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/*
* Copyright (c) 2016 Digital Bazaar, Inc. All rights reserved.
*/
'use strict';
const URDNA2015Sync = require('./URDNA2015Sync');
const util = require('./util');
module.exports = class URDNA2012Sync extends URDNA2015Sync {
constructor() {
super();
this.name = 'URGNA2012';
this.hashAlgorithm = 'sha1';
}
// helper for modifying component during Hash First Degree Quads
modifyFirstDegreeComponent(id, component, key) {
if(component.termType !== 'BlankNode') {
return component;
}
component = util.clone(component);
if(key === 'name') {
component.value = '_:g';
} else {
component.value = (component.value === id ? '_:a' : '_:z');
}
return component;
}
// helper for getting a related predicate
getRelatedPredicate(quad) {
return quad.predicate.value;
}
// helper for creating hash to related blank nodes map
createHashToRelated(id, issuer) {
const self = this;
// 1) Create a hash to related blank nodes map for storing hashes that
// identify related blank nodes.
const hashToRelated = {};
// 2) Get a reference, quads, to the list of quads in the blank node to
// quads map for the key identifier.
const quads = self.blankNodeInfo[id].quads;
// 3) For each quad in quads:
for(let i = 0; i < quads.length; ++i) {
// 3.1) If the quad's subject is a blank node that does not match
// identifier, set hash to the result of the Hash Related Blank Node
// algorithm, passing the blank node identifier for subject as related,
// quad, path identifier issuer as issuer, and p as position.
const quad = quads[i];
let position;
let related;
if(quad.subject.termType === 'BlankNode' && quad.subject.value !== id) {
related = quad.subject.value;
position = 'p';
} else if(
quad.object.termType === 'BlankNode' && quad.object.value !== id) {
// 3.2) Otherwise, if quad's object is a blank node that does not match
// identifier, to the result of the Hash Related Blank Node algorithm,
// passing the blank node identifier for object as related, quad, path
// identifier issuer as issuer, and r as position.
related = quad.object.value;
position = 'r';
} else {
// 3.3) Otherwise, continue to the next quad.
continue;
}
// 3.4) Add a mapping of hash to the blank node identifier for the
// component that matched (subject or object) to hash to related blank
// nodes map, adding an entry as necessary.
const hash = self.hashRelatedBlankNode(related, quad, issuer, position);
if(hash in hashToRelated) {
hashToRelated[hash].push(related);
} else {
hashToRelated[hash] = [related];
}
}
return hashToRelated;
}
};
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