base: Remove OwningMRUCache in favor of scoped_ptrs in MRUCache

chrome/browser/ui/app_list/search/common/webservice_cache.cc

 // Copyright 2013 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/app_list/search/common/webservice_cache.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace app_list {
 namespace {
 
 const unsigned int kWebserviceCacheMaxSize = 1000;
 const unsigned int kWebserviceCacheTimeLimitInMinutes = 1;
 
 const char kKeyResultTime[] = "time";
 const char kKeyResult[] = "result";
 
 const char kWebstoreQueryPrefix[] = "webstore:";
 const char kPeopleQueryPrefix[] = "people:";
 
 }  // namespace
 
-void WebserviceCache::CacheDeletor::operator()(const Payload& payload) {
-  delete payload.result;
-}
-
 WebserviceCache::WebserviceCache(content::BrowserContext* context)
     : cache_(Cache::NO_AUTO_EVICT),
       cache_loaded_(false) {
   const char kStoreDataFileName[] = "Webservice Search Cache";
   const base::FilePath data_file =
       context->GetPath().AppendASCII(kStoreDataFileName);
   data_store_ = new DictionaryDataStore(
       data_file, content::BrowserThread::GetBlockingPool());
   data_store_->Load(base::Bind(&WebserviceCache::OnCacheLoaded, AsWeakPtr()));
 }
 
 WebserviceCache::~WebserviceCache() {
 }
 
 const CacheResult WebserviceCache::Get(QueryType type,
                                        const std::string& query) {
   std::string typed_query = PrependType(type, query);
   Cache::iterator iter = cache_.Get(typed_query);
   if (iter != cache_.end()) {
-    if (base::Time::Now() - iter->second.time <=
+    if (base::Time::Now() - iter->second->time <=
         base::TimeDelta::FromMinutes(kWebserviceCacheTimeLimitInMinutes)) {
-      return std::make_pair(FRESH, iter->second.result);
+      return std::make_pair(FRESH, iter->second->result.get());
     } else {
-      return std::make_pair(STALE, iter->second.result);
+      return std::make_pair(STALE, iter->second->result.get());
     }
   }
   return std::make_pair(STALE, static_cast<base::DictionaryValue*>(NULL));
 }
 
 void WebserviceCache::Put(QueryType type,
                           const std::string& query,
                           scoped_ptr<base::DictionaryValue> result) {
   if (result) {
     std::string typed_query = PrependType(type, query);
-    Payload payload(base::Time::Now(), result.release());
+    scoped_ptr<Payload> scoped_payload(
+        new Payload(base::Time::Now(), std::move(result)));
+    Payload* payload = scoped_payload.get();
 
-    cache_.Put(typed_query, payload);
+    cache_.Put(typed_query, std::move(scoped_payload));
     // If the cache isn't loaded yet, we're fine with losing queries since
     // a 1000 entry cache should load really quickly so the chance of a user
     // already having typed a 3 character search before the cache has loaded is
     // very unlikely.
     if (cache_loaded_) {
-      data_store_->cached_dict()->Set(typed_query, DictFromPayload(payload));
+      data_store_->cached_dict()->Set(typed_query, DictFromPayload(*payload));
       data_store_->ScheduleWrite();
       if (cache_.size() > kWebserviceCacheMaxSize)
         TrimCache();
     }
   }
 }
 
 void WebserviceCache::OnCacheLoaded(scoped_ptr<base::DictionaryValue>) {
   if (!data_store_->cached_dict())
     return;
 
   std::vector<std::string> cleanup_keys;
   for (base::DictionaryValue::Iterator it(*data_store_->cached_dict());
       !it.IsAtEnd();
       it.Advance()) {
     const base::DictionaryValue* payload_dict;
-    Payload payload;
+    scoped_ptr<Payload> payload(new Payload);
     if (!it.value().GetAsDictionary(&payload_dict) ||
         !payload_dict ||
-        !PayloadFromDict(payload_dict, &payload)) {
+        !PayloadFromDict(payload_dict, payload.get())) {
       // In case we don't have a valid payload associated with a given query,
       // clean up that query from our data store.
       cleanup_keys.push_back(it.key());
       continue;
     }
-    cache_.Put(it.key(), payload);
+    cache_.Put(it.key(), std::move(payload));
   }
 
   if (!cleanup_keys.empty()) {
     for (size_t i = 0; i < cleanup_keys.size(); ++i)
       data_store_->cached_dict()->Remove(cleanup_keys[i], NULL);
     data_store_->ScheduleWrite();
   }
   cache_loaded_ = true;
 }
 
 bool WebserviceCache::PayloadFromDict(const base::DictionaryValue* dict,
                                       Payload* payload) {
   std::string time_string;
   if (!dict->GetString(kKeyResultTime, &time_string))
     return false;
   const base::DictionaryValue* result;
   if (!dict->GetDictionary(kKeyResult, &result))
     return false;
 
   int64_t time_val;
   base::StringToInt64(time_string, &time_val);
 
   // The result dictionary will be owned by the cache, hence create a copy
   // instead of returning the original reference. The new dictionary will be
   // owned by our MRU cache.
-  *payload = Payload(base::Time::FromInternalValue(time_val),
-                     result->DeepCopy());
+  payload->time = base::Time::FromInternalValue(time_val);

[danakj, 2016/03/07 21:27:10]

Might be nice to call the constructor here still like before, ensures new fields
don't get missed

[vmpstr, 2016/03/07 21:45:32]

Done.

+  payload->result = make_scoped_ptr(result->DeepCopy());
   return true;
 }
 
 base::DictionaryValue* WebserviceCache::DictFromPayload(
     const Payload& payload) {
   base::DictionaryValue* dict = new base::DictionaryValue();
   dict->SetString(kKeyResultTime, base::Int64ToString(
       payload.time.ToInternalValue()));
   // The payload will still keep ownership of it's result dict, hence put a
   // a copy of the result dictionary here. This dictionary will be owned by
@@ skipping 17 matching lines @@
   switch (type) {
     case WEBSTORE:
       return kWebstoreQueryPrefix + query;
     case PEOPLE:
       return kPeopleQueryPrefix + query;
     default:
       return query;
   }
 }
 
+WebserviceCache::Payload::Payload(const base::Time& time,
+                                  scoped_ptr<base::DictionaryValue> result)
+    : time(time), result(std::move(result)) {}
+
+WebserviceCache::Payload::Payload() = default;
+
+WebserviceCache::Payload::~Payload() = default;
+
 }  // namespace app_list