1Lucy::Index::DataWriterU(s3eprm)Contributed Perl DocumenLtuactyi:o:nIndex::DataWriter(3pm)
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NAME

6       Lucy::Index::DataWriter - Write data to an index.
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SYNOPSIS

9           # Abstract base class.
10

DESCRIPTION

12       DataWriter is an abstract base class for writing index data, generally
13       in segment-sized chunks. Each component of an index – e.g. stored
14       fields, lexicon, postings, deletions – is represented by a
15       DataWriter/DataReader pair.
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17       Components may be specified per index by subclassing Architecture.
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CONSTRUCTORS

20   new
21           my $writer = MyDataWriter->new(
22               snapshot   => $snapshot,      # required
23               segment    => $segment,       # required
24               polyreader => $polyreader,    # required
25           );
26
27       Abstract constructor.
28
29       •   snapshot - The Snapshot that will be committed at the end of the
30           indexing session.
31
32       •   segment - The Segment in progress.
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34       •   polyreader - A PolyReader representing all existing data in the
35           index.  (If the index is brand new, the PolyReader will have no
36           sub-readers).
37

ABSTRACT METHODS

39   add_segment
40           $data_writer->add_segment(
41               reader  => $reader,   # required
42               doc_map => $doc_map,  # default: undef
43           );
44
45       Add content from an existing segment into the one currently being
46       written.
47
48       •   reader - The SegReader containing content to add.
49
50       •   doc_map - An array of integers mapping old document ids to new.
51           Deleted documents are mapped to 0, indicating that they should be
52           skipped.
53
54   finish
55           $data_writer->finish();
56
57       Complete the segment: close all streams, store metadata, etc.
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59   format
60           my $int = $data_writer->format();
61
62       Every writer must specify a file format revision number, which should
63       increment each time the format changes. Responsibility for revision
64       checking is left to the companion DataReader.
65

METHODS

67   delete_segment
68           $data_writer->delete_segment($reader);
69
70       Remove a segment’s data.  The default implementation is a no-op, as all
71       files within the segment directory will be automatically deleted.
72       Subclasses which manage their own files outside of the segment system
73       should override this method and use it as a trigger for cleaning up
74       obsolete data.
75
76       •   reader - The SegReader containing content to merge, which must
77           represent a segment which is part of the the current snapshot.
78
79   merge_segment
80           $data_writer->merge_segment(
81               reader  => $reader,   # required
82               doc_map => $doc_map,  # default: undef
83           );
84
85       Move content from an existing segment into the one currently being
86       written.
87
88       The default implementation calls add_segment() then delete_segment().
89
90       •   reader - The SegReader containing content to merge, which must
91           represent a segment which is part of the the current snapshot.
92
93       •   doc_map - An array of integers mapping old document ids to new.
94           Deleted documents are mapped to 0, indicating that they should be
95           skipped.
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97   metadata
98           my $hashref = $data_writer->metadata();
99
100       Arbitrary metadata to be serialized and stored by the Segment.  The
101       default implementation supplies a hash with a single key-value pair for
102       “format”.
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104   get_snapshot
105           my $snapshot = $data_writer->get_snapshot();
106
107       Accessor for “snapshot” member var.
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109   get_segment
110           my $segment = $data_writer->get_segment();
111
112       Accessor for “segment” member var.
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114   get_polyreader
115           my $poly_reader = $data_writer->get_polyreader();
116
117       Accessor for “polyreader” member var.
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119   get_schema
120           my $schema = $data_writer->get_schema();
121
122       Accessor for “schema” member var.
123
124   get_folder
125           my $folder = $data_writer->get_folder();
126
127       Accessor for “folder” member var.
128

INHERITANCE

130       Lucy::Index::DataWriter isa Clownfish::Obj.
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134perl v5.38.0                      2023-07-20      Lucy::Index::DataWriter(3pm)
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