tstream.h

/*
 * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "os.h"
#include "streamState.h"
#include "tdatablock.h"
#include "tdbInt.h"
#include "tmsg.h"
#include "tmsgcb.h"
#include "tqueue.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef _STREAM_H_
#define _STREAM_H_

typedef struct SStreamTask SStreamTask;

enum {
  STREAM_STATUS__NORMAL = 0,
  STREAM_STATUS__STOP,
  STREAM_STATUS__INIT,
  STREAM_STATUS__FAILED,
  STREAM_STATUS__RECOVER,
  STREAM_STATUS__PAUSE,
};

enum {
  TASK_STATUS__NORMAL = 0,
  TASK_STATUS__DROPPING,
  TASK_STATUS__FAIL,
  TASK_STATUS__STOP,
  TASK_STATUS__SCAN_HISTORY,  // stream task scan history data by using tsdbread in the stream scanner
  TASK_STATUS__SCAN_HISTORY_WAL, // scan history data in wal
  TASK_STATUS__HALT,          // pause, but not be manipulated by user command
  TASK_STATUS__PAUSE,         // pause
};

enum {
  TASK_SCHED_STATUS__INACTIVE = 1,
  TASK_SCHED_STATUS__WAITING,
  TASK_SCHED_STATUS__ACTIVE,
  TASK_SCHED_STATUS__FAILED,
  TASK_SCHED_STATUS__DROPPING,
};

enum {
  TASK_INPUT_STATUS__NORMAL = 1,
  TASK_INPUT_STATUS__BLOCKED,
  TASK_INPUT_STATUS__RECOVER,
  TASK_INPUT_STATUS__STOP,
  TASK_INPUT_STATUS__FAILED,
};

enum {
  TASK_OUTPUT_STATUS__NORMAL = 1,
  TASK_OUTPUT_STATUS__WAIT,
  TASK_OUTPUT_STATUS__BLOCKED,
};

enum {
  TASK_TRIGGER_STATUS__INACTIVE = 1,
  TASK_TRIGGER_STATUS__ACTIVE,
};

typedef enum {
  TASK_LEVEL__SOURCE = 1,
  TASK_LEVEL__AGG,
  TASK_LEVEL__SINK,
} ETASK_LEVEL;

enum {
  TASK_OUTPUT__FIXED_DISPATCH = 1,
  TASK_OUTPUT__SHUFFLE_DISPATCH,
  TASK_OUTPUT__TABLE,
  TASK_OUTPUT__SMA,
  TASK_OUTPUT__FETCH,
};

enum {
  STREAM_QUEUE__SUCESS = 1,
  STREAM_QUEUE__FAILED,
  STREAM_QUEUE__PROCESSING,
};

typedef struct {
  int8_t type;
} SStreamQueueItem;

typedef void    FTbSink(SStreamTask* pTask, void* vnode, int64_t ver, void* data);
typedef int32_t FTaskExpand(void* ahandle, SStreamTask* pTask, int64_t ver);

typedef struct {
  int8_t      type;
  int64_t     ver;
  int32_t*    dataRef;
  SPackedData submit;
} SStreamDataSubmit;

typedef struct {
  int8_t  type;
  int64_t ver;
  SArray* dataRefs;  // SArray<int32_t*>
  SArray* submits;   // SArray<SPackedSubmit>
} SStreamMergedSubmit;

typedef struct {
  int8_t type;

  int32_t srcVgId;
  int32_t childId;
  int64_t sourceVer;
  int64_t reqId;

  SArray* blocks;  // SArray<SSDataBlock>
} SStreamDataBlock;

// ref data block, for delete
typedef struct {
  int8_t       type;
  SSDataBlock* pBlock;
} SStreamRefDataBlock;

typedef struct {
  int8_t type;
} SStreamCheckpoint;

typedef struct {
  int8_t       type;
  SSDataBlock* pBlock;
} SStreamTrigger;

typedef struct SStreamQueueNode SStreamQueueNode;

struct SStreamQueueNode {
  SStreamQueueItem* item;
  SStreamQueueNode* next;
};

typedef struct {
  SStreamQueueNode* head;
  int64_t           size;
} SStreamQueueRes;

void streamFreeQitem(SStreamQueueItem* data);

