Package org.apache.iotdb.db.wal.utils

Class WALFileUtils

  • public class WALFileUtils
extends java.lang.Object

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String WAL_FILE_NAME_FORMAT  
      static java.util.regex.Pattern WAL_FILE_NAME_PATTERN
      versionId is a self-incremented id number, helping to maintain the order of wal files.

    • Constructor Summary

      Constructors 
      Constructor Description
      WALFileUtils()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void ascSortByVersionId​(java.io.File[] walFiles)
      Sort wal files by version id with ascending order
      static int binarySearchFileBySearchIndex​(java.io.File[] files, long targetSearchIndex)
      Find index of the file which probably contains target insert plan.
      static java.lang.String getLogFileName​(long versionId, long startSearchIndex, WALFileStatus status)
      Get .wal filename
      static java.io.File[] listAllWALFiles​(java.io.File dir)
      List all .wal files in the directory
      static long parseStartSearchIndex​(java.lang.String filename)
      Parse start search index from filename
      static WALFileStatus parseStatusCode​(java.lang.String filename)
      Parse status code from filename
      static long parseVersionId​(java.lang.String filename)
      Parse version id from filename
      static boolean walFilenameFilter​(java.io.File dir, java.lang.String name)
      Return true when this file is .wal file

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • WAL_FILE_NAME_PATTERN

        public static final java.util.regex.Pattern WAL_FILE_NAME_PATTERN
        versionId is a self-incremented id number, helping to maintain the order of wal files. startSearchIndex is the valid search index of last flushed wal entry. statusCode is the. For example:
        _0-0-1.wal: 1, 2, 3, -1, -1, 4, 5, -1
        _1-5-0.wal: -1, -1, -1, -1
        _2-5-1.wal: 6, 7, 8, 9, -1, -1, -1, 10, 11, -1, 12, 12
        _3-12-1.wal: 12, 12, 12, 12, 12
        _4-12-1.wal: 12, 13, 14, 15, 16, -1

      • WAL_FILE_NAME_FORMAT

        public static final java.lang.String WAL_FILE_NAME_FORMAT
        See Also:
        Constant Field Values

    • Constructor Detail

      • WALFileUtils

        public WALFileUtils()

    • Method Detail

      • walFilenameFilter

        public static boolean walFilenameFilter​(java.io.File dir,
                                        java.lang.String name)
        Return true when this file is .wal file

      • listAllWALFiles

        public static java.io.File[] listAllWALFiles​(java.io.File dir)
        List all .wal files in the directory

      • parseVersionId

        public static long parseVersionId​(java.lang.String filename)
        Parse version id from filename

      • parseStartSearchIndex

        public static long parseStartSearchIndex​(java.lang.String filename)
        Parse start search index from filename

      • parseStatusCode

        public static WALFileStatus parseStatusCode​(java.lang.String filename)
        Parse status code from filename

      • ascSortByVersionId

        public static void ascSortByVersionId​(java.io.File[] walFiles)
        Sort wal files by version id with ascending order

      • binarySearchFileBySearchIndex

        public static int binarySearchFileBySearchIndex​(java.io.File[] files,
                                                long targetSearchIndex)
        Find index of the file which probably contains target insert plan.
        Given wal files [ _0-0-1.wal, _1-5-0.wal, _2-5-1.wal, _3-12-1.wal, _4-12-1.wal ], details as below:
        _0-0-1.wal: 1, 2, 3, -1, -1, 4, 5, -1
        _1-5-0.wal: -1, -1, -1, -1
        _2-5-1.wal: 6, 7, 8, 9, -1, -1, -1, 10, 11, -1, 12, 12
        _3-12-1.wal: 12, 12, 12, 12, 12
        _4-12-1.wal: 12, 13, 14, 15, 16, -1
        searching [1, 5] will return 0, searching [6, 12] will return 1, search [13, infinity) will return 3， others will return -1
        Parameters:
        files - files to be searched
        targetSearchIndex - search index of target insert plan
        Returns:
        index of the file which probably contains target insert plan , -1 if the target insert plan definitely doesn't exist

      • getLogFileName

        public static java.lang.String getLogFileName​(long versionId,
                                              long startSearchIndex,
                                              WALFileStatus status)
        Get .wal filename