tv.danmaku.ijk.media.drm.util

Class ParsableByteArray

java.lang.Object

tv.danmaku.ijk.media.drm.util.ParsableByteArray

public final class ParsableByteArray
extends java.lang.Object

Wraps a byte array, providing a set of methods for parsing data from it. Numerical values are parsed with the assumption that their constituent bytes are in big endian order.

Constructor Summary

Constructors

Constructor and Description
ParsableByteArray() Creates a new instance that initially has no backing data.
ParsableByteArray(byte[] data) Creates a new instance wrapping data, and sets the limit to data.length.
ParsableByteArray(byte[] data, int limit) Creates a new instance that wraps an existing array.
ParsableByteArray(int limit) Creates a new instance with limit bytes and sets the limit.

Method Summary

Modifier and Type	Method and Description
int	bytesLeft() Returns the number of bytes yet to be read.
int	capacity() Returns the capacity of the array, which may be larger than the limit.
void	ensureCapacity(int requiredCapacity) Ensures the backing array is at least requiredCapacity long.
byte[]	getData() Returns the underlying array.
int	getPosition() Returns the current offset in the array, in bytes.
int	limit() Returns the limit.
char	peekChar() Peeks at the next char.
int	peekUnsignedByte() Peeks at the next byte as an unsigned value.
void	readBytes(byte[] buffer, int offset, int length) Reads the next length bytes into buffer at offset.
void	readBytes(java.nio.ByteBuffer buffer, int length) Reads the next length bytes into buffer.
void	readBytes(ParsableBitArray bitArray, int length) Reads the next length bytes into bitArray, and resets the position of bitArray to zero.
java.lang.String	readDelimiterTerminatedString(char delimiter) Reads up to the next delimiter byte (or the limit) as UTF-8 characters.
double	readDouble() Reads the next eight bytes as a 64-bit floating point value.
float	readFloat() Reads the next four bytes as a 32-bit floating point value.
int	readInt() Reads the next four bytes as a signed value
int	readInt24() Reads the next three bytes as a signed value.
java.lang.String	readLine() Reads a line of text.
int	readLittleEndianInt() Reads the next four bytes as a signed value in little endian order.
int	readLittleEndianInt24() Reads the next three bytes as a signed value in little endian order.
long	readLittleEndianLong() Reads the next eight bytes as a signed value in little endian order.
short	readLittleEndianShort() Reads the next two bytes as a signed value.
long	readLittleEndianUnsignedInt() Reads the next four bytes as an unsigned value in little endian order.
int	readLittleEndianUnsignedInt24() Reads the next three bytes as an unsigned value in little endian order.
int	readLittleEndianUnsignedIntToInt() Reads the next four bytes as a little endian unsigned integer into an integer, if the top bit is a zero.
int	readLittleEndianUnsignedShort() Reads the next two bytes as an unsigned value.
long	readLong() Reads the next eight bytes as a signed value.
java.lang.String	readNullTerminatedString() Reads up to the next NUL byte (or the limit) as UTF-8 characters.
java.lang.String	readNullTerminatedString(int length) Reads the next length bytes as UTF-8 characters.
short	readShort() Reads the next two bytes as a signed value.
java.lang.String	readString(int length) Reads the next length bytes as UTF-8 characters.
java.lang.String	readString(int length, java.nio.charset.Charset charset) Reads the next length bytes as characters in the specified Charset.
int	readSynchSafeInt() Reads a Synchsafe integer.
int	readUnsignedByte() Reads the next byte as an unsigned value.
int	readUnsignedFixedPoint1616() Reads the next four bytes, returning the integer portion of the fixed point 16.16 integer.
long	readUnsignedInt() Reads the next four bytes as an unsigned value.
int	readUnsignedInt24() Reads the next three bytes as an unsigned value.
int	readUnsignedIntToInt() Reads the next four bytes as an unsigned integer into an integer, if the top bit is a zero.
long	readUnsignedLongToLong() Reads the next eight bytes as an unsigned long into a long, if the top bit is a zero.
int	readUnsignedShort() Reads the next two bytes as an unsigned value.
long	readUtf8EncodedLong() Reads a long value encoded by UTF-8 encoding
void	reset(byte[] data) Updates the instance to wrap data, and resets the position to zero and the limit to data.length.
void	reset(byte[] data, int limit) Updates the instance to wrap data, and resets the position to zero.
void	reset(int limit) Resets the position to zero and the limit to the specified value.
void	setLimit(int limit) Sets the limit.
void	setPosition(int position) Sets the reading offset in the array.
void	skipBytes(int bytes) Moves the reading offset by bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

ParsableByteArray

public ParsableByteArray()

Creates a new instance that initially has no backing data.

