DebugOutputBitStream (Blazegraph Database Platform 2.1.5 API)

java.lang.Object
- it.unimi.dsi.io.OutputBitStream
- - it.unimi.dsi.io.DebugOutputBitStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable
```
public class DebugOutputBitStream
extends OutputBitStream
```
A debugging wrapper for output bit streams.
This class can be used to wrap an output bit stream. The semantics of the resulting write operations is unchanged, but each operation will be logged.
To simplify the output, some operations have a simplified representation. In particular:

|
flush();
->
position();
[
creation;
]
close();
{x}
explicit bits;
{x:b}
minimal binary coding of x with bound b;
{M:x}
write x with coding M; the latter can be U (unary), g (γ), z (ζ), d (δ), G (Golomb), GS (skewed Golomb); when appropriate, x is followed by an extra integer (modulus, etc.).

Since:

0.7.1

Author:

Paolo Boldi, Sebastiano Vigna

Field Summary
- Fields inherited from class it.unimi.dsi.io.OutputBitStream
  avail, buffer, DEFAULT_BUFFER_SIZE, DELTA, fileChannel, free, GAMMA, MAX_PRECOMPUTED, os, pos, position, repositionableStream, SHIFTED_GAMMA, wrapping, ZETA_3

Constructor Summary

Constructors
Constructor and Description
`DebugOutputBitStream(OutputBitStream obs)` Creates a new debug output bit stream wrapping a given output bit stream and logging on standard error.
`DebugOutputBitStream(OutputBitStream obs, PrintStream pw)` Creates a new debug output bit stream wrapping a given output bit stream and logging on a given writer.

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`align()` Aligns the stream.
`void`	`close()` Closes the bit stream.
`void`	`flush()` Flushes the bit stream.
`void`	`position(long position)` Sets this stream bit position, if it is based on a `RepositionableStream` or on a `FileChannel`.
`long`	`write(byte[] bits, long len)` Writes a sequence of bits.
`int`	`writeBit(boolean bit)` Writes a bit.
`int`	`writeBit(int bit)` Writes a bit.
`int`	`writeDelta(int x)` Writes a natural number in δ coding.
`int`	`writeGamma(int x)` Writes a natural number in γ coding.
`int`	`writeGolomb(int x, int b)` Writes a natural number in Golomb coding.
`int`	`writeGolomb(int x, int b, int log2b)` Writes a natural number in Golomb coding.
`int`	`writeInt(int x, int len)` Writes a fixed number of bits from an integer.
`int`	`writeLong(long x, int len)` Writes a fixed number of bits from a long.
`int`	`writeLongDelta(long x)` Writes a long natural number in δ coding.
`int`	`writeLongGamma(long x)` Writes a long natural number in γ coding.
`long`	`writeLongGolomb(long x, long b)` Writes a long natural number in Golomb coding.
`long`	`writeLongGolomb(long x, long b, int log2b)` Writes a long natural number in Golomb coding.
`int`	`writeLongMinimalBinary(long x, long b)` Writes a long natural number in a limited range using a minimal binary coding.
`int`	`writeLongMinimalBinary(long x, long b, int log2b)` Writes a long natural number in a limited range using a minimal binary coding.
`int`	`writeLongNibble(long x)` Writes a long natural number in variable-length nibble coding.
`long`	`writeLongSkewedGolomb(long x, long b)` Writes a long natural number in skewed Golomb coding.
`long`	`writeLongUnary(long x)` Writes a long natural number in unary coding.
`int`	`writeLongZeta(long x, int k)` Writes a long natural number in ζ coding.
`int`	`writeMinimalBinary(int x, int b)` Writes a natural number in a limited range using a minimal binary coding.
`int`	`writeMinimalBinary(int x, int b, int log2b)` Writes a natural number in a limited range using a minimal binary coding.
`int`	`writeNibble(int x)` Writes a natural number in variable-length nibble coding.
`int`	`writeSkewedGolomb(int x, int b)` Writes a natural number in skewed Golomb coding.
`int`	`writeUnary(int x)` Writes a natural number in unary coding.
`int`	`writeZeta(int x, int k)` Writes a natural number in ζ coding.
`long`	`writtenBits()` Returns the number of bits written to this bit stream.
`void`	`writtenBits(long writtenBits)` Sets the number of bits written to this bit stream.

