mirror of https://github.com/apache/cloudstack.git
60 lines
2.0 KiB
Java
60 lines
2.0 KiB
Java
//
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// Licensed to the Apache Software Foundation (ASF) under one
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// or more contributor license agreements. See the NOTICE file
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// distributed with this work for additional information
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// regarding copyright ownership. The ASF licenses this file
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// to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance
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// with the License. You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations
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// under the License.
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//
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package com.cloud.utils.storage;
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import java.io.IOException;
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import java.io.InputStream;
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import com.cloud.utils.NumbersUtil;
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public final class QCOW2Utils {
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private static final int VIRTUALSIZE_HEADER_LOCATION = 24;
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private static final int VIRTUALSIZE_HEADER_LENGTH = 8;
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/**
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* Private constructor -> This utility class cannot be instantiated.
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*/
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private QCOW2Utils() {}
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/**
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* @return the header location of the virtual size field.
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*/
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public static int getVirtualSizeHeaderLocation() {
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return VIRTUALSIZE_HEADER_LOCATION;
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}
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/**
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* @param inputStream The QCOW2 object in stream format.
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* @return The virtual size of the QCOW2 object.
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*/
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public static long getVirtualSize(InputStream inputStream) throws IOException {
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byte[] bytes = new byte[VIRTUALSIZE_HEADER_LENGTH];
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if (inputStream.skip(VIRTUALSIZE_HEADER_LOCATION) != VIRTUALSIZE_HEADER_LOCATION) {
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throw new IOException("Unable to skip to the virtual size header");
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}
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if (inputStream.read(bytes) != VIRTUALSIZE_HEADER_LENGTH) {
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throw new IOException("Unable to properly read the size");
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}
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return NumbersUtil.bytesToLong(bytes);
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}
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} |