Persist sessionStorage on disk.

webkit/dom_storage/dom_storage_context.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 "webkit/dom_storage/dom_storage_context.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/guid.h"
 #include "base/location.h"
 #include "base/time.h"
 #include "webkit/dom_storage/dom_storage_area.h"
 #include "webkit/dom_storage/dom_storage_database.h"
 #include "webkit/dom_storage/dom_storage_namespace.h"
 #include "webkit/dom_storage/dom_storage_task_runner.h"
 #include "webkit/dom_storage/dom_storage_types.h"
+#include "webkit/dom_storage/session_storage_database.h"
 #include "webkit/quota/special_storage_policy.h"
 
 using file_util::FileEnumerator;
 
 namespace dom_storage {
 
+static const int kSessionStoraceScavengingSeconds = 60;
+
 DomStorageContext::UsageInfo::UsageInfo() : data_size(0) {}
 DomStorageContext::UsageInfo::~UsageInfo() {}
 
 DomStorageContext::DomStorageContext(
     const FilePath& localstorage_directory,
     const FilePath& sessionstorage_directory,
     quota::SpecialStoragePolicy* special_storage_policy,
     DomStorageTaskRunner* task_runner)
     : localstorage_directory_(localstorage_directory),
       sessionstorage_directory_(sessionstorage_directory),
       task_runner_(task_runner),
       is_shutdown_(false),
       force_keep_session_state_(false),
       special_storage_policy_(special_storage_policy) {
   // AtomicSequenceNum starts at 0 but we want to start session
   // namespace ids at one since zero is reserved for the
   // kLocalStorageNamespaceId.
   session_id_sequence_.GetNext();
+  if (!sessionstorage_directory_.empty()) {
+    session_storage_database_ = new SessionStorageDatabase(
+        sessionstorage_directory_);
+  }
 }
 
 DomStorageContext::~DomStorageContext() {
 }
 
 DomStorageNamespace* DomStorageContext::GetStorageNamespace(
     int64 namespace_id) {
   if (is_shutdown_)
     return NULL;
   StorageNamespaceMap::iterator found = namespaces_.find(namespace_id);
@@ skipping 29 matching lines @@
       info.origin = DomStorageArea::OriginFromDatabaseFileName(path);
       if (include_file_info) {
         FileEnumerator::FindInfo find_info;
         enumerator.GetFindInfo(&find_info);
         info.data_size = FileEnumerator::GetFilesize(find_info);
         info.last_modified = FileEnumerator::GetLastModifiedTime(find_info);
       }
       infos->push_back(info);
     }
   }
+  // TODO(marja): Get usage infos for sessionStorage (crbug.com/123599).
 }
 
 void DomStorageContext::DeleteOrigin(const GURL& origin) {
   DCHECK(!is_shutdown_);
   DomStorageNamespace* local = GetStorageNamespace(kLocalStorageNamespaceId);
   local->DeleteOrigin(origin);
 }
 
 void DomStorageContext::PurgeMemory() {
   // We can only purge memory from the local storage namespace
   // which is backed by disk.
   StorageNamespaceMap::iterator found =
       namespaces_.find(kLocalStorageNamespaceId);
   if (found != namespaces_.end())
     found->second->PurgeMemory();
 }
 
 void DomStorageContext::Shutdown() {
   is_shutdown_ = true;
   StorageNamespaceMap::const_iterator it = namespaces_.begin();
   for (; it != namespaces_.end(); ++it)
     it->second->Shutdown();
 
-  if (localstorage_directory_.empty())
+  if (localstorage_directory_.empty() && !session_storage_database_.get())
     return;
 
   // Respect the content policy settings about what to
   // keep and what to discard.
   if (force_keep_session_state_)
     return;  // Keep everything.
 
   bool has_session_only_origins =
       special_storage_policy_.get() &&
       special_storage_policy_->HasSessionOnlyOrigins();
@@ skipping 54 matching lines @@
 }
 
 void DomStorageContext::CreateSessionNamespace(
     int64 namespace_id,
     const std::string& persistent_namespace_id) {
   if (is_shutdown_)
     return;
   DCHECK(namespace_id != kLocalStorageNamespaceId);
   DCHECK(namespaces_.find(namespace_id) == namespaces_.end());
   namespaces_[namespace_id] = new DomStorageNamespace(
-      namespace_id, persistent_namespace_id, task_runner_);
+      namespace_id, persistent_namespace_id, session_storage_database_.get(),
+      task_runner_);
 }
 
