Package loci.common

Class S3Handle

java.lang.Object

loci.common.StreamHandle

loci.common.S3Handle

All Implemented Interfaces:

DataInput, DataOutput, IRandomAccess

public class S3Handle
extends StreamHandle

Provides random access to S3 buckets using the IRandomAccess interface. Instances of S3Handle are read-only.

See Also:

IRandomAccess, StreamHandle, URLConnection

Nested Class Summary

Nested classes/interfaces inherited from class loci.common.StreamHandle

StreamHandle.Settings

Field Summary

Fields

Modifier and Type	Field	Description
static String	DEFAULT_S3_PROTOCOL	Default protocol for fetching s3://
protected static int	S3_MAX_FORWARD_SEEK	If seeking more than this distance reset and reopen at offset
protected static Pattern	SCHEME_PARSER

Fields inherited from class loci.common.StreamHandle

file, fp, length, mark, order, outStream, stream

Constructor Summary

Constructors

Constructor	Description
S3Handle(String url)	Open an S3 file
S3Handle(String uristr, boolean initialize, StreamHandle.Settings s)	Open an S3 file

Method Summary

Modifier and Type	Method	Description
static String	cacheObject(String url, StreamHandle.Settings s)	Download an S3 object to a file system cache if it doesn't already exist
static boolean	canHandleScheme(String url)	Return true if this is a URL with an s3 scheme
protected void	connect()	Connect to the server
protected void	downloadObject(Path destination)
boolean	exists()	Does this represent an accessible location?
String	getBucket()
String	getCacheKey()
String	getPath()
int	getPort()
String	getServer()
protected void	initialize()	Check bucket or object exists
boolean	isBucket()	Is this an accessible bucket? TODO: If this bucket doesn't exist do we return false or thrown an exception?
long	length()	Returns the length of this stream.
protected void	resetStream()	Close and reopen the stream; the stream pointer and mark should be reset to 0.
protected void	resetStream(long offset)	Reset the stream to an offset position
void	seek(long pos)	Sets the stream pointer offset, measured from the beginning of this stream, at which the next read or write occurs.
String	toString()

Methods inherited from class loci.common.StreamHandle

close, getFilePointer, getOrder, read, read, read, read, readBoolean, readByte, readChar, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedShort, readUTF, setOrder, skipBytes, skipBytes, write, write, write, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_S3_PROTOCOL

public static final String DEFAULT_S3_PROTOCOL

Default protocol for fetching s3://

See Also:

Constant Field Values

SCHEME_PARSER

protected static final Pattern SCHEME_PARSER

S3_MAX_FORWARD_SEEK

protected static final int S3_MAX_FORWARD_SEEK

If seeking more than this distance reset and reopen at offset

See Also:

Constant Field Values

Constructor Detail

S3Handle

public S3Handle(String url)
         throws IOException

Open an S3 file

Parameters:

url - the full URL to the S3 resource

Throws:

IOException - if there is an error during opening

S3Handle

public S3Handle(String uristr,
                boolean initialize,
                StreamHandle.Settings s)
         throws IOException

Open an S3 file

Parameters:

uristr - the full URL to the S3 resource

initialize - If true open the stream, otherwise just parse connection string

s - custom settings object

Throws:

IOException - if there is an error during opening

Method Detail

canHandleScheme

public static boolean canHandleScheme(String url)

Return true if this is a URL with an s3 scheme

Parameters:

url - URL

Returns:

true if this class can handle url

connect

protected void connect()
                throws IOException

Connect to the server

Throws:

IOException - if there was an error connecting to the server

initialize

protected void initialize()
                   throws IOException,
                          S3ClientServiceException

Check bucket or object exists

Throws:

IOException - if unable to get the object

S3ClientServiceException - if unable to get the object

getServer

public String getServer()

getPort

public int getPort()

getBucket

public String getBucket()

getPath

public String getPath()

cacheObject

public static String cacheObject(String url,
                                 StreamHandle.Settings s)
                          throws IOException,
                                 HandleException

Download an S3 object to a file system cache if it doesn't already exist

Parameters:

url - the full URL to the S3 resource

s - custom settings object

Returns:

File path to the cached object

Throws:

IOException - if there is an error during reading or writing

HandleException - if no destination for the cache is provided

getCacheKey

public String getCacheKey()

downloadObject

protected void downloadObject(Path destination)
                       throws HandleException,
                              IOException

Throws:

HandleException

IOException

isBucket

public boolean isBucket()

Is this an accessible bucket? TODO: If this bucket doesn't exist do we return false or thrown an exception?

Returns:

True if a bucket

length

public long length()
            throws IOException

Description copied from interface: IRandomAccess

Returns the length of this stream.

Specified by:

length in interface IRandomAccess

Overrides:

length in class StreamHandle

Returns:

the length in bytes of the stream

Throws:

IOException - if the length cannot be retrieved

seek

public void seek(long pos)
          throws IOException

Description copied from interface: IRandomAccess

Sets the stream pointer offset, measured from the beginning of this stream, at which the next read or write occurs.

Specified by:

seek in interface IRandomAccess

Overrides:

seek in class StreamHandle

Parameters:

pos - new byte offset (pointer) in the current stream. Unless otherwise noted, may be larger or smaller than the current pointer, but must be non-negative and less than the value of #length()

Throws:

IOException - if pos is invalid or the seek fails

See Also:

StreamHandle.seek(long)

resetStream

protected void resetStream()
                    throws IOException

Description copied from class: StreamHandle

Close and reopen the stream; the stream pointer and mark should be reset to 0. This method is called if we need to seek backwards within the stream.

Specified by:

resetStream in class StreamHandle

Throws:

IOException - if the stream cannot be reset

See Also:

StreamHandle.resetStream()

exists

public boolean exists()
               throws IOException

Does this represent an accessible location?

Specified by:

exists in interface IRandomAccess

Overrides:

exists in class StreamHandle

Returns:

true if this location is accessible

Throws:

IOException - if unable to determine whether this location is accessible

resetStream

protected void resetStream(long offset)
                    throws IOException

Reset the stream to an offset position

Parameters:

offset - Offset into object

Throws:

IOException - if there is an error during reading or writing

toString

public String toString()

Overrides:

toString in class Object