Class SegmentReader

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable

    public final class SegmentReader
    extends CodecReader
    IndexReader implementation over a single segment.

    Instances pointing to the same segment (but with different deletes, etc) may share the same core data.

    • Constructor Detail

      • SegmentReader

        SegmentReader​(SegmentCommitInfo si,
                      int createdVersionMajor,
                      IOContext context)
               throws java.io.IOException
        Constructs a new SegmentReader with a new core.
        Throws:
        CorruptIndexException - if the index is corrupt
        java.io.IOException - if there is a low-level IO error
      • SegmentReader

        SegmentReader​(SegmentCommitInfo si,
                      SegmentReader sr,
                      Bits liveDocs,
                      Bits hardLiveDocs,
                      int numDocs,
                      boolean isNRT)
               throws java.io.IOException
        Create new SegmentReader sharing core from a previous SegmentReader and using the provided liveDocs, and recording whether those liveDocs were carried in ram (isNRT=true).
        Throws:
        java.io.IOException
    • Method Detail

      • assertLiveDocs

        private static boolean assertLiveDocs​(boolean isNRT,
                                              Bits hardLiveDocs,
                                              Bits liveDocs)
      • initDocValuesProducer

        private DocValuesProducer initDocValuesProducer()
                                                 throws java.io.IOException
        init most recent DocValues for the current commit
        Throws:
        java.io.IOException
      • initFieldInfos

        private FieldInfos initFieldInfos()
                                   throws java.io.IOException
        init most recent FieldInfos for the current commit
        Throws:
        java.io.IOException
      • getLiveDocs

        public Bits getLiveDocs()
        Description copied from class: LeafReader
        Returns the Bits representing live (not deleted) docs. A set bit indicates the doc ID has not been deleted. If this method returns null it means there are no deleted documents (all documents are live).

        The returned instance has been safely published for use by multiple threads without additional synchronization.

        Specified by:
        getLiveDocs in class LeafReader
      • doClose

        protected void doClose()
                        throws java.io.IOException
        Description copied from class: IndexReader
        Implements close.
        Overrides:
        doClose in class CodecReader
        Throws:
        java.io.IOException
      • getFieldInfos

        public FieldInfos getFieldInfos()
        Description copied from class: LeafReader
        Get the FieldInfos describing all fields in this reader.

        Note: Implementations should cache the FieldInfos instance returned by this method such that subsequent calls to this method return the same instance.

        Specified by:
        getFieldInfos in class LeafReader
      • numDocs

        public int numDocs()
        Description copied from class: IndexReader
        Returns the number of documents in this index.

        NOTE: This operation may run in O(maxDoc). Implementations that can't return this number in constant-time should cache it.

        Specified by:
        numDocs in class IndexReader
      • maxDoc

        public int maxDoc()
        Description copied from class: IndexReader
        Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.
        Specified by:
        maxDoc in class IndexReader
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • getSegmentName

        public java.lang.String getSegmentName()
        Return the name of the segment this reader is reading.
      • getSegmentInfo

        public SegmentCommitInfo getSegmentInfo()
        Return the SegmentInfoPerCommit of the segment this reader is reading.
      • directory

        public Directory directory()
        Returns the directory this index resides in.
      • notifyReaderClosedListeners

        protected void notifyReaderClosedListeners()
                                            throws java.io.IOException
        Description copied from class: IndexReader
        For test framework use only.
        Overrides:
        notifyReaderClosedListeners in class IndexReader
        Throws:
        java.io.IOException
      • getReaderCacheHelper

        public IndexReader.CacheHelper getReaderCacheHelper()
        Description copied from class: IndexReader
        Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this reader. Two readers that have different data or different sets of deleted documents will be considered different.

        A return value of null indicates that this reader is not suited for caching, which is typically the case for short-lived wrappers that alter the content of the wrapped reader.

        Specified by:
        getReaderCacheHelper in class IndexReader
      • getCoreCacheHelper

        public IndexReader.CacheHelper getCoreCacheHelper()
        Description copied from class: LeafReader
        Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this leaf regardless of deletions. Two readers that have the same data but different sets of deleted documents or doc values updates may be considered equal. Consider using IndexReader.getReaderCacheHelper() if you need deletions or dv updates to be taken into account.

        A return value of null indicates that this reader is not suited for caching, which is typically the case for short-lived wrappers that alter the content of the wrapped leaf reader.

        Specified by:
        getCoreCacheHelper in class LeafReader
      • getOriginalSegmentInfo

        SegmentCommitInfo getOriginalSegmentInfo()
        Returns the original SegmentInfo passed to the segment reader on creation time. getSegmentInfo() returns a clone of this instance.
      • getHardLiveDocs

        public Bits getHardLiveDocs()
        Returns the live docs that are not hard-deleted. This is an expert API to be used with soft-deletes to filter out document that hard deleted for instance due to aborted documents or to distinguish soft and hard deleted documents ie. a rolled back tombstone.
      • checkIntegrity

        public void checkIntegrity()
                            throws java.io.IOException
        Description copied from class: LeafReader
        Checks consistency of this reader.

        Note that this may be costly in terms of I/O, e.g. may involve computing a checksum value against large data files.

        Overrides:
        checkIntegrity in class CodecReader
        Throws:
        java.io.IOException