diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DataInputBuffer.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DataInputBuffer.java index f0b67267163..63c41c2e750 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DataInputBuffer.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DataInputBuffer.java @@ -18,13 +18,14 @@ package org.apache.hadoop.io; -import java.io.*; - import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; -/** A reusable {@link DataInput} implementation that reads from an in-memory - * buffer. +import java.io.ByteArrayInputStream; +import java.io.DataInputStream; + +/** A reusable {@link java.io.DataInput} implementation + * that reads from an in-memory buffer. * *

This saves memory over creating a new DataInputStream and * ByteArrayInputStream each time data is read. @@ -56,9 +57,75 @@ public void reset(byte[] input, int start, int length) { this.pos = start; } - public byte[] getData() { return buf; } - public int getPosition() { return pos; } - public int getLength() { return count; } + public byte[] getData() { + return buf; + } + + public int getPosition() { + return pos; + } + + public int getLength() { + return count; + } + + /* functions below comes verbatim from + hive.common.io.NonSyncByteArrayInputStream */ + + /** + * {@inheritDoc} + */ + @Override + public int read() { + return (pos < count) ? (buf[pos++] & 0xff) : -1; + } + + /** + * {@inheritDoc} + */ + @Override + public int read(byte[] b, int off, int len) { + if (b == null) { + throw new NullPointerException(); + } else if (off < 0 || len < 0 || len > b.length - off) { + throw new IndexOutOfBoundsException(); + } + if (pos >= count) { + return -1; + } + if (pos + len > count) { + len = count - pos; + } + if (len <= 0) { + return 0; + } + System.arraycopy(buf, pos, b, off, len); + pos += len; + return len; + } + + /** + * {@inheritDoc} + */ + @Override + public long skip(long n) { + if (pos + n > count) { + n = count - pos; + } + if (n < 0) { + return 0; + } + pos += n; + return n; + } + + /** + * {@inheritDoc} + */ + @Override + public int available() { + return count - pos; + } } private Buffer buffer;