Firefox文件下載過程結構圖

對於我的項目，我需要學習一些信息，如「FireFox/Gecko文件下載結構概述」（如果有），或者有些「FireFox/Gecko文件下載過程流程圖」。到目前爲止，我在互聯網上找不到這樣的東西。有沒有關於它的任何信息？非常感謝。 PS：它必須包含通過FireFox瀏覽器下載的所有文件的路徑，這些路徑通過網絡連接信息API和文件處理API，就像「httpOpenRequest」或「DoFileDownload」API（如果有）一樣。Firefox文件下載過程結構圖

什麼是Firefox下載過程API路徑？有沒有數字或圖表？請幫助我...

來源

2014-12-19 Dio

您可能需要查看代碼才能獲取所需的信息。您需要自己構建流程圖。

在代碼中有幾種不同的下載方式。

如果你是在談論一個Firefox插件進行下載，那麼它可能正在使用做Downloads.jsm（儘管這樣做舊的方法）。該JavaScript模塊的源代碼位於resource://gre/modules/Downloads.jsm（該URL僅在Firefox中有效）。似乎有幾個文件都位於Firefox分發的根目錄中的zip格式文件內的jsloader\resource\gre\modules目錄中。您可以複製該文件並將其名稱更改爲omni.zip，並以普通的.zip文件的形式對其進行訪問。

如果您想知道當用戶請求時，Firefox如何保存頁面：在上下文菜單中定義的oncommand值爲gContextMenu.saveLink();。 saveLink（）的定義如下：chrome://browser/content/nsContextMenu.js。它做了一些家務管理，然後撥打saveHelper() which is in the same file。

的saveHelper()代碼如下：

// Helper function to wait for appropriate MIME-type headers and 
// then prompt the user with a file picker 
saveHelper: function(linkURL, linkText, dialogTitle, bypassCache, doc) { 
    // canonical def in nsURILoader.h 
    const NS_ERROR_SAVE_LINK_AS_TIMEOUT = 0x805d0020; 

    // an object to proxy the data through to 
    // nsIExternalHelperAppService.doContent, which will wait for the 
    // appropriate MIME-type headers and then prompt the user with a 
    // file picker 
    function saveAsListener() {} 
    saveAsListener.prototype = { 
    extListener: null, 

    onStartRequest: function saveLinkAs_onStartRequest(aRequest, aContext) { 

     // if the timer fired, the error status will have been caused by that, 
     // and we'll be restarting in onStopRequest, so no reason to notify 
     // the user 
     if (aRequest.status == NS_ERROR_SAVE_LINK_AS_TIMEOUT) 
     return; 

     timer.cancel(); 

     // some other error occured; notify the user... 
     if (!Components.isSuccessCode(aRequest.status)) { 
     try { 
      const sbs = Cc["@mozilla.org/intl/stringbundle;1"]. 
         getService(Ci.nsIStringBundleService); 
      const bundle = sbs.createBundle(
        "chrome://mozapps/locale/downloads/downloads.properties"); 

      const title = bundle.GetStringFromName("downloadErrorAlertTitle"); 
      const msg = bundle.GetStringFromName("downloadErrorGeneric"); 

      const promptSvc = Cc["@mozilla.org/embedcomp/prompt-service;1"]. 
          getService(Ci.nsIPromptService); 
      promptSvc.alert(doc.defaultView, title, msg); 
     } catch (ex) {} 
     return; 
     } 

     var extHelperAppSvc = 
     Cc["@mozilla.org/uriloader/external-helper-app-service;1"]. 
     getService(Ci.nsIExternalHelperAppService); 
     var channel = aRequest.QueryInterface(Ci.nsIChannel); 
     this.extListener = 
     extHelperAppSvc.doContent(channel.contentType, aRequest, 
            doc.defaultView, true); 
     this.extListener.onStartRequest(aRequest, aContext); 
    }, 

    onStopRequest: function saveLinkAs_onStopRequest(aRequest, aContext, 
                aStatusCode) { 
     if (aStatusCode == NS_ERROR_SAVE_LINK_AS_TIMEOUT) { 
     // do it the old fashioned way, which will pick the best filename 
     // it can without waiting. 
     saveURL(linkURL, linkText, dialogTitle, bypassCache, false, 
       doc.documentURIObject, doc); 
     } 
     if (this.extListener) 
     this.extListener.onStopRequest(aRequest, aContext, aStatusCode); 
    }, 

    onDataAvailable: function saveLinkAs_onDataAvailable(aRequest, aContext, 
                 aInputStream, 
                 aOffset, aCount) { 
     this.extListener.onDataAvailable(aRequest, aContext, aInputStream, 
             aOffset, aCount); 
    } 
    } 

    function callbacks() {} 
    callbacks.prototype = { 
    getInterface: function sLA_callbacks_getInterface(aIID) { 
     if (aIID.equals(Ci.nsIAuthPrompt) || aIID.equals(Ci.nsIAuthPrompt2)) { 
     // If the channel demands authentication prompt, we must cancel it 
     // because the save-as-timer would expire and cancel the channel 
     // before we get credentials from user. Both authentication dialog 
     // and save as dialog would appear on the screen as we fall back to 
     // the old fashioned way after the timeout. 
     timer.cancel(); 
     channel.cancel(NS_ERROR_SAVE_LINK_AS_TIMEOUT); 
     } 
     throw Cr.NS_ERROR_NO_INTERFACE; 
    } 
    } 

    // if it we don't have the headers after a short time, the user 
    // won't have received any feedback from their click. that's bad. so 
    // we give up waiting for the filename. 
    function timerCallback() {} 
    timerCallback.prototype = { 
    notify: function sLA_timer_notify(aTimer) { 
     channel.cancel(NS_ERROR_SAVE_LINK_AS_TIMEOUT); 
     return; 
    } 
    } 

    // set up a channel to do the saving 
    var ioService = Cc["@mozilla.org/network/io-service;1"]. 
        getService(Ci.nsIIOService); 
    var channel = ioService.newChannelFromURI(makeURI(linkURL)); 
    if (channel instanceof Ci.nsIPrivateBrowsingChannel) { 
    let docIsPrivate = PrivateBrowsingUtils.isWindowPrivate(doc.defaultView); 
    channel.setPrivate(docIsPrivate); 
    } 
    channel.notificationCallbacks = new callbacks(); 

    let flags = Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS; 

    if (bypassCache) 
    flags |= Ci.nsIRequest.LOAD_BYPASS_CACHE; 

    if (channel instanceof Ci.nsICachingChannel) 
    flags |= Ci.nsICachingChannel.LOAD_BYPASS_LOCAL_CACHE_IF_BUSY; 

    channel.loadFlags |= flags; 

    if (channel instanceof Ci.nsIHttpChannel) { 
    channel.referrer = doc.documentURIObject; 
    if (channel instanceof Ci.nsIHttpChannelInternal) 
     channel.forceAllowThirdPartyCookie = true; 
    } 

    // fallback to the old way if we don't see the headers quickly 
    var timeToWait = 
    gPrefService.getIntPref("browser.download.saveLinkAsFilenameTimeout"); 
    var timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer); 
    timer.initWithCallback(new timerCallback(), timeToWait, 
         timer.TYPE_ONE_SHOT); 

    // kick off the channel with our proxy object as the listener 
    channel.asyncOpen(new saveAsListener(), null); 
}

來源

2014-12-19 12:19:14 Makyen

Firefox文件下載過程結構圖

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