1 files changed, 357 insertions, 0 deletions
diff --git a/storage/VacuumManager.cpp b/storage/VacuumManager.cpp
new file mode 100644
index 0000000000..26fcdcd838
--- /dev/null
+++ b/storage/VacuumManager.cpp
@@ -0,0 +1,357 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+
+#include "VacuumManager.h"
+
+#include "mozilla/Services.h"
+#include "mozilla/Preferences.h"
+#include "nsIObserverService.h"
+#include "nsIFile.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Logging.h"
+#include "prtime.h"
+#include "mozilla/StaticPrefs_storage.h"
+
+#include "mozStorageConnection.h"
+#include "mozIStorageStatement.h"
+#include "mozIStorageStatementCallback.h"
+#include "mozIStorageAsyncStatement.h"
+#include "mozIStoragePendingStatement.h"
+#include "mozIStorageError.h"
+#include "mozStorageHelper.h"
+#include "nsXULAppAPI.h"
+
+#define OBSERVER_TOPIC_IDLE_DAILY "idle-daily"
+#define OBSERVER_TOPIC_XPCOM_SHUTDOWN "xpcom-shutdown"
+
+// Used to notify begin and end of a heavy IO task.
+#define OBSERVER_TOPIC_HEAVY_IO "heavy-io-task"
+#define OBSERVER_DATA_VACUUM_BEGIN u"vacuum-begin"
+#define OBSERVER_DATA_VACUUM_END u"vacuum-end"
+
+// This preferences root will contain last vacuum timestamps (in seconds) for
+// each database.  The database filename is used as a key.
+#define PREF_VACUUM_BRANCH "storage.vacuum.last."
+
+// Time between subsequent vacuum calls for a certain database.
+#define VACUUM_INTERVAL_SECONDS 30 * 86400  // 30 days.
+
+extern mozilla::LazyLogModule gStorageLog;
+
+namespace mozilla {
+namespace storage {
+
+namespace {
+
+////////////////////////////////////////////////////////////////////////////////
+//// BaseCallback
+
+class BaseCallback : public mozIStorageStatementCallback {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_MOZISTORAGESTATEMENTCALLBACK
+  BaseCallback() {}
+
+ protected:
+  virtual ~BaseCallback() {}
+};
+
+NS_IMETHODIMP
+BaseCallback::HandleError(mozIStorageError* aError) {
+#ifdef DEBUG
+  int32_t result;
+  nsresult rv = aError->GetResult(&result);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsAutoCString message;
+  rv = aError->GetMessage(message);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString warnMsg;
+  warnMsg.AppendLiteral("An error occured during async execution: ");
+  warnMsg.AppendInt(result);
+  warnMsg.Append(' ');
+  warnMsg.Append(message);
+  NS_WARNING(warnMsg.get());
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BaseCallback::HandleResult(mozIStorageResultSet* aResultSet) {
+  // We could get results from PRAGMA statements, but we don't mind them.
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BaseCallback::HandleCompletion(uint16_t aReason) {
+  // By default BaseCallback will just be silent on completion.
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(BaseCallback, mozIStorageStatementCallback)
+
+////////////////////////////////////////////////////////////////////////////////
+//// Vacuumer declaration.
+
+class Vacuumer : public BaseCallback {
+ public:
+  NS_DECL_MOZISTORAGESTATEMENTCALLBACK
+
+  explicit Vacuumer(mozIStorageVacuumParticipant* aParticipant);
+
+  bool execute();
+  nsresult notifyCompletion(bool aSucceeded);
+
+ private:
+  nsCOMPtr<mozIStorageVacuumParticipant> mParticipant;
+  nsCString mDBFilename;
+  nsCOMPtr<mozIStorageConnection> mDBConn;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// Vacuumer implementation.
+
+Vacuumer::Vacuumer(mozIStorageVacuumParticipant* aParticipant)
+    : mParticipant(aParticipant) {}
+
+bool Vacuumer::execute() {
+  MOZ_ASSERT(NS_IsMainThread(), "Must be running on the main thread!");
+
+  // Get the connection and check its validity.
+  nsresult rv = mParticipant->GetDatabaseConnection(getter_AddRefs(mDBConn));
+  NS_ENSURE_SUCCESS(rv, false);
+  bool ready = false;
+  if (!mDBConn || NS_FAILED(mDBConn->GetConnectionReady(&ready)) || !ready) {
+    NS_WARNING("Unable to get a connection to vacuum database");
+    return false;
+  }
+
+  // Ask for the expected page size.  Vacuum can change the page size, unless
+  // the database is using WAL journaling.
