Package org.apache.jackrabbit.oak.segment.remote

Class AbstractRemoteSegmentArchiveReader

java.lang.Object
org.apache.jackrabbit.oak.segment.remote.AbstractRemoteSegmentArchiveReader
All Implemented Interfaces:
Closeable, AutoCloseable, SegmentArchiveReader
Direct Known Subclasses:
AwsSegmentArchiveReader, AzureSegmentArchiveReader, AzureSegmentArchiveReaderV8
public abstract class AbstractRemoteSegmentArchiveReader extends Object implements SegmentArchiveReader

  • Field Details

  • Constructor Details

  • Method Details

    • readSegment

      public Buffer readSegment(long msb, long lsb) throws IOException
      Description copied from interface: SegmentArchiveReader
      Read the segment.
      Specified by:
      readSegment in interface SegmentArchiveReader
      Parameters:
      msb - the most significant bits of the identifier of the segment
      lsb - the least significant bits of the identifier of the segment
      Returns:
      byte buffer containing the segment data or null if the segment doesn't exist
      Throws:
      IOException

    • containsSegment

      public boolean containsSegment(long msb, long lsb)
      Description copied from interface: SegmentArchiveReader
      Check if the segment exists.
      Specified by:
      containsSegment in interface SegmentArchiveReader
      Parameters:
      msb - the most significant bits of the identifier of the segment
      lsb - the least significant bits of the identifier of the segment
      Returns:
      true if the segment exists

    • listSegments

      public List<SegmentArchiveEntry> listSegments()
      Description copied from interface: SegmentArchiveReader
      List all the segments, in the order as they have been written to the archive.
      Specified by:
      listSegments in interface SegmentArchiveReader
      Returns:
      segment list, ordered by their position in the archive

    • getGraph

      public Buffer getGraph() throws IOException
      Description copied from interface: SegmentArchiveReader
      Load the segment graph.
      Specified by:
      getGraph in interface SegmentArchiveReader
      Returns:
      byte buffer representing the graph or null if the graph hasn't been persisted.
      Throws:
      IOException

    • hasGraph

      public boolean hasGraph()
      Description copied from interface: SegmentArchiveReader
      Check if the segment graph has been persisted for this archive.
      Specified by:
      hasGraph in interface SegmentArchiveReader
      Returns:
      true if the graph exists, false otherwise

    • getBinaryReferences

      public Buffer getBinaryReferences() throws IOException
      Description copied from interface: SegmentArchiveReader
      Load binary references.
      Specified by:
      getBinaryReferences in interface SegmentArchiveReader
      Returns:
      byte buffer representing the binary references structure.
      Throws:
      IOException

    • close

      public void close()
      Description copied from interface: SegmentArchiveReader
      Close the archive.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface SegmentArchiveReader

    • getEntrySize

      public int getEntrySize(int size)
      Description copied from interface: SegmentArchiveReader
      Transforms the segment size in bytes into the effective size on disk for the given entry (eg. by adding the number of padding bytes, header, etc.)
      Specified by:
      getEntrySize in interface SegmentArchiveReader
      Parameters:
      size - the segment size in bytes
      Returns:
      the number of bytes effectively used on the storage to save the segment

    • computeArchiveIndexAndLength

      protected abstract long computeArchiveIndexAndLength() throws IOException
      Populates the archive index, summing up each entry's length.
      Returns:
      length, the total length of the archive
      Throws:
      IOException

    • doReadSegmentToBuffer

      protected abstract void doReadSegmentToBuffer(String segmentFileName, Buffer buffer) throws IOException
      Reads the segment from the remote storage.
      Parameters:
      segmentFileName - , the name of the segment (msb + lsb) prefixed by its position in the archive
      buffer - , the buffer to which to read
      Throws:
      IOException

    • doReadDataFile

      protected abstract Buffer doReadDataFile(String extension) throws IOException
      Reads a data file inside the archive. This entry is not a segment. Its full name is given by archive name + extension.
      Parameters:
      extension - , extension of the file
      Returns:
      the buffer containing the data file bytes
      Throws:
      IOException

    • archivePathAsFile

      protected abstract File archivePathAsFile()
      Returns the decoded file component of this archive.
      Returns:
      the decoded file component of this archive.

    • isRemote

      public boolean isRemote()
      Description copied from interface: SegmentArchiveReader
      This method returns true if the storage is accessed via a network protocol, not tight to the traditional storage technology, for example, HTTP. Based on that info, for instance, calling classes can decide to update archive metadata (graph, binary references, index) more frequently, and not only when the archive is being closed. With that multiple Oak processes can access the storage simultaneously, with one process in read-write mode and one or more processes in read-only mode.
      Specified by:
      isRemote in interface SegmentArchiveReader
      Returns: