qsql: apply Qt's PIMPL idiom to Q*ResultPrivate

QResult and QResultPrivate are not derived from QObject and
QObjectPrivate respectively, but can still benefit from Qt's
PIMPL idiom. There are several interrelated aspects to this:

  - Base all driver ResultPrivate classes on QResultPrivate.
    Previously, each level in the Result hierarchy tended to keep
    its own private data class.

  - The ResultPrivate class initializes its own Result (q_ptr)
    and Driver members. This ensures that these pointers are
    correctly set in time for the ResultPrivate constructors
    and Result constructors. This is more efficient and makes
    it a lot easier to follow what's being allocated, initialized,
    and cleaned-up.

  - Use macros Q_DECLARE_PRIVATE, Q_DECLARE_PUBLIC, Q_D, and
    Q_Q for access to and from ResultPrivate objects.

  - ResultPrivate classes refer frequently to their counterpart
    DriverPrivate. Various patterns were used to do this. Now
    Q_DECLARE_SQLDRIVER_PRIVATE arranges this uniformly while
    hiding ugly casting. It creates a public method in the
    ResultPrivate returning the correctly typed pointer to the
    corresponding DriverPrivate object. Since the method is public,
    the Result class and helper classes and functions can also use it.

  - The explicit const is removed from QResultPrivate::sqldriver,
    even though it is treated (mostly) like a const within the
    context of Result and ResultPrivate. This is the same pattern
    seen in Qt's PIMPL idiom. The macro created getter methods
    take care of const.

  - qsql_mysql was using a signal/slot connection to zero its own
    copy of the driver pointer when the driver was destroyed. This is
    no longer necessary.

Change-Id: Ida4933bc92fb3e9a05ea4b53b48085894734e36e
Reviewed-by: Israel Lins Albuquerque <israelins85@yahoo.com.br>
Reviewed-by: Mark Brand <mabrand@mabrand.nl>

1 files changed, 69 insertions, 55 deletions

diff --git a/src/sql/drivers/oci/qsql_oci.cpp b/src/sql/drivers/oci/qsql_oci.cpp
index 3b86c63461..eb35c91e88 100644
--- a/src/sql/drivers/oci/qsql_oci.cpp
+++ b/src/sql/drivers/oci/qsql_oci.cpp
@@ -155,16 +155,37 @@ QT_BEGIN_INCLUDE_NAMESPACE
 Q_DECLARE_METATYPE(QOCIRowIdPointer)
 QT_END_INCLUDE_NAMESPACE
 
+class QOCIDriverPrivate : public QSqlDriverPrivate
+{
+    Q_DECLARE_PUBLIC(QOCIDriver)
+
+public:
+    QOCIDriverPrivate();
+
+    OCIEnv *env;
+    OCISvcCtx *svc;
+    OCIServer *srvhp;
+    OCISession *authp;
+    OCIError *err;
+    bool transaction;
+    int serverVersion;
+    int prefetchRows;
+    int prefetchMem;
+    QString user;
+
+    void allocErrorHandle();
+};
+
 class QOCICols;
-struct QOCIResultPrivate;
+class QOCIResultPrivate;
 
 class QOCIResult: public QSqlCachedResult
 {
+    Q_DECLARE_PRIVATE(QOCIResult)
     friend class QOCIDriver;
-    friend struct QOCIResultPrivate;
     friend class QOCICols;
 public:
-    QOCIResult(const QOCIDriver * db, const QOCIDriverPrivate* p);
+    QOCIResult(const QOCIDriver *db);
     ~QOCIResult();
     bool prepare(const QString &query) Q_DECL_OVERRIDE;
     bool exec() Q_DECL_OVERRIDE;
@@ -179,18 +200,17 @@ protected:
     QVariant lastInsertId() const Q_DECL_OVERRIDE;
     bool execBatch(bool arrayBind = false) Q_DECL_OVERRIDE;
     void virtual_hook(int id, void *data) Q_DECL_OVERRIDE;
-
-private:
-    QOCIResultPrivate *d;
 };
 
