Zookeeper 一种简单的原子操作机制:
Zookeeper 一种简单的原子操作机制://zoo_get()方法: int zoo_get(zhandle_t * zh, const char *path, int watch,
// char *buffer, int *buffer_len, struct Stat *stat);
//zh:连接句柄, path:文件路径, watch: , buffer:获得的数据, stat:状态信//息(比较有用的如:version信息)
char tmpData;
uint32_t tmpDataSize = MAXNODENAMELENS - 1;
rc = zoo_get(zh, nodeName, 1, tmpData, &tmpDataSize, &stat);
sdsfree(nodeName);
if(rc < 0) {
return rc;
}
tmpData = '\0';
char *stop;
uint32_t expectGroupID = strtol(tmpData, &stop, 10);
if (expectGroupID != groupID_src)
{
SlogWrite(LL_FATAL, "ChangeBlockUtil:expectGroupID!=groupID_src.", expectGroupID);
return -1;
}
// optimize: use version set
uint32_t version = stat.version;
sds data = sdscatprintf(sdsempty(), "%d", groupID_dst);
SlogWrite(LL_DEBUG, "Set %s value %s.", nodeName, data);
rc = zoo_set(zh, nodeName, data, sdslen(data), version);
sdsfree(nodeName);
sdsfree(data);
if (rc < 0)
{
SlogWrite(LL_FATAL, "ChangeBlockUtil: fail to zoo_set with version=%d", version);
return rc;
}
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