CartoDB-SQL-API/app/services/stream_copy.js
2018-07-20 15:32:32 +02:00

66 lines
2.0 KiB
JavaScript

const PSQL = require('cartodb-psql');
const copyTo = require('pg-copy-streams').to;
const copyFrom = require('pg-copy-streams').from;
const { Client } = require('pg');
const ACTION_TO = 'to';
const ACTION_FROM = 'from';
const DEFAULT_TIMEOUT = "'5h'";
module.exports = class StreamCopy {
constructor(sql, userDbParams) {
const dbParams = Object.assign({}, userDbParams, {
port: global.settings.db_batch_port || userDbParams.port
});
this.pg = new PSQL(dbParams);
this.sql = sql;
this.stream = null;
this.timeout = global.settings.copy_timeout || DEFAULT_TIMEOUT;
}
static get ACTION_TO() {
return ACTION_TO;
}
static get ACTION_FROM() {
return ACTION_FROM;
}
getPGStream(action, cb) {
this.pg.connect((err, client, done) => {
if (err) {
return cb(err);
}
client.query('SET statement_timeout=' + this.timeout);
let streamMaker = action === ACTION_TO ? copyTo : copyFrom;
this.stream = streamMaker(this.sql);
const pgstream = client.query(this.stream);
pgstream
.on('end', () => done())
.on('error', err => done(err))
.on('cancelQuery', err => {
if(action === ACTION_TO) {
// See https://www.postgresql.org/docs/9.5/static/protocol-flow.html#PROTOCOL-COPY
const cancelingClient = new Client(client.connectionParameters);
cancelingClient.cancel(client, pgstream);
// see https://node-postgres.com/api/pool#releasecallback
done(err);
} else if (action === ACTION_FROM) {
client.connection.sendCopyFail('CARTO SQL API: Connection closed by client');
}
});
cb(null, pgstream);
});
}
getRowCount() {
return this.stream.rowCount;
}
};