Refactor Pipe implementation

* Remove Pipe classes
* Rename BasePipe to Pipe
* Hide Pipe class in anonymous namespace in pipe.cc
* Add CreatePipe static method
* Replace Payload(std::function<InputStream&()>) with Payload(std::unique_ptr<InputStream>)
* Find&Replace Pipe usages

PiperOrigin-RevId: 557276980

internal/platform/implementation/g3/BUILD

@@ -30,7 +30,6 @@ cc_library(
         "log_message.h",
         "multi_thread_executor.h",
         "mutex.h",
-        "pipe.h",
         "preferences_manager.h",
         "scheduled_executor.h",
         "single_thread_executor.h",
@@ -98,7 +97,10 @@ cc_library(
         "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
+        "@com_google_absl//absl/functional:any_invocable",
+        "@com_google_absl//absl/log:check",
         "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/strings:str_format",
         "@com_google_absl//absl/synchronization",

internal/platform/implementation/g3/ble.cc

@@ -17,10 +17,18 @@
 #include <iostream>
 #include <memory>
 #include <string>
+#include <utility>
 
+#include "absl/functional/any_invocable.h"
+#include "absl/log/check.h"
 #include "absl/synchronization/mutex.h"
+#include "internal/platform/byte_array.h"
+#include "internal/platform/cancellation_flag.h"
 #include "internal/platform/cancellation_flag_listener.h"
+#include "internal/platform/exception.h"
 #include "internal/platform/implementation/ble.h"
+#include "internal/platform/implementation/bluetooth_adapter.h"
+#include "internal/platform/implementation/g3/bluetooth_adapter.h"
 #include "internal/platform/implementation/shared/count_down_latch.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/medium_environment.h"

internal/platform/implementation/g3/ble.h

@@ -27,7 +27,6 @@
 #include "internal/platform/implementation/g3/bluetooth_adapter.h"
 #include "internal/platform/implementation/g3/bluetooth_classic.h"
 #include "internal/platform/implementation/g3/multi_thread_executor.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/implementation/g3/socket_base.h"
 #include "internal/platform/input_stream.h"
 #include "internal/platform/output_stream.h"

internal/platform/implementation/g3/ble_v2.cc

@@ -15,7 +15,6 @@
 #include "internal/platform/implementation/g3/ble_v2.h"
 
 #include <algorithm>
-#include <cstdint>
 #include <iostream>
 #include <memory>
 #include <optional>
@@ -23,15 +22,26 @@
 #include <utility>
 #include <vector>
 
+#include "absl/functional/any_invocable.h"
+#include "absl/log/check.h"
 #include "absl/status/status.h"
+#include "absl/status/statusor.h"
 #include "absl/strings/escaping.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
+#include "internal/platform/borrowable.h"
+#include "internal/platform/byte_array.h"
 #include "internal/platform/cancellation_flag_listener.h"
 #include "internal/platform/count_down_latch.h"
+#include "internal/platform/exception.h"
 #include "internal/platform/implementation/ble_v2.h"
+#include "internal/platform/implementation/bluetooth_adapter.h"
 #include "internal/platform/implementation/g3/bluetooth_adapter.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/medium_environment.h"
+#include "internal/platform/prng.h"
+#include "internal/platform/uuid.h"
 
 namespace nearby {
 namespace g3 {

internal/platform/implementation/g3/ble_v2.h

@@ -29,7 +29,6 @@
 #include "internal/platform/byte_array.h"
 #include "internal/platform/implementation/ble_v2.h"
 #include "internal/platform/implementation/g3/bluetooth_adapter.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/implementation/g3/socket_base.h"
 #include "internal/platform/medium_environment.h"
 #include "internal/platform/prng.h"

internal/platform/implementation/g3/bluetooth_classic.cc

@@ -17,12 +17,18 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <utility>
 
+#include "absl/functional/any_invocable.h"
+#include "absl/log/check.h"
+#include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
+#include "internal/platform/cancellation_flag.h"
 #include "internal/platform/cancellation_flag_listener.h"
+#include "internal/platform/exception.h"
+#include "internal/platform/implementation/bluetooth_adapter.h"
 #include "internal/platform/implementation/bluetooth_classic.h"
 #include "internal/platform/implementation/g3/bluetooth_adapter.h"
-#include "internal/platform/input_stream.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/medium_environment.h"
 

