QHostAddress: make it implictly shared

QHostAddress is one of the few classes in Qt which is pimpl'd but not
implictly shared, making it suprisingly expensive to copy around, return
by value and so on. Being pimpl'd it is also still lacking a move
constructor, like most of such types in Qt.

Remove a bit of the surprise factor and make it implictly shared. In
practice this means making it eagerly parse host addresses from strings.

Since it was entirely implemented out of line, replacing it with a
implictly shared implementation is binary compatible.

[ChangeLog][QtNetwork][QHostAddress] QHostAddress is now implicitly
shared.

Change-Id: Ia7ff94efcb74e7321b7607cd690c5c162f685605
Reviewed-by: Richard J. Moore <rich@kde.org>

1 files changed, 25 insertions, 39 deletions

diff --git a/src/network/kernel/qhostaddress.cpp b/src/network/kernel/qhostaddress.cpp
index 2b5fde2a76..1a960e4f7d 100644
--- a/src/network/kernel/qhostaddress.cpp
+++ b/src/network/kernel/qhostaddress.cpp
@@ -63,12 +63,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#define QT_ENSURE_PARSED(a) \
-    do { \
-        if (!(a)->d->isParsed) \
-            (a)->d->parse(); \
-    } while (0)
-
 #ifdef Q_OS_WIN
 // sockaddr_in6 size changed between old and new SDK
 // Only the new version is the correct one, so always
@@ -100,7 +94,7 @@ typedef struct {
 #endif
 
 
-class QHostAddressPrivate
+class QHostAddressPrivate : public QSharedData
 {
 public:
     QHostAddressPrivate();
@@ -109,10 +103,9 @@ public:
     void setAddress(const quint8 *a_);
     void setAddress(const Q_IPV6ADDR &a_);
 
-    bool parse();
+    bool parse(const QString &ipString);
     void clear();
 
-    QString ipString;
     QString scopeId;
 
     union {
@@ -122,13 +115,12 @@ public:
     };
     quint32 a;    // IPv4 address
     qint8 protocol;
-    bool isParsed;
 
     friend class QHostAddress;
 };
 
 QHostAddressPrivate::QHostAddressPrivate()
-    : a(0), protocol(QAbstractSocket::UnknownNetworkLayerProtocol), isParsed(true)
+    : a(0), protocol(QAbstractSocket::UnknownNetworkLayerProtocol)
 {
     memset(&a6, 0, sizeof(a6));
 }
@@ -137,7 +129,6 @@ void QHostAddressPrivate::setAddress(quint32 a_)
 {
     a = a_;
     protocol = QAbstractSocket::IPv4Protocol;
-    isParsed = true;
 
     //create mapped address, except for a_ == 0 (any)
     a6_64.c[0] = 0;
@@ -187,7 +178,6 @@ static bool convertToIpv4(quint32& a, const Q_IPV6ADDR &a6, const QHostAddress::
 void QHostAddressPrivate::setAddress(const quint8 *a_)
 {
     protocol = QAbstractSocket::IPv6Protocol;
-    isParsed = true;
     memcpy(a6.c, a_, sizeof(a6));
     a = 0;
     convertToIpv4(a, a6, (QHostAddress::ConvertV4MappedToIPv4
@@ -212,9 +202,8 @@ static bool parseIp6(const QString &address, QIPAddressUtils::IPv6Address &addr,
     return QIPAddressUtils::parseIp6(addr, tmp.constBegin(), tmp.constEnd()) == 0;
 }
 
-Q_NEVER_INLINE bool QHostAddressPrivate::parse()
+bool QHostAddressPrivate::parse(const QString &ipString)
 {
-    isParsed = true;
     protocol = QAbstractSocket::UnknownNetworkLayerProtocol;
     QString a = ipString.simplified();
     if (a.isEmpty())
@@ -242,13 +231,13 @@ void QHostAddressPrivate::clear()
 {
     a = 0;
     protocol = QAbstractSocket::UnknownNetworkLayerProtocol;
-    isParsed = true;
     memset(&a6, 0, sizeof(a6));
 }
 
 
 bool QNetmaskAddress::setAddress(const QString &address)
 {
+    d.detach();
     length = -1;
     QHostAddress other;
     return other.setAddress(address) && setAddress(other);
@@ -256,6 +245,8 @@ bool QNetmaskAddress::setAddress(const QString &address)
 
