CartoDB-SQL-API/batch/job_canceller.js
2016-01-25 20:07:41 +01:00

98 lines
2.8 KiB
JavaScript

'use strict';
var PSQL = require('cartodb-psql');
function JobCanceller(metadataBackend, userDatabaseMetadataService, jobBackend) {
this.metadataBackend = metadataBackend;
this.userDatabaseMetadataService = userDatabaseMetadataService;
this.jobBackend = jobBackend;
}
JobCanceller.prototype.cancel = function (job_id, callback) {
var self = this;
self.jobBackend.get(job_id, function (err, job) {
if (err) {
return callback(err);
}
if (job.status === 'pending') {
return self.jobBackend.setCancelled(job, callback);
}
if (job.status !== 'running') {
var cancelNotAllowedError = new Error('Job is ' + job.status + ', cancel is not allowed');
cancelNotAllowedError.name = 'CancelNotAllowedError';
return callback(cancelNotAllowedError);
}
self.userDatabaseMetadataService.getUserMetadata(job.user, function (err, userDatabaseMetadata) {
if (err) {
return callback(err);
}
self._query(job, userDatabaseMetadata, function (err, job) {
if (err) {
return callback(err);
}
self.jobBackend.setCancelled(job, callback);
});
});
});
};
JobCanceller.prototype.drain = function (job_id, callback) {
var self = this;
this.cancel(job_id, function (err, job) {
if (err && err.name === 'CancelNotAllowedError') {
return callback(err);
}
if (err) {
console.error('There was an error while draining job %s, %s ', job_id, err);
return self.jobBackend.setUnknown(job_id, callback);
}
self.jobBackend.setPending(job, callback);
});
};
JobCanceller.prototype._query = function (job, userDatabaseMetadata, callback) {
var pg = new PSQL(userDatabaseMetadata, {}, { destroyOnError: true });
var escapedJobQuery = pg.escapeLiteral(job.query + ' /* ' + job.job_id + ' */');
var getPIDQuery = 'SELECT pid FROM pg_stat_activity WHERE query = ' + escapedJobQuery;
pg.query(getPIDQuery, function(err, result) {
if (err) {
return callback(err);
}
if (!result.rows[0] || !result.rows[0].pid) {
return callback(new Error('Query not running currently'));
}
var pid = result.rows[0].pid;
var cancelQuery = 'SELECT pg_cancel_backend(' + pid + ')';
pg.query(cancelQuery, function (err, result) {
if (err) {
return callback(err);
}
var isCancelled = result.rows[0].pg_cancel_backend;
if (!isCancelled) {
return callback(new Error('Query has not been cancelled'));
}
callback(null, job);
});
});
};
module.exports = JobCanceller;