package com.ebuddy.cassandra.dao;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import com.ebuddy.cassandra.BatchContext;
import com.ebuddy.cassandra.Path;
import com.ebuddy.cassandra.StructuredDataSupport;
import com.ebuddy.cassandra.TypeReference;
import com.ebuddy.cassandra.databind.CustomTypeResolverBuilder;
import com.ebuddy.cassandra.structure.Composer;
import com.ebuddy.cassandra.structure.Decomposer;
import com.ebuddy.cassandra.structure.JacksonTypeReference;
/**
* Implementation of StructuredDataSupport for a Thrift SuperColumnFamily.
*
* @param<K> type of row key
*
* @author Eric Zoerner <a href="mailto:ezoerner@ebuddy.com">ezoerner@ebuddy.com</a>
*/
public class ThriftSuperStructuredDataSupport<K> extends AbstractThriftStructuredDataSupport<K> {
private final SuperColumnFamilyOperations<K,String,String,Object> operations;
/**
* Create and configure an instance with a SuperColumnFamilyOperations.
* @param operations a SuperColumnFamilyOperations that has String column and supercolumn names and a
* StructureSerializer for the valueSerializer.
*/
public ThriftSuperStructuredDataSupport(SuperColumnFamilyOperations<K,String,String,Object> operations) {
this.operations = operations;
}
@Override
public BatchContext beginBatch() {
return operations.begin();
}
@Override
public void applyBatch(BatchContext batchContext) {
operations.commit(batchContext);
}
@Override
public <T> T readFromPath(K rowKey, Path path, TypeReference<T> type) {
validateArgs(rowKey, path);
int count = Integer.MAX_VALUE;
boolean reversed = false;
// converting from a string and back normalizes the path, e.g. makes sure ends with the delimiter character
String superColumnName = path.head();
Path rest = path.tail();
String start = rest.toString();
String finish = getFinishString(start);
Map<String,Object> columnsMap = operations.readColumnsAsMap(rowKey,
superColumnName,
start,
finish,
count,
reversed);
if (columnsMap.isEmpty()) {
return null;
}
Map<Path,Object> pathMap = getTerminalPathMap(rest, columnsMap);
Object structure = Composer.get().compose(pathMap);
// convert object structure into POJO of type referred to by TypeReference
return readMapper.convertValue(structure, new JacksonTypeReference<T>(type));
}
@Override
public void writeToPath(K rowKey, Path path, Object value, BatchContext batchContext) {
validateArgs(rowKey, path);
Object structure = writeMapper.convertValue(value, Object.class);
String superColumnName = path.head();
Path rest = path.tail();
Map<Path,Object> pathMap = Collections.singletonMap(rest, structure);
Map<Path,Object> objectMap = Decomposer.get().decompose(pathMap);
Map<String,Object> stringMap = new HashMap<String,Object>();
for (Map.Entry<Path,Object> entry : objectMap.entrySet()) {
stringMap.put(entry.getKey().toString(), entry.getValue());
}
if (batchContext == null) {
operations.writeColumns(rowKey, superColumnName, stringMap);
} else {
operations.writeColumns(rowKey, superColumnName, stringMap, batchContext);
}
}
@Override
public void deletePath(K rowKey, Path path, BatchContext batchContext) {
String superColumnName = path.head();
// normalize path
String start = path.tail().toString();
String finish = getFinishString(start);
if (batchContext == null) {
operations.deleteColumns(rowKey, superColumnName, start, finish);
} else {
operations.deleteColumns(rowKey, superColumnName, start, finish, batchContext);
}
}
}