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Thrift is a software framework for scalable cross-language services development.
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.thrift;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TField;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.protocol.TProtocolFactory;
import org.apache.thrift.protocol.TProtocolUtil;
import org.apache.thrift.protocol.TType;
import org.apache.thrift.transport.TMemoryInputTransport;
import org.apache.thrift.transport.TTransportException;
/**
* Generic utility for easily deserializing objects from a byte array or Java
* String.
*
*/
public class TDeserializer {
private final TProtocol protocol_;
private final TMemoryInputTransport trans_;
/**
* Create a new TDeserializer that uses the TBinaryProtocol by default.
*/
public TDeserializer() throws TTransportException {
this(new TBinaryProtocol.Factory());
}
/**
* Create a new TDeserializer. It will use the TProtocol specified by the
* factory that is passed in.
*
* @param protocolFactory Factory to create a protocol
*/
public TDeserializer(TProtocolFactory protocolFactory) throws TTransportException {
trans_ = new TMemoryInputTransport(new TConfiguration());
protocol_ = protocolFactory.getProtocol(trans_);
}
/**
* Deserialize the Thrift object from a byte array.
*
* @param base The object to read into
* @param bytes The array to read from
*/
public void deserialize(TBase base, byte[] bytes) throws TException {
deserialize(base, bytes, 0, bytes.length);
}
/**
* Deserialize the Thrift object from a byte array.
*
* @param base The object to read into
* @param bytes The array to read from
* @param offset The offset into {@code bytes}
* @param length The length to read from {@code bytes}
*/
public void deserialize(TBase base, byte[] bytes, int offset, int length) throws TException {
try {
trans_.reset(bytes, offset, length);
base.read(protocol_);
} finally {
trans_.clear();
protocol_.reset();
}
}
/**
* Deserialize the Thrift object from a Java string, using a specified
* character set for decoding.
*
* @param base The object to read into
* @param data The string to read from
* @param charset Valid JVM charset
*/
public void deserialize(TBase base, String data, String charset) throws TException {
try {
deserialize(base, data.getBytes(charset));
} catch (UnsupportedEncodingException uex) {
throw new TException("JVM DOES NOT SUPPORT ENCODING: " + charset);
} finally {
protocol_.reset();
}
}
/**
* Deserialize only a single Thrift object (addressed by recursively using field id)
* from a byte record.
* @param tb The object to read into
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path tb
* @param fieldIdPathRest The rest FieldId's that define a path tb
* @throws TException
*/
public void partialDeserialize(TBase tb, byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
try {
if (locateField(bytes, fieldIdPathFirst, fieldIdPathRest) != null) {
// if this line is reached, iprot will be positioned at the start of tb.
tb.read(protocol_);
}
} catch (Exception e) {
throw new TException(e);
} finally {
trans_.clear();
protocol_.reset();
}
}
/**
* Deserialize only a boolean field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to a boolean field
* @param fieldIdPathRest The rest FieldId's that define a path to a boolean field
* @throws TException
*/
public Boolean partialDeserializeBool(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (Boolean) partialDeserializeField(TType.BOOL, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only a byte field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to a byte field
* @param fieldIdPathRest The rest FieldId's that define a path to a byte field
* @throws TException
*/
public Byte partialDeserializeByte(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (Byte) partialDeserializeField(TType.BYTE, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only a double field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to a double field
* @param fieldIdPathRest The rest FieldId's that define a path to a double field
* @throws TException
*/
public Double partialDeserializeDouble(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (Double) partialDeserializeField(TType.DOUBLE, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only an i16 field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to an i16 field
* @param fieldIdPathRest The rest FieldId's that define a path to an i16 field
* @throws TException
*/
public Short partialDeserializeI16(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (Short) partialDeserializeField(TType.I16, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only an i32 field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to an i32 field
* @param fieldIdPathRest The rest FieldId's that define a path to an i32 field
* @throws TException
*/
public Integer partialDeserializeI32(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (Integer) partialDeserializeField(TType.I32, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only an i64 field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to an i64 field
* @param fieldIdPathRest The rest FieldId's that define a path to an i64 field
* @throws TException
*/
public Long partialDeserializeI64(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (Long) partialDeserializeField(TType.I64, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only a string field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to a string field
* @param fieldIdPathRest The rest FieldId's that define a path to a string field
* @throws TException
*/
public String partialDeserializeString(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
return (String) partialDeserializeField(TType.STRING, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only a binary field (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to a binary field
* @param fieldIdPathRest The rest FieldId's that define a path to a binary field
* @throws TException
*/
public ByteBuffer partialDeserializeByteArray(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
// TType does not have binary, so we use the arbitrary num 100
return (ByteBuffer) partialDeserializeField((byte)100, bytes, fieldIdPathFirst, fieldIdPathRest);
}
/**
* Deserialize only the id of the field set in a TUnion (addressed by recursively using field id)
* from a byte record.
