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liza/src/system/DeltaPublisher.ts

130 lines
4.1 KiB
TypeScript

/**
* Delta Publisher
*
* Copyright (C) 2010-2019 R-T Specialty, LLC.
*
* This file is part of liza.
*
* liza is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Publish delta message to a queue
*/
import { AmqpPublisher } from './AmqpPublisher';
import { Delta } from '../bucket/delta';
import { EventEmitter } from 'events';
import { DocumentMeta } from '../document/Document';
import { context } from '../error/ContextError';
import { AmqpError } from '../error/AmqpError';
import { MessageWriter } from './MessageWriter';
import { AmqpConnection } from './amqp/AmqpConnection';
export class DeltaPublisher implements AmqpPublisher
{
/**
* Delta publisher
*
* @param _emitter - event emitter instance
* @param _ts_ctr - a timestamp constructor
* @param _conn - the amqp connection
* @param _writer - message writer
*/
constructor(
private readonly _emitter: EventEmitter,
private readonly _ts_ctr: () => UnixTimestamp,
private readonly _conn: AmqpConnection,
private readonly _writer: MessageWriter,
) {}
/**
* Publish quote message to exchange post-rating
*
* @param meta - document meta data
* @param delta - delta
* @param bucket - bucket
* @param ratedata - rate data bucket
*/
publish(
meta: DocumentMeta,
delta: Delta<any>,
bucket: Record<string, any>,
ratedata: Record<string, any>,
): Promise<void>
{
const ts = this._ts_ctr();
const headers = { version: 1, created: ts };
return this._writer.write(
ts,
meta,
delta,
bucket,
ratedata
).then( ( avro_buffer: Buffer ) =>
{
const channel = this._conn.getAmqpChannel();
if ( !channel )
{
throw context(
new AmqpError( 'Error sending message: No channel' ),
{
doc_id: meta.id,
quote_id: meta.id,
delta_type: delta.type,
delta_ts: delta.timestamp,
},
);
}
// we don't use a routing key; fanout exchange
const published_successfully = channel.publish(
this._conn.getExchangeName(),
'',
avro_buffer,
{ headers: headers },
);
if ( !published_successfully )
{
throw context(
new Error ( 'Delta publish failed' ),
{
doc_id: meta.id,
quote_id: meta.id,
delta_type: delta.type,
delta_ts: delta.timestamp,
}
);
}
} )
.then( ( _: any ) =>
{
this._emitter.emit(
'delta-publish',
{
doc_id: meta.id,
quote_id: meta.id,
type: delta.type,
delta_ts: delta.timestamp,
exchange: this._conn.getExchangeName(),
}
);
} );
}
}