Methods inherited from class it.unimi.dsi.io.OutputBitStream
write, write, writeByteOffset, writeLongShiftedGamma, writeShiftedGamma

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DebugOutputBitStream
```
public DebugOutputBitStream(OutputBitStream obs,
                    PrintStream pw)
```
    Creates a new debug output bit stream wrapping a given output bit stream and logging on a given writer.
    
    Parameters:
    obs - the output bit stream to wrap.
    pw - a print stream that will receive the logging data.
  - DebugOutputBitStream
```
public DebugOutputBitStream(OutputBitStream obs)
```
    Creates a new debug output bit stream wrapping a given output bit stream and logging on standard error.
    
    Parameters:
    obs - the output bit stream to wrap.
- Method Detail
  - flush
```
public void flush()
           throws IOException
```
    Description copied from class: OutputBitStream
    
    Flushes the bit stream.
    This method will align the stream, write the bit buffer, empty the byte buffer and delegate to the OutputStream.flush() method of the underlying output stream.
    This method is provided so that users of this class can easily wrap repositionable streams (for instance, file-based streams, which can be repositioned using the underlying FileChannel).
    It is guaranteed that after calling this method the underlying stream can be repositioned, and that the next write to the underlying output stream will start with the content of the first write method called afterwards.
    
    Specified by:
    
    flush in interface Flushable
    
    Overrides:
    
    flush in class OutputBitStream
    
    Throws:
    
    IOException
  - close
```
public void close()
           throws IOException
```
    Description copied from class: OutputBitStream
    
    Closes the bit stream. All resources associated to the stream are released.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class OutputBitStream
    
    Throws:
    
    IOException
  - writtenBits
```
public long writtenBits()
```
    Description copied from class: OutputBitStream
    
    Returns the number of bits written to this bit stream.
    
    Overrides:
    
    writtenBits in class OutputBitStream
    
    Returns:
    the number of bits written so far.
  - writtenBits
```
public void writtenBits(long writtenBits)
```
    Description copied from class: OutputBitStream
    
    Sets the number of bits written to this bit stream.
    This method is provided so that, for instance, the user can reset via writtenBits(0) the written-bits count after a OutputBitStream.flush().
    
    Overrides:
    
    writtenBits in class OutputBitStream
    
    Parameters:
    writtenBits - the new value for the number of bits written so far.
  - align
```
public int align()
          throws IOException
```
    Description copied from class: OutputBitStream
    
    Aligns the stream. After a call to this method, the stream is byte aligned. Zeroes are used to pad it if necessary.
    
    Overrides:
    
    align in class OutputBitStream
    
    Returns:
    the number of padding bits.
    
    Throws:
    
    IOException
  - position
```
public void position(long position)
              throws IOException
```
    Description copied from class: OutputBitStream
    
    Sets this stream bit position, if it is based on a RepositionableStream or on a FileChannel.
    Given an underlying stream that implements RepositionableStream or that can provide a FileChannel via the getChannel() method, a call to this method has the same semantics of a OutputBitStream.flush(), followed by a call to position(position / 8) on the byte stream. Currently there is no clean, working way of supporting out-of-byte-boundary positioning.
    
    Overrides:
    
    position in class OutputBitStream
    
    Parameters:
    position - the new position expressed as a bit offset; it must be byte-aligned.
    
    Throws:
    
    IOException
    See Also:
    FileChannel.position(long)
  - write
```
public long write(byte[] bits,
         long len)
           throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a sequence of bits. Bits will be written in the natural way: the first bit is bit 7 of the first byte, the eightth bit is bit 0 of the first byte, the ninth bit is bit 7 of the second byte and so on.
    
    Overrides:
    
    write in class OutputBitStream
    
    Parameters:
    bits - a vector containing the bits to be written.
    len - a bit length.
    
    Returns:
    the number of bits written (len).
    
    Throws:
    
    IOException
  - writeBit
```
public int writeBit(boolean bit)
             throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a bit.
    
    Overrides:
    
    writeBit in class OutputBitStream
    
    Parameters:
    bit - a bit.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeBit
```
public int writeBit(int bit)
             throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a bit.
    
    Overrides:
    
    writeBit in class OutputBitStream
    
    Parameters:
    bit - a bit.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeInt
```
public int writeInt(int x,
           int len)
             throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a fixed number of bits from an integer.
    
    Overrides:
    
    writeInt in class OutputBitStream
    
    Parameters:
    x - an integer.
    len - a bit length; this many lower bits of the first argument will be written (the most significant bit first).
    
