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 "js/TypeDecls.h"
  18 #include "Variant.h"
  19
  20 class mozIStorageCompletionCallback;
  21 class nsIRunnable;
  22
  23 namespace mozilla {
  24 namespace storage {
  25
  26 ////////////////////////////////////////////////////////////////////////////////
  27 //// Macros
  28
  29 #define ENSURE_INDEX_VALUE(aIndex, aCount) \
  30   NS_ENSURE_TRUE(aIndex < aCount, NS_ERROR_INVALID_ARG)
  31
  32 ////////////////////////////////////////////////////////////////////////////////
  33 //// Functions
  34
  35 /**
  36  * Returns true if the given SQLite result is an error of come kind.
  37  *
  38  * @param aSQLiteResultCode
  39  *        The SQLite return code to check.
  40  * @returns true if the result represents an error.
  41  */
  42 bool isErrorCode(int aSQLiteResultCode);
  43
  44 /**
  45  * Converts a SQLite return code to an nsresult return code.
  46  *
  47  * @param aSQLiteResultCode
  48  *        The SQLite return code to convert.
  49  * @returns the corresponding nsresult code for aSQLiteResultCode.
  50  */
  51 nsresult convertResultCode(int aSQLiteResultCode);
  52
  53 /**
  54  * Checks the performance of a SQLite statement and logs a warning with
  55  * NS_WARNING.  Currently this only checks the number of sort operations done
  56  * on a statement, and if more than zero have been done, the statement can be
  57  * made faster with the careful use of an index.
  58  *
  59  * @param aStatement
  60  *        The sqlite3_stmt object to check.
  61  */
  62 void checkAndLogStatementPerformance(sqlite3_stmt* aStatement);
  63
  64 /**
  65  * Convert the provided JS::Value into a variant representation if possible.
  66  *
  67  * @param aCtx
  68  *        The JSContext the value is from.
  69  * @param aValue
  70  *        The JavaScript value to convert.  All primitive types are supported,
  71  *        but only Date objects are supported from the Date family.  Date
  72  *        objects are coerced to PRTime (nanoseconds since epoch) values.
  73  * @return the variant if conversion was successful, nullptr if conversion
  74  *         failed.  The caller is responsible for addref'ing if non-null.
  75  */
  76 nsIVariant* convertJSValToVariant(JSContext* aCtx, const JS::Value& aValue);
  77
  78 /**
  79  * Convert a provided nsIVariant implementation to our own thread-safe
  80  * refcounting implementation, if needed.
  81  *
  82  * @param aValue
  83  *        The original nsIVariant to be converted.
  84  * @return a thread-safe refcounting nsIVariant implementation.
  85  */
  86 Variant_base* convertVariantToStorageVariant(nsIVariant* aVariant);
  87
  88 /**
  89  * Obtains an event that will notify a completion callback about completion.
  90  *
  91  * @param aCallback
  92  *        The callback to be notified.
  93  * @return an nsIRunnable that can be dispatched to the calling thread.
  94  */
  95 already_AddRefed<nsIRunnable> newCompletionEvent(
  96     mozIStorageCompletionCallback* aCallback);
  97
  98 /**
  99  * Utility method to get a Blob as a string value.  The string expects
 100  * the interface exposed by nsAString/nsACString/etc.
 101  */
 102 template <class T, class V>
 103 nsresult DoGetBlobAsString(T* aThis, uint32_t aIndex, V& aValue) {
 104   typedef typename V::char_type char_type;
 105
 106   uint32_t size;
 107   char_type* blob;
 108   nsresult rv =
 109       aThis->GetBlob(aIndex, &size, reinterpret_cast<uint8_t**>(&blob));
 110   NS_ENSURE_SUCCESS(rv, rv);
 111
 112   aValue.Assign(blob, size / sizeof(char_type));
 113   delete[] blob;
 114   return NS_OK;
 115 }
 116
 117 /**
 118  * Utility method to bind a string value as a Blob.  The string expects
 119  * the interface exposed by nsAString/nsACString/etc.
 120  */
 121 template <class T, class V>
 122 nsresult DoBindStringAsBlobByName(T* aThis, const nsACString& aName,
 123                                   const V& aValue) {
 124   typedef typename V::char_type char_type;
 125   return aThis->BindBlobByName(
 126       aName, reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
 127       aValue.Length() * sizeof(char_type));
 128 }
 129
 130 /**
 131  * Utility method to bind a string value as a Blob.  The string expects
 132  * the interface exposed by nsAString/nsACString/etc.
 133  */
 134 template <class T, class V>
 135 nsresult DoBindStringAsBlobByIndex(T* aThis, uint32_t aIndex, const V& aValue) {
 136   typedef typename V::char_type char_type;
 137   return aThis->BindBlobByIndex(
 138       aIndex, reinterpret_cast<const uint8_t*>(aValue.BeginReading()),
 139       aValue.Length() * sizeof(char_type));
 140 }
 141
 142 }  // namespace storage
 143 }  // namespace mozilla
 144
 145 #endif  // mozStoragePrivateHelpers_h