Home | History | Annotate | Download | only in predictors 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "chrome/browser/predictors/resource_prefetcher_manager.h"
      6 
      7 #include "base/bind.h"
      8 #include "base/stl_util.h"
      9 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
     10 #include "content/public/browser/browser_thread.h"
     11 #include "net/url_request/url_request.h"
     12 #include "net/url_request/url_request_context_getter.h"
     13 
     14 using content::BrowserThread;
     15 
     16 namespace predictors {
     17 
     18 ResourcePrefetcherManager::ResourcePrefetcherManager(
     19     ResourcePrefetchPredictor* predictor,
     20     const ResourcePrefetchPredictorConfig& config,
     21     net::URLRequestContextGetter* context_getter)
     22     : predictor_(predictor),
     23       config_(config),
     24       context_getter_(context_getter) {
     25   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     26   CHECK(predictor_);
     27   CHECK(context_getter_);
     28 }
     29 
     30 ResourcePrefetcherManager::~ResourcePrefetcherManager() {
     31   DCHECK(prefetcher_map_.empty())
     32       << "Did not call ShutdownOnUIThread or ShutdownOnIOThread. "
     33          " Will leak Prefetcher pointers.";
     34 }
     35 
     36 void ResourcePrefetcherManager::ShutdownOnUIThread() {
     37   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     38 
     39   predictor_ = NULL;
     40   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
     41       base::Bind(&ResourcePrefetcherManager::ShutdownOnIOThread,
     42                  this));
     43 }
     44 
     45 void ResourcePrefetcherManager::ShutdownOnIOThread() {
     46   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
     47   STLDeleteContainerPairSecondPointers(prefetcher_map_.begin(),
     48                                        prefetcher_map_.end());
     49 }
     50 
     51 void ResourcePrefetcherManager::MaybeAddPrefetch(
     52     const NavigationID& navigation_id,
     53     PrefetchKeyType key_type,
     54     scoped_ptr<ResourcePrefetcher::RequestVector> requests) {
     55   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
     56 
     57   // Don't add a duplicate prefetch for the same host or URL.
     58   std::string key = key_type == PREFETCH_KEY_TYPE_HOST ?
     59       navigation_id.main_frame_url.host() : navigation_id.main_frame_url.spec();
     60   PrefetcherMap::iterator prefetcher_it = prefetcher_map_.find(key);
     61   if (prefetcher_it != prefetcher_map_.end())
     62     return;
     63 
     64   ResourcePrefetcher* prefetcher = new ResourcePrefetcher(
     65       this, config_, navigation_id, key_type, requests.Pass());
     66   prefetcher_map_.insert(std::make_pair(key, prefetcher));
     67   prefetcher->Start();
     68 }
     69 
     70 void ResourcePrefetcherManager::MaybeRemovePrefetch(
     71     const NavigationID& navigation_id) {
     72   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
     73 
     74   // Look for a URL based prefetch first.
     75   PrefetcherMap::iterator it = prefetcher_map_.find(
     76       navigation_id.main_frame_url.spec());
     77   if (it != prefetcher_map_.end() &&
     78       it->second->navigation_id() == navigation_id) {
     79     it->second->Stop();
     80     return;
     81   }
     82 
     83   // No URL based prefetching, look for host based.
     84   it = prefetcher_map_.find(navigation_id.main_frame_url.host());
     85   if (it != prefetcher_map_.end() &&
     86       it->second->navigation_id() == navigation_id) {
     87     it->second->Stop();
     88   }
     89 }
     90 
     91 void ResourcePrefetcherManager::ResourcePrefetcherFinished(
     92     ResourcePrefetcher* resource_prefetcher,
     93     ResourcePrefetcher::RequestVector* requests) {
     94   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
     95 
     96   // |predictor_| can only be accessed from the UI thread.
     97   scoped_ptr<ResourcePrefetcher::RequestVector> requests_ptr(requests);
     98   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
     99       base::Bind(&ResourcePrefetcherManager::ResourcePrefetcherFinishedOnUI,
    100                  this,
    101                  resource_prefetcher->navigation_id(),
    102                  resource_prefetcher->key_type(),
    103                  base::Passed(&requests_ptr)));
    104 
    105   const GURL& main_frame_url =
    106       resource_prefetcher->navigation_id().main_frame_url;
    107   const std::string key =
    108       resource_prefetcher->key_type() == PREFETCH_KEY_TYPE_HOST ?
    109           main_frame_url.host() : main_frame_url.spec();
    110   PrefetcherMap::iterator it = prefetcher_map_.find(key);
    111   DCHECK(it != prefetcher_map_.end());
    112   delete it->second;
    113   prefetcher_map_.erase(it);
    114 }
    115 
    116 void ResourcePrefetcherManager::ResourcePrefetcherFinishedOnUI(
    117     const NavigationID& navigation_id,
    118     PrefetchKeyType key_type,
    119     scoped_ptr<ResourcePrefetcher::RequestVector> requests) {
    120   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
    121 
    122   // |predictor_| may have been set to NULL if the predictor is shutting down.
    123   if (predictor_)
    124     predictor_->FinishedPrefetchForNavigation(navigation_id,
    125                                               key_type,
    126                                               requests.release());
    127 }
    128 
    129 net::URLRequestContext* ResourcePrefetcherManager::GetURLRequestContext() {
    130   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
    131 
    132   return context_getter_->GetURLRequestContext();
    133 }
    134 
    135 }  // namespace predictors
    136