-struct QOCIResultPrivate
+class QOCIResultPrivate: public QSqlCachedResultPrivate
 {
-    QOCIResultPrivate(QOCIResult *result, const QOCIDriverPrivate *driver);
+public:
+    Q_DECLARE_PUBLIC(QOCIResult)
+    Q_DECLARE_SQLDRIVER_PRIVATE(QOCIDriver)
+    QOCIResultPrivate(QOCIResult *q, const QOCIDriver *drv);
     ~QOCIResultPrivate();
 
     QOCICols *cols;
-    QOCIResult *q;
     OCIEnv *env;
     OCIError *err;
     OCISvcCtx *&svc;
@@ -207,9 +227,9 @@ struct QOCIResultPrivate
     void outValues(QVector<QVariant> &values, IndicatorArray &indicators,
                    QList<QByteArray> &tmpStorage);
     inline bool isOutValue(int i) const
-    { return q->bindValueType(i) & QSql::Out; }
+    { Q_Q(const QOCIResult); return q->bindValueType(i) & QSql::Out; }
     inline bool isBinaryValue(int i) const
-    { return q->bindValueType(i) & QSql::Binary; }
+    { Q_Q(const QOCIResult); return q->bindValueType(i) & QSql::Binary; }
 
     void setCharset(dvoid* handle, ub4 type) const
     {
@@ -485,25 +505,6 @@ void QOCIResultPrivate::outValues(QVector<QVariant> &values, IndicatorArray &ind
 }
 
 
-class QOCIDriverPrivate : public QSqlDriverPrivate
-{
-public:
-    QOCIDriverPrivate();
-
-    OCIEnv *env;
-    OCISvcCtx *svc;
-    OCIServer *srvhp;
-    OCISession *authp;
-    OCIError *err;
-    bool transaction;
-    int serverVersion;
-    int prefetchRows;
-    int prefetchMem;
-    QString user;
-
-    void allocErrorHandle();
-};
-
 QOCIDriverPrivate::QOCIDriverPrivate()
     : QSqlDriverPrivate(), env(0), svc(0), srvhp(0), authp(0), err(0), transaction(false),
       serverVersion(-1), prefetchRows(-1), prefetchMem(QOCI_PREFETCH_MEM)
@@ -1221,7 +1222,7 @@ OraFieldInfo QOCICols::qMakeOraField(const QOCIResultPrivate* p, OCIParam* param
     if (r != 0)
         qOraWarning("qMakeOraField:", p->err);
 
-    type = qDecodeOCIType(colType, p->q->numericalPrecisionPolicy());
+    type = qDecodeOCIType(colType, p->q_func()->numericalPrecisionPolicy());
 
     if (type == QVariant::Int) {
         if (colLength == 22 && colPrecision == 0 && colScale == 0)
@@ -1232,16 +1233,16 @@ OraFieldInfo QOCICols::qMakeOraField(const QOCIResultPrivate* p, OCIParam* param
 
     // bind as double if the precision policy asks for it
     if (((colType == SQLT_FLT) || (colType == SQLT_NUM))
-            && (p->q->numericalPrecisionPolicy() == QSql::LowPrecisionDouble)) {
+            && (p->q_func()->numericalPrecisionPolicy() == QSql::LowPrecisionDouble)) {
         type = QVariant::Double;
     }
 
     // bind as int32 or int64 if the precision policy asks for it
     if ((colType == SQLT_NUM) || (colType == SQLT_VNU) || (colType == SQLT_UIN)
             || (colType == SQLT_INT)) {
-        if (p->q->numericalPrecisionPolicy() == QSql::LowPrecisionInt64)
+        if (p->q_func()->numericalPrecisionPolicy() == QSql::LowPrecisionInt64)
             type = QVariant::LongLong;
-        else if (p->q->numericalPrecisionPolicy() == QSql::LowPrecisionInt32)
+        else if (p->q_func()->numericalPrecisionPolicy() == QSql::LowPrecisionInt32)
             type = QVariant::Int;
     }
 