+  // TODO Bug 634374: figure out a strategy to fix page size with WAL.
+  int32_t expectedPageSize = 0;
+  rv = mParticipant->GetExpectedDatabasePageSize(&expectedPageSize);
+  if (NS_FAILED(rv) || !Service::pageSizeIsValid(expectedPageSize)) {
+    NS_WARNING("Invalid page size requested for database, will use default ");
+    NS_WARNING(mDBFilename.get());
+    expectedPageSize = Service::kDefaultPageSize;
+  }
+
+  // Get the database filename.  Last vacuum time is stored under this name
+  // in PREF_VACUUM_BRANCH.
+  nsCOMPtr<nsIFile> databaseFile;
+  mDBConn->GetDatabaseFile(getter_AddRefs(databaseFile));
+  if (!databaseFile) {
+    NS_WARNING("Trying to vacuum a in-memory database!");
+    return false;
+  }
+  nsAutoString databaseFilename;
+  rv = databaseFile->GetLeafName(databaseFilename);
+  NS_ENSURE_SUCCESS(rv, false);
+  CopyUTF16toUTF8(databaseFilename, mDBFilename);
+  MOZ_ASSERT(!mDBFilename.IsEmpty(), "Database filename cannot be empty");
+
+  // Check interval from last vacuum.
+  int32_t now = static_cast<int32_t>(PR_Now() / PR_USEC_PER_SEC);
+  int32_t lastVacuum;
+  nsAutoCString prefName(PREF_VACUUM_BRANCH);
+  prefName += mDBFilename;
+  rv = Preferences::GetInt(prefName.get(), &lastVacuum);
+  if (NS_SUCCEEDED(rv) && (now - lastVacuum) < VACUUM_INTERVAL_SECONDS) {
+    // This database was vacuumed recently, skip it.
+    return false;
+  }
+
+  // Notify that we are about to start vacuuming.  The participant can opt-out
+  // if it cannot handle a vacuum at this time, and then we'll move to the next
+  // one.
+  bool vacuumGranted = false;
+  rv = mParticipant->OnBeginVacuum(&vacuumGranted);
+  NS_ENSURE_SUCCESS(rv, false);
+  if (!vacuumGranted) {
+    return false;
+  }
+
+  // Notify a heavy IO task is about to start.
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (os) {
+    rv = os->NotifyObservers(nullptr, OBSERVER_TOPIC_HEAVY_IO,
+                             OBSERVER_DATA_VACUUM_BEGIN);
+    MOZ_ASSERT(NS_SUCCEEDED(rv), "Should be able to notify");
+  }
+
+  // Execute the statements separately, since the pragma may conflict with the
+  // vacuum, if they are executed in the same transaction.
+  nsCOMPtr<mozIStorageAsyncStatement> pageSizeStmt;
+  nsAutoCString pageSizeQuery(MOZ_STORAGE_UNIQUIFY_QUERY_STR
+                              "PRAGMA page_size = ");
+  pageSizeQuery.AppendInt(expectedPageSize);
+  rv = mDBConn->CreateAsyncStatement(pageSizeQuery,
+                                     getter_AddRefs(pageSizeStmt));
+  NS_ENSURE_SUCCESS(rv, false);
+  RefPtr<BaseCallback> callback = new BaseCallback();
+  nsCOMPtr<mozIStoragePendingStatement> ps;
+  rv = pageSizeStmt->ExecuteAsync(callback, getter_AddRefs(ps));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  nsCOMPtr<mozIStorageAsyncStatement> stmt;
+  rv = mDBConn->CreateAsyncStatement("VACUUM"_ns, getter_AddRefs(stmt));
+  NS_ENSURE_SUCCESS(rv, false);
+  rv = stmt->ExecuteAsync(this, getter_AddRefs(ps));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// mozIStorageStatementCallback
+
+NS_IMETHODIMP
+Vacuumer::HandleError(mozIStorageError* aError) {
+  int32_t result;
+  nsresult rv;
+  nsAutoCString message;
+
+#ifdef DEBUG
+  rv = aError->GetResult(&result);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = aError->GetMessage(message);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString warnMsg;
+  warnMsg.AppendLiteral("Unable to vacuum database: ");
+  warnMsg.Append(mDBFilename);
+  warnMsg.AppendLiteral(" - ");
+  warnMsg.AppendInt(result);
+  warnMsg.Append(' ');
+  warnMsg.Append(message);
+  NS_WARNING(warnMsg.get());
+#endif
+
+  if (MOZ_LOG_TEST(gStorageLog, LogLevel::Error)) {
+    rv = aError->GetResult(&result);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aError->GetMessage(message);
+    NS_ENSURE_SUCCESS(rv, rv);
+    MOZ_LOG(gStorageLog, LogLevel::Error,
+            ("Vacuum failed with error: %d '%s'. Database was: '%s'", result,
+             message.get(), mDBFilename.get()));
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Vacuumer::HandleResult(mozIStorageResultSet* aResultSet) {
+  MOZ_ASSERT_UNREACHABLE("Got a resultset from a vacuum?");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Vacuumer::HandleCompletion(uint16_t aReason) {
+  if (aReason == REASON_FINISHED) {
+    // Update last vacuum time.
