storage/StorageBaseStatementInternal.cpp
author Samael Wang <freesamael@gmail.com>
Fri, 11 Aug 2017 14:49:09 +0800
changeset 413793 1f8a03070122f8c5fa92ebe76478dcd0b2b1a357
parent 401914 312f7a5a2c08d394a2403c837e5ee546dd4103d7
child 450616 4bcb64fd8fa1aae1bdb7a2a019a283eacb7af4ca
permissions -rw-r--r--
Bug 1375833 - Part 2: Set mHistoryID to aSHEntry->DocshellID() in both reload and history navigation. r=smaug The root cause of bug 1326845 is that reloading would apply frame history entries without setting new child docshells' mHistoryID to the entrys' DocshellID. So SHistory can not find corresponding entries for subframes in a consequent GoBack(), and cause history navigation being broken (it would return NS_ERROR_FAILURE). MozReview-Commit-ID: 6syGYkoP1eZ

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=2 sts=2 expandtab
 * 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 "StorageBaseStatementInternal.h"

#include "nsProxyRelease.h"

#include "mozStorageBindingParamsArray.h"
#include "mozStorageStatementData.h"
#include "mozStorageAsyncStatementExecution.h"

namespace mozilla {
namespace storage {

////////////////////////////////////////////////////////////////////////////////
//// Local Classes

/**
 * Used to finalize an asynchronous statement on the background thread.
 */
class AsyncStatementFinalizer : public Runnable
{
public:
  /**
   * Constructor for the event.
   *
   * @param aStatement
   *        We need the AsyncStatement to be able to get at the sqlite3_stmt;
   *        we only access/create it on the async thread.
   * @param aConnection
   *        We need the connection to know what thread to release the statement
   *        on.  We release the statement on that thread since releasing the
   *        statement might end up releasing the connection too.
   */
  AsyncStatementFinalizer(StorageBaseStatementInternal* aStatement,
                          Connection* aConnection)
    : Runnable("storage::AsyncStatementFinalizer")
    , mStatement(aStatement)
    , mConnection(aConnection)
  {
  }

  NS_IMETHOD Run() override
  {
    if (mStatement->mAsyncStatement) {
      sqlite3_finalize(mStatement->mAsyncStatement);
      mStatement->mAsyncStatement = nullptr;
    }

    nsCOMPtr<nsIThread> targetThread(mConnection->threadOpenedOn);
    NS_ProxyRelease(
      "AsyncStatementFinalizer::mStatement", targetThread, mStatement.forget());
    return NS_OK;
  }
private:
  RefPtr<StorageBaseStatementInternal> mStatement;
  RefPtr<Connection> mConnection;
};

/**
 * Finalize a sqlite3_stmt on the background thread for a statement whose
 * destructor was invoked and the statement was non-null.
 */
class LastDitchSqliteStatementFinalizer : public Runnable
{
public:
  /**
   * Event constructor.
   *
   * @param aConnection
   *        Used to keep the connection alive.  If we failed to do this, it
   *        is possible that the statement going out of scope invoking us
   *        might have the last reference to the connection and so trigger
   *        an attempt to close the connection which is doomed to fail
   *        (because the asynchronous execution thread must exist which will
   *        trigger the failure case).
   * @param aStatement
   *        The sqlite3_stmt to finalize.  This object takes ownership /
   *        responsibility for the instance and all other references to it
   *        should be forgotten.
   */
  LastDitchSqliteStatementFinalizer(RefPtr<Connection>& aConnection,
                                    sqlite3_stmt* aStatement)
    : Runnable("storage::LastDitchSqliteStatementFinalizer")
    , mConnection(aConnection)
    , mAsyncStatement(aStatement)
  {
    NS_PRECONDITION(aConnection, "You must provide a Connection");
  }

  NS_IMETHOD Run() override
  {
    (void)::sqlite3_finalize(mAsyncStatement);
    mAsyncStatement = nullptr;

    nsCOMPtr<nsIThread> target(mConnection->threadOpenedOn);
    (void)::NS_ProxyRelease(
      "LastDitchSqliteStatementFinalizer::mConnection",
      target, mConnection.forget());
    return NS_OK;
  }
private:
  RefPtr<Connection> mConnection;
  sqlite3_stmt *mAsyncStatement;
};

