gecko/parser/html/nsHtml5SpeculativeLoader.cpp

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
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 * The Original Code is mozilla.org code.
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 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *   Pierre Phaneuf <pp@ludusdesign.com>
 *   Henri Sivonen <hsivonen@iki.fi>
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 * either of the GNU General Public License Version 2 or later (the "GPL"),
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#include "nsHtml5SpeculativeLoader.h"
#include "nsICSSLoader.h"
#include "nsNetUtil.h"
#include "nsScriptLoader.h"
#include "nsICSSLoaderObserver.h"
#include "nsIDocument.h"

/**
 * Used if we need to pass an nsICSSLoaderObserver as parameter,
 * but don't really need its services
 */
class nsHtml5DummyCSSLoaderObserver : public nsICSSLoaderObserver {
public:
  NS_IMETHOD
  StyleSheetLoaded(nsICSSStyleSheet* aSheet, PRBool aWasAlternate, nsresult aStatus) {
      return NS_OK;
  }
  NS_DECL_ISUPPORTS
};

NS_IMPL_ISUPPORTS1(nsHtml5DummyCSSLoaderObserver, nsICSSLoaderObserver)

nsHtml5SpeculativeLoader::nsHtml5SpeculativeLoader(nsHtml5TreeOpExecutor* aExecutor)
  : mExecutor(aExecutor)
{
  MOZ_COUNT_CTOR(nsHtml5SpeculativeLoader);
  mPreloadedURLs.Init(23); // Mean # of preloadable resources per page on dmoz
}

nsHtml5SpeculativeLoader::~nsHtml5SpeculativeLoader()
{
  MOZ_COUNT_DTOR(nsHtml5SpeculativeLoader);
}

NS_IMPL_THREADSAFE_ADDREF(nsHtml5SpeculativeLoader)

NS_IMPL_THREADSAFE_RELEASE(nsHtml5SpeculativeLoader)

already_AddRefed<nsIURI>
nsHtml5SpeculativeLoader::ConvertIfNotPreloadedYet(const nsAString& aURL)
{
  nsIDocument* doc = mExecutor->GetDocument();
  if (!doc) {
    return nsnull;
  }
  nsIURI* base = doc->GetBaseURI();
  const nsCString& charset = doc->GetDocumentCharacterSet();
  nsCOMPtr<nsIURI> uri;
  nsresult rv = NS_NewURI(getter_AddRefs(uri), aURL, charset.get(), base);
  if (NS_FAILED(rv)) {
    NS_WARNING("Failed to create a URI");
    return nsnull;
  }
  nsCAutoString spec;
  uri->GetSpec(spec);
  if (mPreloadedURLs.Contains(spec)) {
    return nsnull;
  }
  mPreloadedURLs.Put(spec);
  nsIURI* retURI = uri;
  NS_ADDREF(retURI);
  return retURI;
}

void
nsHtml5SpeculativeLoader::PreloadScript(const nsAString& aURL,
                                        const nsAString& aCharset,
                                        const nsAString& aType)
{
  nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
  if (!uri) {
    return;
  }
  nsIDocument* doc = mExecutor->GetDocument();
  if (doc) {
    doc->ScriptLoader()->PreloadURI(uri, aCharset, aType);
  }
}

void
nsHtml5SpeculativeLoader::PreloadStyle(const nsAString& aURL,
                                       const nsAString& aCharset)
{
  nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
  if (!uri) {
    return;
  }
  nsCOMPtr<nsICSSLoaderObserver> obs = new nsHtml5DummyCSSLoaderObserver();
  nsIDocument* doc = mExecutor->GetDocument();
  if (doc) {
    doc->CSSLoader()->LoadSheet(uri, 
                                doc->NodePrincipal(),
                                NS_LossyConvertUTF16toASCII(aCharset),
                                obs);
  }
}

void
nsHtml5SpeculativeLoader::PreloadImage(const nsAString& aURL)
{
  nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
  if (!uri) {
    return;
  }
  nsIDocument* doc = mExecutor->GetDocument();
  if (doc) {
    doc->MaybePreLoadImage(uri);
  }
}

void
nsHtml5SpeculativeLoader::ProcessManifest(const nsAString& aURL)
{
  mExecutor->ProcessOfflineManifest(aURL);
}