Class BDecoder

java.lang.Object

com.biglybt.core.util.BDecoder

public class BDecoder
extends Object

A set of utility methods to decode a bencoded array of byte into a Map. integer are represented as Long, String as byte[], dictionaries as Map, and list as List.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	BDecoder.BDecoderInputStreamArray
static interface	BDecoder.MapDecodeListener

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	force_utf8_keys
private byte[]	keyBytes
private ByteBuffer	keyBytesBuffer
private int	keyBytesLen
private CharBuffer	keyCharsBuffer
private final Charset	keyCharset
private Charset	keyCharsetUTF8
private final CharsetDecoder	keyDecoder
private CharsetDecoder	keyDecoderUTF8
private BDecoder.MapDecodeListener	mapDecodeListener
static final int	MAX_BYTE_ARRAY_SIZE
private static final int	MAX_MAP_KEY_SIZE
private static final boolean	NEWDECODER_FOR_DEF_CHARSET
private final char[]	numberChars	only create the array once per decoder instance (no issues with recursion as it's only used in a leaf method)
private static final byte[]	PORTABLE_ROOT
private boolean	recovery_mode
private static final boolean	TRACE
private boolean	useNewDecoder
private boolean	verify_map_order

Constructor Summary

Constructors

Modifier	Constructor	Description
	BDecoder()	Create a BDecoder using BYTE_ENCODING_CHARSET (ISO_8859_1)
	BDecoder(Charset keyCharset)	Create a BDecoder using specified charset.
private	BDecoder(Charset keyCharset, boolean useNewDecoder)

Method Summary

Modifier and Type	Method	Description
static Map<String,Object>	decode(byte[] data)
static Map<String,Object>	decode(byte[] data, int offset, int length)
static Map<String,Object>	decode(BufferedInputStream is)
private Map<String,Object>	decode(InputStream data, boolean internKeys)
Map<String,Object>	decodeByteArray(byte[] data)
Map<String,Object>	decodeByteArray(byte[] data, int offset, int length)
Map<String,Object>	decodeByteArray(byte[] data, int offset, int length, boolean internKeys)
Map<String,Object>	decodeByteBuffer(ByteBuffer buffer, boolean internKeys)
static Map	decodeFromJSON(String json)
static List	decodeFromJSONArray(List j_list)
private static Object	decodeFromJSONGeneric(Object obj)
static Map	decodeFromJSONObject(Map<Object,Object> j_map)
private Object	decodeInputStream(InputStream dbis, String context, int nesting, boolean internKeys)
private Object	decodeInputStream2(InputStream dbis, String context, int nesting, boolean internKeys)	Differences between decodeInputStream This: Uses byte[] for keys Other: Uses ByteBuffer This: Uses new String(byte[], pos, len, charset) Other: Uses CharsetDecoder.decode(ByteBuffer, CharBuffer) and new String(charBuffer.array(), 0, len) This: Verifies map order using key in String form Other: Verifies map order by copying bytes and comparing
Map<String,Object>	decodeStream(BufferedInputStream data)
Map<String,Object>	decodeStream(BufferedInputStream data, boolean internKeys)
static List	decodeStrings(List list)	Decodes byte arrays into strings.
static Map	decodeStrings(Map map)	Converts any byte[] entries into UTF-8 strings.
private void	getByteArrayFromStream(InputStream dbis, int length, byte[] targetArray)
private byte[]	getByteArrayFromStream(InputStream dbis, String context)
BDecoder.MapDecodeListener	getMapDecodeListener()
private long	getNumberFromStream(InputStream dbis, char parseChar)
private int	getPositiveNumberFromStream(InputStream dbis, char parseChar)
static void	main(String[] args)
static long	parseLong(char[] chars, int start, int length)
private static void	print(File f, File output)
static void	print(PrintWriter writer, Object obj)
private static void	print(PrintWriter writer, Object obj, String indent, boolean skip_indent)
static void	print(Object obj)
void	setMapDecodeListener(BDecoder.MapDecodeListener mapDecodeListener)
void	setRecoveryMode(boolean r)
void	setVerifyMapOrder(boolean b)

Methods inherited from class Object

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

Field Details

MAX_BYTE_ARRAY_SIZE

public static final int MAX_BYTE_ARRAY_SIZE

See Also:

• Constant Field Values

MAX_MAP_KEY_SIZE

private static final int MAX_MAP_KEY_SIZE

See Also:

• Constant Field Values

NEWDECODER_FOR_DEF_CHARSET

private static final boolean NEWDECODER_FOR_DEF_CHARSET

TRACE

private static final boolean TRACE

See Also:

• Constant Field Values

PORTABLE_ROOT

private static final byte[] PORTABLE_ROOT

recovery_mode

private boolean recovery_mode

verify_map_order

private boolean verify_map_order

useNewDecoder

private boolean useNewDecoder

keyDecoder

private final CharsetDecoder keyDecoder

keyCharset

private final Charset keyCharset

keyDecoderUTF8

private CharsetDecoder keyDecoderUTF8

keyCharsetUTF8

private Charset keyCharsetUTF8

keyBytesLen

private int keyBytesLen

keyBytesBuffer

private ByteBuffer keyBytesBuffer

keyBytes

private byte[] keyBytes

keyCharsBuffer

private CharBuffer keyCharsBuffer

mapDecodeListener

private BDecoder.MapDecodeListener mapDecodeListener

force_utf8_keys

private boolean force_utf8_keys

numberChars

private final char[] numberChars

only create the array once per decoder instance (no issues with recursion as it's only used in a leaf method)

Constructor Details

BDecoder

public BDecoder()

Create a BDecoder using BYTE_ENCODING_CHARSET (ISO_8859_1)

BDecoder

public BDecoder(Charset keyCharset)

Create a BDecoder using specified charset.

