jkuchar/MultipleFileUpload

/*
    Proxy Plug-in
    
    Features:
        Times an upload to see if it appear suspiciously fast which might indicate a proxy server or anti-virus suite intercepting the upload. 
        If the upload seems too fast an uploadError event is fired with PROXY error code after the final uploadProgress event.
        
        Adds a SWFUpload setting allowing you to tweak the bytes/s for triggering the error:
            proxy_detect_threshold : 256000
            
        Adds an UPLOAD_ERROR entry called PROXY:
            function uploadError(file, errorCode, message) {
                if (errorCode === SWFUpload.UPLOAD_ERROR.PROXY) {
                    alert("You might have a proxy!");
                }
            }
    */

var SWFUpload;
if (typeof(SWFUpload) === "function") {
    SWFUpload.proxyDetect = {};
    SWFUpload.UPLOAD_ERROR.PROXY = -30300;
    
    SWFUpload.prototype.initSettings = (function (oldInitSettings) {
        return function (userSettings) {
            if (typeof(oldInitSettings) === "function") {
                oldInitSettings.call(this, userSettings);
            }
            
            this.ensureDefault = function (settingName, defaultValue) {
                this.settings[settingName] = (userSettings[settingName] == undefined) ? defaultValue : userSettings[settingName];
            };

            // List used to keep the speed stats for the files we are tracking
            this.proxyDetectFileStartTimes = {};
            this.proxyDetectSettings = {};

            this.ensureDefault("proxy_detect_threshold", 256000); // Default is 250 KB per second
            
            this.proxyDetectSettings.user_upload_progress_handler = this.settings.upload_progress_handler;
            this.proxyDetectSettings.user_upload_complete_handler = this.settings.upload_complete_handler;
            
            this.settings.upload_progress_handler = SWFUpload.proxyDetect.uploadProgressHandler;
            this.settings.upload_complete_handler = SWFUpload.proxyDetect.uploadCompleteHandler;
            
            
            delete this.ensureDefault;
        };
    }(SWFUpload.prototype.initSettings));

    SWFUpload.proxyDetect.uploadProgressHandler = function (file, bytesComplete, bytesTotal) {
        var ex1 = null, time, differenceMS, bps;
        try {
            if (typeof this.proxyDetectSettings.user_upload_progress_handler === "function") {
                this.proxyDetectSettings.user_upload_progress_handler.call(this, file, bytesComplete, bytesTotal);
            }
        } catch (ex1) { }
            
        
        if (bytesComplete === 0) {
            this.proxyDetectFileStartTimes[file.ID] = new Date();

        } else if (bytesComplete === bytesTotal) {
            try {
                // Calculate the Bps and decide if we should trigger the error
                time = new Date();
                differenceMS = time.getTime() - this.proxyDetectFileStartTimes[file.ID].getTime();
                
                if (differenceMS === 0) {
                    differenceMS = 1;
                }
                
                bps = bytesTotal / (differenceMS * 1000);
                if (bps > parseInt(this.settings.proxy_detect_threshold, 10)) {
                    this.queueEvent("upload_error_handler", [file, SWFUpload.UPLOAD_ERROR.PROXY, bps]);
                }                    
            } catch (ex) {
            }
        }
        
        if (ex1 !== null) {
            throw(ex1);
        }
    };
    
    SWFUpload.proxyDetect.uploadCompleteHandler = function (file) {
        try {
            delete this.proxyDetectFileStartTimes[file.ID];
        } catch (ex) {
        }
        
        if (typeof this.proxyDetectSettings.user_upload_progress_handler === "function") {
            return this.proxyDetectSettings.user_upload_progress_handler.call(this, file);
        }
    };    
}