storage/mozStoragePrivateHelpers.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozStoragePrivateHelpers_h
   8 #define mozStoragePrivateHelpers_h
   9
  10 /**
  11  * This file contains convenience methods for mozStorage.
  12  */
  13
  14 #include "sqlite3.h"
  15 #include "nsIVariant.h"
  16 #include "nsError.h"
  17 #include "nsAutoPtr.h"
  18 #include "js/TypeDecls.h"
  19 #include "Variant.h"
  20
  21 class mozIStorageCompletionCallback;
  22 class nsIRunnable;
  23
  24 namespace mozilla {
  25 namespace storage {
  26
  27 ////////////////////////////////////////////////////////////////////////////////
  28 //// Macros
  29
  30 #define ENSURE_INDEX_VALUE(aIndex, aCount) \
  31   NS_ENSURE_TRUE(aIndex < aCount, NS_ERROR_INVALID_ARG)
  32
  33 ////////////////////////////////////////////////////////////////////////////////
  34 //// Functions
  35
  36 /**
  37  * Converts a SQLite return code to an nsresult return code.
  38  *
  39  * @param aSQLiteResultCode
  40  *        The SQLite return code to convert.
  41  * @returns the corresponding nsresult code for aSQLiteResultCode.
  42  */
  43 nsresult convertResultCode(int aSQLiteResultCode);
  44
  45 /**
  46  * Checks the performance of a SQLite statement and logs a warning with
  47  * NS_WARNING.  Currently this only checks the number of sort operations done
  48  * on a statement, and if more than zero have been done, the statement can be
  49  * made faster with the careful use of an index.
  50  *
  51  * @param aStatement
  52  *        The sqlite3_stmt object to check.
  53  */
  54 void checkAndLogStatementPerformance(sqlite3_stmt* aStatement);
  55
  56 /**
  57  * Convert the provided JS::Value into a variant representation if possible.
  58  *
  59  * @param aCtx
  60  *        The JSContext the value is from.
  61  * @param aValue
  62  *        The JavaScript value to convert.  All primitive types are supported,
  63  *        but only Date objects are supported from the Date family.  Date
  64  *        objects are coerced to PRTime (nanoseconds since epoch) values.
  65  * @return the variant if conversion was successful, nullptr if conversion
  66  *         failed.  The caller is responsible for addref'ing if non-null.
  67  */
  68 nsIVariant* convertJSValToVariant(JSContext* aCtx, const JS::Value& aValue);
  69
  70 /**
  71  * Convert a provided nsIVariant implementation to our own thread-safe
  72  * refcounting implementation, if needed.
  73  *
  74  * @param aValue
  75  *        The original nsIVariant to be converted.
  76  * @return a thread-safe refcounting nsIVariant implementation.
  77  */
  78 Variant_base* convertVariantToStorageVariant(nsIVariant* aVariant);
  79
  80 /**
  81  * Obtains an event that will notify a completion callback about completion.
  82  *
  83  * @param aCallback
  84  *        The callback to be notified.
  85  * @return an nsIRunnable that can be dispatched to the calling thread.
  86  */
  87 already_AddRefed<nsIRunnable> newCompletionEvent(
  88     mozIStorageCompletionCallback* aCallback);
  89
  90 /**
  91  * Utility method to get a Blob as a string value.  The string expects
  92  * the interface exposed by nsAString/nsACString/etc.
  93  */
  94 template <class T, class V>
  95 nsresult DoGetBlobAsString(T* aThis, uint32_t aIndex, V& aValue) {
  96   typedef typename V::char_type char_type;
  97
  98   uint32_t size;
  99   char_type* blob;
 100   nsresult rv =
 101       aThis->GetBlob(aIndex, &size, reinterpret_cast<uint8_t**>(&blob));
 102   NS_ENSURE_SUCCESS(rv, rv);
 103
 104   aValue.Assign(blob, size / sizeof(char_type));
 105   delete[] blob;
 106   return NS_OK;
 107 }
 108
 109 /**
 110  * Utility method to bind a string value as a Blob.  The string expects
 111  * the interface exposed by nsAString/nsACString/etc.
 112  */
 113 template <class T, class V>
 114 nsresult DoBindStringAsBlobByName(T* aThis, const nsACString& aName,
 115                                   const V& aValue) {
 116   typedef typename V::char_type char_type;
 117   return aThis->BindBlobByName(
 118       aName, reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
 119       aValue.Length() * sizeof(char_type));
 120 }
 121
 122 /**
 123  * Utility method to bind a string value as a Blob.  The string expects
 124  * the interface exposed by nsAString/nsACString/etc.
 125  */
 126 template <class T, class V>
 127 nsresult DoBindStringAsBlobByIndex(T* aThis, uint32_t aIndex, const V& aValue) {
 128   typedef typename V::char_type char_type;
 129   return aThis->BindBlobByIndex(
 130       aIndex, reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
 131       aValue.Length() * sizeof(char_type));
 132 }
 133
 134 }  // namespace storage
 135 }  // namespace mozilla
 136
 137 #endif  // mozStoragePrivateHelpers_h