org.apache.hadoop.fs.s3a.prefetch

Class S3AInMemoryInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.fs.s3a.prefetch.S3ARemoteInputStream

org.apache.hadoop.fs.s3a.prefetch.S3AInMemoryInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.fs.CanSetReadahead, org.apache.hadoop.fs.statistics.IOStatisticsSource, org.apache.hadoop.fs.StreamCapabilities

public class S3AInMemoryInputStream
extends S3ARemoteInputStream

Provides an InputStream that allows reading from an S3 file. The entire file is read into memory before reads can begin. Use of this class is recommended only for small files that can fit entirely in memory.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.fs.StreamCapabilities

org.apache.hadoop.fs.StreamCapabilities.StreamCapability

Field Summary

Fields inherited from interface org.apache.hadoop.fs.StreamCapabilities

ABORTABLE_STREAM, DROPBEHIND, HFLUSH, HSYNC, IOSTATISTICS, IOSTATISTICS_CONTEXT, PREADBYTEBUFFER, READAHEAD, READBYTEBUFFER, UNBUFFER, VECTOREDIO

Constructor Summary

Constructors

Constructor and Description
S3AInMemoryInputStream(S3AReadOpContext context, S3ObjectAttributes s3Attributes, S3AInputStream.InputStreamCallbacks client, S3AInputStreamStatistics streamStatistics) Initializes a new instance of the S3AInMemoryInputStream class.

Method Summary

Modifier and Type	Method and Description
protected boolean	ensureCurrentBuffer() Ensures that a non-empty valid buffer is available for immediate reading.

Methods inherited from class org.apache.hadoop.fs.s3a.prefetch.S3ARemoteInputStream

available, close, getBlockData, getContext, getFile, getFilePosition, getIOStatistics, getName, getNextReadPos, getOffsetStr, getPos, getReader, getS3AStreamStatistics, getS3File, getS3ObjectAttributes, hasCapability, isClosed, mark, markSupported, read, read, read, reset, seek, setReadahead, skip, throwIfClosed, throwIfInvalidSeek, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

S3AInMemoryInputStream

public S3AInMemoryInputStream(S3AReadOpContext context,
                              S3ObjectAttributes s3Attributes,
                              S3AInputStream.InputStreamCallbacks client,
                              S3AInputStreamStatistics streamStatistics)

Initializes a new instance of the S3AInMemoryInputStream class.

Parameters:

context - read-specific operation context.

s3Attributes - attributes of the S3 object being read.

client - callbacks used for interacting with the underlying S3 client.

streamStatistics - statistics for this stream.

Throws:

IllegalArgumentException - if context is null.

IllegalArgumentException - if s3Attributes is null.

IllegalArgumentException - if client is null.

Method Detail

ensureCurrentBuffer

protected boolean ensureCurrentBuffer()
                               throws IOException

Ensures that a non-empty valid buffer is available for immediate reading. It returns true when at least one such buffer is available for reading. It returns false on reaching the end of the stream.

Specified by:

ensureCurrentBuffer in class S3ARemoteInputStream

Returns:

true if at least one such buffer is available for reading, false otherwise.

Throws:

IOException - if there is an IO error during this operation.