1 files changed, 286 insertions, 0 deletions
diff --git a/dom/base/nsPropertyTable.cpp b/dom/base/nsPropertyTable.cpp
new file mode 100644
index 0000000000..63343a8141
--- /dev/null
+++ b/dom/base/nsPropertyTable.cpp
@@ -0,0 +1,286 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * nsPropertyTable allows a set of arbitrary key/value pairs to be stored
+ * for any number of nodes, in a global hashtable rather than on the nodes
+ * themselves.  Nodes can be any type of object; the hashtable keys are
+ * nsAtom pointers, and the values are void pointers.
+ */
+
+#include "nsPropertyTable.h"
+
+#include "mozilla/MemoryReporting.h"
+
+#include "PLDHashTable.h"
+#include "nsError.h"
+#include "nsAtom.h"
+
+struct PropertyListMapEntry : public PLDHashEntryHdr {
+  const void* key;
+  void* value;
+};
+
+//----------------------------------------------------------------------
+
+class nsPropertyTable::PropertyList {
+ public:
+  PropertyList(nsAtom* aName, NSPropertyDtorFunc aDtorFunc, void* aDtorData,
+               bool aTransfer);
+  ~PropertyList();
+
+  // Removes the property associated with the given object, and destroys
+  // the property value
+  bool RemovePropertyFor(nsPropertyOwner aObject);
+
+  // Destroy all remaining properties (without removing them)
+  void Destroy();
+
+  bool Equals(const nsAtom* aPropertyName) { return mName == aPropertyName; }
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
+
+  RefPtr<nsAtom> mName;          // property name
+  PLDHashTable mObjectValueMap;  // map of object/value pairs
+  NSPropertyDtorFunc mDtorFunc;  // property specific value dtor function
+  void* mDtorData;               // pointer to pass to dtor
+  bool mTransfer;                // whether to transfer in
+                                 // TransferOrRemoveAllPropertiesFor
+
+  PropertyList* mNext;
+};
+
+void nsPropertyTable::RemoveAllProperties() {
+  while (mPropertyList) {
+    PropertyList* tmp = mPropertyList;
+
+    mPropertyList = mPropertyList->mNext;
+    tmp->Destroy();
+    delete tmp;
+  }
+}
+
+void nsPropertyTable::RemoveAllPropertiesFor(nsPropertyOwner aObject) {
+  for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
+    prop->RemovePropertyFor(aObject);
+  }
+}
+
+nsresult nsPropertyTable::TransferOrRemoveAllPropertiesFor(
+    nsPropertyOwner aObject, nsPropertyTable& aOtherTable) {
+  nsresult rv = NS_OK;
+  for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
+    if (prop->mTransfer) {
+      auto entry = static_cast<PropertyListMapEntry*>(
+          prop->mObjectValueMap.Search(aObject));
+      if (entry) {
+        rv = aOtherTable.SetProperty(aObject, prop->mName, entry->value,
+                                     prop->mDtorFunc, prop->mDtorData,
+                                     prop->mTransfer);
+        if (NS_FAILED(rv)) {
+          RemoveAllPropertiesFor(aObject);
+          aOtherTable.RemoveAllPropertiesFor(aObject);
+          break;
+        }
+
+        prop->mObjectValueMap.RemoveEntry(entry);
+      }
+    } else {
+      prop->RemovePropertyFor(aObject);
+    }
+  }
+
+  return rv;
+}
+
+void nsPropertyTable::Enumerate(nsPropertyOwner aObject,
+                                NSPropertyFunc aCallback, void* aData) {
+  PropertyList* prop;
+  for (prop = mPropertyList; prop; prop = prop->mNext) {
+    auto entry = static_cast<PropertyListMapEntry*>(
+        prop->mObjectValueMap.Search(aObject));
+    if (entry) {
+      aCallback(const_cast<void*>(aObject.get()), prop->mName, entry->value,
+                aData);
+    }
+  }
+}
+
+void nsPropertyTable::EnumerateAll(NSPropertyFunc aCallBack, void* aData) {
+  for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
+    for (auto iter = prop->mObjectValueMap.ConstIter(); !iter.Done();
+         iter.Next()) {
+      auto entry = static_cast<PropertyListMapEntry*>(iter.Get());
+      aCallBack(const_cast<void*>(entry->key), prop->mName, entry->value,
+                aData);
+    }
+  }
+}
+
+void* nsPropertyTable::GetPropertyInternal(nsPropertyOwner aObject,
+                                           const nsAtom* aPropertyName,
+                                           bool aRemove, nsresult* aResult) {
+  MOZ_ASSERT(aPropertyName && aObject, "unexpected null param");
+  nsresult rv = NS_PROPTABLE_PROP_NOT_THERE;
+  void* propValue = nullptr;
+
+  PropertyList* propertyList = GetPropertyListFor(aPropertyName);
+  if (propertyList) {
+    auto entry = static_cast<PropertyListMapEntry*>(
+        propertyList->mObjectValueMap.Search(aObject));
+    if (entry) {
+      propValue = entry->value;
+      if (aRemove) {
+        // don't call propertyList->mDtorFunc.  That's the caller's job now.
