gremlin
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JavaScript Gremlin Language Variant
217 lines (188 loc) • 6.62 kB
JavaScript
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/**
* @author Igor Ostapenko
*/
'use strict';
const { Buffer } = require('buffer');
const g = require('../../../graph');
module.exports = class EdgeSerializer {
constructor(ioc) {
this.ioc = ioc;
this.ioc.serializers[ioc.DataType.EDGE] = this;
}
canBeUsedFor(value) {
return value instanceof g.Edge;
}
serialize(item, fullyQualifiedFormat = true) {
if (item === undefined || item === null) {
if (fullyQualifiedFormat) {
return Buffer.from([this.ioc.DataType.EDGE, 0x01]);
}
const id = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00]; // String ''
const label = [0x00, 0x00, 0x00, 0x00]; // ''
const inVId = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00]; // String ''
const inVLabel = [0x00, 0x00, 0x00, 0x00]; // ''
const outVId = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00]; // String ''
const outVLabel = [0x00, 0x00, 0x00, 0x00]; // ''
const parent = [0xfe, 0x01]; // null
const properties = [0xfe, 0x01]; // null
return Buffer.from([...id, ...label, ...inVId, ...inVLabel, ...outVId, ...outVLabel, ...parent, ...properties]);
}
const bufs = [];
if (fullyQualifiedFormat) {
bufs.push(Buffer.from([this.ioc.DataType.EDGE, 0x00]));
}
// {id}
bufs.push(this.ioc.anySerializer.serialize(item.id));
// {label}
bufs.push(this.ioc.stringSerializer.serialize(item.label, false));
// {inVId}
const inVId = item.inV && item.inV.id;
bufs.push(this.ioc.anySerializer.serialize(inVId));
// {inVLabel}
const inVLabel = item.inV && item.inV.label;
bufs.push(this.ioc.stringSerializer.serialize(inVLabel, false));
// {outVId}
const outVId = item.outV && item.outV.id;
bufs.push(this.ioc.anySerializer.serialize(outVId));
// {outVLabel}
const outVLabel = item.outV && item.outV.label;
bufs.push(this.ioc.stringSerializer.serialize(outVLabel, false));
// {parent}
bufs.push(this.ioc.unspecifiedNullSerializer.serialize(null));
// {properties}
bufs.push(this.ioc.unspecifiedNullSerializer.serialize(null));
return Buffer.concat(bufs);
}
deserialize(buffer, fullyQualifiedFormat = true) {
let len = 0;
let cursor = buffer;
try {
if (buffer === undefined || buffer === null || !(buffer instanceof Buffer)) {
throw new Error('buffer is missing');
}
if (buffer.length < 1) {
throw new Error('buffer is empty');
}
if (fullyQualifiedFormat) {
const type_code = cursor.readUInt8();
len++;
if (type_code !== this.ioc.DataType.EDGE) {
throw new Error('unexpected {type_code}');
}
cursor = cursor.slice(1);
if (cursor.length < 1) {
throw new Error('{value_flag} is missing');
}
const value_flag = cursor.readUInt8();
len++;
if (value_flag === 1) {
return { v: null, len };
}
if (value_flag !== 0) {
throw new Error('unexpected {value_flag}');
}
cursor = cursor.slice(1);
}
let id, id_len;
try {
({ v: id, len: id_len } = this.ioc.anySerializer.deserialize(cursor));
len += id_len;
} catch (err) {
err.message = '{id}: ' + err.message;
throw err;
}
cursor = cursor.slice(id_len);
let label, label_len;
try {
({ v: label, len: label_len } = this.ioc.stringSerializer.deserialize(cursor, false));
len += label_len;
} catch (err) {
err.message = '{label}: ' + err.message;
throw err;
}
cursor = cursor.slice(label_len);
let inVId, inVId_len;
try {
({ v: inVId, len: inVId_len } = this.ioc.anySerializer.deserialize(cursor));
len += inVId_len;
} catch (err) {
err.message = '{inVId}: ' + err.message;
throw err;
}
cursor = cursor.slice(inVId_len);
let inVLabel, inVLabel_len;
try {
({ v: inVLabel, len: inVLabel_len } = this.ioc.stringSerializer.deserialize(cursor, false));
len += inVLabel_len;
} catch (err) {
err.message = '{inVLabel}: ' + err.message;
throw err;
}
cursor = cursor.slice(inVLabel_len);
let outVId, outVId_len;
try {
({ v: outVId, len: outVId_len } = this.ioc.anySerializer.deserialize(cursor));
len += outVId_len;
} catch (err) {
err.message = '{outVId}: ' + err.message;
throw err;
}
cursor = cursor.slice(outVId_len);
let outVLabel, outVLabel_len;
try {
({ v: outVLabel, len: outVLabel_len } = this.ioc.stringSerializer.deserialize(cursor, false));
len += outVLabel_len;
} catch (err) {
err.message = '{outVLabel}: ' + err.message;
throw err;
}
cursor = cursor.slice(outVLabel_len);
let parent_len;
try {
({ len: parent_len } = this.ioc.anySerializer.deserialize(cursor));
len += parent_len;
} catch (err) {
err.message = '{parent}: ' + err.message;
throw err;
}
cursor = cursor.slice(parent_len);
let properties, properties_len;
try {
({ v: properties, len: properties_len } = this.ioc.anySerializer.deserialize(cursor));
len += properties_len;
} catch (err) {
err.message = '{properties}: ' + err.message;
throw err;
}
cursor = cursor.slice(properties_len);
const v = new g.Edge(
id,
new g.Vertex(outVId, outVLabel, null),
label,
new g.Vertex(inVId, inVLabel, null),
properties,
);
return { v, len };
} catch (err) {
throw this.ioc.utils.des_error({ serializer: this, args: arguments, cursor, err });
}
}
};