@@ -1336,7 +1337,7 @@ bool QOCICols::execBatch(QOCIResultPrivate *d, QVector<QVariant> &boundValues, b
 
             if (r != OCI_SUCCESS && r != OCI_SUCCESS_WITH_INFO) {
                 qOraWarning("QOCIPrivate::execBatch: unable to bind column:", d->err);
-                d->q->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
+                d->q_func()->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
                          "Unable to bind column for batch execute"),
                          QSqlError::StatementError, d->err));
                 return false;
@@ -1530,7 +1531,7 @@ bool QOCICols::execBatch(QOCIResultPrivate *d, QVector<QVariant> &boundValues, b
 
         if (r != OCI_SUCCESS && r != OCI_SUCCESS_WITH_INFO) {
             qOraWarning("QOCIPrivate::execBatch: unable to bind column:", d->err);
-            d->q->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
+            d->q_func()->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
                      "Unable to bind column for batch execute"),
                      QSqlError::StatementError, d->err));
             return false;
@@ -1545,7 +1546,7 @@ bool QOCICols::execBatch(QOCIResultPrivate *d, QVector<QVariant> &boundValues, b
 
         if (r != OCI_SUCCESS && r != OCI_SUCCESS_WITH_INFO) {
             qOraWarning("QOCIPrivate::execBatch: unable to bind column:", d->err);
-            d->q->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
+            d->q_func()->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
                      "Unable to bind column for batch execute"),
                      QSqlError::StatementError, d->err));
             return false;
@@ -1560,7 +1561,7 @@ bool QOCICols::execBatch(QOCIResultPrivate *d, QVector<QVariant> &boundValues, b
 
     if (r != OCI_SUCCESS && r != OCI_SUCCESS_WITH_INFO) {
         qOraWarning("QOCIPrivate::execBatch: unable to execute batch statement:", d->err);
-        d->q->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
+        d->q_func()->setLastError(qMakeError(QCoreApplication::translate("QOCIResult",
                         "Unable to execute batch statement"),
                         QSqlError::StatementError, d->err));
         return false;
@@ -1635,9 +1636,9 @@ bool QOCICols::execBatch(QOCIResultPrivate *d, QVector<QVariant> &boundValues, b
         }
     }
 
-    d->q->setSelect(false);
-    d->q->setAt(QSql::BeforeFirstRow);
-    d->q->setActive(true);
+    d->q_func()->setSelect(false);
+    d->q_func()->setAt(QSql::BeforeFirstRow);
+    d->q_func()->setActive(true);
 
     return true;
 }
@@ -1752,12 +1753,12 @@ void QOCICols::getValues(QVector<QVariant> &v, int index)
         case QVariant::Double:
         case QVariant::Int:
         case QVariant::LongLong:
-            if (d->q->numericalPrecisionPolicy() != QSql::HighPrecision) {
-                if ((d->q->numericalPrecisionPolicy() == QSql::LowPrecisionDouble)
+            if (d->q_func()->numericalPrecisionPolicy() != QSql::HighPrecision) {
+                if ((d->q_func()->numericalPrecisionPolicy() == QSql::LowPrecisionDouble)
                         && (fld.typ == QVariant::Double)) {
                     v[index + i] = *reinterpret_cast<double *>(fld.data);
                     break;
-                } else if ((d->q->numericalPrecisionPolicy() == QSql::LowPrecisionInt64)
+                } else if ((d->q_func()->numericalPrecisionPolicy() == QSql::LowPrecisionInt64)
                         && (fld.typ == QVariant::LongLong)) {
                     qint64 qll = 0;
                     int r = OCINumberToInt(d->err, reinterpret_cast<OCINumber *>(fld.data), sizeof(qint64),
@@ -1767,7 +1768,7 @@ void QOCICols::getValues(QVector<QVariant> &v, int index)
                     else
                         v[index + i] = QVariant();
                     break;
-                } else if ((d->q->numericalPrecisionPolicy() == QSql::LowPrecisionInt32)
+                } else if ((d->q_func()->numericalPrecisionPolicy() == QSql::LowPrecisionInt32)
                         && (fld.typ == QVariant::Int)) {
                     v[index + i] = *reinterpret_cast<int *>(fld.data);
                     break;
@@ -1790,10 +1791,17 @@ void QOCICols::getValues(QVector<QVariant> &v, int index)
     }
 }
 
