Package org.kairosdb.bigqueue

Interface IBigArray

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static long NOT_FOUND  

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      long append​(byte[] data)
      Append the data into the head of the array
      long findClosestIndex​(long timestamp)
      Find an index closest to the specific timestamp when the corresponding item was appended
      void flush()
      Force to persist newly appended data, normally, you don't need to flush explicitly since: 1.)
      byte[] get​(long index)
      Get the data at specific index
      long getBackFileSize()
      Get total size of back files(index and data files) of the big array
      int getDataPageSize()
      Get the back data file size per page.
      long getHeadIndex()
      The head of the array.
      int getItemLength​(long index)
      Get the data item length at specific index
      long getTailIndex()
      The tail of the array.
      long getTimestamp​(long index)
      Get the timestamp of data at specific index, this is the timestamp when the data was appended.
      boolean isEmpty()
      Check if the array is empty or not
      boolean isFull()
      Check if the ring space of java long type has all been used up.
      void limitBackFileSize​(long sizeLimit)
      limit the back file size, truncate back file and advance array tail index accordingly, Note, this is a best effort call, exact size limit can't be guaranteed
      void removeAll()
      Remove all data in this array, this will empty the array and delete all back page files.
      void removeBefore​(long timestamp)
      Remove all data before specific timestamp, this will advance the array tail and delete back page files accordingly.
      void removeBeforeIndex​(long index)
      Remove all data before specific index, this will advance the array tail to index and delete back page files before index.
      long size()
      The total number of items has been appended into the array

    • Method Detail

      • append

        long append​(byte[] data)
     throws IOException
        Append the data into the head of the array
        Parameters:
        data - binary data to append
        Returns:
        appended index
        Throws:
        IOException - if there is any IO error

      • get

        byte[] get​(long index)
    throws IOException
        Get the data at specific index
        Parameters:
        index - valid data index
        Returns:
        binary data if the index is valid
        Throws:
        IOException - if there is any IO error

      • getTimestamp

        long getTimestamp​(long index)
           throws IOException
        Get the timestamp of data at specific index, this is the timestamp when the data was appended.
        Parameters:
        index - valid data index
        Returns:
        timestamp when the data was appended
        Throws:
        IOException - if there is any IO error

      • size

        long size()
        The total number of items has been appended into the array
        Returns:
        total number

      • getDataPageSize

        int getDataPageSize()
        Get the back data file size per page.
        Returns:
        size per page

      • getHeadIndex

        long getHeadIndex()
        The head of the array. This is the next to append index, the index of the last appended data is [headIndex - 1] if the array is not empty.
        Returns:
        an index

      • getTailIndex

        long getTailIndex()
        The tail of the array. The is the index of the first appended data
        Returns:
        an index

      • isEmpty

        boolean isEmpty()
        Check if the array is empty or not
        Returns:
        true if empty false otherwise

      • isFull

        boolean isFull()
        Check if the ring space of java long type has all been used up. can always assume false, if true, the world is end:)
        Returns:
        array full or not

      • removeAll

        void removeAll()
        throws IOException
        Remove all data in this array, this will empty the array and delete all back page files.
        Throws:
        IOException - exception thrown if IO error occurs durring remove all

      • removeBeforeIndex

        void removeBeforeIndex​(long index)
                throws IOException
        Remove all data before specific index, this will advance the array tail to index and delete back page files before index.
        Parameters:
        index - an index
        Throws:
        IOException - exception thrown if there was any IO error during the removal operation

      • removeBefore

        void removeBefore​(long timestamp)
           throws IOException
        Remove all data before specific timestamp, this will advance the array tail and delete back page files accordingly.
        Parameters:
        timestamp - a timestamp
        Throws:
        IOException - exception thrown if there was any IO error during the removal operation

      • flush

        void flush()
        Force to persist newly appended data, normally, you don't need to flush explicitly since: 1.) BigArray will automatically flush a cached page when it is replaced out, 2.) BigArray uses memory mapped file technology internally, and the OS will flush the changes even your process crashes, call this periodically only if you need transactional reliability and you are aware of the cost to performance.

      • findClosestIndex

        long findClosestIndex​(long timestamp)
               throws IOException
        Find an index closest to the specific timestamp when the corresponding item was appended
        Parameters:
        timestamp - when the corresponding item was appended
        Returns:
        an index
        Throws:
        IOException - exception thrown if there was any IO error during the getClosestIndex operation

      • getBackFileSize

        long getBackFileSize()
              throws IOException
        Get total size of back files(index and data files) of the big array
        Returns:
        total size of back files
        Throws:
        IOException - exception thrown if there was any IO error during the getBackFileSize operation

      • limitBackFileSize

        void limitBackFileSize​(long sizeLimit)
                throws IOException
        limit the back file size, truncate back file and advance array tail index accordingly, Note, this is a best effort call, exact size limit can't be guaranteed
        Parameters:
        sizeLimit - the size to limit
        Throws:
        IOException - exception thrown if there was any IO error during the limitBackFileSize operation

      • getItemLength

        int getItemLength​(long index)
           throws IOException
        Get the data item length at specific index
        Parameters:
        index - valid data index
        Returns:
        the length of binary data if the index is valid
        Throws:
        IOException - if there is any IO error