Reuse the hash value inside identifier to hash them

Hashing on the pointer value of an identifier doesn't
really make sense. We already have a good hash value
for the identifier, so let's re-use it. In addition, this
allows to look up strings that aren't identifiers.

Change-Id: I9bdb4aa89ae36410f24b3e58c641339e115e4c5f
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

3 files changed, 24 insertions, 20 deletions

diff --git a/src/qml/qml/v4/qv4identifier.cpp b/src/qml/qml/v4/qv4identifier.cpp
index 1a078bb015..4e66e48194 100644
--- a/src/qml/qml/v4/qv4identifier.cpp
+++ b/src/qml/qml/v4/qv4identifier.cpp
@@ -87,7 +87,7 @@ IdentifierHashEntry *IdentifierHashBase::addEntry(const Identifier *identifier)
             const IdentifierHashEntry &e = d->entries[i];
             if (!e.identifier)
                 continue;
-            uint idx = Identifier::hash(e.identifier) % newAlloc;
+            uint idx = e.identifier->hashValue % newAlloc;
             while (newEntries[idx].identifier) {
                 ++idx;
                 idx %= newAlloc;
@@ -99,7 +99,7 @@ IdentifierHashEntry *IdentifierHashBase::addEntry(const Identifier *identifier)
         d->alloc = newAlloc;
     }
 
-    uint idx = Identifier::hash(identifier) % d->alloc;
+    uint idx = identifier->hashValue % d->alloc;
     while (d->entries[idx].identifier) {
         Q_ASSERT(d->entries[idx].identifier != identifier);
         ++idx;
@@ -116,12 +116,12 @@ const IdentifierHashEntry *IdentifierHashBase::lookup(const Identifier *identifi
         return 0;
     assert(d->entries);
 
-    uint idx = Identifier::hash(identifier) % d->alloc;
+    uint idx = identifier->hashValue % d->alloc;
     while (1) {
-        if (d->entries[idx].identifier == identifier)
-            return d->entries + idx;
         if (!d->entries[idx].identifier)
             return 0;
+        if (d->entries[idx].identifier == identifier)
+            return d->entries + idx;
         ++idx;
         idx %= d->alloc;
     }
@@ -131,14 +131,27 @@ const IdentifierHashEntry *IdentifierHashBase::lookup(const QString &str) const
 {
     if (!d)
         return 0;
-    return lookup(d->identifierTable->identifier(str));
+    assert(d->entries);
+
+    uint hash = String::createHashValue(str.constData(), str.length());
+    uint idx = hash % d->alloc;
+    while (1) {
+        if (!d->entries[idx].identifier)
+            return 0;
+        if (d->entries[idx].identifier->string == str)
+            return d->entries + idx;
+        ++idx;
+        idx %= d->alloc;
+    }
 }
 
 const IdentifierHashEntry *IdentifierHashBase::lookup(String *str) const
 {
     if (!d)
         return 0;
-    return lookup(d->identifierTable->identifier(str));
+    if (str->identifier)
+        return lookup(str->identifier);
+    return lookup(str->toQString());
 }
 
 const Identifier *IdentifierHashBase::toIdentifier(const QString &str) const
diff --git a/src/qml/qml/v4/qv4identifier_p.h b/src/qml/qml/v4/qv4identifier_p.h
index 35f4d17b05..250f4bece0 100644
--- a/src/qml/qml/v4/qv4identifier_p.h
+++ b/src/qml/qml/v4/qv4identifier_p.h
@@ -55,15 +55,6 @@ struct Identifier
 {
     QString string;
     uint hashValue;
-
-    static inline uint hash(const QV4::Identifier *id)
-    {
-        quintptr h = (quintptr)id;
-        if (sizeof(quintptr) == sizeof(uint))
-            return h ^ (h >> 8);
-        else
-            return (uint)(h ^ (h >> 8) ^ (h >> 32));
-    }
 };
 
 
diff --git a/src/qml/qml/v4/qv4internalclass.cpp b/src/qml/qml/v4/qv4internalclass.cpp
index 043e6238a0..635b796dd8 100644
--- a/src/qml/qml/v4/qv4internalclass.cpp
+++ b/src/qml/qml/v4/qv4internalclass.cpp
@@ -50,7 +50,7 @@ QT_BEGIN_NAMESPACE
 
 uint QV4::qHash(const QV4::InternalClassTransition &t, uint)
 {
-    return Identifier::hash(t.id) ^ t.flags;
+    return t.id->hashValue ^ t.flags;
 }
 
 using namespace QV4;
@@ -91,7 +91,7 @@ void PropertyHash::addEntry(const PropertyHash::Entry &entry, int classSize)
             const Entry &e = d->entries[i];
             if (!e.identifier || e.index >= classSize)
                 continue;
-            uint idx = Identifier::hash(e.identifier) % dd->alloc;
+            uint idx = e.identifier->hashValue % dd->alloc;
             while (dd->entries[idx].identifier) {
                 ++idx;
                 idx %= dd->alloc;
@@ -104,7 +104,7 @@ void PropertyHash::addEntry(const PropertyHash::Entry &entry, int classSize)
         d = dd;
     }
 
-    uint idx = Identifier::hash(entry.identifier) % d->alloc;
+    uint idx = entry.identifier->hashValue % d->alloc;
     while (d->entries[idx].identifier) {
         ++idx;
         idx %= d->alloc;
@@ -117,7 +117,7 @@ uint PropertyHash::lookup(const Identifier *identifier) const
 {
     assert(d->entries);
 
-    uint idx = Identifier::hash(identifier) % d->alloc;
+    uint idx = identifier->hashValue % d->alloc;
     while (1) {
         if (d->entries[idx].identifier == identifier)
             return d->entries[idx].index;