ParsableByteArray

public ParsableByteArray(int limit)

Creates a new instance with limit bytes and sets the limit.

Parameters:

limit - The limit to set.

ParsableByteArray

public ParsableByteArray(byte[] data)

Creates a new instance wrapping data, and sets the limit to data.length.

Parameters:

data - The array to wrap.

ParsableByteArray

public ParsableByteArray(byte[] data,
                         int limit)

Creates a new instance that wraps an existing array.

Parameters:

data - The data to wrap.

limit - The limit to set.

Method Detail

reset

public void reset(int limit)

Resets the position to zero and the limit to the specified value. This might replace or wipe the underlying array, potentially invalidating any local references.

Parameters:

limit - The limit to set.

reset

public void reset(byte[] data)

Updates the instance to wrap data, and resets the position to zero and the limit to data.length.

Parameters:

data - The array to wrap.

reset

public void reset(byte[] data,
                  int limit)

Updates the instance to wrap data, and resets the position to zero.

Parameters:

data - The array to wrap.

limit - The limit to set.

ensureCapacity

public void ensureCapacity(int requiredCapacity)

Ensures the backing array is at least requiredCapacity long.

position, limit, and all data in the underlying array (including that beyond limit()) are preserved.

This might replace or wipe the underlying array, potentially invalidating any local references.

bytesLeft

public int bytesLeft()

Returns the number of bytes yet to be read.

limit

public int limit()

Returns the limit.

setLimit

public void setLimit(int limit)

Sets the limit.

Parameters:

limit - The limit to set.

getPosition

public int getPosition()

Returns the current offset in the array, in bytes.

setPosition

public void setPosition(int position)

Sets the reading offset in the array.

Parameters:

position - Byte offset in the array from which to read.

Throws:

java.lang.IllegalArgumentException - Thrown if the new position is neither in nor at the end of the array.

getData

public byte[] getData()

Returns the underlying array.

Changes to this array are reflected in the results of the read...() methods.

This reference must be assumed to become invalid when reset(int) or ensureCapacity(int) are called (because the array might get reallocated).

capacity

public int capacity()

Returns the capacity of the array, which may be larger than the limit.

skipBytes

public void skipBytes(int bytes)

Moves the reading offset by bytes.

Parameters:

bytes - The number of bytes to skip.

Throws:

java.lang.IllegalArgumentException - Thrown if the new position is neither in nor at the end of the array.

readBytes

public void readBytes(ParsableBitArray bitArray,
                      int length)

Reads the next length bytes into bitArray, and resets the position of bitArray to zero.

Parameters:

bitArray - The ParsableBitArray into which the bytes should be read.

length - The number of bytes to write.

readBytes

public void readBytes(byte[] buffer,
                      int offset,
                      int length)

Reads the next length bytes into buffer at offset.

Parameters:

buffer - The array into which the read data should be written.

offset - The offset in buffer at which the read data should be written.

length - The number of bytes to read.

See Also:

System.arraycopy(Object, int, Object, int, int)

readBytes

public void readBytes(java.nio.ByteBuffer buffer,
                      int length)

Reads the next length bytes into buffer.

Parameters:

buffer - The ByteBuffer into which the read data should be written.

length - The number of bytes to read.

