CartoDB-SQL-API/app/models/formats/ogr.js
2017-04-18 11:40:37 +02:00

325 lines
8.3 KiB
JavaScript

var crypto = require('crypto');
var step = require('step');
var fs = require('fs');
var _ = require('underscore');
var PSQL = require('cartodb-psql');
var spawn = require('child_process').spawn;
var assert = require('assert');
// Keeps track of what's waiting baking for export
var bakingExports = {};
function OgrFormat(id) {
this.id = id;
}
OgrFormat.prototype = {
id: "ogr",
is_file: true,
getQuery: function(/*sql, options*/) {
return null; // dont execute the query
},
transform: function(/*result, options, callback*/) {
throw "should not be called for file formats";
},
getContentType: function(){ return this._contentType; },
getFileExtension: function(){ return this._fileExtension; },
getKey: function(options) {
return [this.id,
options.dbopts.dbname,
options.dbopts.user,
options.gn,
this.generateMD5(options.filename),
this.generateMD5(options.sql)].concat(options.skipfields).join(':');
},
generateMD5: function (data){
var hash = crypto.createHash('md5');
hash.update(data);
return hash.digest('hex');
}
};
// Internal function usable by all OGR-driven outputs
OgrFormat.prototype.toOGR = function(options, out_format, out_filename, callback) {
//var gcol = options.gn;
var sql = options.sql;
var skipfields = options.skipfields;
var out_layername = options.filename;
var dbopts = options.dbopts;
var ogr2ogr = global.settings.ogr2ogrCommand || 'ogr2ogr';
var dbhost = dbopts.host;
var dbport = dbopts.port;
var dbuser = dbopts.user;
var dbpass = dbopts.pass;
var dbname = dbopts.dbname;
var that = this;
var columns = [];
var geocol;
var pg;
// Drop ending semicolon (ogr doens't like it)
sql = sql.replace(/;\s*$/, '');
step (
function fetchColumns() {
var colsql = 'SELECT * FROM (' + sql + ') as _cartodbsqlapi LIMIT 0';
pg = new PSQL(dbopts, {}, { destroyOnError: true });
pg.query(colsql, this);
},
// jshint maxcomplexity:9
function findSRS(err, result) {
assert.ifError(err);
//if ( ! result.rows.length ) throw new Error("Query returns no rows");
var needSRS = that._needSRS;
// Skip system columns, find geom column
for (var i=0; i<result.fields.length; ++i) {
var field = result.fields[i];
var k = field.name;
if ( skipfields.indexOf(k) !== -1 ) {
continue;
}
if ( out_format !== 'CSV' && k === "the_geom_webmercator" ) {
continue;
} // TODO: drop ?
if ( out_format === 'CSV' ) {
columns.push(pg.quoteIdentifier(k)+'::text');
} else {
columns.push(pg.quoteIdentifier(k));
}
if ( needSRS ) {
if ( ! geocol && pg.typeName(field.dataTypeID) === 'geometry' ) {
geocol = k;
}
}
}
//console.log(columns.join(','));
if ( ! needSRS || ! geocol ) {
return null;
}
var next = this;
var qgeocol = pg.quoteIdentifier(geocol);
var sridsql = 'SELECT ST_Srid(' + qgeocol + ') as srid, GeometryType(' +
qgeocol + ') as type FROM (' + sql + ') as _cartodbsqlapi WHERE ' +
qgeocol + ' is not null limit 1';
pg.query(sridsql, function(err, result) {
if ( err ) { next(err); return; }
if ( result.rows.length ) {
var srid = result.rows[0].srid;
var type = result.rows[0].type;
next(null, srid, type);
} else {
// continue as srid and geom type are not critical when there are no results
next(null);
}
});
},
function spawnDumper(err, srid, type) {
assert.ifError(err);
var next = this;
var ogrsql = 'SELECT ' + columns.join(',') + ' FROM (' + sql + ') as _cartodbsqlapi';
var ogrargs = [
'-f', out_format,
'-lco', 'ENCODING=UTF-8',
'-lco', 'LINEFORMAT=CRLF',
out_filename,
"PG:host=" + dbhost + " port=" + dbport + " user=" + dbuser + " dbname=" + dbname + " password=" + dbpass,