////////////////////////////////////////////////////////////////////////////////
//// StorageBaseStatementInternal

StorageBaseStatementInternal::StorageBaseStatementInternal()
: mAsyncStatement(nullptr)
{
}

void
StorageBaseStatementInternal::asyncFinalize()
{
  nsIEventTarget *target = mDBConnection->getAsyncExecutionTarget();
  if (target) {
    // Attempt to finalize asynchronously
    nsCOMPtr<nsIRunnable> event =
      new AsyncStatementFinalizer(this, mDBConnection);

    // Dispatch. Note that dispatching can fail, typically if
    // we have a race condition with asyncClose(). It's ok,
    // let asyncClose() win.
    (void)target->Dispatch(event, NS_DISPATCH_NORMAL);
  }
  // If we cannot get the background thread,
  // mozStorageConnection::AsyncClose() has already been called and
  // the statement either has been or will be cleaned up by
  // internalClose().
}

void
StorageBaseStatementInternal::destructorAsyncFinalize()
{
  if (!mAsyncStatement)
    return;

  bool isOwningThread = false;
  (void)mDBConnection->threadOpenedOn->IsOnCurrentThread(&isOwningThread);
  if (isOwningThread) {
    // If we are the owning thread (currently that means we're also the
    // main thread), then we can get the async target and just dispatch
    // to it.
    nsIEventTarget *target = mDBConnection->getAsyncExecutionTarget();
    if (target) {
      nsCOMPtr<nsIRunnable> event =
        new LastDitchSqliteStatementFinalizer(mDBConnection, mAsyncStatement);
      (void)target->Dispatch(event, NS_DISPATCH_NORMAL);
    }
  } else {
    // If we're not the owning thread, assume we're the async thread, and
    // just run the statement.
    nsCOMPtr<nsIRunnable> event =
      new LastDitchSqliteStatementFinalizer(mDBConnection, mAsyncStatement);
    (void)event->Run();
  }


  // We might not be able to dispatch to the background thread,
  // presumably because it is being shutdown. Since said shutdown will
  // finalize the statement, we just need to clean-up around here.
  mAsyncStatement = nullptr;
}

NS_IMETHODIMP
StorageBaseStatementInternal::NewBindingParamsArray(
  mozIStorageBindingParamsArray **_array
)
{
  nsCOMPtr<mozIStorageBindingParamsArray> array = new BindingParamsArray(this);
  NS_ENSURE_TRUE(array, NS_ERROR_OUT_OF_MEMORY);

  array.forget(_array);
  return NS_OK;
}

NS_IMETHODIMP
StorageBaseStatementInternal::ExecuteAsync(
  mozIStorageStatementCallback *aCallback,
  mozIStoragePendingStatement **_stmt
)
{
  // We used to call Connection::ExecuteAsync but it takes a
  // mozIStorageBaseStatement signature because it is also a public API.  Since
  // our 'this' has no static concept of mozIStorageBaseStatement and Connection
  // would just QI it back across to a StorageBaseStatementInternal and the
  // actual logic is very simple, we now roll our own.
  nsTArray<StatementData> stmts(1);
  StatementData data;
  nsresult rv = getAsynchronousStatementData(data);
  NS_ENSURE_SUCCESS(rv, rv);
  NS_ENSURE_TRUE(stmts.AppendElement(data), NS_ERROR_OUT_OF_MEMORY);

  // Dispatch to the background
  return AsyncExecuteStatements::execute(stmts, mDBConnection,
                                         mNativeConnection, aCallback, _stmt);
}

NS_IMETHODIMP
StorageBaseStatementInternal::EscapeStringForLIKE(
  const nsAString &aValue,
  const char16_t aEscapeChar,
  nsAString &_escapedString
)
{
  const char16_t MATCH_ALL('%');
  const char16_t MATCH_ONE('_');

  _escapedString.Truncate(0);

  for (uint32_t i = 0; i < aValue.Length(); i++) {
    if (aValue[i] == aEscapeChar || aValue[i] == MATCH_ALL ||
        aValue[i] == MATCH_ONE) {
      _escapedString += aEscapeChar;
    }
    _escapedString += aValue[i];
  }
  return NS_OK;
}

} // namespace storage
} // namespace mozilla