Package org.eclipse.rdf4j.rio.hdt
package org.eclipse.rdf4j.rio.hdt
Parser/writer for the HDT v1.0 format.
Unfortunately the draft specification is not entirely clear and probably slightly out of date, since the open source
reference implementation HDT-It seems to implement a slightly different version. This parser tries to be compatible
with HDT-It 1.0.
File structure:
+---------------------+ | Global | | Header | | Dictionary (Shared) | | Dictionary (S) | | Dictionary (P) | | Dictionary (O) | | Triples | +---------------------+
General structure for Global, Header, Dictionary and Triples
These part all starts with$HDT
, followed by a byte indicating the type of the part, the format, and
optionally one or more key=value;
properties.
Then a NULL
byte, followed by the 16-bit CRC ($HDT
and NULL
included)
+------+------+--------+------+------------+------+-------+ | $HDT | type | format | NULL | key=value; | NULL | CRC16 | +------+------+--------+------+------------+------+-------+The
format
varies slightly: depending on the section, it can either be a string or a URI.-
ClassDescriptionCRC16-ANSI checksumCRC32C checksumCRC8-CCIT checksumHDT ArrayHDT Array factory.Log64HDT Dictionary Part.HDT DictionarySection part.HDT DictionarySection factory.HDT DictionarySection Plain Front Coding.HDT Global Part.HDT Header Part.RDF parser for HDT v1.0 files.An
RDFParserFactory
for HDT parsers.Helper class for different HDT parts.HDT Triples Part.HDT TriplesSection part.HDT Triples section.HDT Array factory.Variable byte encoding for numbers.