+    int32_t now = static_cast<int32_t>(PR_Now() / PR_USEC_PER_SEC);
+    MOZ_ASSERT(!mDBFilename.IsEmpty(), "Database filename cannot be empty");
+    nsAutoCString prefName(PREF_VACUUM_BRANCH);
+    prefName += mDBFilename;
+    DebugOnly<nsresult> rv = Preferences::SetInt(prefName.get(), now);
+    MOZ_ASSERT(NS_SUCCEEDED(rv), "Should be able to set a preference");
+  }
+
+  notifyCompletion(aReason == REASON_FINISHED);
+
+  return NS_OK;
+}
+
+nsresult Vacuumer::notifyCompletion(bool aSucceeded) {
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (os) {
+    os->NotifyObservers(nullptr, OBSERVER_TOPIC_HEAVY_IO,
+                        OBSERVER_DATA_VACUUM_END);
+  }
+
+  nsresult rv = mParticipant->OnEndVacuum(aSucceeded);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+//// VacuumManager
+
+NS_IMPL_ISUPPORTS(VacuumManager, nsIObserver)
+
+VacuumManager* VacuumManager::gVacuumManager = nullptr;
+
+already_AddRefed<VacuumManager> VacuumManager::getSingleton() {
+  // Don't allocate it in the child Process.
+  if (!XRE_IsParentProcess()) {
+    return nullptr;
+  }
+
+  if (!gVacuumManager) {
+    auto manager = MakeRefPtr<VacuumManager>();
+    MOZ_ASSERT(gVacuumManager == manager.get());
+    return manager.forget();
+  }
+  return do_AddRef(gVacuumManager);
+}
+
+VacuumManager::VacuumManager() : mParticipants("vacuum-participant") {
+  MOZ_ASSERT(!gVacuumManager,
+             "Attempting to create two instances of the service!");
+  gVacuumManager = this;
+}
+
+VacuumManager::~VacuumManager() {
+  // Remove the static reference to the service.  Check to make sure its us
+  // in case somebody creates an extra instance of the service.
+  MOZ_ASSERT(gVacuumManager == this,
+             "Deleting a non-singleton instance of the service");
+  if (gVacuumManager == this) {
+    gVacuumManager = nullptr;
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// nsIObserver
+
+NS_IMETHODIMP
+VacuumManager::Observe(nsISupports* aSubject, const char* aTopic,
+                       const char16_t* aData) {
+  if (strcmp(aTopic, OBSERVER_TOPIC_IDLE_DAILY) == 0) {
+    // Try to run vacuum on all registered entries.  Will stop at the first
+    // successful one.
+    nsCOMArray<mozIStorageVacuumParticipant> entries;
+    mParticipants.GetEntries(entries);
+    // If there are more entries than what a month can contain, we could end up
+    // skipping some, since we run daily.  So we use a starting index.
+    static const char* kPrefName = PREF_VACUUM_BRANCH "index";
+    int32_t startIndex = Preferences::GetInt(kPrefName, 0);
+    if (startIndex >= entries.Count()) {
+      startIndex = 0;
+    }
+    int32_t index;
+    for (index = startIndex; index < entries.Count(); ++index) {
+      RefPtr<Vacuumer> vacuum = new Vacuumer(entries[index]);
+      // Only vacuum one database per day.
+      if (vacuum->execute()) {
+        break;
+      }
+    }
+    DebugOnly<nsresult> rv = Preferences::SetInt(kPrefName, index);
+    MOZ_ASSERT(NS_SUCCEEDED(rv), "Should be able to set a preference");
+  }
+
+  return NS_OK;
+}
+
+}  // namespace storage
+}  // namespace mozilla