[Chrome OS Tether] Create BleAdvertisementDeviceQueue.

chromeos/components/tether/ble_advertisement_device_queue.cc

Index: chromeos/components/tether/ble_advertisement_device_queue.cc
diff --git a/chromeos/components/tether/ble_advertisement_device_queue.cc b/chromeos/components/tether/ble_advertisement_device_queue.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4f53fcf6035023f83c9f7c7380aa1145b416e1f4
--- /dev/null
+++ b/chromeos/components/tether/ble_advertisement_device_queue.cc
@@ -0,0 +1,118 @@
+// Copyright 2016 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 "chromeos/components/tether/ble_advertisement_device_queue.h"
+
+#include <algorithm>
+#include <string>
+
+#include "base/logging.h"
+#include "components/proximity_auth/logging/logging.h"
+
+namespace chromeos {
+
+namespace tether {
+
+const int BleAdvertisementDeviceQueue::kMaxConcurrentAdvertisements = 2;
+
+BleAdvertisementDeviceQueue::BleAdvertisementDeviceQueue() {}
+
+BleAdvertisementDeviceQueue::~BleAdvertisementDeviceQueue() {}
+
+bool BleAdvertisementDeviceQueue::SetDevices(
+    std::vector<cryptauth::RemoteDevice> devices) {
+  // Determine which devices exist in |devices| but not in |device_queue_|, then
+  // add them to |device_queue_|.
+  std::vector<cryptauth::RemoteDevice> missing_from_queue;
+  for (auto& device : devices) {
+    if (std::find(device_queue_.begin(), device_queue_.end(), device) ==
+        device_queue_.end()) {
+      missing_from_queue.push_back(device);
+    }
+  }
+  if (!missing_from_queue.empty()) {
+    std::string log_message = "Adding device IDs: [";
+    for (auto& device : missing_from_queue) {
+      device_queue_.push_back(device);
+      log_message += device.GetTruncatedDeviceIdForLogs() + ",";
+    }
+    log_message.replace(log_message.length() - 1, log_message.length(), "]");
+    PA_LOG(INFO) << log_message;
+  }
+
+  // Determine which devices do not exist in |devices| but do exist in
+  // |device_queue_|, then remove them from |device_queue_|.
+  std::vector<cryptauth::RemoteDevice> to_remove_from_queue;
+  for (auto& device : device_queue_) {
+    if (std::find(devices.begin(), devices.end(), device) == devices.end()) {
+      to_remove_from_queue.push_back(device);
+    }
+  }
+  if (!to_remove_from_queue.empty()) {
+    std::string log_message = "Removing device IDs: [";
+    for (auto& device : to_remove_from_queue) {
+      device_queue_.erase(
+          std::find(device_queue_.begin(), device_queue_.end(), device));
+      log_message += device.GetTruncatedDeviceIdForLogs() + ",";
+    }
+    log_message.replace(log_message.length() - 1, log_message.length(), "]");
+    PA_LOG(INFO) << log_message;
+  }
+
+  return !missing_from_queue.empty() || !to_remove_from_queue.empty();
+}
+
+void BleAdvertisementDeviceQueue::MoveDeviceToEnd(std::string device_id) {
+  if (device_id.empty()) {
+    return;
+  }
+
+  int index = -1;
+  for (size_t i = 0; i < device_queue_.size(); i++) {
+    if (device_id == device_queue_[i].GetDeviceId()) {
+      index = i;
+      break;
+    }
+  }
+
+  if (index >= 0) {
+    cryptauth::RemoteDevice to_move = device_queue_[index];
+    device_queue_.erase(device_queue_.begin() + index);
+    device_queue_.push_back(to_move);
+  }
+}
+
+std::vector<cryptauth::RemoteDevice>
+BleAdvertisementDeviceQueue::GetDevicesToWhichToAdvertise() const {
+  std::vector<cryptauth::RemoteDevice> to_advertise;
+
+  if (device_queue_.empty()) {
+    PA_LOG(INFO) << "No devices to which to advertise.";
+    return to_advertise;
+  }
+
+  std::string log_message = "Should advertise to the following device IDs: [";
+  for (auto& device : device_queue_) {
+    to_advertise.push_back(device);
+    log_message += device.GetTruncatedDeviceIdForLogs() + ",";
+
+    if (to_advertise.size() ==
+        static_cast<size_t>(kMaxConcurrentAdvertisements)) {
+      break;
+    }
+  }
+
+  log_message.replace(log_message.length() - 1, log_message.length(), "]");
+  PA_LOG(INFO) << log_message;
+
+  return to_advertise;
+}
+
+size_t BleAdvertisementDeviceQueue::GetSize() const {
+  return device_queue_.size();
+}
+
+}  // namespace tether
+
+}  // namespace chromeos