+        propertyList->mObjectValueMap.RemoveEntry(entry);
+      }
+      rv = NS_OK;
+    }
+  }
+
+  if (aResult) *aResult = rv;
+
+  return propValue;
+}
+
+nsresult nsPropertyTable::SetPropertyInternal(
+    nsPropertyOwner aObject, nsAtom* aPropertyName, void* aPropertyValue,
+    NSPropertyDtorFunc aPropDtorFunc, void* aPropDtorData, bool aTransfer) {
+  MOZ_ASSERT(aPropertyName && aObject, "unexpected null param");
+
+  PropertyList* propertyList = GetPropertyListFor(aPropertyName);
+
+  if (propertyList) {
+    // Make sure the dtor function and data and the transfer flag match
+    if (aPropDtorFunc != propertyList->mDtorFunc ||
+        aPropDtorData != propertyList->mDtorData ||
+        aTransfer != propertyList->mTransfer) {
+      NS_WARNING("Destructor/data mismatch while setting property");
+      return NS_ERROR_INVALID_ARG;
+    }
+
+  } else {
+    propertyList = new PropertyList(aPropertyName, aPropDtorFunc, aPropDtorData,
+                                    aTransfer);
+    propertyList->mNext = mPropertyList;
+    mPropertyList = propertyList;
+  }
+
+  // The current property value (if there is one) is replaced and the current
+  // value is destroyed
+  nsresult result = NS_OK;
+  auto entry = static_cast<PropertyListMapEntry*>(
+      propertyList->mObjectValueMap.Add(aObject, mozilla::fallible));
+  if (!entry) return NS_ERROR_OUT_OF_MEMORY;
+  // A nullptr entry->key is the sign that the entry has just been allocated
+  // for us.  If it's non-nullptr then we have an existing entry.
+  if (entry->key) {
+    if (propertyList->mDtorFunc) {
+      propertyList->mDtorFunc(const_cast<void*>(entry->key), aPropertyName,
+                              entry->value, propertyList->mDtorData);
+    }
+    result = NS_PROPTABLE_PROP_OVERWRITTEN;
+  }
+  entry->key = aObject;
+  entry->value = aPropertyValue;
+
+  return result;
+}
+
+nsresult nsPropertyTable::RemoveProperty(nsPropertyOwner aObject,
+                                         const nsAtom* aPropertyName) {
+  MOZ_ASSERT(aPropertyName && aObject, "unexpected null param");
+
+  PropertyList* propertyList = GetPropertyListFor(aPropertyName);
+  if (propertyList) {
+    if (propertyList->RemovePropertyFor(aObject)) {
+      return NS_OK;
+    }
+  }
+
+  return NS_PROPTABLE_PROP_NOT_THERE;
+}
+
+nsPropertyTable::PropertyList* nsPropertyTable::GetPropertyListFor(
+    const nsAtom* aPropertyName) const {
+  PropertyList* result;
+
+  for (result = mPropertyList; result; result = result->mNext) {
+    if (result->Equals(aPropertyName)) {
+      break;
+    }
+  }
+
+  return result;
+}
+
+//----------------------------------------------------------------------
+
+nsPropertyTable::PropertyList::PropertyList(nsAtom* aName,
+                                            NSPropertyDtorFunc aDtorFunc,
+                                            void* aDtorData, bool aTransfer)
+    : mName(aName),
+      mObjectValueMap(PLDHashTable::StubOps(), sizeof(PropertyListMapEntry)),
+      mDtorFunc(aDtorFunc),
+      mDtorData(aDtorData),
+      mTransfer(aTransfer),
+      mNext(nullptr) {}
+
+nsPropertyTable::PropertyList::~PropertyList() = default;
+
+void nsPropertyTable::PropertyList::Destroy() {
+  // Enumerate any remaining object/value pairs and destroy the value object.
+  if (mDtorFunc) {
+    for (auto iter = mObjectValueMap.ConstIter(); !iter.Done(); iter.Next()) {
+      auto entry = static_cast<PropertyListMapEntry*>(iter.Get());
+      mDtorFunc(const_cast<void*>(entry->key), mName, entry->value, mDtorData);
+    }
+  }
+}
+
+bool nsPropertyTable::PropertyList::RemovePropertyFor(nsPropertyOwner aObject) {
+  auto entry =
+      static_cast<PropertyListMapEntry*>(mObjectValueMap.Search(aObject));
+  if (!entry) return false;
+
+  void* value = entry->value;
+  mObjectValueMap.RemoveEntry(entry);
+
+  if (mDtorFunc)
+    mDtorFunc(const_cast<void*>(aObject.get()), mName, value, mDtorData);
+
+  return true;
+}
+
+size_t nsPropertyTable::PropertyList::SizeOfIncludingThis(
+    mozilla::MallocSizeOf aMallocSizeOf) {
+  size_t n = aMallocSizeOf(this);
+  n += mObjectValueMap.ShallowSizeOfExcludingThis(aMallocSizeOf);
+  return n;
+}
+
+size_t nsPropertyTable::SizeOfExcludingThis(
+    mozilla::MallocSizeOf aMallocSizeOf) const {
+  size_t n = 0;
+
+  for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
+    n += prop->SizeOfIncludingThis(aMallocSizeOf);
+  }
+
+  return n;
+}
+
+size_t nsPropertyTable::SizeOfIncludingThis(
+    mozilla::MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+/* static */
+void nsPropertyTable::SupportsDtorFunc(void* aObject, nsAtom* aPropertyName,
+                                       void* aPropertyValue, void* aData) {
+  nsISupports* propertyValue = static_cast<nsISupports*>(aPropertyValue);
+  NS_IF_RELEASE(propertyValue);
+}