public class SimpleTextDocValuesFormat extends DocValuesFormat
FOR RECREATIONAL USE ONLY
the .dat file contains the data. for numbers this is a "fixed-width" file, for example a single byte range:
field myField type NUMERIC minvalue 0 pattern 000 005 T 234 T 123 T ...so a document's value (delta encoded from minvalue) can be retrieved by seeking to startOffset + (1+pattern.length()+2)*docid. The extra 1 is the newline. The extra 2 is another newline and 'T' or 'F': true if the value is real, false if missing. for bytes this is also a "fixed-width" file, for example:
field myField type BINARY maxlength 6 pattern 0 length 6 foobar[space][space] T length 3 baz[space][space][space][space][space] T ...so a doc's value can be retrieved by seeking to startOffset + (9+pattern.length+maxlength+2)*doc the extra 9 is 2 newlines, plus "length " itself. the extra 2 is another newline and 'T' or 'F': true if the value is real, false if missing. for sorted bytes this is a fixed-width file, for example:
field myField type SORTED numvalues 10 maxLength 8 pattern 0 ordpattern 00 length 6 foobar[space][space] length 3 baz[space][space][space][space][space] ... 03 06 01 10 ...so the "ord section" begins at startOffset + (9+pattern.length+maxlength)*numValues. a document's ord can be retrieved by seeking to "ord section" + (1+ordpattern.length())*docid an ord's value can be retrieved by seeking to startOffset + (9+pattern.length+maxlength)*ord for sorted set this is a fixed-width file very similar to the SORTED case, for example:
field myField type SORTED_SET numvalues 10 maxLength 8 pattern 0 ordpattern XXXXX length 6 foobar[space][space] length 3 baz[space][space][space][space][space] ... 0,3,5 1,2 10 ...so the "ord section" begins at startOffset + (9+pattern.length+maxlength)*numValues. a document's ord list can be retrieved by seeking to "ord section" + (1+ordpattern.length())*docid this is a comma-separated list, and it's padded with spaces to be fixed width. so trim() and split() it. and beware the empty string! an ord's value can be retrieved by seeking to startOffset + (9+pattern.length+maxlength)*ord for sorted numerics, it's encoded (not very creatively) as a comma-separated list of strings the same as binary. beware the empty string! the reader can just scan this file when it opens, skipping over the data blocks and saving the offset/etc for each field.
Constructor and Description |
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SimpleTextDocValuesFormat() |
Modifier and Type | Method and Description |
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DocValuesConsumer |
fieldsConsumer(SegmentWriteState state)
Returns a
DocValuesConsumer to write docvalues to the
index. |
DocValuesProducer |
fieldsProducer(SegmentReadState state)
Returns a
DocValuesProducer to read docvalues from the index. |
availableDocValuesFormats, forName, getName, reloadDocValuesFormats, toString
public DocValuesConsumer fieldsConsumer(SegmentWriteState state) throws IOException
DocValuesFormat
DocValuesConsumer
to write docvalues to the
index.fieldsConsumer
in class DocValuesFormat
IOException
public DocValuesProducer fieldsProducer(SegmentReadState state) throws IOException
DocValuesFormat
DocValuesProducer
to read docvalues from the index.
NOTE: by the time this call returns, it must hold open any files it will need to use; else, those files may be deleted. Additionally, required files may be deleted during the execution of this call before there is a chance to open them. Under these circumstances an IOException should be thrown by the implementation. IOExceptions are expected and will automatically cause a retry of the segment opening logic with the newly revised segments.
fieldsProducer
in class DocValuesFormat
IOException
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