dump1090/public_html/dbloader.js
2016-08-29 10:07:03 -05:00

149 lines
4.8 KiB
JavaScript

// -*- mode: javascript; indent-tabs-mode: nil; c-basic-offset: 8 -*-
// Part of dump1090, a Mode S message decoder for RTLSDR devices.
//
// dbloader.js: load aircraft metadata from static json files
//
// Copyright (c) 2014,2015 Oliver Jowett <oliver@mutability.co.uk>
//
// This file is free software: you may copy, redistribute and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation, either version 2 of the License, or (at your
// option) any later version.
//
// This file 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/>.
"use strict";
var _aircraft_cache = {};
var _aircraft_type_cache = null;
function getAircraftData(icao) {
var defer;
icao = icao.toUpperCase();
if (icao in _aircraft_cache) {
defer = _aircraft_cache[icao];
} else {
// load from blocks:
defer = _aircraft_cache[icao] = $.Deferred();
request_from_db(icao, 1, defer);
}
return defer;
}
function request_from_db(icao, level, defer) {
var bkey = icao.substring(0, level);
var dkey = icao.substring(level);
var req = db_ajax(bkey);
req.done(function(data) {
var subkey;
if (dkey in data) {
getIcaoAircraftTypeData(data[dkey], defer);
return;
}
if ("children" in data) {
subkey = bkey + dkey.substring(0,1);
if (data.children.indexOf(subkey) != -1) {
request_from_db(icao, level+1, defer);
return;
}
}
defer.reject();
});
req.fail(function(jqXHR,textStatus,errorThrown) {
defer.reject();
});
}
function getIcaoAircraftTypeData(aircraftData, defer) {
if (_aircraft_type_cache === null) {
$.getJSON("db/aircraft_types/icao_aircraft_types.json")
.done(function(typeLookupData) {
_aircraft_type_cache = typeLookupData;
})
.always(function() {
lookupIcaoAircraftType(aircraftData, defer);
});
}
else {
lookupIcaoAircraftType(aircraftData, defer);
}
}
function lookupIcaoAircraftType(aircraftData, defer) {
if (_aircraft_type_cache !== null && "t" in aircraftData) {
var typeDesignator = aircraftData.t.toUpperCase();
if (typeDesignator in _aircraft_type_cache) {
var typeData = _aircraft_type_cache[typeDesignator];
if (typeData.desc != undefined && typeData.desc != null && typeData.desc.length == 3) {
aircraftData.desc = typeData.desc;
}
aircraftData.wtc = typeData.wtc;
}
}
defer.resolve(aircraftData);
}
var _request_count = 0;
var _request_queue = [];
var _request_cache = {};
var MAX_REQUESTS = 2;
function db_ajax(bkey) {
var defer;
if (bkey in _request_cache) {
return _request_cache[bkey];
}
if (_request_count < MAX_REQUESTS) {
// just do ajax directly
++_request_count;
defer = _request_cache[bkey] = $.ajax({ url: 'db/' + bkey + '.json',
cache: true,
timeout: 5000,
dataType : 'json' });
defer.always(db_ajax_request_complete);
} else {
// put it in the queue
defer = _request_cache[bkey] = $.Deferred();
defer.bkey = bkey;
_request_queue.push(defer);
}
return defer;
}
function db_ajax_request_complete() {
var req;
var ajaxreq;
if (_request_queue.length == 0) {
--_request_count;
} else {
req = _request_queue.shift();
ajaxreq = $.ajax({ url: 'db/' + req.bkey + '.json',
cache: true,
timeout: 5000,
dataType : 'json' });
ajaxreq.done(function(data) { req.resolve(data); });
ajaxreq.fail(function(jqxhr, status, error) { req.reject(jqxhr, status, error); });
ajaxreq.always(db_ajax_request_complete);
}
}