Package net.metanotion.io.block

Class BlockFile

  • All Implemented Interfaces:
    Closeable, AutoCloseable
    public class BlockFile
extends Object
implements Closeable
    On-disk format: Magic number (6 bytes) Version major/minor (2 bytes) file length (long) free list start (unsigned int) is mounted (unsigned short) 0 = no, 1 = yes span size (unsigned short) block size (unsigned int) Metaindex skiplist is on page 2 Pages are 1 KB and are numbered starting from 1. e.g. the Metaindex skiplist is at offset 1024 bytes

    • Method Detail

      • main

        public static void main​(String[] args)
        Run an integrity check on the blockfile and all the skiplists in it. WARNING: This only works on skiplists using UTF8StringBytes as a key serializer, unless the exception has been coded in bfck below. Will CORRUPT other skiplists.

      • writeMultiPageData

        public int writeMultiPageData​(byte[] data,
                              int page,
                              int[] curPageOff,
                              int[] nextPage)
                       throws IOException
        Write bytes This will allocate additional continuation pages as necessary.
        Parameters:
        data - data to write
        page - current page
        curPageOff - in (current) and out (new) parameter at index 0
        nextPage - in (current) and out (new) parameter at index 0
        Returns:
        current page
        Throws:
        IOException

      • readMultiPageData

        public int readMultiPageData​(byte[] arr,
                             int page,
                             int[] curPageOff,
                             int[] nextPage)
                      throws IOException
        Read bytes
        Parameters:
        arr - fill this array fully with data
        page - current page
        curPageOff - in (current) and out (new) parameter at index 0
        nextPage - in (current) and out (new) parameter at index 0
        Returns:
        current page
        Throws:
        IOException

      • skipMultiPageBytes

        public int skipMultiPageBytes​(int length,
                              int page,
                              int[] curPageOff,
                              int[] nextPage)
                       throws IOException
        Skip length bytes The same as readMultiPageData() without returning a result
        Parameters:
        length - number of bytes to skip
        page - current page
        curPageOff - in (current) and out (new) parameter at index 0
        nextPage - in (current) and out (new) parameter at index 0
        Returns:
        current page
        Throws:
        IOException

      • wasMounted

        public boolean wasMounted()
        I2P was the file locked when we opened it?
        Since:
        0.8.8

      • pageSeek

        public static void pageSeek​(RandomAccessInterface file,
                            int page)
                     throws IOException
        Go to any page but the superblock. Page 1 is the superblock, must use file.seek(0) to get there.
        Parameters:
        page - >= 2
        Throws:
        IOException

      • freePage

        public void freePage​(int page)
        Add the page to the free list. The file is never shrunk. TODO: Reclaim free pages at end of file, or even do a full compaction. Does not throw exceptions; logs on failure.

      • getIndex

        public <K extends Comparable<? super K>,​V> BSkipList<K,​V> getIndex​(String name,
                                                                               Serializer<K> key,
                                                                               Serializer<V> val)
                                                                        throws IOException
        Open a skiplist if it exists. Returns null if the skiplist does not exist. Empty skiplists are not preserved after close. If the file is writable, this runs an integrity check and repair on first open.
        Returns:
        null if not found
        Throws:
        IOException

      • delIndex

        public void delIndex​(String name)
              throws IOException
        Delete a skiplist if it exists. Must be open. Throws IOException if exists but is closed. Broken before 0.9.26.
        Throws:
        IOException - if it is closed.

      • closeIndex

        public void closeIndex​(String name)
        Close a skiplist if it is open. Added I2P

      • reformatIndex

        public <K extends Comparable<? super K>,​V> void reformatIndex​(String name,
                                                                    Serializer<K> oldKey,
                                                                    Serializer<V> oldVal,
                                                                    Serializer<K> newKey,
                                                                    Serializer<V> newVal)
                                                             throws IOException
        Reformat a skiplist with new Serializers if it exists. The skiplist must be closed. Throws IOException if the skiplist is open. The skiplist will remain closed after completion.
        Throws:
        IOException - if it is open or on errors
        Since:
        0.9.26

      • bfck

        public boolean bfck​(boolean fix)
        Run an integrity check on the blockfile and all the skiplists in it
        Returns:
        true if the levels were modified.