 bool QNetmaskAddress::setAddress(const QHostAddress &address)
 {
+    d.detach();
+
     static const quint8 zeroes[16] = { 0 };
     union {
         quint32 v4;
@@ -343,6 +334,7 @@ int QNetmaskAddress::prefixLength() const
 
 void QNetmaskAddress::setPrefixLength(QAbstractSocket::NetworkLayerProtocol proto, int newLength)
 {
+    d.detach();
     length = newLength;
     if (length < 0 || length > (proto == QAbstractSocket::IPv4Protocol ? 32 :
                                 proto == QAbstractSocket::IPv6Protocol ? 128 : -1)) {
@@ -371,6 +363,7 @@ void QNetmaskAddress::setPrefixLength(QAbstractSocket::NetworkLayerProtocol prot
     \class QHostAddress
     \brief The QHostAddress class provides an IP address.
     \ingroup network
+    \ingroup shared
     \inmodule QtNetwork
 
     This class holds an IPv4 or IPv6 address in a platform- and
@@ -478,8 +471,7 @@ QHostAddress::QHostAddress(const Q_IPV6ADDR &ip6Addr)
 QHostAddress::QHostAddress(const QString &address)
     : d(new QHostAddressPrivate)
 {
-    d->ipString = address;
-    d->isParsed = false;
+    d->parse(address);
 }
 
 /*!
@@ -507,7 +499,7 @@ QHostAddress::QHostAddress(const struct sockaddr *sockaddr)
     Constructs a copy of the given \a address.
 */
 QHostAddress::QHostAddress(const QHostAddress &address)
-    : d(new QHostAddressPrivate(*address.d.data()))
+    : d(address.d)
 {
 }
 
@@ -576,7 +568,7 @@ QHostAddress::~QHostAddress()
 */
 QHostAddress &QHostAddress::operator=(const QHostAddress &address)
 {
-    *d.data() = *address.d.data();
+    d = address.d;
     return *this;
 }
 
@@ -627,6 +619,7 @@ QHostAddress &QHostAddress::operator=(SpecialAddress address)
 */
 void QHostAddress::clear()
 {
+    d.detach();
     d->clear();
 }
 
@@ -635,6 +628,7 @@ void QHostAddress::clear()
 */
 void QHostAddress::setAddress(quint32 ip4Addr)
 {
+    d.detach();
     d->setAddress(ip4Addr);
 }
 
@@ -648,6 +642,7 @@ void QHostAddress::setAddress(quint32 ip4Addr)
 */
 void QHostAddress::setAddress(quint8 *ip6Addr)
 {
+    d.detach();
     d->setAddress(ip6Addr);
 }
 
@@ -662,6 +657,7 @@ void QHostAddress::setAddress(quint8 *ip6Addr)
 */
 void QHostAddress::setAddress(const quint8 *ip6Addr)
 {
+    d.detach();
     d->setAddress(ip6Addr);
 }
 
@@ -672,6 +668,7 @@ void QHostAddress::setAddress(const quint8 *ip6Addr)
 */
 void QHostAddress::setAddress(const Q_IPV6ADDR &ip6Addr)
 {
+    d.detach();
     d->setAddress(ip6Addr);
 }
 
@@ -685,8 +682,8 @@ void QHostAddress::setAddress(const Q_IPV6ADDR &ip6Addr)
 */
 bool QHostAddress::setAddress(const QString &address)
 {
-    d->ipString = address;
-    return d->parse();
+    d.detach();
+    return d->parse(address);
 }
 
 /*!
@@ -699,6 +696,7 @@ bool QHostAddress::setAddress(const QString &address)
 */
 void QHostAddress::setAddress(const struct sockaddr *sockaddr)
 {
+    d.detach();
 #ifndef Q_OS_WINRT
     clear();
     if (sockaddr->sa_family == AF_INET)
@@ -746,7 +744,6 @@ quint32 QHostAddress::toIPv4Address() const
 */
 quint32 QHostAddress::toIPv4Address(bool *ok) const
 {
-    QT_ENSURE_PARSED(this);
     quint32 dummy;
     if (ok)
         *ok = d->protocol == QAbstractSocket::IPv4Protocol || d->protocol == QAbstractSocket::AnyIPProtocol
@@ -761,7 +758,6 @@ quint32 QHostAddress::toIPv4Address(bool *ok) const
 */
 QAbstractSocket::NetworkLayerProtocol QHostAddress::protocol() const
 {
-    QT_ENSURE_PARSED(this);
     return QAbstractSocket::NetworkLayerProtocol(d->protocol);
 }
 
