Chrome: Crash Report : InstantService::MaybeTranslateInstantPathOnIO

chrome/browser/ui/webui/ntp/thumbnail_source.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/ntp/thumbnail_source.h"
 
 #include "base/callback.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/message_loop.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/instant_io_context.h"
 #include "chrome/browser/search/instant_service.h"
 #include "chrome/browser/search/instant_service_factory.h"
 #include "chrome/browser/thumbnails/thumbnail_service.h"
 #include "chrome/browser/thumbnails/thumbnail_service_factory.h"
 #include "chrome/common/url_constants.h"
 #include "googleurl/src/gurl.h"
 #include "grit/theme_resources.h"
 #include "net/url_request/url_request.h"
 #include "ui/base/resource/resource_bundle.h"
 
 using content::BrowserThread;
 
 // Set ThumbnailService now as Profile isn't thread safe.
 ThumbnailSource::ThumbnailSource(Profile* profile)
     : thumbnail_service_(ThumbnailServiceFactory::GetForProfile(profile)),
-      current_request_(NULL),
       profile_(profile) {
 }
 
 ThumbnailSource::~ThumbnailSource() {
 }
 
 std::string ThumbnailSource::GetSource() {
   return chrome::kChromeUIThumbnailHost;
 }
 
 void ThumbnailSource::StartDataRequest(
     const std::string& raw_path,
     bool is_incognito,
     const content::URLDataSource::GotDataCallback& callback) {
   // Translate to regular path if |raw_path| is of the form
-  // chrome-search://favicon/<rid>, where rid is a uint64.
+  // chrome-search://favicon/<id> or chrome-search://thumb/<id>, where <id> is
+  // an integer.
   std::string path = raw_path;
   if (BrowserThread::CurrentlyOn(BrowserThread::IO)) {
-    path = InstantService::MaybeTranslateInstantPathOnIO(
-        current_request_, raw_path);
+    std::map<std::string, std::string>::iterator it =
+        id_to_url_map_.find(raw_path);
+    if (it != id_to_url_map_.end()) {
+      path = id_to_url_map_[raw_path];
+      id_to_url_map_.erase(it);
+    }
   } else if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     path = InstantService::MaybeTranslateInstantPathOnUI(profile_, raw_path);
   }
 
   scoped_refptr<base::RefCountedMemory> data;
   if (thumbnail_service_->GetPageThumbnail(GURL(path), &data)) {
     // We have the thumbnail.
     callback.Run(data.get());
   } else {
     callback.Run(default_thumbnail_);
   }
-  current_request_ = NULL;
 }
 
 std::string ThumbnailSource::GetMimeType(const std::string&) const {
   // We need to explicitly return a mime type, otherwise if the user tries to
   // drag the image they get no extension.
   return "image/png";
 }
 
 MessageLoop* ThumbnailSource::MessageLoopForRequestPath(
     const std::string& path) const {
   // TopSites can be accessed from the IO thread.
   return thumbnail_service_.get() ?
       NULL : content::URLDataSource::MessageLoopForRequestPath(path);
 }
 
 bool ThumbnailSource::ShouldServiceRequest(
     const net::URLRequest* request) const {
-  current_request_ = request;
   if (request->url().SchemeIs(chrome::kChromeSearchScheme)) {
-    return InstantService::IsInstantPath(request->url()) &&
-        InstantIOContext::ShouldServiceRequest(request);
+    if (InstantService::IsInstantPath(request->url()) &&
+        InstantIOContext::ShouldServiceRequest(request)) {
+      // If this request will be serviced on the IO thread, then do the
+      // translation from raw_path to path here, where we have the |request|
+      // object in-hand, saving the result for later use.
+      std::string raw_path = request->url().path().substr(1);

[Dan Beam, 2013/03/20 19:26:13]

why .substr(1)?

[dhollowa, 2013/03/20 19:58:54]

Done.  Added comment.

+      if (!MessageLoopForRequestPath(raw_path)) {
+        std::string path =
+            InstantService::MaybeTranslateInstantPathOnIO(request, raw_path);
+        id_to_url_map_[raw_path] = path;

[Dan Beam, 2013/03/20 19:26:13]

nit:

  id_to_url_map_[raw_path] =
      InstantService::MaybeTranslateInstantPathOnIO(request, raw_path);

[dhollowa, 2013/03/20 19:58:54]

Done.

+      }
+      return true;
+    }

[Dan Beam, 2013/03/20 19:26:13]

should there be a NOTREACHED() here or anything?

[dhollowa, 2013/03/20 19:58:54]

Not really, no.  It is allowable to request a non-conformant URL, we just don't
want to serve anything back.  This would not be a Chromium programmer error, but
a web-programmer error.  So at most a log warning might be appropriate, but
that's not common in these data-source classes, so I've left it out.

+    return false;
   }
   return URLDataSource::ShouldServiceRequest(request);
 }