59 lines
1.8 KiB
JavaScript
59 lines
1.8 KiB
JavaScript
const PSQL = require('cartodb-psql');
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const copyTo = require('pg-copy-streams').to;
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const copyFrom = require('pg-copy-streams').from;
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const { Client } = require('pg');
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const ACTION_TO = 'to';
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const ACTION_FROM = 'from';
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module.exports = class StreamCopy {
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constructor(sql, userDbParams) {
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this.pg = new PSQL(userDbParams);
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this.sql = sql;
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this.connectionClosedByClient = false;
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this.stream = null;
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}
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static get ACTION_TO() {
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return ACTION_TO;
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}
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static get ACTION_FROM() {
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return ACTION_FROM;
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}
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getStream(action, cb) {
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this.pg.connect((err, client, done) => {
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if (err) {
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return cb(err);
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}
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let streamMaker = action === ACTION_TO ? copyTo : copyFrom;
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this.stream = streamMaker(this.sql);
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const pgstream = client.query(this.stream);
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pgstream
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.on('end', () => done())
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.on('error', err => done(err))
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.on('cancelQuery', err => {
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if(action === ACTION_TO) {
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// See https://www.postgresql.org/docs/9.5/static/protocol-flow.html#PROTOCOL-COPY
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const cancelingClient = new Client(client.connectionParameters);
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cancelingClient.cancel(client, pgstream);
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// see https://node-postgres.com/api/pool#releasecallback
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done(err);
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} else if (action === ACTION_FROM) {
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client.connection.sendCopyFail('CARTO SQL API: Connection closed by client');
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}
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});
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cb(null, pgstream);
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});
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}
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getRowCount() {
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return this.stream.rowCount;
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}
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};
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