* @param bytes The serialized object to read from
* @param fieldIdPathFirst First of the FieldId's that define a path to a TUnion
* @param fieldIdPathRest The rest FieldId's that define a path to a TUnion
* @throws TException
*/
public Short partialDeserializeSetFieldIdInUnion(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
try {
TField field = locateField(bytes, fieldIdPathFirst, fieldIdPathRest);
if (field != null){
protocol_.readStructBegin(); // The Union
return protocol_.readFieldBegin().id; // The field set in the union
}
return null;
} catch (Exception e) {
throw new TException(e);
} finally {
trans_.clear();
protocol_.reset();
}
}
private Object partialDeserializeField(byte ttype, byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
try {
TField field = locateField(bytes, fieldIdPathFirst, fieldIdPathRest);
if (field != null) {
if (ttype == field.type) {
// if this point is reached, iprot will be positioned at the start of
// the field
switch (ttype) {
case TType.BOOL:
return protocol_.readBool();
case TType.BYTE:
return protocol_.readByte();
case TType.DOUBLE:
return protocol_.readDouble();
case TType.I16:
return protocol_.readI16();
case TType.I32:
return protocol_.readI32();
case TType.I64:
return protocol_.readI64();
case TType.STRING:
return protocol_.readString();
default:
return null;
}
}
// hack to differentiate between string and binary
if (ttype == 100 && field.type == TType.STRING) {
return protocol_.readBinary();
}
}
return null;
} catch (Exception e) {
throw new TException(e);
} finally {
trans_.clear();
protocol_.reset();
}
}
private TField locateField(byte[] bytes, TFieldIdEnum fieldIdPathFirst, TFieldIdEnum ... fieldIdPathRest) throws TException {
trans_.reset(bytes);
TFieldIdEnum[] fieldIdPath = new TFieldIdEnum[fieldIdPathRest.length + 1];
fieldIdPath[0] = fieldIdPathFirst;
System.arraycopy(fieldIdPathRest, 0, fieldIdPath, 1, fieldIdPathRest.length);
// index into field ID path being currently searched for
int curPathIndex = 0;
// this will be the located field, or null if it is not located
TField field = null;
protocol_.readStructBegin();
while (curPathIndex < fieldIdPath.length) {
field = protocol_.readFieldBegin();
// we can stop searching if we either see a stop or we go past the field
// id we're looking for (since fields should now be serialized in asc
// order).
if (field.type == TType.STOP || field.id > fieldIdPath[curPathIndex].getThriftFieldId()) {
return null;
}
if (field.id != fieldIdPath[curPathIndex].getThriftFieldId()) {
// Not the field we're looking for. Skip field.
TProtocolUtil.skip(protocol_, field.type);
protocol_.readFieldEnd();
} else {
// This field is the next step in the path. Step into field.
curPathIndex++;
if (curPathIndex < fieldIdPath.length) {
protocol_.readStructBegin();
}
}
}
return field;
}
/**
* Deserialize the Thrift object from a Java string, using the default JVM
* charset encoding.
*
* @param base The object to read into
* @param data The string to read from
*/
public void fromString(TBase base, String data) throws TException {
deserialize(base, data.getBytes());
}
}