cb = nullptr) override;
/**
* Removes any entries in the backend that have expired. Can be overridden by
* derived classes.
*/
void Expire() override;
// IOSource interface
double GetNextTimeout() override { return -1; }
void Process() override {}
void ProcessFd(int fd, int flags) override;
// Hiredis async interface
void OnConnect(int status);
void OnDisconnect(int status);
void HandlePutResult(redisReply* reply, OperationResultCallback* callback);
void HandleGetResult(redisReply* reply, OperationResultCallback* callback);
void HandleEraseResult(redisReply* reply, OperationResultCallback* callback);
void HandleZRANGEBYSCORE(redisReply* reply);
// HandleGeneric exists so that async-running-as-sync operations can remove
// themselves from the list of active operations.
void HandleGeneric() { --active_ops; }
protected:
void Poll() override;
private:
OperationResult ParseGetReply(redisReply* reply) const;
redisAsyncContext* async_ctx = nullptr;
// When running in sync mode, this is used to keep a queue of replies as
// responses come in from the remote calls until we run out of data to
// poll.
std::deque<redisReply*> reply_queue;
OpenResultCallback* open_cb;
std::string server_addr;
std::string key_prefix;
std::atomic<bool> connected = false;
int active_ops = 0;
};
} // namespace zeek::storage::backend::redis