rdfhash 0.2.2

Command-line tool for hashing RDF definitions into resolvable identifiers. (Default: sha256)

RDF Hash

Command-line tool for hashing RDF definitions into resolvable identifiers ( sha256, md5, blake2b, etc. ).

Selected subjects are replaced with hash of their triples (Default: blank node subjects).

Set of triples on a given subject are sorted by {predicate} {object}.\n, then hashed together. The hash result replaces the subject URI (Ex: <md5:fdd61ec7cdbc7241f0289339678dd008>).

Setup

Dependencies

• Python: 3.10
  • MacOS/Windows Installer
  • Debian/Ubuntu (apt) Installation Guide

Getting Started

• Install pip packages

  python3.10 -m pip install rdfhash
  

• Test script

  rdfhash --data="[ a <def:class:Person> ] ." --method=sha1
  

  <sha1:f0392681a6a701d9672925133bf1207f4be9e412> a <def:class:Person> .
  

Command-Line Interface

rdfhash [-h] -d DATA [-f {turtle,n-triples,trig,n-quads,n3,rdf}]
        [-m {md5,sha1,sha224,sha256,sha384,sha512,sha3_224,sha3_256,sha3_384,sha3_512,blake2b,blake2s}]
        [-a ACCEPT [ACCEPT ...]] [-v] [--debug] [--sparql SPARQL]

Replace selected subjects with hash of their triples (`{predicate} {object}.\n` sorted + joined).

options:
  -h, --help            show this help message and exit
  -d DATA, --data DATA  Input data. (RDF)
  -f {turtle,n-triples,trig,n-quads,n3,rdf}, --format {turtle,n-triples,trig,n-quads,n3,rdf}
                        Input format.
  -m {md5,sha1,sha224,sha256,sha384,sha512,sha3_224,sha3_256,sha3_384,sha3_512,blake2b,blake2s}, --method {md5,sha1,sha224,sha256,sha384,sha512,sha3_224,sha3_256,sha3_384,sha3_512,blake2b,blake2s}
                        Hash method.
  -a ACCEPT [ACCEPT ...], --accept ACCEPT [ACCEPT ...]
                        Accept format.
  -v, --verbose         Show 'info' level logs.
  --debug               Show 'debug' level logs.
  --sparql SPARQL, --sparql-select-subjects SPARQL
                        SPARQL SELECT query returning subject URIs to replace with hash of their triples. Defaults to all
                        blank node subjects.

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Example

Test the tool out on the directory ./examples.

rdfhash --data ./examples/product_0.ttl

Blank Node Input

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

@prefix c:         <def:class:> .
@prefix currency:  <def:class:currency> .
@prefix p:         <def:property:> .

_:xbox_series_x
    rdf:type c:Product ;
    p:name "Microsoft - Xbox Series X 1TB Console - Black" ;
    p:url <https://www.bestbuy.com/site/microsoft-xbox-series-x-1tb-console-black/6428324.p> ;
    p:available false ;
    p:price [
        rdf:type currency:USDollar ;
        p:amount "499.99"^^xsd:decimal ;
    ] .

_:ps5
    rdf:type c:Product ;
    p:name "Sony - PlayStation 5 Console" ;
    p:url <https://www.bestbuy.com/site/sony-playstation-5-console/6426149.p> ;
    p:available false ;
    p:price [
        rdf:type currency:USDollar ;
        p:amount "499.99"^^xsd:decimal ;
    ] .

md5 Output

<md5:e2edf345944d2d2360ca0af3a2e263e5>
    a c:Product ;
    p:available false ;
    p:name "Microsoft - Xbox Series X 1TB Console - Black" ;
    p:price <md5:230919236fbe71a692d10c9a693fdd2b> ;
    p:url <https://www.bestbuy.com/site/microsoft-xbox-series-x-1tb-console-black/6428324.p> .

<md5:64c8f3c04879effcad67df5e62c00245>
    a c:Product ;
    p:available false ;
    p:name "Sony - PlayStation 5 Console" ;
    p:price <md5:230919236fbe71a692d10c9a693fdd2b> ;
    p:url <https://www.bestbuy.com/site/sony-playstation-5-console/6426149.p> .

<md5:230919236fbe71a692d10c9a693fdd2b>
    a currency:USDollar ;
    p:amount 499.99 .

• The nested definition for 499.99 USD is referenced 2 times and defined only once.

Simple time-entry data

@prefix d:  <data:> .

d:TimeEntry__ps5__2020_11_12
    a c:TimeEntry ;
    p:date "2020-11-12"^^xsd:date ;
    p:value <md5:64c8f3c04879effcad67df5e62c00245> .

d:TimeEntry__xbox_series_x__2020_10_12
    a c:TimeEntry ;
    p:date "2020-10-12"^^xsd:date ;
    p:value <md5:e2edf345944d2d2360ca0af3a2e263e5> .

d:TimeEntry__ps5__2022_06_01
    a c:TimeEntry ;
    p:date "2022-06-01"^^xsd:date ;
    p:value <md5:64c8f3c04879effcad67df5e62c00245> .

• If a webscraper encounters the exact same definition, output RDF will be identical. Only triples added are references to the existing triples.

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Limitations

• Named graphs are currently not supported.

• Cannot update triples on hashed subjects.

  • Updating statements on a hashed subject will result in a hash mismatch.

  • Blank node statement input:

    [ a <def:class:Person> ] .
    

  • Hashed subject output:

    <sha1:f0392681a6a701d9672925133bf1207f4be9e412>
        a <def:class:Person> .
    

  • Updating statements on hashed subject:

    # Actual sha1 Result: 0c0140462cb569cb700fe5d01bf5efb3185cdb4d
    
    <sha1:f0392681a6a701d9672925133bf1207f4be9e412>
        a <def:class:Person> ;
        <def:property:age> "24"^^<http://www.w3.org/2001/XMLSchema#integer> .
    

    • Mismatch between original hash and actual hash result.
      • Original: <sha1:f0392681a6a701d9672925133bf1207f4be9e412>
      • Actual: <sha1:0c0140462cb569cb700fe5d01bf5efb3185cdb4d>

• Cannot resolve circular dependencies between selected subjects.

  _:b1 <def:property:connectedTo> _:b2 .
  _:b2 <def:property:connectedTo> _:b1 .
  

• Using multiple hashing methods is not recommended.

  _:error_multiple_hash_methods
      <p:0> <md5:64eee8e358fd1b6340385f4588e5536b> ;
      <p:1> <sha1:2408f5f487b26247f9a82a6b9ea76f21b79bb12f> .
  

  • Using multiple hashing methods can result in duplicate hashed statements.
  • Sticking with 1 hashing method allows for the smallest possible graph size.