homework-jianmu/source/libs/sync/src/syncRaftStore.c

132 lines
3.7 KiB
C

/*
* 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 "syncRaftStore.h"
#include "cJSON.h"
SRaftStore *raftStoreOpen(const char *path) {
int32_t ret;
SRaftStore *pRaftStore = malloc(sizeof(SRaftStore));
if (pRaftStore == NULL) {
sError("raftStoreOpen malloc error");
return NULL;
}
memset(pRaftStore, 0, sizeof(*pRaftStore));
snprintf(pRaftStore->path, sizeof(pRaftStore->path), "%s", path);
char storeBuf[RAFT_STORE_BLOCK_SIZE];
memset(storeBuf, 0, sizeof(storeBuf));
if (!raftStoreFileExist(pRaftStore->path)) {
ret = raftStoreInit(pRaftStore);
assert(ret == 0);
}
pRaftStore->fd = taosOpenFileReadWrite(pRaftStore->path);
if (pRaftStore->fd < 0) {
return NULL;
}
int len = taosReadFile(pRaftStore->fd, storeBuf, sizeof(storeBuf));
assert(len == RAFT_STORE_BLOCK_SIZE);
ret = raftStoreDeserialize(pRaftStore, storeBuf, len);
assert(ret == 0);
return pRaftStore;
}
static int32_t raftStoreInit(SRaftStore *pRaftStore) {
pRaftStore->fd = taosOpenFileCreateWrite(pRaftStore->path);
if (pRaftStore->fd < 0) {
return -1;
}
pRaftStore->currentTerm = 0;
pRaftStore->voteFor.addr = 0;
pRaftStore->voteFor.vgId = 0;
int32_t ret = raftStorePersist(pRaftStore);
assert(ret == 0);
taosCloseFile(pRaftStore->fd);
return 0;
}
int32_t raftStoreClose(SRaftStore *pRaftStore) {
taosCloseFile(pRaftStore->fd);
free(pRaftStore);
return 0;
}
int32_t raftStorePersist(SRaftStore *pRaftStore) {
int32_t ret;
char storeBuf[RAFT_STORE_BLOCK_SIZE];
ret = raftStoreSerialize(pRaftStore, storeBuf, sizeof(storeBuf));
assert(ret == 0);
taosLSeekFile(pRaftStore->fd, 0, SEEK_SET);
ret = taosWriteFile(pRaftStore->fd, storeBuf, sizeof(storeBuf));
assert(ret == RAFT_STORE_BLOCK_SIZE);
fsync(pRaftStore->fd);
return 0;
}
static bool raftStoreFileExist(char *path) { return taosStatFile(path, NULL, NULL) >= 0; }
int32_t raftStoreSerialize(SRaftStore *pRaftStore, char *buf, size_t len) {
cJSON *pRoot = cJSON_CreateObject();
cJSON_AddNumberToObject(pRoot, "current_term", pRaftStore->currentTerm);
cJSON_AddNumberToObject(pRoot, "vote_for_addr", pRaftStore->voteFor.addr);
cJSON_AddNumberToObject(pRoot, "vote_for_vgid", pRaftStore->voteFor.vgId);
char *serialized = cJSON_Print(pRoot);
int len2 = strlen(serialized);
assert(len2 < len);
memset(buf, 0, len);
snprintf(buf, len, "%s", serialized);
free(serialized);
cJSON_Delete(pRoot);
return 0;
}
int32_t raftStoreDeserialize(SRaftStore *pRaftStore, char *buf, size_t len) {
assert(len > 0 && len <= RAFT_STORE_BLOCK_SIZE);
cJSON *pRoot = cJSON_Parse(buf);
cJSON *pCurrentTerm = cJSON_GetObjectItem(pRoot, "current_term");
pRaftStore->currentTerm = pCurrentTerm->valueint;
cJSON *pVoteForAddr = cJSON_GetObjectItem(pRoot, "vote_for_addr");
pRaftStore->voteFor.addr = pVoteForAddr->valueint;
cJSON *pVoteForVgid = cJSON_GetObjectItem(pRoot, "vote_for_vgid");
pRaftStore->voteFor.vgId = pVoteForVgid->valueint;
cJSON_Delete(pRoot);
return 0;
}
void raftStorePrint(SRaftStore *pRaftStore) {
char storeBuf[RAFT_STORE_BLOCK_SIZE];
raftStoreSerialize(pRaftStore, storeBuf, sizeof(storeBuf));
printf("%s\n", storeBuf);
}