| /* |
| * 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. |
| */ |
| package org.apache.cassandra.io.util; |
| |
| import java.io.DataInput; |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import org.apache.cassandra.utils.Shared; |
| import org.apache.cassandra.utils.vint.VIntCoding; |
| import org.apache.cassandra.utils.vint.VIntCoding.VIntOutOfRangeException; |
| |
| import static org.apache.cassandra.utils.Shared.Scope.SIMULATION; |
| |
| /** |
| * Extension to DataInput that provides support for reading varints |
| */ |
| @Shared(scope = SIMULATION) |
| public interface DataInputPlus extends DataInput |
| { |
| /** |
| * Read a 64-bit integer back. |
| * |
| * This method assumes it was originally written using |
| * {@link DataOutputPlus#writeVInt(long)} or similar that zigzag encodes the vint. |
| */ |
| default long readVInt() throws IOException |
| { |
| return VIntCoding.readVInt(this); |
| } |
| |
| /** |
| * Read up to a 32-bit integer back. |
| * |
| * This method assumes the integer was originally written using |
| * {@link DataOutputPlus#writeVInt32(int)} or similar that zigzag encodes the vint. |
| * |
| * @throws VIntOutOfRangeException If the vint doesn't fit into a 32-bit integer |
| */ |
| default int readVInt32() throws IOException |
| { |
| return VIntCoding.readVInt32(this); |
| } |
| |
| /** |
| * Think hard before opting for an unsigned encoding. Is this going to bite someone because some day |
| * they might need to pass in a sentinel value using negative numbers? Is the risk worth it |
| * to save a few bytes? |
| * |
| * Signed, not a fan of unsigned values in protocols and formats |
| */ |
| default long readUnsignedVInt() throws IOException |
| { |
| return VIntCoding.readUnsignedVInt(this); |
| } |
| |
| /** |
| * Read up to a 32-bit integer back. |
| * |
| * This method assumes the original integer was written using {@link DataOutputPlus#writeUnsignedVInt32(int)} |
| * or similar that doesn't zigzag encodes the vint. |
| * |
| * @throws VIntOutOfRangeException If the vint doesn't fit into a 32-bit integer |
| */ |
| default int readUnsignedVInt32() throws IOException |
| { |
| return VIntCoding.readUnsignedVInt32(this); |
| } |
| |
| /** |
| * Always skips the requested number of bytes, unless EOF is reached |
| * |
| * @param n number of bytes to skip |
| * @return number of bytes skipped |
| */ |
| public int skipBytes(int n) throws IOException; |
| |
| public default void skipBytesFully(int n) throws IOException |
| { |
| int skipped = skipBytes(n); |
| if (skipped != n) |
| throw new EOFException("EOF after " + skipped + " bytes out of " + n); |
| } |
| |
| /** |
| * Wrapper around an InputStream that provides no buffering but can decode varints |
| */ |
| abstract class DataInputStreamPlus extends InputStream implements DataInputPlus |
| { |
| } |
| } |