@@ -781,7 +777,6 @@ QAbstractSocket::NetworkLayerProtocol QHostAddress::protocol() const
 */
 Q_IPV6ADDR QHostAddress::toIPv6Address() const
 {
-    QT_ENSURE_PARSED(this);
     return d->a6;
 }
 
@@ -797,7 +792,6 @@ Q_IPV6ADDR QHostAddress::toIPv6Address() const
 */
 QString QHostAddress::toString() const
 {
-    QT_ENSURE_PARSED(this);
     QString s;
     if (d->protocol == QAbstractSocket::IPv4Protocol
         || d->protocol == QAbstractSocket::AnyIPProtocol) {
@@ -849,7 +843,6 @@ QString QHostAddress::toString() const
 */
 QString QHostAddress::scopeId() const
 {
-    QT_ENSURE_PARSED(this);
     return (d->protocol == QAbstractSocket::IPv6Protocol) ? d->scopeId : QString();
 }
 
@@ -867,7 +860,7 @@ QString QHostAddress::scopeId() const
 */
 void QHostAddress::setScopeId(const QString &id)
 {
-    QT_ENSURE_PARSED(this);
+    d.detach();
     if (d->protocol == QAbstractSocket::IPv6Protocol)
         d->scopeId = id;
 }
@@ -880,7 +873,7 @@ void QHostAddress::setScopeId(const QString &id)
 */
 bool QHostAddress::operator==(const QHostAddress &other) const
 {
-    return isEqual(other, StrictConversion);
+    return d == other.d || isEqual(other, StrictConversion);
 }
 
 /*!
@@ -897,8 +890,8 @@ bool QHostAddress::operator==(const QHostAddress &other) const
  */
 bool QHostAddress::isEqual(const QHostAddress &other, ConversionMode mode) const
 {
-    QT_ENSURE_PARSED(this);
-    QT_ENSURE_PARSED(&other);
+    if (d == other.d)
+        return true;
 
     if (d->protocol == QAbstractSocket::IPv4Protocol) {
         switch (other.d->protocol) {
@@ -950,7 +943,6 @@ bool QHostAddress::isEqual(const QHostAddress &other, ConversionMode mode) const
 */
 bool QHostAddress::operator ==(SpecialAddress other) const
 {
-    QT_ENSURE_PARSED(this);
     quint32 ip4 = INADDR_ANY;
     switch (other) {
     case Null:
@@ -990,7 +982,6 @@ bool QHostAddress::operator ==(SpecialAddress other) const
 */
 bool QHostAddress::isNull() const
 {
-    QT_ENSURE_PARSED(this);
     return d->protocol == QAbstractSocket::UnknownNetworkLayerProtocol;
 }
 
@@ -1015,7 +1006,6 @@ bool QHostAddress::isNull() const
 */
 bool QHostAddress::isInSubnet(const QHostAddress &subnet, int netmask) const
 {
-    QT_ENSURE_PARSED(this);
     if (subnet.protocol() != d->protocol || netmask < 0)
         return false;
 
@@ -1198,7 +1188,6 @@ QPair<QHostAddress, int> QHostAddress::parseSubnet(const QString &subnet)
 */
 bool QHostAddress::isLoopback() const
 {
-    QT_ENSURE_PARSED(this);
     if ((d->a & 0xFF000000) == 0x7F000000)
         return true; // v4 range (including IPv6 wrapped IPv4 addresses)
     if (d->protocol == QAbstractSocket::IPv6Protocol) {
@@ -1224,7 +1213,6 @@ bool QHostAddress::isLoopback() const
 */
 bool QHostAddress::isMulticast() const
 {
-    QT_ENSURE_PARSED(this);
     if ((d->a & 0xF0000000) == 0xE0000000)
         return true; // 224.0.0.0-239.255.255.255 (including v4-mapped IPv6 addresses)
     if (d->protocol == QAbstractSocket::IPv6Protocol)
@@ -1245,10 +1233,8 @@ QDebug operator<<(QDebug d, const QHostAddress &address)
 }
 #endif
 
-uint qHash(const QHostAddress &key, uint seed)
+uint qHash(const QHostAddress &key, uint seed) Q_DECL_NOTHROW
 {
-    // both lines might throw
-    QT_ENSURE_PARSED(&key);
     return qHashBits(key.d->a6.c, 16, seed);
 }