'-sql', ogrsql
];
if ( srid ) {
ogrargs.push('-a_srs', 'EPSG:'+srid);
}
if ( type ) {
ogrargs.push('-nlt', type);
}
if (options.cmd_params){
ogrargs = ogrargs.concat(options.cmd_params);
}
ogrargs.push('-nln', out_layername);
var child = spawn(ogr2ogr, ogrargs);
child.on('error', function (err) {
next(err);
});
var stderrData = [];
child.stderr.setEncoding('utf8');
child.stderr.on('data', function (data) {
stderrData.push(data);
});
child.on('exit', function(code) {
if (code !== 0) {
var errMessage = 'ogr2ogr command return code ' + code;
if (stderrData.length > 0) {
errMessage += ', Error: ' + stderrData.join('\n');
}
return next(new Error(errMessage));
}
return next();
});
},
function finish(err) {
callback(err, out_filename);
}
);
};
OgrFormat.prototype.toOGR_SingleFile = function(options, fmt, callback) {
var dbname = options.dbopts.dbname;
var user_id = options.dbopts.user;
var gcol = options.gcol;
var sql = options.sql;
var skipfields = options.skipfields;
var ext = this._fileExtension;
var layername = options.filename;
var tmpdir = global.settings.tmpDir || '/tmp';
var reqKey = [
fmt,
dbname,
user_id,
gcol,
this.generateMD5(layername),
this.generateMD5(sql)
].concat(skipfields).join(':');
var outdirpath = tmpdir + '/sqlapi-' + process.pid + '-' + reqKey;
var dumpfile = outdirpath + ':cartodb-query.' + ext;
// TODO: following tests:
// - fetch query with no "the_geom" column
this.toOGR(options, fmt, dumpfile, callback);
};
OgrFormat.prototype.sendResponse = function(opts, callback) {
//var next = callback;
var reqKey = this.getKey(opts);
var qElem = new ExportRequest(opts.sink, callback, opts.beforeSink);
var baking = bakingExports[reqKey];
if ( baking ) {
baking.req.push( qElem );
} else {
baking = bakingExports[reqKey] = { req: [ qElem ] };
this.generate(opts, function(err, dumpfile) {
if ( opts.profiler ) {
opts.profiler.done('generate');
}
step (
function sendResults() {
var nextPipe = function(finish) {
var r = baking.req.shift();
if ( ! r ) { finish(null); return; }
r.sendFile(err, dumpfile, function() {
nextPipe(finish);
});
};
if ( ! err ) {
nextPipe(this);
} else {
_.each(baking.req, function(r) {
r.cb(err);
});
return true;
}
},
function cleanup(/*err*/) {
delete bakingExports[reqKey];
// unlink dump file (sync to avoid race condition)
console.log("removing", dumpfile);
try { fs.unlinkSync(dumpfile); }
catch (e) {
if ( e.code !== 'ENOENT' ) {
console.log("Could not unlink dumpfile " + dumpfile + ": " + e);
}
}
}
);
});
}
};
// TODO: put in an ExportRequest.js ----- {
function ExportRequest(ostream, callback, beforeSink) {
this.cb = callback;
this.beforeSink = beforeSink;
this.ostream = ostream;
this.istream = null;
this.canceled = false;
var that = this;
this.ostream.on('close', function() {
//console.log("Request close event, qElem.stream is " + qElem.stream);
that.canceled = true;
if ( that.istream ) {
that.istream.destroy();
}
});
}
ExportRequest.prototype.sendFile = function (err, filename, callback) {
var that = this;
if ( ! this.canceled ) {
//console.log("Creating readable stream out of dumpfile");
this.istream = fs.createReadStream(filename)
.on('open', function(/*fd*/) {
if ( that.beforeSink ) {
that.beforeSink();
}
that.istream.pipe(that.ostream);
callback();
})
.on('error', function(e) {
console.log("Can't send response: " + e);
that.ostream.end();
callback();
});
} else {
//console.log("Response was canceled, not streaming the file");
callback();
}
this.cb();
};
//------ }
module.exports = OgrFormat;