Reuse the index in the object for existing keys

This makes the code slightly more performant when
inserting items into the object.

Change-Id: I316929b0f23d4f17f3934b9dd8eb58bb6236777f
Reviewed-by: Jamey Hicks <jamey.hicks@nokia.com>

3 files changed, 29 insertions, 10 deletions

diff --git a/src/qjson.cpp b/src/qjson.cpp
index 8261703..b99640d 100644
--- a/src/qjson.cpp
+++ b/src/qjson.cpp
@@ -165,17 +165,23 @@ int Object::indexOf(const QString &key)
 {
     for (int i = 0; i < (int)length; ++i) {
         Entry *e = entryAt(i);
-        if (e->value.latinKey) {
-            if (e->shallowLatin1Key() == key)
-                return i;
-        } else {
-            if (e->shallowKey() == key)
-                return i;
-        }
+        if (e->matchesKey(key))
+            return i;
     }
     return -1;
 }
 
+int Object::insertKey(const QString &key)
+{
+    // assumes we already have space for another entry in the index table
+    for (int i = 0; i < (int)length; ++i) {
+        Entry *e = entryAt(i);
+        if (e->matchesKey(key))
+            return i;
+    }
+    return length;
+}
+
 
 bool Object::isValid() const
 {
@@ -211,6 +217,15 @@ bool Array::isValid() const
 }
 
 
+bool Entry::matchesKey(const QString &key)
+{
+    if (value.latinKey)
+        return (shallowLatin1Key() == key);
+    else
+        return (shallowKey() == key);
+}
+
+
 int Value::usedStorage(const Base *b) const
 {
     int s = 0;
diff --git a/src/qjson_p.h b/src/qjson_p.h
index f0aa5a3..9a49948 100644
--- a/src/qjson_p.h
+++ b/src/qjson_p.h
@@ -322,6 +322,7 @@ struct Object : public Base
         return reinterpret_cast<Entry *>(((char *)this) + table()[i]);
     }
     int indexOf(const QString &key);
+    int insertKey(const QString &key);
 
     bool isValid() const;
 };
@@ -421,6 +422,8 @@ struct Entry {
         int length = *(int *) ((const char *)this + sizeof(Entry));
         return QString((const QChar *)keyData(), length);
     }
+
+    bool matchesKey(const QString &key);
 };
 
 struct Header {
diff --git a/src/qjsonobject.cpp b/src/qjsonobject.cpp
index 5eefd1c..e75dccc 100644
--- a/src/qjsonobject.cpp
+++ b/src/qjsonobject.cpp
@@ -187,10 +187,11 @@ void JsonObject::insert(const QString &key, const JsonValue &value)
     if (!o->length)
         o->tableOffset = sizeof(Object);
 
-    // ### this is crude!
-    remove(key);
 
-    int pos = o->length;
+    int pos = o->insertKey(key);
+    if (pos < o->length)
+        ++d->compactionCounter;
+
     o->reserveSpace(requiredSize, pos, 1);
     Entry *e = o->entryAt(pos);
     e->value.type = value.t;