#if 0
bool              streamQueueResEmpty(const SStreamQueueRes* pRes);
int64_t           streamQueueResSize(const SStreamQueueRes* pRes);
SStreamQueueNode* streamQueueResFront(SStreamQueueRes* pRes);
SStreamQueueNode* streamQueueResPop(SStreamQueueRes* pRes);
void              streamQueueResClear(SStreamQueueRes* pRes);
SStreamQueueRes   streamQueueBuildRes(SStreamQueueNode* pNode);
#endif

typedef struct {
  SStreamQueueNode* pHead;
} SStreamQueue1;

#if 0
bool            streamQueueHasTask(const SStreamQueue1* pQueue);
int32_t         streamQueuePush(SStreamQueue1* pQueue, SStreamQueueItem* pItem);
SStreamQueueRes streamQueueGetRes(SStreamQueue1* pQueue);
#endif

typedef struct {
  STaosQueue* queue;
  STaosQall*  qall;
  void*       qItem;
  int8_t      status;
} SStreamQueue;

int32_t streamInit();
void    streamCleanUp();

SStreamQueue* streamQueueOpen(int64_t cap);
void          streamQueueClose(SStreamQueue* queue);

static FORCE_INLINE void streamQueueProcessSuccess(SStreamQueue* queue) {
  ASSERT(atomic_load_8(&queue->status) == STREAM_QUEUE__PROCESSING);
  queue->qItem = NULL;
  atomic_store_8(&queue->status, STREAM_QUEUE__SUCESS);
}

static FORCE_INLINE void streamQueueProcessFail(SStreamQueue* queue) {
  ASSERT(atomic_load_8(&queue->status) == STREAM_QUEUE__PROCESSING);
  atomic_store_8(&queue->status, STREAM_QUEUE__FAILED);
}

void* streamQueueNextItem(SStreamQueue* pQueue);

SStreamDataSubmit* streamDataSubmitNew(SPackedData* pData, int32_t type);
void               streamDataSubmitDestroy(SStreamDataSubmit* pDataSubmit);

typedef struct {
  char*              qmsg;
  void*              pExecutor;   // not applicable to encoder and decoder
  struct SWalReader* pWalReader;  // not applicable to encoder and decoder
} STaskExec;

typedef struct {
  int32_t taskId;
  int32_t nodeId;
  SEpSet  epSet;
} STaskDispatcherFixedEp;

typedef struct {
  char      stbFullName[TSDB_TABLE_FNAME_LEN];
  int32_t   waitingRspCnt;
  SUseDbRsp dbInfo;
} STaskDispatcherShuffle;

typedef struct {
  int64_t         stbUid;
  char            stbFullName[TSDB_TABLE_FNAME_LEN];
  SSchemaWrapper* pSchemaWrapper;
  void*           vnode;  // not available to encoder and decoder
  FTbSink*        tbSinkFunc;
  STSchema*       pTSchema;
  SSHashObj*      pTblInfo;
} STaskSinkTb;

typedef void FSmaSink(void* vnode, int64_t smaId, const SArray* data);

typedef struct {
  int64_t smaId;
  // following are not applicable to encoder and decoder
  void*     vnode;
  FSmaSink* smaSink;
} STaskSinkSma;

typedef struct {
  int8_t reserved;
} STaskSinkFetch;

typedef struct SStreamChildEpInfo {
  int32_t nodeId;
  int32_t childId;
  int32_t taskId;
  SEpSet  epSet;
} SStreamChildEpInfo;

typedef struct SStreamId {
  int64_t     streamId;
  int32_t     taskId;
  const char* idStr;
} SStreamId;

typedef struct SCheckpointInfo {
  int64_t id;
  int64_t version;     // offset in WAL
  int64_t currentVer;  // current offset in WAL, not serialize it
} SCheckpointInfo;

typedef struct SStreamStatus {
  int8_t        taskStatus;
  int8_t        downstreamReady; // downstream tasks are all ready now, if this flag is set
  int8_t        schedStatus;
  int8_t        keepTaskStatus;
  bool          transferState;
  int8_t        timerActive;     // timer is active
  int8_t        pauseAllowed;    // allowed task status to be set to be paused
} SStreamStatus;

typedef struct SHistDataRange {
  SVersionRange range;
  STimeWindow   window;
} SHistDataRange;

typedef struct SSTaskBasicInfo {
  int32_t nodeId;  // vgroup id or snode id
  SEpSet  epSet;
  int32_t selfChildId;
  int32_t totalLevel;
  int8_t  taskLevel;
  int8_t  fillHistory;  // is fill history task or not
} SSTaskBasicInfo;

