storage/mozStoragePrivateHelpers.h
author Chris H-C <chutten@mozilla.com>
Mon, 04 Jul 2016 11:16:05 -0400
changeset 312997 df28918fe2361f0b54ca9ce4773a29c4c0675d06
parent 284513 1b3ab4045d79f6a136f1b2b7707d59fe82f85fa3
child 316076 a2c62b2557b44af96ccf8913cacc9a71cd292c51
permissions -rw-r--r--
bug 1218576 - Support remote accumulation via JS histograms. r=gfritzsche The JS histograms, too, need to dispatch their accumulations from child to parent. JSHistograms_Add now only supports histograms that are in gHistogramsMap or that were created in the parent process. After bug 1288745, maybe we'll be able to change this to be less convoluted. MozReview-Commit-ID: 3qTH89YKbGP

/* -*- 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/. */

#ifndef mozStoragePrivateHelpers_h
#define mozStoragePrivateHelpers_h

/**
 * This file contains convenience methods for mozStorage.
 */

#include "sqlite3.h"
#include "nsIVariant.h"
#include "nsError.h"
#include "nsAutoPtr.h"
#include "js/TypeDecls.h"
#include "Variant.h"

class mozIStorageCompletionCallback;
class nsIRunnable;

namespace mozilla {
namespace storage {

////////////////////////////////////////////////////////////////////////////////
//// Macros

#define ENSURE_INDEX_VALUE(aIndex, aCount) \
  NS_ENSURE_TRUE(aIndex < aCount, NS_ERROR_INVALID_ARG)

////////////////////////////////////////////////////////////////////////////////
//// Functions

/**
 * Converts a SQLite return code to an nsresult return code.
 *
 * @param aSQLiteResultCode
 *        The SQLite return code to convert.
 * @returns the corresponding nsresult code for aSQLiteResultCode.
 */
nsresult convertResultCode(int aSQLiteResultCode);

/**
 * Checks the performance of a SQLite statement and logs a warning with
 * NS_WARNING.  Currently this only checks the number of sort operations done
 * on a statement, and if more than zero have been done, the statement can be
 * made faster with the careful use of an index.
 *
 * @param aStatement
 *        The sqlite3_stmt object to check.
 */
void checkAndLogStatementPerformance(sqlite3_stmt *aStatement);

/**
 * Convert the provided JS::Value into a variant representation if possible.
 *
 * @param aCtx
 *        The JSContext the value is from.
 * @param aValue
 *        The JavaScript value to convert.  All primitive types are supported,
 *        but only Date objects are supported from the Date family.  Date
 *        objects are coerced to PRTime (nanoseconds since epoch) values.
 * @return the variant if conversion was successful, nullptr if conversion
 *         failed.  The caller is responsible for addref'ing if non-null.
 */
nsIVariant *convertJSValToVariant(JSContext *aCtx, JS::Value aValue);

/**
 * Convert a provided nsIVariant implementation to our own thread-safe
 * refcounting implementation, if needed.
 *
 * @param aValue
 *        The original nsIVariant to be converted.
 * @return a thread-safe refcounting nsIVariant implementation.
 */
Variant_base *convertVariantToStorageVariant(nsIVariant *aVariant);

/**
 * Obtains an event that will notify a completion callback about completion.
 *
 * @param aCallback
 *        The callback to be notified.
 * @return an nsIRunnable that can be dispatched to the calling thread.
 */
already_AddRefed<nsIRunnable> newCompletionEvent(
  mozIStorageCompletionCallback *aCallback
);

/**
 * Utility method to get a Blob as a string value.  The string expects
 * the interface exposed by nsAString/nsACString/etc.
 */
template<class T, class V>
nsresult
DoGetBlobAsString(T* aThis, uint32_t aIndex, V& aValue)
{
  typedef typename V::char_type char_type;

  uint32_t size;
  char_type* blob;
  nsresult rv =
    aThis->GetBlob(aIndex, &size, reinterpret_cast<uint8_t**>(&blob));
  NS_ENSURE_SUCCESS(rv, rv);

  aValue.Assign(blob, size / sizeof(char_type));
  delete[] blob;
  return NS_OK;
}

/**
 * Utility method to bind a string value as a Blob.  The string expects
 * the interface exposed by nsAString/nsACString/etc.
 */
template<class T, class V>
nsresult
DoBindStringAsBlobByName(T* aThis, const nsACString& aName, const V& aValue)
{
  typedef typename V::char_type char_type;
  return aThis->BindBlobByName(aName,
                        reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
                        aValue.Length() * sizeof(char_type));
}

/**
 * Utility method to bind a string value as a Blob.  The string expects
 * the interface exposed by nsAString/nsACString/etc.
 */
template<class T, class V>
nsresult
DoBindStringAsBlobByIndex(T* aThis, uint32_t aIndex, const V& aValue)
{
  typedef typename V::char_type char_type;
  return aThis->BindBlobByIndex(aIndex,
                        reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
                        aValue.Length() * sizeof(char_type));
}

} // namespace storage
} // namespace mozilla

#endif // mozStoragePrivateHelpers_h