Index: content/common/worker_use_counter.cc |
diff --git a/content/common/worker_use_counter.cc b/content/common/worker_use_counter.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..538903db2cf4edc1b0c40c2ade78fc946b7adecd |
--- /dev/null |
+++ b/content/common/worker_use_counter.cc |
@@ -0,0 +1,56 @@ |
+// Copyright 2017 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#include "content/common/worker_use_counter.h" |
+ |
+#include "base/memory/ptr_util.h" |
+ |
+namespace content { |
+ |
+// Used for reserving a buffer of a bit vector. If a feature count is larger |
+// than this buffer size, it's expanded on Count(). |
+// TODO(nhiroki): How do we synchronize this with UseCounter::Feature? |
+const size_t kNumberOfFeatures = 2048; |
+ |
+const size_t kBitsPerByte = 8; |
+constexpr size_t kNumberOfBytes = kNumberOfFeatures / kBitsPerByte; |
kinuko
2017/01/24 13:56:31
Do we need to use vector<char> here? Maybe we cou
nhiroki
2017/01/24 15:07:30
I think std::bitset is a good option. Before movin
kinuko
2017/01/25 05:12:52
Usually sending IPC up to 2KB doesn't make a lot d
nhiroki
2017/01/25 10:16:11
I think it's not so big for now because most of fe
|
+ |
+WorkerUseCounter::WorkerUseCounter() |
+ : counter_(std::vector<char>(kNumberOfBytes)) { |
+} |
+ |
+WorkerUseCounter::WorkerUseCounter(std::vector<char> counter) |
+ : counter_(counter) { |
+} |
+ |
+WorkerUseCounter::~WorkerUseCounter() = default; |
+ |
+void WorkerUseCounter::Count(uint32_t feature) { |
+ size_t byte_pos = feature / kBitsPerByte; |
+ size_t bit_pos = feature % kBitsPerByte; |
+ char bit_mask = 0x1 << bit_pos; |
+ if (counter_.size() < byte_pos) |
+ counter_.resize(byte_pos + 1); |
+ counter_[byte_pos] |= bit_mask; |
+} |
+ |
+bool WorkerUseCounter::IsCounted(uint32_t feature) { |
+ size_t byte_pos = feature / kBitsPerByte; |
+ size_t bit_pos = feature % kBitsPerByte; |
+ if (counter_.size() < byte_pos) |
+ return false; |
+ char bit_mask = 0x1 << bit_pos; |
+ return (counter_[byte_pos] & bit_mask) != 0; |
+} |
+ |
+std::vector<char> WorkerUseCounter::Dump() { |
+ return counter_; |
+} |
+ |
+size_t WorkerUseCounter::GetNumberOfBits() const { |
+ size_t number_of_bytes = counter_.size(); |
+ return number_of_bytes * kBitsPerByte; |
+} |
+ |
+} // namespace content |