hbase-server/src/main/java/org/apache/hadoop/hbase/util/ProtoUtil.java

/**
 * 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.
 *
 * The portion of this file denoted by 'Copied from com.google.protobuf.CodedInputStream'
 * is from Protocol Buffers v2.4.1 under the following license
 *
 * Copyright 2008 Google Inc.  All rights reserved.
 * http://code.google.com/p/protobuf/
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

package org.apache.hadoop.hbase.util;

import java.io.DataInput;
import java.io.IOException;

import org.apache.hadoop.hbase.classification.InterfaceAudience;

@InterfaceAudience.Private
public abstract class ProtoUtil {

  /**
   * Read a variable length integer in the same format that ProtoBufs encodes.
   * @param in the input stream to read from
   * @return the integer
   * @throws IOException if it is malformed or EOF.
   */
  public static int readRawVarint32(DataInput in) throws IOException {
  // Copied from com.google.protobuf.CodedInputStream v2.4.1 readRawVarint32
    byte tmp = in.readByte();
    if (tmp >= 0) {
      return tmp;
    }
    int result = tmp & 0x7f;
    if ((tmp = in.readByte()) >= 0) {
      result |= tmp << 7;
    } else {
      result |= (tmp & 0x7f) << 7;
      if ((tmp = in.readByte()) >= 0) {
        result |= tmp << 14;
      } else {
        result |= (tmp & 0x7f) << 14;
        if ((tmp = in.readByte()) >= 0) {
          result |= tmp << 21;
        } else {
          result |= (tmp & 0x7f) << 21;
          result |= (tmp = in.readByte()) << 28;
          if (tmp < 0) {
            // Discard upper 32 bits.
            for (int i = 0; i < 5; i++) {
              if (in.readByte() >= 0) {
                return result;
              }
            }
            throw new IOException("Malformed varint");
          }
        }
      }
    }
    return result;
  }
  // end of copied from protobuf

}