typedef struct SDispatchMsgInfo {
  void*   pData;       // current dispatch data
  int16_t msgType;     // dispatch msg type
  int32_t retryCount;  // retry send data count
  int64_t blockingTs;  // output blocking timestamp
} SDispatchMsgInfo;

typedef struct {
  int8_t        type;
  int8_t        status;
  SStreamQueue* queue;
} STaskOutputInfo;

typedef struct {
  int64_t init;
  int64_t step1Start;
  int64_t step2Start;
} STaskTimestamp;

struct SStreamTask {
  SStreamId        id;
  SSTaskBasicInfo  info;
  STaskOutputInfo  outputInfo;
  SDispatchMsgInfo msgInfo;
  SStreamStatus    status;
  SCheckpointInfo  chkInfo;
  STaskExec        exec;
  SHistDataRange   dataRange;
  SStreamId        historyTaskId;
  SStreamId        streamTaskId;
  SArray*          pUpstreamEpInfoList;  // SArray<SStreamChildEpInfo*>, // children info
  int32_t          nextCheckId;
  SArray*          checkpointInfo;  // SArray<SStreamCheckpointInfo>
  STaskTimestamp   tsInfo;
  // output
  union {
    STaskDispatcherFixedEp fixedEpDispatcher;
    STaskDispatcherShuffle shuffleDispatcher;
    STaskSinkTb            tbSink;
    STaskSinkSma           smaSink;
    STaskSinkFetch         fetchSink;
  };

  int8_t        inputStatus;
  SStreamQueue* inputQueue;

  // trigger
  int8_t        triggerStatus;
  int64_t       triggerParam;
  void*         schedTimer;
  void*         launchTaskTimer;
  SMsgCb*       pMsgCb;  // msg handle
  SStreamState* pState;  // state backend
  SArray*       pRspMsgList;
  TdThreadMutex lock;

  // the followings attributes don't be serialized
  int32_t             notReadyTasks;
  int32_t             numOfWaitingUpstream;
  int64_t             checkReqId;
  SArray*             checkReqIds;  // shuffle
  int32_t             refCnt;
  int64_t             checkpointingId;
  int32_t             checkpointAlignCnt;
  int32_t             transferStateAlignCnt;
  struct SStreamMeta* pMeta;
  SSHashObj*          pNameMap;
};

// meta
typedef struct SStreamMeta {
  char*         path;
  TDB*          db;
  TTB*          pTaskDb;
  TTB*          pCheckpointDb;
  SHashObj*     pTasks;
  SArray*       pTaskList;  // SArray<task_id*>
  void*         ahandle;
  TXN*          txn;
  FTaskExpand*  expandFunc;
  int32_t       vgId;
  SRWLatch      lock;
  int32_t       walScanCounter;
  void*         streamBackend;
  int64_t       streamBackendRid;
  SHashObj*     pTaskBackendUnique;
  TdThreadMutex backendMutex;
} SStreamMeta;

int32_t tEncodeStreamEpInfo(SEncoder* pEncoder, const SStreamChildEpInfo* pInfo);
int32_t tDecodeStreamEpInfo(SDecoder* pDecoder, SStreamChildEpInfo* pInfo);

SStreamTask* tNewStreamTask(int64_t streamId, int8_t taskLevel, int8_t fillHistory, int64_t triggerParam,
                            SArray* pTaskList);
int32_t      tEncodeStreamTask(SEncoder* pEncoder, const SStreamTask* pTask);
int32_t      tDecodeStreamTask(SDecoder* pDecoder, SStreamTask* pTask);
void         tFreeStreamTask(SStreamTask* pTask);
int32_t      tAppendDataToInputQueue(SStreamTask* pTask, SStreamQueueItem* pItem);
bool         tInputQueueIsFull(const SStreamTask* pTask);

typedef struct {
  SMsgHead head;
  int64_t  streamId;
  int32_t  taskId;
} SStreamTaskRunReq;

typedef struct {
  int64_t streamId;
  int32_t taskId;
  int32_t dataSrcVgId;
  int32_t upstreamTaskId;
  int32_t upstreamChildId;
  int32_t upstreamNodeId;
  int32_t blockNum;
  int64_t totalLen;
  SArray* dataLen;  // SArray<int32_t>
  SArray* data;     // SArray<SRetrieveTableRsp*>
} SStreamDispatchReq;

typedef struct {
  int64_t streamId;
  int32_t upstreamNodeId;
  int32_t upstreamTaskId;
  int32_t downstreamNodeId;
  int32_t downstreamTaskId;
  int8_t  inputStatus;
} SStreamDispatchRsp;

