NAME¶
Lucy::Index::DataWriter - Write data to an index.
SYNOPSIS¶
# Abstract base class.
DESCRIPTION¶
DataWriter is an abstract base class for writing index data, generally in
segment-sized chunks. Each component of an index -- e.g. stored fields,
lexicon, postings, deletions -- is represented by a DataWriter/DataReader
pair.
Components may be specified per index by subclassing Architecture.
CONSTRUCTORS¶
new( [labeled params] )¶
my $writer = MyDataWriter->new(
snapshot => $snapshot, # required
segment => $segment, # required
polyreader => $polyreader, # required
);
- •
- snapshot - The Snapshot that will be committed at the end of the
indexing session.
- •
- segment - The Segment in progress.
- •
- polyreader - A PolyReader representing all existing data in the
index. (If the index is brand new, the PolyReader will have no
sub-readers).
ABSTRACT METHODS¶
add_inverted_doc( [labeled params] )¶
Process a document, previously inverted by "inverter".
- •
- inverter - An Inverter wrapping an inverted document.
- •
- doc_id - Internal number assigned to this document within the
segment.
add_segment( [labeled params] )¶
Add content from an existing segment into the one currently being written.
- •
- reader - The SegReader containing content to add.
- •
- doc_map - An array of integers mapping old document ids to new.
Deleted documents are mapped to 0, indicating that they should be
skipped.
finish()¶
Complete the segment: close all streams, store metadata, etc.
Every writer must specify a file format revision number, which should increment
each time the format changes. Responsibility for revision checking is left to
the companion DataReader.
METHODS¶
delete_segment(reader)¶
Remove a segment's data. The default implementation is a no-op, as all files
within the segment directory will be automatically deleted. Subclasses which
manage their own files outside of the segment system should override this
method and use it as a trigger for cleaning up obsolete data.
- •
- reader - The SegReader containing content to merge, which must
represent a segment which is part of the the current snapshot.
merge_segment( [labeled params] )¶
Move content from an existing segment into the one currently being written.
The default implementation calls
add_segment() then
delete_segment().
- •
- reader - The SegReader containing content to merge, which must
represent a segment which is part of the the current snapshot.
- •
- doc_map - An array of integers mapping old document ids to new.
Deleted documents are mapped to 0, indicating that they should be
skipped.
Arbitrary metadata to be serialized and stored by the Segment. The default
implementation supplies a Hash with a single key-value pair for
"format".
get_snapshot()¶
Accessor for "snapshot" member var.
get_segment()¶
Accessor for "segment" member var.
get_polyreader()¶
Accessor for "polyreader" member var.
get_schema()¶
Accessor for "schema" member var.
get_folder()¶
Accessor for "folder" member var.
INHERITANCE¶
Lucy::Index::DataWriter isa Lucy::Object::Obj.