Package db.buffers

Class BufferFileAdapter

java.lang.Object
db.buffers.BufferFileAdapter
All Implemented Interfaces:
BufferFile
Direct Known Subclasses:
ManagedBufferFileAdapter
public class BufferFileAdapter extends Object implements BufferFile
BufferFileAdapter provides a BufferFile implementation which wraps a BufferFileHandle.

  • Constructor Details

    • BufferFileAdapter

      public BufferFileAdapter(BufferFileHandle remoteBufferFile)
      Constructor.
      Parameters:
      remoteBufferFile - remote buffer file handle

  • Method Details

    • getParameter

      public int getParameter(String name) throws NoSuchElementException, IOException
      Description copied from interface: BufferFile
      Get a the stored value for a named parameter.
      Specified by:
      getParameter in interface BufferFile
      Parameters:
      name - parameter name
      Returns:
      integer value
      Throws:
      NoSuchElementException - thrown if parameter not found
      IOException

    • setParameter

      public void setParameter(String name, int value) throws IOException
      Description copied from interface: BufferFile
      Set the integer value for a named parameter.
      Specified by:
      setParameter in interface BufferFile
      Parameters:
      name - parameter name
      value - parameter value
      Throws:
      IOException

    • clearParameters

      public void clearParameters() throws IOException
      Description copied from interface: BufferFile
      Deletes all parameters
      Specified by:
      clearParameters in interface BufferFile
      Throws:
      IOException

    • getParameterNames

      public String[] getParameterNames() throws IOException
      Description copied from interface: BufferFile
      Returns a list of all parameter names.
      Specified by:
      getParameterNames in interface BufferFile
      Throws:
      IOException

    • getBufferSize

      public int getBufferSize() throws IOException
      Description copied from interface: BufferFile
      Return the actual size of a user data buffer. This value should be used when constructing DataBuffer objects.
      Specified by:
      getBufferSize in interface BufferFile
      Returns:
      DataBuffer data size as a number of bytes
      Throws:
      IOException - if an I/O error occurs

    • getIndexCount

      public int getIndexCount() throws IOException
      Description copied from interface: BufferFile
      Returns the number of allocated buffer indexes. When a new buffer is allocated, and the file size grows, the buffer will remain allocated although it may be added to the list of free-indexes. A file will never shrink in size due to this permanent allocation.
      Specified by:
      getIndexCount in interface BufferFile
      Throws:
      IOException

    • getFreeIndexes

      public int[] getFreeIndexes() throws IOException
      Description copied from interface: BufferFile
      Returns the list of free indexes sorted by value. The management of the free-index-list is implementation specific.
      Specified by:
      getFreeIndexes in interface BufferFile
      Throws:
      IOException

    • setFreeIndexes

      public void setFreeIndexes(int[] indexes) throws IOException
      Description copied from interface: BufferFile
      Sets the list of free buffer indexes. The management of the free-index-list is implementation specific.
      Specified by:
      setFreeIndexes in interface BufferFile
      Throws:
      IOException

    • isReadOnly

      public boolean isReadOnly() throws IOException
      Description copied from interface: BufferFile
      Returns true if this file may not be modified via the buffer put method. A read-only file may be considered "updateable" if the canSave method returns true. The term "updateable" means that a Save file can be obtained via the getSaveFile method.
      Specified by:
      isReadOnly in interface BufferFile
      Throws:
      IOException - if an I/O error occurs

    • setReadOnly

      public boolean setReadOnly() throws IOException
      Description copied from interface: BufferFile
      If file is open read-write, the modified contents are flushed and the file re-opened as read-only. This is also used to commit a new version if the file had been modified for update.
      Specified by:
      setReadOnly in interface BufferFile
      Returns:
      true if successfully transitioned from read-write to read-only
      Throws:
      IOException - if an I/O error occurs

    • close

      public void close() throws IOException
      Description copied from interface: BufferFile
      Close the buffer file. If the file was open for write access, all buffers are flushed and the file header updated. Once closed, this object is immediately disposed and may no longer be used.
      Specified by:
      close in interface BufferFile
      Throws:
      IOException - if an I/O error occurs

    • delete

      public boolean delete() throws IOException
      Description copied from interface: BufferFile
      Delete this buffer file if writable. Once deleted, this object is immediately disposed and may no longer be used.
      Specified by:
      delete in interface BufferFile
      Returns:
      true if deleted, false if the file is read-only
      Throws:
      IOException - if an I/O error occurs.

    • dispose

      public void dispose()
      Description copied from interface: BufferFile
      Dispose of this buffer file object. If file is not readOnly and has not been closed, an attempt will be made to delete the associated file(s). Once disposed, it may no longer be used.
      Specified by:
      dispose in interface BufferFile

    • get

      public DataBuffer get(DataBuffer buf, int index) throws IOException
      Description copied from interface: BufferFile
      Get the specified buffer. DataBuffer data and flags are read from the file at index and stored within the supplied DataBuffer object. If the read buffer is empty, the DataBuffer's data field will remain unchanged (which could be null).
      Specified by:
      get in interface BufferFile
      Parameters:
      buf - a buffer whose data array will be filled-in or replaced.
      index - index of buffer to be read. First user buffer is at index 0.
      Throws:
      EOFException - if the requested buffer index is greater than the number of available buffers of the end-of-file was encountered while reading the buffer.
      IOException - if an I/O error occurs

    • put

      public void put(DataBuffer buf, int index) throws IOException
      Description copied from interface: BufferFile
      Store a data buffer at the specified block index.
      Specified by:
      put in interface BufferFile
      Parameters:
      buf - data buffer
      index - block index
      Throws:
      IOException - thrown if an IO error occurs

    • isRemote

      public boolean isRemote()
      Determine if this file is remotely accessed
      Returns:
      true if file is remote