tsync.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/>.
 */

#ifndef TDENGINE_SYNC_H
#define TDENGINE_SYNC_H

#ifdef __cplusplus
extern "C" {
#endif

#define TAOS_SYNC_MAX_REPLICA 5
#define TAOS_SYNC_MAX_INDEX   0x7FFFFFFF

typedef enum _TAOS_SYNC_ROLE {
  TAOS_SYNC_ROLE_OFFLINE,
  TAOS_SYNC_ROLE_UNSYNCED,
  TAOS_SYNC_ROLE_SLAVE,
  TAOS_SYNC_ROLE_MASTER,
} ESyncRole;

typedef enum _TAOS_SYNC_STATUS {
  TAOS_SYNC_STATUS_INIT,
  TAOS_SYNC_STATUS_START,
  TAOS_SYNC_STATUS_FILE,
  TAOS_SYNC_STATUS_CACHE,
} ESyncStatus;

typedef struct {
  uint32_t  nodeId;    // node ID assigned by TDengine
  uint16_t  nodePort;  // node sync Port
  char      nodeFqdn[TSDB_FQDN_LEN]; // node FQDN  
} SNodeInfo;

typedef struct {
  int8_t     quorum;    // number of confirms required, >=1 
  int8_t     replica;   // number of replications, >=1
  SNodeInfo  nodeInfo[TAOS_SYNC_MAX_REPLICA];
} SSyncCfg;

typedef struct {
  int       selfIndex;
  uint32_t  nodeId[TAOS_SYNC_MAX_REPLICA];
  int       role[TAOS_SYNC_MAX_REPLICA];  
} SNodesRole;

/* 
  if name is empty(name[0] is zero), get the file from index or after, but not larger than eindex. If a file
  is found between index and eindex, index shall be updated, name shall be set, size shall be set to 
  file size, and file magic number shall be returned. 

  if name is provided(name[0] is not zero), get the named file at the specified index. If not there, return
  zero. If it is there, set the size to file size, and return file magic number. Index shall not be updated.
*/
typedef uint32_t (*FGetFileInfo)(void *ahandle, char *name, uint32_t *index, uint32_t eindex, int32_t *size, uint64_t *fversion); 

// get the wal file from index or after
// return value, -1: error, 1:more wal files, 0:last WAL. if name[0]==0, no WAL file
typedef int      (*FGetWalInfo)(void *ahandle, char *name, uint32_t *index); 
 
// when a forward pkt is received, call this to handle data 
typedef int      (*FWriteToCache)(void *ahandle, void *pHead, int type);

// when forward is confirmed by peer, master call this API to notify app
typedef void     (*FConfirmForward)(void *ahandle, void *mhandle, int32_t code);

// when role is changed, call this to notify app
typedef void     (*FNotifyRole)(void *ahandle, int8_t role);

// if a number of retrieving data failed, call this to start flow control 
typedef void     (*FNotifyFlowCtrl)(void *ahandle, int32_t mseconds);

// when data file is synced successfully, notity app
typedef int      (*FNotifyFileSynced)(void *ahandle, uint64_t fversion);

typedef struct {
  int32_t    vgId;      // vgroup ID
  uint64_t   version;   // initial version
  SSyncCfg   syncCfg;   // configuration from mgmt
  char       path[128]; // path to the file
 
  void      *ahandle;   // handle provided by APP 
  FGetFileInfo    getFileInfo;
  FGetWalInfo     getWalInfo;
  FWriteToCache   writeToCache;
  FConfirmForward confirmForward;
  FNotifyRole     notifyRole;
  FNotifyFlowCtrl notifyFlowCtrl;
  FNotifyFileSynced notifyFileSynced;
} SSyncInfo;

typedef void* tsync_h;

tsync_h syncStart(const SSyncInfo *);
void    syncStop(tsync_h shandle);
int32_t syncReconfig(tsync_h shandle, const SSyncCfg *);
int32_t syncForwardToPeer(tsync_h shandle, void *pHead, void *mhandle, int qtype);
void    syncConfirmForward(tsync_h shandle, uint64_t version, int32_t code);
void    syncRecover(tsync_h shandle);      // recover from other nodes:
int     syncGetNodesRole(tsync_h shandle, SNodesRole *);

extern  char *syncRole[];

//global configurable parameters
extern  int   tsMaxSyncNum;
extern  int   tsSyncTcpThreads;
extern  int   tsMaxWatchFiles;
extern  int   tsSyncTimer;
extern  int   tsMaxFwdInfo; 
extern  int   sDebugFlag;
extern  char  tsArbitrator[];
extern  uint16_t tsSyncPort;

#ifdef __cplusplus
}
#endif

#endif  // TDENGINE_SYNC_H