    Returns:
    the number of bits written (len).
    
    Throws:
    
    IOException
  - writeLong
```
public int writeLong(long x,
            int len)
              throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a fixed number of bits from a long.
    
    Overrides:
    
    writeLong in class OutputBitStream
    
    Parameters:
    x - a long.
    len - a bit length; this many lower bits of the first argument will be written (the most significant bit first).
    
    Returns:
    the number of bits written (len).
    
    Throws:
    
    IOException
  - writeUnary
```
public int writeUnary(int x)
               throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in unary coding.
    The unary coding of a natural number n is given by 0ⁿ1.
    
    Overrides:
    
    writeUnary in class OutputBitStream
    
    Parameters:
    x - a natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeLongUnary
```
public long writeLongUnary(long x)
                    throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in unary coding.
    
    Overrides:
    
    writeLongUnary in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeUnary(int)
  - writeGamma
```
public int writeGamma(int x)
               throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in γ coding.
    The γ coding of a positive number of k bits is obtained writing k-1 in unary, followed by the lower k-1 bits of the number. The coding of a natural number is obtained by adding one and coding.
    
    Overrides:
    
    writeGamma in class OutputBitStream
    
    Parameters:
    x - a natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeLongGamma
```
public int writeLongGamma(long x)
                   throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in γ coding.
    
    Overrides:
    
    writeLongGamma in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeGamma(int)
  - writeDelta
```
public int writeDelta(int x)
               throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in δ coding. The δ coding of a positive number of k bits is obtained writing k-1 in γ coding, followed by the lower k-1 bits of the number. The coding of a natural number is obtained by adding one and coding.
    
    Overrides:
    
    writeDelta in class OutputBitStream
    
    Parameters:
    x - a natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeLongDelta
```
public int writeLongDelta(long x)
                   throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in δ coding.
    
    Overrides:
    
    writeLongDelta in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeDelta(int)
  - writeMinimalBinary
```
public int writeMinimalBinary(int x,
                     int b)
                       throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in a limited range using a minimal binary coding.
    A minimal binary code is an optimal code for the uniform distribution. This method uses an optimal code in which shorter words are assigned to smaller integers.
    
    Overrides:
    
    writeMinimalBinary in class OutputBitStream
    
    Parameters:
    x - a natural number.
    b - a strict upper bound for x.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeMinimalBinary
```
public int writeMinimalBinary(int x,
                     int b,
                     int log2b)
                       throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in a limited range using a minimal binary coding. This method is faster than OutputBitStream.writeMinimalBinary(int,int) because it does not have to compute log2b.
    
    Overrides:
    
    writeMinimalBinary in class OutputBitStream
    
    Parameters:
    x - a natural number.
    b - a strict upper bound for x.
    log2b - the floor of the base-2 logarithm of the bound.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeMinimalBinary(int, int)
  - writeLongMinimalBinary
```
public int writeLongMinimalBinary(long x,
                         long b)
                           throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in a limited range using a minimal binary coding.
    
    Overrides:
    
    writeLongMinimalBinary in class OutputBitStream
    
    Parameters:
    x - a natural number.
    b - a strict upper bound for x.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeMinimalBinary(int, int)
  - writeLongMinimalBinary
```
public int writeLongMinimalBinary(long x,
                         long b,
                         int log2b)
                           throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in a limited range using a minimal binary coding. This method is faster than OutputBitStream.writeLongMinimalBinary(long,long) because it does not have to compute log2b.
    
    Overrides:
    
    writeLongMinimalBinary in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    b - a strict upper bound for x.
    log2b - the floor of the base-2 logarithm of the bound.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeMinimalBinary(int, int)
  - writeGolomb
```
public int writeGolomb(int x,
              int b)
                throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in Golomb coding.
    Golomb coding with modulo b writes a natural number x as the quotient of the division of x and b in unary, followed by the remainder in minimal binary code.
    This method implements also the case in which b is 0: in this case, the argument x may only be zero, and nothing will be written.
    
    Overrides:
    
    writeGolomb in class OutputBitStream
    
    Parameters:
    x - a natural number.
    b - the modulus for the coding.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeGolomb
```
public int writeGolomb(int x,
              int b,
              int log2b)
                throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in Golomb coding. This method is faster than OutputBitStream.writeGolomb(int,int) because it does not have to compute log2b.
    
    Overrides:
    
    writeGolomb in class OutputBitStream
    
    Parameters:
    x - a natural number.
    b - the modulus for the coding.
    log2b - the floor of the base-2 logarithm of the coding modulus (it is irrelevant when b is zero).
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeGolomb(int, int)
  - writeLongGolomb
```
public long writeLongGolomb(long x,
                   long b)
                     throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in Golomb coding.
    
