storage/src/mozStorageStatementData.h

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   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
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  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
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  15  *
  16  * The Original Code is mozilla.org code.
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  18  * The Initial Developer of the Original Code is
  19  * Mozilla Corporation.
  20  * Portions created by the Initial Developer are Copyright (C) 2009
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *   Shawn Wilsher <me@shawnwilsher.com> (Original Author)
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either the GNU General Public License Version 2 or later (the "GPL"), or
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  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #ifndef mozStorageStatementData_h
  41 #define mozStorageStatementData_h
  42
  43 #include "sqlite3.h"
  44
  45 #include "nsAutoPtr.h"
  46 #include "nsTArray.h"
  47
  48 #include "mozStorageBindingParamsArray.h"
  49 #include "mozIStorageBaseStatement.h"
  50 #include "mozStorageConnection.h"
  51 #include "StorageBaseStatementInternal.h"
  52
  53 struct sqlite3_stmt;
  54
  55 namespace mozilla {
  56 namespace storage {
  57
  58 class StatementData
  59 {
  60 public:
  61   StatementData(sqlite3_stmt *aStatement,
  62                 already_AddRefed<BindingParamsArray> aParamsArray,
  63                 StorageBaseStatementInternal *aStatementOwner)
  64   : mStatement(aStatement)
  65   , mParamsArray(aParamsArray)
  66   , mStatementOwner(aStatementOwner)
  67   {
  68   }
  69   StatementData(const StatementData &aSource)
  70   : mStatement(aSource.mStatement)
  71   , mParamsArray(aSource.mParamsArray)
  72   , mStatementOwner(aSource.mStatementOwner)
  73   {
  74   }
  75   StatementData()
  76   {
  77   }
  78
  79   /**
  80    * Return the sqlite statement, fetching it from the storage statement.  In
  81    * the case of AsyncStatements this may actually create the statement
  82    */
  83   inline int getSqliteStatement(sqlite3_stmt **_stmt)
  84   {
  85     if (!mStatement) {
  86       int rc = mStatementOwner->getAsyncStatement(&mStatement);
  87       NS_ENSURE_TRUE(rc == SQLITE_OK, rc);
  88     }
  89     *_stmt = mStatement;
  90     return SQLITE_OK;
  91   }
  92
  93   operator BindingParamsArray *() const { return mParamsArray; }
  94
  95   /**
  96    * Provide the ability to coerce back to a sqlite3 * connection for purposes
  97    * of getting an error message out of it.
  98    */
  99   operator sqlite3 *() const
 100   {
 101     return mStatementOwner->getOwner()->GetNativeConnection();
 102   }
 103
 104   /**
 105    * NULLs out our sqlite3_stmt (it is held by the owner) after reseting it and
 106    * clear all bindings to it.  This is expected to occur on the async thread.
 107    *
 108    * We do not clear mParamsArray out because we only want to release
 109    * mParamsArray on the calling thread because of XPCVariant addref/release
 110    * thread-safety issues.  The same holds for mStatementOwner which can be
 111    * holding such a reference chain as well.
 112    */
 113   inline void finalize()
 114   {
 115     // In the AsyncStatement case we may never have populated mStatement if the
 116     // AsyncExecuteStatements got canceled or a failure occurred in constructing
 117     // the statement.
 118     if (mStatement) {
 119       (void)::sqlite3_reset(mStatement);
 120       (void)::sqlite3_clear_bindings(mStatement);
 121       mStatement = NULL;
 122     }
 123   }
 124
 125   /**
 126    * Indicates if this statement has parameters to be bound before it is
 127    * executed.
 128    *
 129    * @return true if the statement has parameters to bind against, false
 130    *         otherwise.
 131    */
 132   inline bool hasParametersToBeBound() const { return !!mParamsArray; }
 133   /**
 134    * Indicates if this statement needs a transaction for execution.
 135    *
 136    * @return true if the statement needs a transaction, false otherwise.
 137    */
 138   inline bool needsTransaction() const
 139   {
 140     return mParamsArray != nsnull && mParamsArray->length() > 1;
 141   }
 142
 143 private:
 144   sqlite3_stmt *mStatement;
 145   nsRefPtr<BindingParamsArray> mParamsArray;
 146
 147   /**
 148    * We hold onto a reference of the statement's owner so it doesn't get
 149    * destroyed out from under us.
 150    */
 151   nsCOMPtr<StorageBaseStatementInternal> mStatementOwner;
 152 };
 153
 154 } // namespace storage
 155 } // namespace mozilla
 156
 157 #endif // mozStorageStatementData_h