storage/mozStorageStatementData.h
author Brian Stack <bstack@mozilla.com>
Wed, 12 Apr 2017 21:01:46 -0700
changeset 404168 5748607f3014e8cec573fccebce5dcbf83b6ffd6
parent 322179 c75f253f4335d4069676dd3a978940716508d9fb
child 415860 ec459f72f2ea2d7ed50f1935e1da3e8efe5c1185
child 415972 89963ba78c353b23feab0042ebe264049f8d4533
permissions -rw-r--r--
Bug 591688 - Notify when decision task fails r=dustin,gps This uses the email provided by mozilla-taskcluster to find who to email about failed decision tasks. It also adds some validation of the try syntax that we've previously ignored. Any platforms or build types specified in try sytax that don't exist in the full task graph will throw an error. MozReview-Commit-ID: JOKkLle7hEe

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

#ifndef mozStorageStatementData_h
#define mozStorageStatementData_h

#include "sqlite3.h"

#include "nsAutoPtr.h"
#include "nsTArray.h"
#include "nsIEventTarget.h"
#include "MainThreadUtils.h"

#include "mozStorageBindingParamsArray.h"
#include "mozIStorageBaseStatement.h"
#include "mozStorageConnection.h"
#include "StorageBaseStatementInternal.h"

struct sqlite3_stmt;

namespace mozilla {
namespace storage {

class StatementData
{
public:
  StatementData(sqlite3_stmt *aStatement,
                already_AddRefed<BindingParamsArray> aParamsArray,
                StorageBaseStatementInternal *aStatementOwner)
  : mStatement(aStatement)
  , mParamsArray(aParamsArray)
  , mStatementOwner(aStatementOwner)
  {
    NS_PRECONDITION(mStatementOwner, "Must have a statement owner!");
  }
  StatementData(const StatementData &aSource)
  : mStatement(aSource.mStatement)
  , mParamsArray(aSource.mParamsArray)
  , mStatementOwner(aSource.mStatementOwner)
  {
    NS_PRECONDITION(mStatementOwner, "Must have a statement owner!");
  }
  StatementData()
  : mStatement(nullptr)
  {
  }
  ~StatementData()
  {
    // We need to ensure that mParamsArray is released on the main thread,
    // as the binding arguments may be XPConnect values, which are safe
    // to release only on the main thread.
    NS_ReleaseOnMainThread(mParamsArray.forget());
  }

  /**
   * Return the sqlite statement, fetching it from the storage statement.  In
   * the case of AsyncStatements this may actually create the statement 
   */
  inline int getSqliteStatement(sqlite3_stmt **_stmt)
  {
    if (!mStatement) {
      int rc = mStatementOwner->getAsyncStatement(&mStatement);
      NS_ENSURE_TRUE(rc == SQLITE_OK, rc);
    }
    *_stmt = mStatement;
    return SQLITE_OK;
  }

  operator BindingParamsArray *() const { return mParamsArray; }

  /**
   * NULLs out our sqlite3_stmt (it is held by the owner) after reseting it and
   * clear all bindings to it.  This is expected to occur on the async thread.
   */
  inline void reset()
  {
    NS_PRECONDITION(mStatementOwner, "Must have a statement owner!");
#ifdef DEBUG
    {
      nsCOMPtr<nsIEventTarget> asyncThread =
        mStatementOwner->getOwner()->getAsyncExecutionTarget();
      // It's possible that we are shutting down the async thread, and this
      // method would return nullptr as a result.
      if (asyncThread) {
        bool onAsyncThread;
        NS_ASSERTION(NS_SUCCEEDED(asyncThread->IsOnCurrentThread(&onAsyncThread)) && onAsyncThread,
                     "This should only be running on the async thread!");
      }
    }
#endif
    // In the AsyncStatement case we may never have populated mStatement if the
    // AsyncExecuteStatements got canceled or a failure occurred in constructing
    // the statement.
    if (mStatement) {
      (void)::sqlite3_reset(mStatement);
      (void)::sqlite3_clear_bindings(mStatement);
      mStatement = nullptr;
    }
  }

  /**
   * Indicates if this statement has parameters to be bound before it is
   * executed.
   *
   * @return true if the statement has parameters to bind against, false
   *         otherwise.
   */
  inline bool hasParametersToBeBound() const { return !!mParamsArray; }
  /**
   * Indicates the number of implicit statements generated by this statement
   * requiring a transaction for execution.  For example a single statement
   * with N BindingParams will execute N implicit staments.
   *
   * @return number of statements requiring a transaction for execution.
   *
   * @note In the case of AsyncStatements this may actually create the
   *       statement.
   */
  inline uint32_t needsTransaction()
  {
    MOZ_ASSERT(!NS_IsMainThread());
    // Be sure to use the getSqliteStatement helper, since sqlite3_stmt_readonly
    // can only analyze prepared statements and AsyncStatements are prepared
    // lazily.
    sqlite3_stmt *stmt;
    int rc = getSqliteStatement(&stmt);
    if (SQLITE_OK != rc || ::sqlite3_stmt_readonly(stmt)) {
      return 0;
    }
    return mParamsArray ? mParamsArray->length() : 1;
  }

private:
  sqlite3_stmt *mStatement;
  RefPtr<BindingParamsArray> mParamsArray;

  /**
   * We hold onto a reference of the statement's owner so it doesn't get
   * destroyed out from under us.
   */
  nsCOMPtr<StorageBaseStatementInternal> mStatementOwner;
};

} // namespace storage
} // namespace mozilla

#endif // mozStorageStatementData_h