components/dom_distiller/core/distilled_content_store.cc

   1 // Copyright 2014 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 "components/dom_distiller/core/distilled_content_store.h"
   6
   7 #include "base/thread_task_runner_handle.h"
   8
   9 namespace dom_distiller {
  10
  11 InMemoryContentStore::InMemoryContentStore(const int max_num_entries)
  12     : cache_(max_num_entries, CacheDeletor(this)) {
  13 }
  14
  15 InMemoryContentStore::~InMemoryContentStore() {
  16   // Clear the cache before destruction to ensure the CacheDeletor is not called
  17   // after InMemoryContentStore has been destroyed.
  18   cache_.Clear();
  19 }
  20
  21 void InMemoryContentStore::SaveContent(
  22     const ArticleEntry& entry,
  23     const DistilledArticleProto& proto,
  24     InMemoryContentStore::SaveCallback callback) {
  25   InjectContent(entry, proto);
  26   if (!callback.is_null()) {
  27     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
  28                                                   base::Bind(callback, true));
  29   }
  30 }
  31
  32 void InMemoryContentStore::LoadContent(
  33     const ArticleEntry& entry,
  34     InMemoryContentStore::LoadCallback callback) {
  35   if (callback.is_null())
  36     return;
  37
  38   ContentMap::const_iterator it = cache_.Get(entry.entry_id());
  39   bool success = it != cache_.end();
  40   if (!success) {
  41     // Could not find article by entry ID, so try looking it up by URL.
  42     for (int i = 0; i < entry.pages_size(); ++i) {
  43       UrlMap::const_iterator url_it = url_to_id_.find(entry.pages(i).url());
  44       if (url_it != url_to_id_.end()) {
  45         it = cache_.Get(url_it->second);
  46         success = it != cache_.end();
  47         if (success) {
  48           break;
  49         }
  50       }
  51     }
  52   }
  53   scoped_ptr<DistilledArticleProto> distilled_article;
  54   if (success) {
  55     distilled_article.reset(new DistilledArticleProto(it->second));
  56   } else {
  57     distilled_article.reset(new DistilledArticleProto());
  58   }
  59   base::ThreadTaskRunnerHandle::Get()->PostTask(
  60       FROM_HERE,
  61       base::Bind(callback, success, base::Passed(&distilled_article)));
  62 }
  63
  64 void InMemoryContentStore::InjectContent(const ArticleEntry& entry,
  65                                          const DistilledArticleProto& proto) {
  66   cache_.Put(entry.entry_id(), proto);
  67   AddUrlToIdMapping(entry, proto);
  68 }
  69
  70 void InMemoryContentStore::AddUrlToIdMapping(
  71     const ArticleEntry& entry,
  72     const DistilledArticleProto& proto) {
  73   for (int i = 0; i < proto.pages_size(); i++) {
  74     const DistilledPageProto& page = proto.pages(i);
  75     if (page.has_url()) {
  76       url_to_id_[page.url()] = entry.entry_id();
  77     }
  78   }
  79 }
  80
  81 void InMemoryContentStore::EraseUrlToIdMapping(
  82     const DistilledArticleProto& proto) {
  83   for (int i = 0; i < proto.pages_size(); i++) {
  84     const DistilledPageProto& page = proto.pages(i);
  85     if (page.has_url()) {
  86       url_to_id_.erase(page.url());
  87     }
  88   }
  89 }
  90
  91 InMemoryContentStore::CacheDeletor::CacheDeletor(InMemoryContentStore* store)
  92     : store_(store) {
  93 }
  94
  95 InMemoryContentStore::CacheDeletor::~CacheDeletor() {
  96 }
  97
  98 void InMemoryContentStore::CacheDeletor::operator()(
  99     const DistilledArticleProto& proto) {
 100   // When InMemoryContentStore is deleted, the |store_| pointer becomes invalid,
 101   // but since the ContentMap is cleared in the InMemoryContentStore destructor,
 102   // this should never be called after the destructor.
 103   store_->EraseUrlToIdMapping(proto);
 104 }
 105
 106 }  // namespace dom_distiller