/* | |
* Copyright 2015 Open Networking Laboratory | |
* | |
* Licensed 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.onosproject.ovsdb.rfc.utils; | |
import io.netty.buffer.ByteBuf; | |
import io.netty.buffer.ByteBufInputStream; | |
import java.io.IOException; | |
import java.util.List; | |
import java.util.Stack; | |
import org.onosproject.ovsdb.rfc.error.UnsupportedException; | |
import org.onosproject.ovsdb.rfc.jsonrpc.JsonReadContext; | |
import com.fasterxml.jackson.core.JsonEncoding; | |
import com.fasterxml.jackson.core.JsonParseException; | |
import com.fasterxml.jackson.core.JsonParser; | |
import com.fasterxml.jackson.core.io.IOContext; | |
import com.fasterxml.jackson.core.json.ByteSourceJsonBootstrapper; | |
import com.fasterxml.jackson.core.util.BufferRecycler; | |
import com.fasterxml.jackson.databind.JsonNode; | |
import com.fasterxml.jackson.databind.MappingJsonFactory; | |
/** | |
* Decoder utility class. | |
*/ | |
public final class JsonRpcReaderUtil { | |
/** | |
* Constructs a JsonRpcReaderUtil object. Utility classes should not have a | |
* public or default constructor, otherwise IDE will compile unsuccessfully. | |
* This class should not be instantiated. | |
*/ | |
private JsonRpcReaderUtil() { | |
} | |
/** | |
* Decode the bytes to Json object. | |
* @param in input of bytes | |
* @param out ouput of Json object list | |
* @param jrContext context for the last decoding process | |
* @throws IOException IOException | |
* @throws JsonParseException JsonParseException | |
*/ | |
public static void readToJsonNode(ByteBuf in, List<Object> out, JsonReadContext jrContext) | |
throws JsonParseException, IOException { | |
int lastReadBytes = jrContext.getLastReadBytes(); | |
if (lastReadBytes == 0) { | |
if (in.readableBytes() < 4) { | |
return; | |
} | |
checkEncoding(in); | |
} | |
int i = lastReadBytes + in.readerIndex(); | |
Stack<Byte> bufStack = jrContext.getBufStack(); | |
for (; i < in.writerIndex(); i++) { | |
byte b = in.getByte(i); | |
switch (b) { | |
case '{': | |
if (!isDoubleQuote(bufStack)) { | |
bufStack.push(b); | |
jrContext.setStartMatch(true); | |
} | |
break; | |
case '}': | |
if (!isDoubleQuote(bufStack)) { | |
bufStack.pop(); | |
} | |
break; | |
case '"': | |
if (in.getByte(i - 1) != '\\') { | |
if (!bufStack.isEmpty() && bufStack.peek() != '"') { | |
bufStack.push(b); | |
} else { | |
bufStack.pop(); | |
} | |
} | |
break; | |
default: | |
break; | |
} | |
if (jrContext.isStartMatch() && bufStack.isEmpty()) { | |
ByteBuf buf = in.readSlice(i - in.readerIndex() + 1); | |
JsonParser jf = new MappingJsonFactory().createParser(new ByteBufInputStream(buf)); | |
JsonNode jsonNode = jf.readValueAsTree(); | |
out.add(jsonNode); | |
lastReadBytes = 0; | |
jrContext.setLastReadBytes(lastReadBytes); | |
break; | |
} | |
} | |
if (i >= in.writerIndex()) { | |
lastReadBytes = in.readableBytes(); | |
jrContext.setLastReadBytes(lastReadBytes); | |
} | |
} | |
/** | |
* Filter the invalid characters before decoding. | |
* @param in input of bytes | |
* @param lastReadBytes the bytes for last decoding incomplete record | |
*/ | |
private static void fliterCharaters(ByteBuf in) { | |
while (in.isReadable()) { | |
int ch = in.getByte(in.readerIndex()); | |
if ((ch != ' ') && (ch != '\n') && (ch != '\t') && (ch != '\r')) { | |
break; | |
} else { | |
in.readByte(); | |
} | |
} | |
} | |
/** | |
* Check whether the peek of the stack element is double quote. | |
* @param jrContext context for the last decoding process | |
* @return boolean | |
*/ | |
private static boolean isDoubleQuote(Stack<Byte> bufStack) { | |
if (!bufStack.isEmpty() && bufStack.peek() == '"') { | |
return true; | |
} | |
return false; | |
} | |
/** | |
* Check whether the encoding is valid. | |
* @param in input of bytes | |
* @throws IOException this is an IO exception | |
* @throws UnsupportedException this is an unsupported exception | |
*/ | |
private static void checkEncoding(ByteBuf in) throws IOException { | |
int inputStart = 0; | |
int inputLength = 4; | |
fliterCharaters(in); | |
byte[] buff = new byte[4]; | |
in.getBytes(in.readerIndex(), buff); | |
ByteSourceJsonBootstrapper strapper = new ByteSourceJsonBootstrapper(new IOContext(new BufferRecycler(), | |
null, | |
false), | |
buff, inputStart, | |
inputLength); | |
JsonEncoding jsonEncoding = strapper.detectEncoding(); | |
if (!JsonEncoding.UTF8.equals(jsonEncoding)) { | |
throw new UnsupportedException("Only UTF-8 encoding is supported."); | |
} | |
} | |
} |