 void DomStorageContext::DeleteSessionNamespace(
     int64 namespace_id, bool should_persist_data) {
   DCHECK_NE(kLocalStorageNamespaceId, namespace_id);
-  // TODO(marja): Protect the sessionStorage data (once it's written on disk).
+  StorageNamespaceMap::const_iterator it = namespaces_.find(namespace_id);
+  if (it == namespaces_.end())
+    return;
+  std::string persistent_namespace_id = it->second->persistent_namespace_id();
+  if (session_storage_database_.get()) {
+    if (!should_persist_data) {
+      bool success = task_runner_->PostShutdownBlockingTask(
+          FROM_HERE,
+          DomStorageTaskRunner::COMMIT_SEQUENCE,
+          base::Bind(
+              base::IgnoreResult(&SessionStorageDatabase::DeleteNamespace),
+              session_storage_database_,
+              persistent_namespace_id));
+      DCHECK(success);
+    } else {
+      // Protect the persistent namespace ID from scavenging.
+      protected_persistent_session_ids_.insert(persistent_namespace_id);
+    }
+  }
   namespaces_.erase(namespace_id);
 }
 
 void DomStorageContext::CloneSessionNamespace(
     int64 existing_id, int64 new_id,
     const std::string& new_persistent_id) {
   if (is_shutdown_)
     return;
   DCHECK_NE(kLocalStorageNamespaceId, existing_id);
   DCHECK_NE(kLocalStorageNamespaceId, new_id);
   StorageNamespaceMap::iterator found = namespaces_.find(existing_id);
   if (found != namespaces_.end())
     namespaces_[new_id] = found->second->Clone(new_id, new_persistent_id);
   else
     CreateSessionNamespace(new_id, new_persistent_id);
 }
 
 void DomStorageContext::ClearSessionOnlyOrigins() {
-  std::vector<UsageInfo> infos;
-  const bool kDontIncludeFileInfo = false;
-  GetUsageInfo(&infos, kDontIncludeFileInfo);
-  for (size_t i = 0; i < infos.size(); ++i) {
-    const GURL& origin = infos[i].origin;
-    if (special_storage_policy_->IsStorageProtected(origin))
-      continue;
-    if (!special_storage_policy_->IsStorageSessionOnly(origin))
-      continue;
+  if (!localstorage_directory_.empty()) {
+    std::vector<UsageInfo> infos;
+    const bool kDontIncludeFileInfo = false;
+    GetUsageInfo(&infos, kDontIncludeFileInfo);
+    for (size_t i = 0; i < infos.size(); ++i) {
+      const GURL& origin = infos[i].origin;
+      if (special_storage_policy_->IsStorageProtected(origin))
+        continue;
+      if (!special_storage_policy_->IsStorageSessionOnly(origin))
+        continue;
 
-    const bool kNotRecursive = false;
-    FilePath database_file_path = localstorage_directory_.Append(
-        DomStorageArea::DatabaseFileNameFromOrigin(origin));
-    file_util::Delete(database_file_path, kNotRecursive);
-    file_util::Delete(
-        DomStorageDatabase::GetJournalFilePath(database_file_path),
-        kNotRecursive);
+      const bool kNotRecursive = false;
+      FilePath database_file_path = localstorage_directory_.Append(
+          DomStorageArea::DatabaseFileNameFromOrigin(origin));
+      file_util::Delete(database_file_path, kNotRecursive);
+      file_util::Delete(
+          DomStorageDatabase::GetJournalFilePath(database_file_path),
+          kNotRecursive);
+    }
+  }
+  if (session_storage_database_.get()) {

[michaeln, 2012/06/26 06:15:12]

this is so weird to be clearing 'session only' stuff from the set of 'session
only' storage namespace :)

[marja, 2012/06/26 14:18:05]

Ack :)

+    std::vector<std::string> namespace_ids;
+    session_storage_database_->ReadNamespaceIds(&namespace_ids);
+    for (std::vector<std::string>::const_iterator it = namespace_ids.begin();
+         it != namespace_ids.end(); ++it) {
+      std::vector<GURL> origins;
+      session_storage_database_->ReadOriginsInNamespace(*it, &origins);
+
+      for (std::vector<GURL>::const_iterator origin_it = origins.begin();
+           origin_it != origins.end(); ++origin_it) {
+        if (special_storage_policy_->IsStorageProtected(*origin_it))
+          continue;
+        if (!special_storage_policy_->IsStorageSessionOnly(*origin_it))
+          continue;
+        session_storage_database_->DeleteArea(*it, *origin_it);
+      }
+    }
   }
 }
 
