Home | History | Annotate | Download | only in value_store 
      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/value_store/value_store_frontend.h"
      6 
      7 #include "base/bind.h"
      8 #include "base/debug/trace_event.h"
      9 #include "base/files/file_path.h"
     10 #include "base/logging.h"
     11 #include "chrome/browser/value_store/leveldb_value_store.h"
     12 #include "content/public/browser/browser_thread.h"
     13 
     14 using content::BrowserThread;
     15 
     16 class ValueStoreFrontend::Backend : public base::RefCountedThreadSafe<Backend> {
     17  public:
     18   Backend() : storage_(NULL) {}
     19 
     20   void Init(const base::FilePath& db_path) {
     21     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
     22     DCHECK(!storage_);
     23     TRACE_EVENT0("ValueStoreFrontend::Backend", "Init");
     24     db_path_ = db_path;
     25     storage_ = new LeveldbValueStore(db_path);
     26   }
     27 
     28   // This variant is useful for testing (using a mock ValueStore).
     29   void InitWithStore(scoped_ptr<ValueStore> storage) {
     30     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
     31     DCHECK(!storage_);
     32     storage_ = storage.release();
     33   }
     34 
     35   void Get(const std::string& key,
     36            const ValueStoreFrontend::ReadCallback& callback) {
     37     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
     38     ValueStore::ReadResult result = storage_->Get(key);
     39 
     40     // Extract the value from the ReadResult and pass ownership of it to the
     41     // callback.
     42     scoped_ptr<base::Value> value;
     43     if (!result->HasError()) {
     44       result->settings()->RemoveWithoutPathExpansion(key, &value);
     45     } else {
     46       LOG(INFO) << "Reading " << key << " from " << db_path_.value()
     47                 << " failed: " << result->error();
     48     }
     49 
     50     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
     51         base::Bind(&ValueStoreFrontend::Backend::RunCallback,
     52                    this, callback, base::Passed(&value)));
     53   }
     54 
     55   void Set(const std::string& key, scoped_ptr<base::Value> value) {
     56     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
     57     // We don't need the old value, so skip generating changes.
     58     storage_->Set(ValueStore::IGNORE_QUOTA | ValueStore::NO_GENERATE_CHANGES,
     59                   key, *value.get());
     60   }
     61 
     62   void Remove(const std::string& key) {
     63     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
     64     storage_->Remove(key);
     65   }
     66 
     67  private:
     68   friend class base::RefCountedThreadSafe<Backend>;
     69 
     70   virtual ~Backend() {
     71     if (BrowserThread::CurrentlyOn(BrowserThread::FILE)) {
     72       delete storage_;
     73     } else {
     74       BrowserThread::DeleteSoon(BrowserThread::FILE, FROM_HERE, storage_);
     75     }
     76   }
     77 
     78   void RunCallback(const ValueStoreFrontend::ReadCallback& callback,
     79                    scoped_ptr<base::Value> value) {
     80     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     81     callback.Run(value.Pass());
     82   }
     83 
     84   // The actual ValueStore that handles persisting the data to disk. Used
     85   // exclusively on the FILE thread.
     86   ValueStore* storage_;
     87 
     88   base::FilePath db_path_;
     89 
     90   DISALLOW_COPY_AND_ASSIGN(Backend);
     91 };
     92 
     93 ValueStoreFrontend::ValueStoreFrontend()
     94     : backend_(new Backend()) {
     95 }
     96 
     97 ValueStoreFrontend::ValueStoreFrontend(const base::FilePath& db_path)
     98     : backend_(new Backend()) {
     99   Init(db_path);
    100 }
    101 
    102 ValueStoreFrontend::ValueStoreFrontend(ValueStore* value_store)
    103     : backend_(new Backend()) {
    104   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
    105       base::Bind(&ValueStoreFrontend::Backend::InitWithStore,
    106                  backend_, base::Passed(scoped_ptr<ValueStore>(value_store))));
    107 }
    108 
    109 ValueStoreFrontend::~ValueStoreFrontend() {
    110   DCHECK(CalledOnValidThread());
    111 }
    112 
    113 void ValueStoreFrontend::Init(const base::FilePath& db_path) {
    114   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
    115       base::Bind(&ValueStoreFrontend::Backend::Init,
    116                  backend_, db_path));
    117 }
    118 
    119 void ValueStoreFrontend::Get(const std::string& key,
    120                              const ReadCallback& callback) {
    121   DCHECK(CalledOnValidThread());
    122 
    123   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
    124       base::Bind(&ValueStoreFrontend::Backend::Get,
    125                  backend_, key, callback));
    126 }
    127 
    128 void ValueStoreFrontend::Set(const std::string& key,
    129                              scoped_ptr<base::Value> value) {
    130   DCHECK(CalledOnValidThread());
    131 
    132   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
    133       base::Bind(&ValueStoreFrontend::Backend::Set,
    134                  backend_, key, base::Passed(&value)));
    135 }
    136 
    137 void ValueStoreFrontend::Remove(const std::string& key) {
    138   DCHECK(CalledOnValidThread());
    139 
    140   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
    141       base::Bind(&ValueStoreFrontend::Backend::Remove,
    142                  backend_, key));
    143 }
    144