Module kala.compress.compressors.pack200
Package kala.compress.harmony.unpack200

Class Segment

java.lang.Object
kala.compress.harmony.unpack200.Segment
public class Segment extends Object
A Pack200 archive consists of one or more segments. Each segment is stand-alone, in the sense that every segment has the magic number header; thus, every segment is also a valid archive. However, it is possible to combine (non-GZipped) archives into a single large archive by concatenation alone. Thus, all the hard work in unpacking an archive falls to understanding a segment. The first component of a segment is the header; this contains (amongst other things) the expected counts of constant pool entries, which in turn defines how many values need to be read from the stream. Because values are variable width (see Codec), it is not possible to calculate the start of the next segment, although one of the header values does hint at the size of the segment if non-zero, which can be used for buffering purposes. Note that this does not perform any buffering of the input stream; each value will be read on a byte-by-byte basis. It does not perform GZip decompression automatically; both of these are expected to be done by the caller if the stream has the magic header for GZip streams (GZIPInputStream.GZIP_MAGIC). In any case, if GZip decompression is being performed the input stream will be buffered at a higher level, and thus this can read on a byte-oriented basis.

  • Field Details

    • LOG_LEVEL_VERBOSE

      public static final int LOG_LEVEL_VERBOSE
      See Also:

    • LOG_LEVEL_STANDARD

      public static final int LOG_LEVEL_STANDARD
      See Also:

    • LOG_LEVEL_QUIET

      public static final int LOG_LEVEL_QUIET
      See Also:

    • cpBands

      private CpBands cpBands

    • attrDefinitionBands

      private AttrDefinitionBands attrDefinitionBands

    • icBands

      private IcBands icBands

    • classBands

      private ClassBands classBands

    • bcBands

      private BcBands bcBands

    • fileBands

      private FileBands fileBands

    • overrideDeflateHint

      private boolean overrideDeflateHint

    • deflateHint

      private boolean deflateHint

    • doPreRead

      private boolean doPreRead

    • logLevel

      private int logLevel

    • logStream

      private PrintWriter logStream

    • classFilesContents

      private byte[][] classFilesContents

    • fileDeflate

      private boolean[] fileDeflate

    • fileIsClass

      private boolean[] fileIsClass

    • internalBuffer

      private InputStream internalBuffer

  • Constructor Details

    • Segment

      public Segment()

  • Method Details

    • buildClassFile

      private ClassFile buildClassFile(int classNum)

    • computeIcStored

      private List<IcTuple> computeIcStored(IcTuple[] icLocal, IcTuple[] icRelevant)
      Given an ic_local and an ic_relevant, use them to calculate what should be added as ic_stored.
      Parameters:
      icLocal - IcTuple[] array of local transmitted tuples
      icRelevant - IcTuple[] array of relevant tuples
      Returns:
      List of tuples to be stored. If ic_local is null or empty, the values returned may not be correct. The caller will have to determine if this is the case.

    • getAttrDefinitionBands

      protected AttrDefinitionBands getAttrDefinitionBands()

    • getClassBands

      protected ClassBands getClassBands()

    • getConstantPool

      public SegmentConstantPool getConstantPool()

    • getCpBands

      protected CpBands getCpBands()

    • getIcBands

      protected IcBands getIcBands()

    • getSegmentHeader

      public SegmentHeader getSegmentHeader()

    • log

      public void log(int logLevel, String message)

    • overrideDeflateHint

      public void overrideDeflateHint(boolean deflateHint)
      Override the archive's deflate hint with the given boolean
      Parameters:
      deflateHint - the deflate hint to use

    • parseSegment

      private void parseSegment() throws IOException, Pack200Exception
      This performs the actual work of parsing against a non-static instance of Segment. This method is intended to run concurrently for multiple segments.
      Throws:
      IOException - if a problem occurs during reading from the underlying stream
      Pack200Exception - if a problem occurs with an unexpected value or unsupported codec

    • readSegment

      private void readSegment(InputStream in) throws IOException, Pack200Exception
      This performs reading the data from the stream into non-static instance of Segment. After the completion of this method stream can be freed.
      Parameters:
      in - the input stream to read from
      Throws:
      IOException - if a problem occurs during reading from the underlying stream
      Pack200Exception - if a problem occurs with an unexpected value or unsupported codec

    • setLogLevel

      public void setLogLevel(int logLevel)

    • setLogStream

      public void setLogStream(OutputStream logStream)

    • setPreRead

      public void setPreRead(boolean value)

    • unpack

      public void unpack(InputStream inputStream, JarOutputStream out) throws IOException, Pack200Exception
      Unpacks a packed stream (either .pack. or .pack.gz) into a corresponding JarOuputStream.
      Parameters:
      inputStream - a packed input stream, preferably a BoundedInputStream.
      out - output stream.
      Throws:
      Pack200Exception - if there is a problem unpacking
      IOException - if there is a problem with I/O during unpacking

    • unpackProcess

      void unpackProcess() throws IOException, Pack200Exception
      Throws:
      IOException
      Pack200Exception

    • unpackRead

      void unpackRead(InputStream inputStream) throws IOException, Pack200Exception
      Throws:
      IOException
      Pack200Exception

    • unpackWrite

      void unpackWrite(JarOutputStream out) throws IOException
      Throws:
      IOException

    • writeJar

      public void writeJar(JarOutputStream out) throws IOException
      Writes the segment to an output stream. The output stream should be pre-buffered for efficiency. Also takes the same input stream for reading, since the file bits may not be loaded and thus just copied from one stream to another. Doesn't close the output stream when finished, in case there are more entries (e.g. further segments) to be written.
      Parameters:
      out - the JarOutputStream to write data to
      Throws:
      IOException - if an error occurs while reading or writing to the streams