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// Copyright ©2020 The Gonum Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package rdf_test
import (
"crypto/md5"
"fmt"
"log"
"os"
"slices"
"strings"
"text/tabwriter"
"gonum.org/v1/gonum/graph/formats/rdf"
)
func ExampleIsoCanonicalHashes_isomorphisms() {
for _, statements := range []string{
`
<https://example.com/1> <https://example.com/2> <https://example.com/3> .
<https://example.com/3> <https://example.com/4> <https://example.com/5> .
`,
`
_:a <ex:q> <ex:p> .
_:b <ex:q> <ex:p> .
_:c <ex:p> _:a .
_:d <ex:p> _:b .
_:c <ex:r> _:d .
`,
`
_:a1 <ex:q> <ex:p> .
_:b1 <ex:q> <ex:p> .
_:c1 <ex:p> _:a1 .
_:d1 <ex:p> _:b1 .
_:c1 <ex:r> _:d1 .
`,
`
# G
<ex:p> <ex:q> _:a .
<ex:p> <ex:q> _:b .
<ex:s> <ex:p> _:a .
<ex:s> <ex:r> _:c .
_:c <ex:p> _:b .
# H
<ex:p> <ex:q> _:d .
<ex:p> <ex:q> _:e .
_:f <ex:p> _:d .
_:f <ex:r> _:g .
_:g <ex:p> _:e .
`,
`
_:greet <l:is> "hola"@es .
`,
} {
// Decode the statement stream.
dec := rdf.NewDecoder(strings.NewReader(statements))
var s []*rdf.Statement
for {
l, err := dec.Unmarshal()
if err != nil {
break
}
s = append(s, l)
}
// Get the node label to hash look-up table.
hashes, _ := rdf.IsoCanonicalHashes(s, false, true, md5.New(), make([]byte, 16))
// Get all the blank nodes.
var blanks []string
for k := range hashes {
if strings.HasPrefix(k, "_:") {
blanks = append(blanks, k)
}
}
slices.Sort(blanks)
if len(blanks) == 0 {
fmt.Println("No blank nodes.")
} else {
w := tabwriter.NewWriter(os.Stdout, 0, 4, 1, ' ', 0)
fmt.Fprintln(w, "Node\tHash")
for _, k := range blanks {
fmt.Fprintf(w, "%s\t%032x\n", k, hashes[k])
}
w.Flush()
}
fmt.Println()
}
// Output:
//
// No blank nodes.
//
// Node Hash
// _:a d4db6df055d5611e9d8aa6ea621561d1
// _:b ad70e47f2b026064c7f0922060512b9a
// _:c dafd81e6fa603d3e11c898d631e8673f
// _:d 7e318557b09444e88791721becc2a8e7
//
// Node Hash
// _:a1 d4db6df055d5611e9d8aa6ea621561d1
// _:b1 ad70e47f2b026064c7f0922060512b9a
// _:c1 dafd81e6fa603d3e11c898d631e8673f
// _:d1 7e318557b09444e88791721becc2a8e7
//
// Node Hash
// _:a 44ad49b6df3aea91ddbcef932c93e3b4
// _:b ba3ffd8b271a8545b1a3a9042e75ce4b
// _:c 34e1bd90b6758b4a766e000128caa6a6
// _:d eb2a47c1032f623647d0497a2ff74052
// _:e 1d9ed02f28d87e555feb904688bc2449
// _:f d3b00d36ea503dcc8d234e4405feab81
// _:g 55127e4624c0a4fe5990933a48840af8
//
// Node Hash
// _:greet 0d9ba18a037a3fa67e46fce821fe51b4
}
func ExampleIsoCanonicalHashes_isomorphicParts() {
for _, statements := range []string{
`
# Part 1
_:a <ex:q> <ex:p> .
_:b <ex:q> <ex:p> .
_:c <ex:p> _:a .
_:d <ex:p> _:b .
_:c <ex:r> _:d .
# Part 2
_:a1 <ex:q> <ex:p> .
_:b1 <ex:q> <ex:p> .
_:c1 <ex:p> _:a1 .
_:d1 <ex:p> _:b1 .
_:c1 <ex:r> _:d1 .
`,
} {
// Decode the statement stream.
dec := rdf.NewDecoder(strings.NewReader(statements))
var s []*rdf.Statement
for {
l, err := dec.Unmarshal()
if err != nil {
break
}
s = append(s, l)
}
// Get the node label to hash look-up table. This time
// we will decompose the dataset into splits and not
// distinguish nodes. This will then group nodes from
// the two isomorphic parts. Otherwise each node in
// the complete dataset would get a unique hash.
hashes, _ := rdf.IsoCanonicalHashes(s, true, false, md5.New(), make([]byte, 16))
// Get all the blank nodes.
var blanks []string
for k := range hashes {
if strings.HasPrefix(k, "_:") {
blanks = append(blanks, k)
}
}
slices.Sort(blanks)
if len(blanks) == 0 {
fmt.Println("No blank nodes.")
} else {
w := tabwriter.NewWriter(os.Stdout, 0, 4, 1, ' ', 0)
fmt.Fprintln(w, "Node\tHash")
for _, k := range blanks {
fmt.Fprintf(w, "%s\t%032x\n", k, hashes[k])
}
w.Flush()
}
fmt.Println()
}
// Output:
//
// Node Hash
// _:a d4db6df055d5611e9d8aa6ea621561d1
// _:a1 d4db6df055d5611e9d8aa6ea621561d1
// _:b ad70e47f2b026064c7f0922060512b9a
// _:b1 ad70e47f2b026064c7f0922060512b9a
// _:c dafd81e6fa603d3e11c898d631e8673f
// _:c1 dafd81e6fa603d3e11c898d631e8673f
// _:d 7e318557b09444e88791721becc2a8e7
// _:d1 7e318557b09444e88791721becc2a8e7
}
func ExampleC14n() {
for _, statements := range []string{
`
_:a <ex:q> <ex:p> .
_:b <ex:q> <ex:p> .
_:c <ex:p> _:a .
_:d <ex:p> _:b .
_:c <ex:r> _:d .
`,
`
_:c1 <ex:p> _:a1 .
_:b1 <ex:q> <ex:p> .
_:d1 <ex:p> _:b1 .
_:a1 <ex:q> <ex:p> .
_:c1 <ex:r> _:d1 .
`,
} {
// Decode the statement stream.
dec := rdf.NewDecoder(strings.NewReader(statements))
var s []*rdf.Statement
for {
l, err := dec.Unmarshal()
if err != nil {
break
}
s = append(s, l)
}
// Get the hash to term label look-up table.
_, terms := rdf.IsoCanonicalHashes(s, false, true, md5.New(), make([]byte, 16))
relabeled, err := rdf.C14n(nil, s, terms)
if err != nil {
log.Fatal(err)
}
for _, s := range relabeled {
fmt.Println(s)
}
fmt.Println()
}
// Output:
//
// _:c14n0 <ex:p> _:c14n1 .
// _:c14n1 <ex:q> <ex:p> .
// _:c14n2 <ex:q> <ex:p> .
// _:c14n3 <ex:p> _:c14n2 .
// _:c14n3 <ex:r> _:c14n0 .
//
// _:c14n0 <ex:p> _:c14n1 .
// _:c14n1 <ex:q> <ex:p> .
// _:c14n2 <ex:q> <ex:p> .
// _:c14n3 <ex:p> _:c14n2 .
// _:c14n3 <ex:r> _:c14n0 .
}
|