typedef struct {
  int64_t            streamId;
  int64_t            reqId;
  int32_t            srcTaskId;
  int32_t            srcNodeId;
  int32_t            dstTaskId;
  int32_t            dstNodeId;
  int32_t            retrieveLen;
  SRetrieveTableRsp* pRetrieve;
} SStreamRetrieveReq;

typedef struct {
  int64_t streamId;
  int32_t childId;
  int32_t rspFromTaskId;
  int32_t rspToTaskId;
} SStreamRetrieveRsp;

typedef struct {
  int64_t reqId;
  int64_t streamId;
  int32_t upstreamNodeId;
  int32_t upstreamTaskId;
  int32_t downstreamNodeId;
  int32_t downstreamTaskId;
  int32_t childId;
} SStreamTaskCheckReq;

typedef struct {
  int64_t reqId;
  int64_t streamId;
  int32_t upstreamNodeId;
  int32_t upstreamTaskId;
  int32_t downstreamNodeId;
  int32_t downstreamTaskId;
  int32_t childId;
  int8_t  status;
} SStreamTaskCheckRsp;

typedef struct {
  SMsgHead msgHead;
  int64_t  streamId;
  int32_t  taskId;
  int8_t   igUntreated;
} SStreamScanHistoryReq;

typedef struct {
  int64_t streamId;
  int32_t upstreamTaskId;
  int32_t downstreamTaskId;
  int32_t upstreamNodeId;
  int32_t childId;
} SStreamScanHistoryFinishReq, SStreamTransferReq;

int32_t tEncodeStreamScanHistoryFinishReq(SEncoder* pEncoder, const SStreamScanHistoryFinishReq* pReq);
int32_t tDecodeStreamScanHistoryFinishReq(SDecoder* pDecoder, SStreamScanHistoryFinishReq* pReq);

typedef struct {
  int64_t streamId;
  int64_t checkpointId;
  int32_t taskId;
  int32_t nodeId;
  int64_t expireTime;
} SStreamCheckpointSourceReq;

typedef struct {
  int64_t streamId;
  int64_t checkpointId;
  int32_t taskId;
  int32_t nodeId;
  int64_t expireTime;
} SStreamCheckpointSourceRsp;

int32_t tEncodeSStreamCheckpointSourceReq(SEncoder* pEncoder, const SStreamCheckpointSourceReq* pReq);
int32_t tDecodeSStreamCheckpointSourceReq(SDecoder* pDecoder, SStreamCheckpointSourceReq* pReq);

int32_t tEncodeSStreamCheckpointSourceRsp(SEncoder* pEncoder, const SStreamCheckpointSourceRsp* pRsp);
int32_t tDecodeSStreamCheckpointSourceRsp(SDecoder* pDecoder, SStreamCheckpointSourceRsp* pRsp);

typedef struct {
  SMsgHead msgHead;
  int64_t  streamId;
  int64_t  checkpointId;
  int32_t  downstreamTaskId;
  int32_t  downstreamNodeId;
  int32_t  upstreamTaskId;
  int32_t  upstreamNodeId;
  int32_t  childId;
  int64_t  expireTime;
  int8_t   taskLevel;
} SStreamCheckpointReq;

typedef struct {
  SMsgHead msgHead;
  int64_t  streamId;
  int64_t  checkpointId;
  int32_t  downstreamTaskId;
  int32_t  downstreamNodeId;
  int32_t  upstreamTaskId;
  int32_t  upstreamNodeId;
  int32_t  childId;
  int64_t  expireTime;
  int8_t   taskLevel;
} SStreamCheckpointRsp;

int32_t tEncodeSStreamCheckpointReq(SEncoder* pEncoder, const SStreamCheckpointReq* pReq);
int32_t tDecodeSStreamCheckpointReq(SDecoder* pDecoder, SStreamCheckpointReq* pReq);

int32_t tEncodeSStreamCheckpointRsp(SEncoder* pEncoder, const SStreamCheckpointRsp* pRsp);
int32_t tDecodeSStreamCheckpointRsp(SDecoder* pDecoder, SStreamCheckpointRsp* pRsp);

typedef struct {
  int64_t streamId;
  int32_t upstreamTaskId;
  int32_t upstreamNodeId;
  int32_t downstreamId;
  int32_t downstreamNode;
} SStreamCompleteHistoryMsg;