-QOCIResultPrivate::QOCIResultPrivate(QOCIResult *result, const QOCIDriverPrivate *driver)
-    : cols(0), q(result), env(driver->env), err(0), svc(const_cast<OCISvcCtx*&>(driver->svc)),
-      sql(0), transaction(driver->transaction), serverVersion(driver->serverVersion),
-      prefetchRows(driver->prefetchRows), prefetchMem(driver->prefetchMem)
+QOCIResultPrivate::QOCIResultPrivate(QOCIResult *q, const QOCIDriver *drv)
+    : QSqlCachedResultPrivate(q, drv),
+      cols(0),
+      env(drv_d_func()->env),
+      err(0),
+      svc(const_cast<OCISvcCtx*&>(drv_d_func()->svc)),
+      sql(0),
+      transaction(drv_d_func()->transaction),
+      serverVersion(drv_d_func()->serverVersion),
+      prefetchRows(drv_d_func()->prefetchRows),
+      prefetchMem(drv_d_func()->prefetchMem)
 {
     int r = OCIHandleAlloc(env,
                            reinterpret_cast<void **>(&err),
@@ -1816,24 +1824,24 @@ QOCIResultPrivate::~QOCIResultPrivate()
 
 ////////////////////////////////////////////////////////////////////////////
 
-QOCIResult::QOCIResult(const QOCIDriver * db, const QOCIDriverPrivate* p)
-    : QSqlCachedResult(db)
+QOCIResult::QOCIResult(const QOCIDriver *db)
+    : QSqlCachedResult(*new QOCIResultPrivate(this, db))
 {
-    d = new QOCIResultPrivate(this, p);
 }
 
 QOCIResult::~QOCIResult()
 {
+    Q_D(QOCIResult);
     if (d->sql) {
         int r = OCIHandleFree(d->sql, OCI_HTYPE_STMT);
         if (r != 0)
             qWarning("~QOCIResult: unable to free statement handle");
     }
-    delete d;
 }
 
 QVariant QOCIResult::handle() const
 {
+    Q_D(const QOCIResult);
     return QVariant::fromValue(d->sql);
 }
 
@@ -1846,6 +1854,7 @@ bool QOCIResult::reset (const QString& query)
 
 bool QOCIResult::gotoNext(QSqlCachedResult::ValueCache &values, int index)
 {
+    Q_D(QOCIResult);
     if (at() == QSql::AfterLastRow)
         return false;
 
@@ -1905,6 +1914,7 @@ int QOCIResult::size()
 
 int QOCIResult::numRowsAffected()
 {
+    Q_D(QOCIResult);
     int rowCount;
     OCIAttrGet(d->sql,
                 OCI_HTYPE_STMT,
@@ -1917,6 +1927,7 @@ int QOCIResult::numRowsAffected()
 
 bool QOCIResult::prepare(const QString& query)
 {
+    Q_D(QOCIResult);
     int r = 0;
     QSqlResult::prepare(query);
 
@@ -1962,6 +1973,7 @@ bool QOCIResult::prepare(const QString& query)
 
 bool QOCIResult::exec()
 {
+    Q_D(QOCIResult);
     int r = 0;
     ub2 stmtType=0;
     ub4 iters;
@@ -2043,6 +2055,7 @@ bool QOCIResult::exec()
 
 QSqlRecord QOCIResult::record() const
 {
+    Q_D(const QOCIResult);
     QSqlRecord inf;
     if (!isActive() || !isSelect() || !d->cols)
         return inf;
@@ -2051,6 +2064,7 @@ QSqlRecord QOCIResult::record() const
 
 QVariant QOCIResult::lastInsertId() const
 {
+    Q_D(const QOCIResult);
     if (isActive()) {
         QOCIRowIdPointer ptr(new QOCIRowId(d->env));
 
@@ -2064,6 +2078,7 @@ QVariant QOCIResult::lastInsertId() const
 
 bool QOCIResult::execBatch(bool arrayBind)
 {
+    Q_D(QOCIResult);
     QOCICols::execBatch(d, boundValues(), arrayBind);
     resetBindCount();
     return lastError().type() == QSqlError::NoError;
@@ -2301,8 +2316,7 @@ void QOCIDriver::close()
 
 QSqlResult *QOCIDriver::createResult() const
 {
-    Q_D(const QOCIDriver);
-    return new QOCIResult(this, d);
+    return new QOCIResult(this);
 }
 
 bool QOCIDriver::beginTransaction()