+void DomStorageContext::StartScavengingUnusedSessionStorage() {
+  if (session_storage_database_.get()) {
+    bool success = task_runner_->PostShutdownBlockingTask(
+        FROM_HERE,
+        DomStorageTaskRunner::COMMIT_SEQUENCE,
+        base::Bind(
+            &DomStorageContext::FindUnusedSessionStorageInCommitSequence,
+            this));
+    DCHECK(success);
+  }
+}
+
+void DomStorageContext::FindUnusedSessionStorageInCommitSequence() {
+  DCHECK(session_storage_database_.get());
+  // Delete all namespaces which don't have an associated DomStorageNamespace
+  // alive.
+  std::set<std::string> namespace_ids_in_use;
+  for (StorageNamespaceMap::const_iterator it = namespaces_.begin();

[michaeln, 2012/06/26 06:15:12]

The namespaces_ collection shouldn't be accessed on the COMMIT sequence. Maybe
make StartScavenging only callable on the READ sequence (the content layer class
can PostTask to it as is done for all of the other methods), and put this set<>
together in Start and pass it as an OwnPtr'd param to this method.

Also once we start scavenging, should we clear out the
protected_persistent_session_ids_ and arrange to no longer add to it?

[marja, 2012/06/26 14:18:05]

How about this version which passes const std::set<std::string>
namespace_ids_in_use? Do we need the OwnedPtr, shouldn't this just work as
expected?

Also, cleared protected_persistent_session_ids.

+       it != namespaces_.end(); ++it)
+    namespace_ids_in_use.insert(it->second->persistent_namespace_id());
+
+  std::vector<std::string> namespace_ids;
+  session_storage_database_->ReadNamespaceIds(&namespace_ids);
+  for (std::vector<std::string>::const_iterator it = namespace_ids.begin();
+       it != namespace_ids.end(); ++it) {
+    if (namespace_ids_in_use.find(*it) == namespace_ids_in_use.end() &&
+        protected_persistent_session_ids_.find(*it) ==
+        protected_persistent_session_ids_.end()) {
+      // This namespace should get deleted.
+      deletable_persistent_namespace_ids_.push_back(*it);
+    }
+  }
+  if (!deletable_persistent_namespace_ids_.empty()) {
+    task_runner_->PostDelayedTask(

[michaeln, 2012/06/26 06:15:12]

This will post a task to the PRIMARYsequence which i think is not what you
intend? Looks like you intend to call db->DeleteNamespace(id) on the COMMIT
sequence, which i think is a good idea.

[marja, 2012/06/26 14:18:05]

Done, yes, this was a bug, I meant COMMIT_SEQUENCE here.

There is no PostDelayedTask which would take a sequence id as a param; I first
PostDelayedTask into the primary sequence, from there PostShutdownBlockingTask
into the COMMIT_SEQUENCE.

I also added a kSessionStorageScavengingSeconds delay before finding the unused
session storages; it's probably better to wait a bit before doing it in case we
have just restored a session and all the tabs try to load...

+        FROM_HERE,
+        base::Bind(
+            &DomStorageContext::DeleteNextUnunsedNamespaceInCommitSequence,
+            this),
+        base::TimeDelta::FromSeconds(kSessionStoraceScavengingSeconds));
+  }
+}
+
+void DomStorageContext::DeleteNextUnunsedNamespaceInCommitSequence() {
+  const std::string& persistent_id = deletable_persistent_namespace_ids_.back();
+  session_storage_database_->DeleteNamespace(persistent_id);
+  deletable_persistent_namespace_ids_.pop_back();
+  if (!deletable_persistent_namespace_ids_.empty()) {
+    task_runner_->PostDelayedTask(

[michaeln, 2012/06/26 06:15:12]

Ditto about this will post something for execution on the PRIMARY sequence.

[marja, 2012/06/26 14:18:05]

Done.

+        FROM_HERE,
+        base::Bind(
+            &DomStorageContext::DeleteNextUnunsedNamespaceInCommitSequence,
+            this),
+        base::TimeDelta::FromSeconds(kSessionStoraceScavengingSeconds));
+  }
+}
+
 }  // namespace dom_storage