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 "nsISerialEventTarget.h"
  16 #include "nsIVariant.h"
  17 #include "nsError.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  * Returns true if the given SQLite result is an error of come kind.
  38  *
  39  * @param aSQLiteResultCode
  40  *        The SQLite return code to check.
  41  * @returns true if the result represents an error.
  42  */
  43 bool isErrorCode(int aSQLiteResultCode);
  44
  45 /**
  46  * Converts a SQLite return code to an nsresult return code.
  47  *
  48  * @param aSQLiteResultCode
  49  *        The SQLite return code to convert.
  50  * @returns the corresponding nsresult code for aSQLiteResultCode.
  51  */
  52 nsresult convertResultCode(int aSQLiteResultCode);
  53
  54 /**
  55  * Checks the performance of a SQLite statement and logs a warning with
  56  * NS_WARNING.  Currently this only checks the number of sort operations done
  57  * on a statement, and if more than zero have been done, the statement can be
  58  * made faster with the careful use of an index.
  59  *
  60  * @param aStatement
  61  *        The sqlite3_stmt object to check.
  62  */
  63 void checkAndLogStatementPerformance(sqlite3_stmt* aStatement);
  64
  65 /**
  66  * Convert the provided JS::Value into a variant representation if possible.
  67  *
  68  * @param aCtx
  69  *        The JSContext the value is from.
  70  * @param aValue
  71  *        The JavaScript value to convert.  All primitive types are supported,
  72  *        but only Date objects are supported from the Date family.  Date
  73  *        objects are coerced to PRTime (nanoseconds since epoch) values.
  74  * @return the variant if conversion was successful, nullptr if conversion
  75  *         failed.  The caller is responsible for addref'ing if non-null.
  76  */
  77 nsIVariant* convertJSValToVariant(JSContext* aCtx, const JS::Value& aValue);
  78
  79 /**
  80  * Convert a provided nsIVariant implementation to our own thread-safe
  81  * refcounting implementation, if needed.
  82  *
  83  * @param aValue
  84  *        The original nsIVariant to be converted.
  85  * @return a thread-safe refcounting nsIVariant implementation.
  86  */
  87 Variant_base* convertVariantToStorageVariant(nsIVariant* aVariant);
  88
  89 /**
  90  * Obtains an event that will notify a completion callback about completion.
  91  *
  92  * @param aCallback
  93  *        The callback to be notified.
  94  * @return an nsIRunnable that can be dispatched to the calling thread.
  95  */
  96 already_AddRefed<nsIRunnable> newCompletionEvent(
  97     mozIStorageCompletionCallback* aCallback);
  98
  99 /**
 100  * Utility method to get a Blob as a string value.  The string expects
 101  * the interface exposed by nsAString/nsACString/etc.
 102  */
 103 template <class T, class V>
 104 nsresult DoGetBlobAsString(T* aThis, uint32_t aIndex, V& aValue) {
 105   typedef typename V::char_type char_type;
 106
 107   uint32_t size;
 108   char_type* blob;
 109   nsresult rv =
 110       aThis->GetBlob(aIndex, &size, reinterpret_cast<uint8_t**>(&blob));
 111   NS_ENSURE_SUCCESS(rv, rv);
 112
 113   aValue.Assign(blob, size / sizeof(char_type));
 114   delete[] blob;
 115   return NS_OK;
 116 }
 117
 118 /**
 119  * Utility method to bind a string value as a Blob.  The string expects
 120  * the interface exposed by nsAString/nsACString/etc.
 121  */
 122 template <class T, class V>
 123 nsresult DoBindStringAsBlobByName(T* aThis, const nsACString& aName,
 124                                   const V& aValue) {
 125   typedef typename V::char_type char_type;
 126   return aThis->BindBlobByName(
 127       aName, reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
 128       aValue.Length() * sizeof(char_type));
 129 }
 130
 131 /**
 132  * Utility method to bind a string value as a Blob.  The string expects
 133  * the interface exposed by nsAString/nsACString/etc.
 134  */
 135 template <class T, class V>
 136 nsresult DoBindStringAsBlobByIndex(T* aThis, uint32_t aIndex, const V& aValue) {
 137   typedef typename V::char_type char_type;
 138   return aThis->BindBlobByIndex(
 139       aIndex, reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
 140       aValue.Length() * sizeof(char_type));
 141 }
 142
 143 /**
 144  * Utility function to check if a serial event target may run runnables
 145  * on the current thread.
 146  */
 147 inline bool IsOnCurrentSerialEventTarget(nsISerialEventTarget* aTarget) {
 148   return aTarget->IsOnCurrentThread();
 149 }
 150
 151 }  // namespace storage
 152 }  // namespace mozilla
 153
 154 #endif  // mozStoragePrivateHelpers_h