Add BluetoothInputStream, BluetoothOutputStream.

internal/platform/implementation/linux/bluetooth_classic_socket.cc

@@ -0,0 +1,123 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <array>
+#include <cerrno>
+#include <cstdint>
+#include <cstring>
+
+#include "internal/platform/byte_array.h"
+#include "internal/platform/exception.h"
+#include "internal/platform/implementation/linux/bluetooth_classic_socket.h"
+#include "internal/platform/logging.h"
+
+namespace nearby {
+namespace linux {
+Exception Poller::Ready() {
+  while (true) {
+    auto ret = poll(fds_, 1, -1);
+    if (ret < 0) {
+      if (errno == EAGAIN) continue;
+      NEARBY_LOGS(ERROR) << __func__ << ": error polling socket for I/O: "
+                         << std::strerror(errno);
+      return {Exception::kIo};
+    }
+    if ((fds_[0].revents & poll_event_) != 0) {
+      return {Exception::kSuccess};
+    }
+    if ((fds_[0].revents & POLLHUP) != 0) {
+      NEARBY_LOGS(ERROR) << __func__ << ": socket disconnected";
+      return {Exception::kIo};
+    }
+    if ((fds_[0].revents & (POLLERR | POLLNVAL)) != 0) {
+      NEARBY_LOGS(ERROR) << __func__ << ": an error occured on the socket";
+      return {Exception::kIo};
+    }
+  }
+}
+
+ExceptionOr<ByteArray> BluetoothInputStream::Read(std::int64_t size) {
+  if (!fd_.isValid()) return Exception{Exception::kIo};
+
+  auto poller = Poller::CreateInputPoller(fd_);
+
+  std::string buffer;
+  buffer.resize(size);
+  char *data = buffer.data();
+
+  size_t total_read = 0;
+
+  while (total_read < size) {
+    auto result = poller.Ready();
+    if (result.Raised()) return result;
+
+    auto bytes_read = read(fd_.get(), &data[total_read], (size - total_read));
+    if (bytes_read < 0) {
+      if (errno == EAGAIN || errno == EWOULDBLOCK) continue;
+      NEARBY_LOGS(ERROR) << __func__
+                         << ": error reading data on bluetooth socket: "
+                         << std::strerror(errno);
+      return {Exception::kIo};
+    }
+    total_read += bytes_read;
+  }
+
+  return ExceptionOr{ByteArray(std::move(buffer))};
+}
+
+Exception BluetoothInputStream::Close() {
+  if (!fd_.isValid()) return {Exception::kIo};
+  fd_.reset();
+  return {Exception::kSuccess};
+}
+
+Exception BluetoothOutputStream::Write(const ByteArray &data) {
+  if (!fd_.isValid()) return Exception{Exception::kIo};
+
+  auto poller = Poller::CreateOutputPoller(fd_);
+
+  size_t total_wrote = 0;
+
+  while (total_wrote < data.size()) {
+    auto result = poller.Ready();
+    if (result.Raised()) return result;
+
+    const char *buf = data.data();
+    auto wrote =
+        write(fd_.get(), &buf[total_wrote], (data.size() - total_wrote));
+    if (wrote < 0) {
+      if (errno == EAGAIN || errno == EWOULDBLOCK) continue;
+      NEARBY_LOGS(ERROR) << __func__
+                         << ": error writing data on bluetooth socket: "
+                         << std::strerror(errno);
+      return {Exception::kIo};
+    }
+
+    total_wrote += wrote;
+  }
+
+  return {Exception::kSuccess};
+}
+
+Exception BluetoothOutputStream::Close() {
+  if (!fd_.isValid()) return {Exception::kIo};
+  fd_.reset();
+  return {Exception::kSuccess};
+}
+
+}  // namespace linux
+}  // namespace nearby