v8/src/lookup-cache.h
Mathias Bynens 62f929ff4c Use nullptr instead of NULL where possible
New code should use nullptr instead of NULL.

This patch updates existing use of NULL to nullptr where applicable,
making the code base more consistent.

BUG=v8:6928,v8:6921

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng;master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: I4687f5b96fcfd88b41fa970a2b937b4f6538777c
Reviewed-on: https://chromium-review.googlesource.com/718338
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48557}
2017-10-13 17:21:49 +00:00

59 lines
1.4 KiB
C++

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_LOOKUP_CACHE_H_
#define V8_LOOKUP_CACHE_H_
#include "src/objects.h"
namespace v8 {
namespace internal {
// Cache for mapping (map, property name) into descriptor index.
// The cache contains both positive and negative results.
// Descriptor index equals kNotFound means the property is absent.
// Cleared at startup and prior to any gc.
class DescriptorLookupCache {
public:
// Lookup descriptor index for (map, name).
// If absent, kAbsent is returned.
inline int Lookup(Map* source, Name* name);
// Update an element in the cache.
inline void Update(Map* source, Name* name, int result);
// Clear the cache.
void Clear();
static const int kAbsent = -2;
private:
DescriptorLookupCache() {
for (int i = 0; i < kLength; ++i) {
keys_[i].source = nullptr;
keys_[i].name = nullptr;
results_[i] = kAbsent;
}
}
static inline int Hash(Object* source, Name* name);
static const int kLength = 64;
struct Key {
Map* source;
Name* name;
};
Key keys_[kLength];
int results_[kLength];
friend class Isolate;
DISALLOW_COPY_AND_ASSIGN(DescriptorLookupCache);
};
} // namespace internal
} // namespace v8
#endif // V8_LOOKUP_CACHE_H_