Line data    Source code

       1             : // Copyright 2019 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_OBJECTS_JS_COLLECTION_ITERATOR_H_
       6             : #define V8_OBJECTS_JS_COLLECTION_ITERATOR_H_
       7             : 
       8             : #include "src/globals.h"
       9             : #include "src/objects.h"
      10             : #include "src/objects/js-objects.h"
      11             : #include "src/objects/smi.h"
      12             : 
      13             : // Has to be the last include (doesn't have include guards):
      14             : #include "src/objects/object-macros.h"
      15             : 
      16             : namespace v8 {
      17             : namespace internal {
      18             : 
      19             : class JSCollectionIterator : public JSObject {
      20             :  public:
      21             :   // [table]: the backing hash table mapping keys to values.
      22             :   DECL_ACCESSORS(table, Object)
      23             : 
      24             :   // [index]: The index into the data table.
      25             :   DECL_ACCESSORS(index, Object)
      26             : 
      27             :   void JSCollectionIteratorPrint(std::ostream& os, const char* name);
      28             : 
      29             :   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
      30             :                                 TORQUE_GENERATED_JSCOLLECTION_ITERATOR_FIELDS)
      31             : 
      32             :   OBJECT_CONSTRUCTORS(JSCollectionIterator, JSObject);
      33             : };
      34             : 
      35             : // OrderedHashTableIterator is an iterator that iterates over the keys and
      36             : // values of an OrderedHashTable.
      37             : //
      38             : // The iterator has a reference to the underlying OrderedHashTable data,
      39             : // [table], as well as the current [index] the iterator is at.
      40             : //
      41             : // When the OrderedHashTable is rehashed it adds a reference from the old table
      42             : // to the new table as well as storing enough data about the changes so that the
      43             : // iterator [index] can be adjusted accordingly.
      44             : //
      45             : // When the [Next] result from the iterator is requested, the iterator checks if
      46             : // there is a newer table that it needs to transition to.
      47             : template <class Derived, class TableType>
      48             : class OrderedHashTableIterator : public JSCollectionIterator {
      49             :  public:
      50             :   // Whether the iterator has more elements. This needs to be called before
      51             :   // calling |CurrentKey| and/or |CurrentValue|.
      52             :   bool HasMore();
      53             : 
      54             :   // Move the index forward one.
      55           0 :   void MoveNext() { set_index(Smi::FromInt(Smi::ToInt(index()) + 1)); }
      56             : 
      57             :   // Returns the current key of the iterator. This should only be called when
      58             :   // |HasMore| returns true.
      59             :   inline Object CurrentKey();
      60             : 
      61             :  private:
      62             :   // Transitions the iterator to the non obsolete backing store. This is a NOP
      63             :   // if the [table] is not obsolete.
      64             :   void Transition();
      65             : 
      66             :   OBJECT_CONSTRUCTORS(OrderedHashTableIterator, JSCollectionIterator);
      67             : };
      68             : 
      69             : }  // namespace internal
      70             : }  // namespace v8
      71             : 
      72             : #include "src/objects/object-macros-undef.h"
      73             : 
      74             : #endif  // V8_OBJECTS_JS_COLLECTION_ITERATOR_H_