com.seanchenxi.gwt.storage.client.serializer.StorageSerializationStreamWriter.java Source code

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Here is the source code for com.seanchenxi.gwt.storage.client.serializer.StorageSerializationStreamWriter.java

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/*
 * Copyright 2013 Xi CHEN
 *
 * 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 com.seanchenxi.gwt.storage.client.serializer;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.ListIterator;

import com.google.gwt.core.client.JsonUtils;
import com.google.gwt.lang.LongLib;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter;
import com.google.gwt.user.client.rpc.impl.Serializer;

final class StorageSerializationStreamWriter extends AbstractSerializationStreamWriter {

    private static final String APOSTROPHE = "'";
    private static final String BLANK = "";
    private static final String CLOSE_BRACKET = "]";
    private static final String COMMA = ",";
    private static final String OPEN_BRACKET = "[";

    private static void append(StringBuffer sb, String token) {
        assert (token != null);
        sb.append(token).append(COMMA);
    }

    private final Serializer serializer;
    private ArrayList<String> tokenList;

    public StorageSerializationStreamWriter(Serializer serializer) {
        this.serializer = serializer;
    }

    @Override
    public void prepareToWrite() {
        super.prepareToWrite();
        tokenList = new ArrayList<>();
    }

    @Override
    public String toString() {
        StringBuffer buffer = new StringBuffer(OPEN_BRACKET);
        writePayload(buffer);
        writeStringTable(buffer);
        writeHeader(buffer);
        return JsonUtils.escapeJsonForEval(buffer.append(CLOSE_BRACKET).toString());
    }

    @Override
    public void writeLong(long value) {
        append(APOSTROPHE + LongLib.toBase64(value) + APOSTROPHE);
    }

    @Override
    protected void append(String token) {
        assert (token != null);
        tokenList.add(tokenList.size(), token);
    }

    @Override
    protected String getObjectTypeSignature(Object o) {
        Class<?> clazz = o.getClass();
        if (o instanceof Enum<?>) {
            Enum<?> e = (Enum<?>) o;
            clazz = e.getDeclaringClass();
        }
        return serializer.getSerializationSignature(clazz);
    }

    @Override
    protected void serialize(Object instance, String typeSignature) throws SerializationException {
        serializer.serialize(this, instance, typeSignature);
    }

    private String escapeString(String toEscape) {
        if (toEscape == null)
            return null;
        return JsonUtils.escapeValue(toEscape);
    }

    private void writeHeader(StringBuffer buffer) {
        append(buffer, String.valueOf(getFlags()));
        buffer.append(getVersion());
    }

    private void writePayload(StringBuffer buffer) {
        ListIterator<String> list = tokenList.listIterator(tokenList.size());
        while (list.hasPrevious()) {
            append(buffer, list.previous());
        }
    }

    private void writeStringTable(StringBuffer buffer) {
        StringBuffer sb = new StringBuffer(OPEN_BRACKET);
        Iterator<String> stringTable = getStringTable().iterator();
        while (stringTable.hasNext()) {
            append(sb, escapeString(stringTable.next()));
        }
        sb.append(CLOSE_BRACKET);
        int index = sb.lastIndexOf(COMMA);
        String table = (index > -1) ? sb.replace(index, index + 1, BLANK).toString() : sb.toString();
        append(buffer, table);
    }

}