See Also:

ByteBuffer.put(byte[], int, int)

peekUnsignedByte

public int peekUnsignedByte()

Peeks at the next byte as an unsigned value.

peekChar

public char peekChar()

Peeks at the next char.

readUnsignedByte

public int readUnsignedByte()

Reads the next byte as an unsigned value.

readUnsignedShort

public int readUnsignedShort()

Reads the next two bytes as an unsigned value.

readLittleEndianUnsignedShort

public int readLittleEndianUnsignedShort()

Reads the next two bytes as an unsigned value.

readShort

public short readShort()

Reads the next two bytes as a signed value.

readLittleEndianShort

public short readLittleEndianShort()

Reads the next two bytes as a signed value.

readUnsignedInt24

public int readUnsignedInt24()

Reads the next three bytes as an unsigned value.

readInt24

public int readInt24()

Reads the next three bytes as a signed value.

readLittleEndianInt24

public int readLittleEndianInt24()

Reads the next three bytes as a signed value in little endian order.

readLittleEndianUnsignedInt24

public int readLittleEndianUnsignedInt24()

Reads the next three bytes as an unsigned value in little endian order.

readUnsignedInt

public long readUnsignedInt()

Reads the next four bytes as an unsigned value.

readLittleEndianUnsignedInt

public long readLittleEndianUnsignedInt()

Reads the next four bytes as an unsigned value in little endian order.

readInt

public int readInt()

Reads the next four bytes as a signed value

readLittleEndianInt

public int readLittleEndianInt()

Reads the next four bytes as a signed value in little endian order.

readLong

public long readLong()

Reads the next eight bytes as a signed value.

readLittleEndianLong

public long readLittleEndianLong()

Reads the next eight bytes as a signed value in little endian order.

readUnsignedFixedPoint1616

public int readUnsignedFixedPoint1616()

Reads the next four bytes, returning the integer portion of the fixed point 16.16 integer.

readSynchSafeInt

public int readSynchSafeInt()

Reads a Synchsafe integer.

Synchsafe integers keep the highest bit of every byte zeroed. A 32 bit synchsafe integer can store 28 bits of information.

Returns:

The parsed value.

readUnsignedIntToInt

public int readUnsignedIntToInt()

Reads the next four bytes as an unsigned integer into an integer, if the top bit is a zero.

Throws:

java.lang.IllegalStateException - Thrown if the top bit of the input data is set.

readLittleEndianUnsignedIntToInt

public int readLittleEndianUnsignedIntToInt()

Reads the next four bytes as a little endian unsigned integer into an integer, if the top bit is a zero.

Throws:

java.lang.IllegalStateException - Thrown if the top bit of the input data is set.

readUnsignedLongToLong

public long readUnsignedLongToLong()

Reads the next eight bytes as an unsigned long into a long, if the top bit is a zero.

Throws:

java.lang.IllegalStateException - Thrown if the top bit of the input data is set.

readFloat

public float readFloat()

Reads the next four bytes as a 32-bit floating point value.

readDouble

public double readDouble()

Reads the next eight bytes as a 64-bit floating point value.

readString

public java.lang.String readString(int length)

Reads the next length bytes as UTF-8 characters.

Parameters:

length - The number of bytes to read.

Returns:

The string encoded by the bytes.

readString

public java.lang.String readString(int length,
                                   java.nio.charset.Charset charset)

Reads the next length bytes as characters in the specified Charset.

Parameters:

length - The number of bytes to read.

charset - The character set of the encoded characters.

Returns:

The string encoded by the bytes in the specified character set.

readNullTerminatedString

public java.lang.String readNullTerminatedString(int length)

Reads the next length bytes as UTF-8 characters. A terminating NUL byte is discarded, if present.

Parameters:

length - The number of bytes to read.

Returns:

The string, not including any terminating NUL byte.

readNullTerminatedString

public java.lang.String readNullTerminatedString()

Reads up to the next NUL byte (or the limit) as UTF-8 characters.

Returns:

The string not including any terminating NUL byte, or null if the end of the data has already been reached.

readDelimiterTerminatedString

public java.lang.String readDelimiterTerminatedString(char delimiter)

Reads up to the next delimiter byte (or the limit) as UTF-8 characters.

Returns:

The string not including any terminating delimiter byte, or null if the end of the data has already been reached.

readLine

public java.lang.String readLine()

Reads a line of text.

A line is considered to be terminated by any one of a carriage return ('\r'), a line feed ('\n'), or a carriage return followed immediately by a line feed ('\r\n'). The UTF-8 charset is used. This method discards leading UTF-8 byte order marks, if present.

Returns:

The line not including any line-termination characters, or null if the end of the data has already been reached.

readUtf8EncodedLong

public long readUtf8EncodedLong()

Reads a long value encoded by UTF-8 encoding

Returns:

Decoded long value

Throws:

java.lang.NumberFormatException - if there is a problem with decoding