org.brekka.paveway.core.services.impl.MultipartInputStream.java Source code

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Here is the source code for org.brekka.paveway.core.services.impl.MultipartInputStream.java

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/*
 * Copyright 2012 the original author or authors.
 *
 * 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.brekka.paveway.core.services.impl;

import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.List;
import java.util.UUID;

import org.apache.commons.io.IOUtils;
import org.brekka.paveway.core.model.ByteSequence;
import org.brekka.paveway.core.model.CryptedFile;
import org.brekka.paveway.core.model.CryptedPart;
import org.brekka.paveway.core.services.ResourceCryptoService;
import org.brekka.paveway.core.services.ResourceStorageService;
import org.brekka.phoenix.api.StreamCryptor;
import org.brekka.phoenix.api.SymmetricCryptoSpec;

class MultipartInputStream extends InputStream {

    private final CryptedFile cryptedFile;
    private final Iterator<CryptedPart> partsIterator;

    private final ResourceStorageService resourceStorageService;
    private final ResourceCryptoService resourceCryptoService;

    private InputStream current = null;

    public MultipartInputStream(CryptedFile cryptedFile, ResourceStorageService resourceStorageService,
            ResourceCryptoService resourceCryptoService) {
        this.cryptedFile = cryptedFile;
        this.resourceCryptoService = resourceCryptoService;
        this.resourceStorageService = resourceStorageService;
        List<CryptedPart> parts = PavewayServiceImpl.sortByOffset(cryptedFile.getParts());
        this.partsIterator = parts.iterator();
        toNextStream();
    }

    @Override
    public int read() throws IOException {
        throw new UnsupportedOperationException();
    }

    /* (non-Javadoc)
     * @see java.io.InputStream#read(byte[], int, int)
     */
    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        int i = current.read(b, off, len);
        if (i == -1) {
            toNextStream();
            if (current != null) {
                i = current.read(b, off, len);
            }
        }
        return i;
    }

    /* (non-Javadoc)
     * @see java.io.InputStream#close()
     */
    @Override
    public void close() throws IOException {
        IOUtils.closeQuietly(current);
    }

    /**
     * @return
     */
    private void toNextStream() {
        // Close any existing stream
        IOUtils.closeQuietly(current);
        if (!partsIterator.hasNext()) {
            this.current = null;
            return;
        }
        CryptedPart cryptedPart = partsIterator.next();
        UUID partId = cryptedPart.getId();
        ByteSequence byteSequence = resourceStorageService.retrieve(partId);
        InputStream is = byteSequence.getInputStream();
        StreamCryptor<InputStream, SymmetricCryptoSpec> decryptor = resourceCryptoService.decryptor(cryptedPart,
                cryptedFile.getCompression());
        this.current = decryptor.getStream(is);
    }
}