int32_t tEncodeCompleteHistoryDataMsg(SEncoder* pEncoder, const SStreamCompleteHistoryMsg* pReq);
int32_t tDecodeCompleteHistoryDataMsg(SDecoder* pDecoder, SStreamCompleteHistoryMsg* pReq);

typedef struct {
  int64_t streamId;
  int32_t downstreamTaskId;
  int32_t taskId;
} SStreamRecoverDownstreamReq;

typedef struct {
  int64_t streamId;
  int32_t downstreamTaskId;
  int32_t taskId;
  SArray* checkpointVer;  // SArray<SStreamCheckpointInfo>
} SStreamRecoverDownstreamRsp;

int32_t tEncodeStreamTaskCheckReq(SEncoder* pEncoder, const SStreamTaskCheckReq* pReq);
int32_t tDecodeStreamTaskCheckReq(SDecoder* pDecoder, SStreamTaskCheckReq* pReq);

int32_t tEncodeStreamTaskCheckRsp(SEncoder* pEncoder, const SStreamTaskCheckRsp* pRsp);
int32_t tDecodeStreamTaskCheckRsp(SDecoder* pDecoder, SStreamTaskCheckRsp* pRsp);

int32_t tEncodeSStreamTaskScanHistoryReq(SEncoder* pEncoder, const SStreamRecoverDownstreamReq* pReq);
int32_t tDecodeSStreamTaskScanHistoryReq(SDecoder* pDecoder, SStreamRecoverDownstreamReq* pReq);

int32_t tEncodeSStreamTaskRecoverRsp(SEncoder* pEncoder, const SStreamRecoverDownstreamRsp* pRsp);
int32_t tDecodeSStreamTaskRecoverRsp(SDecoder* pDecoder, SStreamRecoverDownstreamRsp* pRsp);

int32_t tDecodeStreamDispatchReq(SDecoder* pDecoder, SStreamDispatchReq* pReq);
int32_t tDecodeStreamRetrieveReq(SDecoder* pDecoder, SStreamRetrieveReq* pReq);
void    tDeleteStreamRetrieveReq(SStreamRetrieveReq* pReq);

int32_t tInitStreamDispatchReq(SStreamDispatchReq* pReq, const SStreamTask* pTask, int32_t vgId, int32_t numOfBlocks,
                               int64_t dstTaskId);
void    tDeleteStreamDispatchReq(SStreamDispatchReq* pReq);

int32_t streamSetupScheduleTrigger(SStreamTask* pTask);

int32_t streamProcessRunReq(SStreamTask* pTask);
int32_t streamProcessDispatchMsg(SStreamTask* pTask, SStreamDispatchReq* pReq, SRpcMsg* pMsg, bool exec);
int32_t streamProcessDispatchRsp(SStreamTask* pTask, SStreamDispatchRsp* pRsp, int32_t code);

int32_t streamProcessRetrieveReq(SStreamTask* pTask, SStreamRetrieveReq* pReq, SRpcMsg* pMsg);

void    streamTaskInputFail(SStreamTask* pTask);
int32_t streamTryExec(SStreamTask* pTask);
int32_t streamSchedExec(SStreamTask* pTask);
int32_t streamTaskOutputResultBlock(SStreamTask* pTask, SStreamDataBlock* pBlock);
bool    streamTaskShouldStop(const SStreamStatus* pStatus);
bool    streamTaskShouldPause(const SStreamStatus* pStatus);
bool    streamTaskIsIdle(const SStreamTask* pTask);
int32_t streamTaskEndScanWAL(SStreamTask* pTask);

SStreamChildEpInfo * streamTaskGetUpstreamTaskEpInfo(SStreamTask* pTask, int32_t taskId);
int32_t streamScanExec(SStreamTask* pTask, int32_t batchSz);

char*   createStreamTaskIdStr(int64_t streamId, int32_t taskId);

