MeshAgent/modules/wget.js

/*
Copyright 2019 Intel Corporation

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/


var promise = require('promise');
var http = require('http');
var writable = require('stream').Writable;


function wget(remoteUri, localFilePath, wgetoptions)
{
    var ret = new promise(function (res, rej) { this._res = res; this._rej = rej; });
    var agentConnected = false;
    require('events').EventEmitter.call(ret, true)
        .createEvent('bytes')
        .createEvent('abort')
        .addMethod('abort', function () { this._request.abort(); });

    try
    {
        agentConnected = require('MeshAgent').isControlChannelConnected;
    }
    catch (e)
    {
    }

    // We only need to check proxy settings if the agent is not connected, because when the agent
    // connects, it automatically configures the proxy for JavaScript.
    if (!agentConnected)
    {
        if (process.platform == 'win32')
        {
            var reg = require('win-registry');
            if (reg.QueryKey(reg.HKEY.CurrentUser, 'Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings', 'ProxyEnable') == 1)
            {
                var proxyUri = reg.QueryKey(reg.HKEY.CurrentUser, 'Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings', 'ProxyServer');
                var options = require('http').parseUri('http://' + proxyUri);

                console.log('proxy => ' + proxyUri);
                require('global-tunnel').initialize(options);
            }
        }
    }

    var reqOptions = require('http').parseUri(remoteUri);
    if (wgetoptions)
    {
        for (var inputOption in wgetoptions) {
            reqOptions[inputOption] = wgetoptions[inputOption];
        }
    }
    ret._totalBytes = 0;
    ret._request = http.get(reqOptions);
    ret._localFilePath = localFilePath;
    ret._request.promise = ret;
    ret._request.on('error', function (e) { this.promise._rej(e); });
    ret._request.on('abort', function () { this.promise.emit('abort'); });
    ret._request.on('response', function (imsg)
    {
        if(imsg.statusCode != 200)
        {
            this.promise._rej('Server responsed with Status Code: ' + imsg.statusCode);
        }
        else
        {
            try
            {
                this._file = require('fs').createWriteStream(this.promise._localFilePath, { flags: 'wb' });
                this._sha = require('SHA384Stream').create();
                this._sha.promise = this.promise;
            }
            catch(e)
            {
                this.promise._rej(e);
                return;
            }
            this._sha.on('hash', function (h) { this.promise._res(h.toString('hex')); });
            this._accumulator = new writable(
                {
                    write: function(chunk, callback)
                    {
                        this.promise._totalBytes += chunk.length;
                        this.promise.emit('bytes', this.promise._totalBytes);
                        return (true);
                    },
                    final: function(callback)
                    {
                        callback();
                    }
                });
            this._accumulator.promise = this.promise;
            imsg.pipe(this._file);
            imsg.pipe(this._accumulator);
            imsg.pipe(this._sha);
        }
    });
    ret.progress = function () { return (this._totalBytes); };
    return (ret);
}

module.exports = wget;