org.apache.hadoop.hdfs.client.impl.BlockReaderUtil Maven / Gradle / Ivy
/**
* 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.hadoop.hdfs.client.impl;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.BlockReader;
import java.io.IOException;
/**
* For sharing between the local and remote block reader implementations.
*/
@InterfaceAudience.Private
class BlockReaderUtil {
/* See {@link BlockReader#readAll(byte[], int, int)} */
public static int readAll(BlockReader reader,
byte[] buf, int offset, int len) throws IOException {
int n = 0;
for (;;) {
int nread = reader.read(buf, offset + n, len - n);
if (nread <= 0)
return (n == 0) ? nread : n;
n += nread;
if (n >= len)
return n;
}
}
/* See {@link BlockReader#readFully(byte[], int, int)} */
public static void readFully(BlockReader reader,
byte[] buf, int off, int len) throws IOException {
int toRead = len;
while (toRead > 0) {
int ret = reader.read(buf, off, toRead);
if (ret < 0) {
throw new IOException("Premature EOF from inputStream");
}
toRead -= ret;
off += ret;
}
}
}