// recover and fill history
void    streamTaskCheckDownstreamTasks(SStreamTask* pTask);
int32_t streamTaskDoCheckDownstreamTasks(SStreamTask* pTask);
int32_t streamTaskLaunchScanHistory(SStreamTask* pTask);
int32_t streamTaskCheckStatus(SStreamTask* pTask);
int32_t streamSendCheckRsp(const SStreamMeta* pMeta, const SStreamTaskCheckReq* pReq, SStreamTaskCheckRsp* pRsp,
                           SRpcHandleInfo* pRpcInfo, int32_t taskId);
int32_t streamProcessCheckRsp(SStreamTask* pTask, const SStreamTaskCheckRsp* pRsp);
int32_t streamLaunchFillHistoryTask(SStreamTask* pTask);
int32_t streamTaskScanHistoryDataComplete(SStreamTask* pTask);
int32_t streamStartRecoverTask(SStreamTask* pTask, int8_t igUntreated);
bool    streamHistoryTaskSetVerRangeStep2(SStreamTask* pTask, int64_t latestVer);

bool    streamTaskRecoverScanStep1Finished(SStreamTask* pTask);
bool    streamTaskRecoverScanStep2Finished(SStreamTask* pTask);
int32_t streamTaskRecoverSetAllStepFinished(SStreamTask* pTask);

// common
int32_t     streamSetParamForScanHistory(SStreamTask* pTask);
int32_t     streamRestoreParam(SStreamTask* pTask);
int32_t     streamSetStatusNormal(SStreamTask* pTask);
const char* streamGetTaskStatusStr(int32_t status);
void        streamTaskPause(SStreamTask* pTask);
void        streamTaskResume(SStreamTask* pTask);
void        streamTaskHalt(SStreamTask* pTask);
void        streamTaskResumeFromHalt(SStreamTask* pTask);
void        streamTaskDisablePause(SStreamTask* pTask);
void        streamTaskEnablePause(SStreamTask* pTask);

// source level
int32_t streamSetParamForStreamScannerStep1(SStreamTask* pTask, SVersionRange* pVerRange, STimeWindow* pWindow);
int32_t streamSetParamForStreamScannerStep2(SStreamTask* pTask, SVersionRange* pVerRange, STimeWindow* pWindow);
int32_t streamBuildSourceRecover1Req(SStreamTask* pTask, SStreamScanHistoryReq* pReq, int8_t igUntreated);
int32_t streamSourceScanHistoryData(SStreamTask* pTask);
int32_t streamDispatchScanHistoryFinishMsg(SStreamTask* pTask);

int32_t streamDispatchTransferStateMsg(SStreamTask* pTask);

// agg level
int32_t streamTaskScanHistoryPrepare(SStreamTask* pTask);
int32_t streamProcessScanHistoryFinishReq(SStreamTask* pTask, SStreamScanHistoryFinishReq *pReq, SRpcHandleInfo* pRpcInfo);
int32_t streamProcessScanHistoryFinishRsp(SStreamTask* pTask);

// stream task meta
void         streamMetaInit();
void         streamMetaCleanup();
SStreamMeta* streamMetaOpen(const char* path, void* ahandle, FTaskExpand expandFunc, int32_t vgId);
void         streamMetaClose(SStreamMeta* streamMeta);

// save to b-tree meta store
int32_t      streamMetaSaveTask(SStreamMeta* pMeta, SStreamTask* pTask);
int32_t      streamMetaRemoveTask(SStreamMeta* pMeta, int32_t taskId);
int32_t      streamMetaRegisterTask(SStreamMeta* pMeta, int64_t ver, SStreamTask* pTask);
int32_t      streamMetaUnregisterTask(SStreamMeta* pMeta, int32_t taskId);
int32_t      streamMetaGetNumOfTasks(const SStreamMeta* pMeta);   // todo remove it
SStreamTask* streamMetaAcquireTask(SStreamMeta* pMeta, int32_t taskId);
void         streamMetaReleaseTask(SStreamMeta* pMeta, SStreamTask* pTask);

int32_t streamMetaBegin(SStreamMeta* pMeta);
int32_t streamMetaCommit(SStreamMeta* pMeta);
int32_t streamLoadTasks(SStreamMeta* pMeta, int64_t ver);

// checkpoint
int32_t streamProcessCheckpointSourceReq(SStreamMeta* pMeta, SStreamTask* pTask, SStreamCheckpointSourceReq* pReq);
int32_t streamProcessCheckpointReq(SStreamMeta* pMeta, SStreamTask* pTask, SStreamCheckpointReq* pReq);
int32_t streamProcessCheckpointRsp(SStreamMeta* pMeta, SStreamTask* pTask, SStreamCheckpointRsp* pRsp);

int32_t streamTaskReleaseState(SStreamTask* pTask);
int32_t streamTaskReloadState(SStreamTask* pTask);
int32_t streamAlignTransferState(SStreamTask* pTask);


#ifdef __cplusplus
}
#endif

#endif /* ifndef _STREAM_H_ */