New decoder will be used, which can handle UTF-8 properly

BDecoder

private BDecoder(Charset keyCharset,
 boolean useNewDecoder)

Method Details

decode

public static Map<String,Object> decode(byte[] data)
                                 throws IOException

Throws:

IOException

decode

public static Map<String,Object> decode(byte[] data,
 int offset,
 int length)
                                 throws IOException

Throws:

IOException

decode

public static Map<String,Object> decode(BufferedInputStream is)
                                 throws IOException

Throws:

IOException

decodeByteArray

public Map<String,Object> decodeByteArray(byte[] data)
                                   throws IOException

Throws:

IOException

decodeByteArray

public Map<String,Object> decodeByteArray(byte[] data,
 int offset,
 int length)
                                   throws IOException

Throws:

IOException

decodeByteArray

public Map<String,Object> decodeByteArray(byte[] data,
 int offset,
 int length,
 boolean internKeys)
                                   throws IOException

Throws:

IOException

decodeByteBuffer

public Map<String,Object> decodeByteBuffer(ByteBuffer buffer,
 boolean internKeys)
                                    throws IOException

Throws:

IOException

decodeStream

public Map<String,Object> decodeStream(BufferedInputStream data)
                                throws IOException

Throws:

IOException

decodeStream

public Map<String,Object> decodeStream(BufferedInputStream data,
 boolean internKeys)
                                throws IOException

Throws:

IOException

decode

private Map<String,Object> decode(InputStream data,
 boolean internKeys)
                           throws IOException

Throws:

IOException

decodeInputStream

private Object decodeInputStream(InputStream dbis,
 String context,
 int nesting,
 boolean internKeys)
                          throws IOException

Throws:

IOException

decodeInputStream2

private Object decodeInputStream2(InputStream dbis,
 String context,
 int nesting,
 boolean internKeys)
                           throws IOException

Differences between decodeInputStream
This: Uses byte[] for keys
Other: Uses ByteBuffer

This: Uses new String(byte[], pos, len, charset)
Other: Uses CharsetDecoder.decode(ByteBuffer, CharBuffer) and new String(charBuffer.array(), 0, len)

This: Verifies map order using key in String form
Other: Verifies map order by copying bytes and comparing

On a torrent with 100k files and set to verify map order, this method is 2.5x faster.

Throws:

IOException

getPositiveNumberFromStream

private int getPositiveNumberFromStream(InputStream dbis,
 char parseChar)
                                 throws IOException

Throws:

IOException

getNumberFromStream

private long getNumberFromStream(InputStream dbis,
 char parseChar)
                          throws IOException

Throws:

IOException

parseLong

public static long parseLong(char[] chars,
 int start,
 int length)

getByteArrayFromStream

private byte[] getByteArrayFromStream(InputStream dbis,
 String context)
                               throws IOException

Throws:

IOException

getByteArrayFromStream

private void getByteArrayFromStream(InputStream dbis,
 int length,
 byte[] targetArray)
                             throws IOException

Throws:

IOException

setVerifyMapOrder

public void setVerifyMapOrder(boolean b)

setRecoveryMode

public void setRecoveryMode(boolean r)

print

public static void print(Object obj)

print

public static void print(PrintWriter writer,
 Object obj)

print

private static void print(PrintWriter writer,
 Object obj,
 String indent,
 boolean skip_indent)

decodeStrings

public static Map decodeStrings(Map map)

Converts any byte[] entries into UTF-8 strings. REPLACES EXISTING MAP VALUES

Parameters:

map -

Returns:

decodeStrings

public static List decodeStrings(List list)

Decodes byte arrays into strings. REPLACES EXISTING LIST VALUES

Parameters:

list -

Returns:

the same list passed in

print

private static void print(File f,
 File output)

decodeFromJSONGeneric

private static Object decodeFromJSONGeneric(Object obj)

decodeFromJSONArray

public static List decodeFromJSONArray(List j_list)

decodeFromJSONObject

public static Map decodeFromJSONObject(Map<Object,Object> j_map)

decodeFromJSON

public static Map decodeFromJSON(String json)

getMapDecodeListener

public BDecoder.MapDecodeListener getMapDecodeListener()

setMapDecodeListener

public void setMapDecodeListener(BDecoder.MapDecodeListener mapDecodeListener)

main

public static void main(String[] args)