/**
* sync update
*
* @return: updatedData on success, or null on fail
*/
public T update(
String path, DataUpdater<T> updater, List<String> createPaths, Stat stat, int options) {
CreateMode mode = AccessOption.getMode(options);
if (mode == null) {
LOG.error("Invalid update mode. options: " + options);
return null;
}
boolean retry;
T updatedData = null;
do {
retry = false;
try {
Stat readStat = new Stat();
T oldData = (T) _zkClient.readData(path, readStat);
T newData = updater.update(oldData);
Stat setStat = _zkClient.writeDataGetStat(path, newData, readStat.getVersion());
if (stat != null) {
DataTree.copyStat(setStat, stat);
}
updatedData = newData;
} catch (ZkBadVersionException e) {
retry = true;
} catch (ZkNoNodeException e) {
// node not exist, try create
try {
T newData = updater.update(null);
RetCode rc = create(path, newData, createPaths, options);
switch (rc) {
case OK:
updatedData = newData;
break;
case NODE_EXISTS:
retry = true;
break;
default:
LOG.error("Fail to update path by creating: " + path);
return null;
}
} catch (Exception e1) {
LOG.error("Exception while updating path by creating: " + path, e1);
return null;
}
} catch (Exception e) {
LOG.error("Exception while updating path: " + path, e);
return null;
}
} while (retry);
return updatedData;
}
/**
* sync set
*
* @param setstat : if node is created instead of set, stat will NOT be set
*/
public boolean set(
String path,
T record,
List<String> pathsCreated,
Stat setstat,
int expectVersion,
int options) {
CreateMode mode = AccessOption.getMode(options);
if (mode == null) {
LOG.error("Invalid set mode. options: " + options);
return false;
}
boolean retry;
do {
retry = false;
try {
// _zkClient.writeData(path, record);
Stat setStat = _zkClient.writeDataGetStat(path, record, expectVersion);
if (setstat != null) DataTree.copyStat(setStat, setstat);
} catch (ZkNoNodeException e) {
// node not exists, try create. in this case, stat will not be set
try {
RetCode rc = create(path, record, pathsCreated, options);
// if (rc == RetCode.OK || rc == RetCode.NODE_EXISTS)
// retry = true;
switch (rc) {
case OK:
// not set stat if node is created (instead of set)
break;
case NODE_EXISTS:
retry = true;
break;
default:
LOG.error("Fail to set path by creating: " + path);
return false;
}
} catch (Exception e1) {
LOG.error("Exception while setting path by creating: " + path, e);
return false;
}
} catch (ZkBadVersionException e) {
throw e;
} catch (Exception e) {
LOG.error("Exception while setting path: " + path, e);
return false;
}
} while (retry);
return true;
}