    Overrides:
    
    writeLongGolomb in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    b - the modulus for the coding.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeGolomb(int, int)
  - writeLongGolomb
```
public long writeLongGolomb(long x,
                   long b,
                   int log2b)
                     throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in Golomb coding. This method is faster than OutputBitStream.writeLongGolomb(long,long) because it does not have to compute log2b.
    
    Overrides:
    
    writeLongGolomb in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    b - the modulus for the coding.
    log2b - the floor of the base-2 logarithm of the coding modulus (it is irrelevant when b is zero).
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeGolomb(int, int)
  - writeSkewedGolomb
```
public int writeSkewedGolomb(int x,
                    int b)
                      throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in skewed Golomb coding.
    This method implements also the case in which b is 0: in this case, the argument x may only be zero, and nothing will be written.
    
    Overrides:
    
    writeSkewedGolomb in class OutputBitStream
    
    Parameters:
    x - a natural number.
    b - the modulus for the coding.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeLongSkewedGolomb
```
public long writeLongSkewedGolomb(long x,
                         long b)
                           throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in skewed Golomb coding.
    This method implements also the case in which b is 0: in this case, the argument x may only be zero, and nothing will be written.
    
    Overrides:
    
    writeLongSkewedGolomb in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    b - the modulus for the coding.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeSkewedGolomb(int, int)
  - writeZeta
```
public int writeZeta(int x,
            int k)
              throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in ζ coding.
    ζ coding (with modulo k) records positive numbers in the intervals [1,2^k-1],[2^k,2^k+1-1],…,[2^hk,2^(h+1)k-1] by coding h in unary, followed by a minimal binary coding of the offset in the interval. The coding of a natural number is obtained by adding one and coding.
    ζ codes were defined by Paolo Boldi and Sebastiano Vigna in “Codes for the World−Wide Web”, Internet Math., 2(4):405-427, 2005. The paper contains also a detailed analysis.
    
    Overrides:
    
    writeZeta in class OutputBitStream
    
    Parameters:
    x - a natural number.
    k - the shrinking factor.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeLongZeta
```
public int writeLongZeta(long x,
                int k)
                  throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in ζ coding.
    
    Overrides:
    
    writeLongZeta in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    k - the shrinking factor.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeZeta(int, int)
  - writeNibble
```
public int writeNibble(int x)
                throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a natural number in variable-length nibble coding.
    Variable-length nibble coding records a natural number by padding its binary representation to the left using zeroes, until its length is a multiple of three. Then, the resulting string is broken in blocks of 3 bits, and each block is prefixed with a bit, which is zero for all blocks except for the last one.
    
    Overrides:
    
    writeNibble in class OutputBitStream
    
    Parameters:
    x - a natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
  - writeLongNibble
```
public int writeLongNibble(long x)
                    throws IOException
```
    Description copied from class: OutputBitStream
    
    Writes a long natural number in variable-length nibble coding.
    
    Overrides:
    
    writeLongNibble in class OutputBitStream
    
    Parameters:
    x - a long natural number.
    
    Returns:
    the number of bits written.
    
    Throws:
    
    IOException
    See Also:
    OutputBitStream.writeNibble(int)

Class DebugOutputBitStream

Field Summary

Fields inherited from class it.unimi.dsi.io.OutputBitStream

Constructor Summary

Method Summary

Methods inherited from class it.unimi.dsi.io.OutputBitStream

Methods inherited from class java.lang.Object

Constructor Detail

DebugOutputBitStream

DebugOutputBitStream

Method Detail

flush

close

writtenBits

writtenBits

align

position

write

writeBit

writeBit

writeInt

writeLong

writeUnary

writeLongUnary

writeGamma

writeLongGamma

writeDelta

writeLongDelta

writeMinimalBinary

writeMinimalBinary

writeLongMinimalBinary

writeLongMinimalBinary

writeGolomb

writeGolomb

writeLongGolomb

writeLongGolomb

writeSkewedGolomb

writeLongSkewedGolomb

writeZeta

writeLongZeta

writeNibble

writeLongNibble