internal/platform/implementation/g3/bluetooth_classic.h

@@ -26,7 +26,6 @@
 #include "internal/platform/exception.h"
 #include "internal/platform/implementation/bluetooth_classic.h"
 #include "internal/platform/implementation/g3/bluetooth_adapter.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/implementation/g3/socket_base.h"
 #include "internal/platform/input_stream.h"
 #include "internal/platform/listeners.h"

internal/platform/implementation/g3/pipe.h

@@ -1,42 +0,0 @@
-// Copyright 2020 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.
-
-#ifndef PLATFORM_IMPL_G3_PIPE_H_
-#define PLATFORM_IMPL_G3_PIPE_H_
-
-#include <memory>
-
-#include "internal/platform/base_pipe.h"
-#include "internal/platform/implementation/g3/condition_variable.h"
-#include "internal/platform/implementation/g3/mutex.h"
-
-namespace nearby {
-namespace g3 {
-
-class Pipe : public BasePipe {
- public:
-  Pipe() {
-    auto mutex = std::make_unique<g3::Mutex>(/*check=*/true);
-    auto cond = std::make_unique<g3::ConditionVariable>(mutex.get());
-    Setup(std::move(mutex), std::move(cond));
-  }
-  ~Pipe() override = default;
-  Pipe(Pipe&&) = delete;
-  Pipe& operator=(Pipe&&) = delete;
-};
-
-}  // namespace g3
-}  // namespace nearby
-
-#endif  // PLATFORM_IMPL_G3_PIPE_H_

internal/platform/implementation/g3/socket_base.h

@@ -18,14 +18,16 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <tuple>
+#include <utility>
 
 #include "absl/base/thread_annotations.h"
 #include "absl/synchronization/mutex.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/exception.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/input_stream.h"
 #include "internal/platform/output_stream.h"
+#include "internal/platform/pipe.h"
 
 namespace nearby {
 namespace g3 {
@@ -33,6 +35,7 @@ namespace g3 {
 // Common base for BT, BLE and Wifi socket implementations.
 class SocketBase {
  public:
+  SocketBase() { std::tie(input_for_remote_, output_) = CreatePipe(); }
   virtual ~SocketBase() {
     absl::MutexLock lock(&mutex_);
     DoClose();
@@ -43,23 +46,17 @@ class SocketBase {
   void Connect(SocketBase& other) ABSL_LOCKS_EXCLUDED(mutex_) {
     absl::MutexLock lock(&mutex_);
     remote_socket_ = &other;
-    input_ = other.output_;
+    input_ = std::move(other.input_for_remote_);
   }
 
   // Returns the InputStream of this connected socket.
-  InputStream& GetInputStream() ABSL_LOCKS_EXCLUDED(mutex_) {
-    absl::MutexLock lock(&mutex_);
-    if (IsConnectedLocked()) {
-      return input_->GetInputStream();
-    }
-    return invalid_input_stream_;
-  }
+  InputStream& GetInputStream() { return input_proxy_; }
 
   // Returns the OutputStream of this connected socket.
   // This stream is for local side to write.
   OutputStream& GetOutputStream() ABSL_LOCKS_EXCLUDED(mutex_) {
     absl::MutexLock lock(&mutex_);
-    return output_->GetOutputStream();
+    return *output_;
   }
 
   // Returns true if connection exists to the (possibly closed) remote socket.
@@ -95,13 +92,15 @@ class SocketBase {
   void DoClose() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mutex_) {
     if (!closed_) {
       remote_socket_ = nullptr;
-      output_->GetOutputStream().Close();
-      output_->GetInputStream().Close();
-      if (IsConnectedLocked()) {
-        input_->GetOutputStream().Close();
-        input_->GetInputStream().Close();
-        input_.reset();
+      // The client can hold references to `output_` and `input_` streams. We
+      // can close them but we cannot destroy them.
+      output_->Close();
+      if (input_) {
+        input_->Close();
       }
+      // The client does not hold a reference to `input_for_remote_`, so we can
+      // destroy it. Connecting to this socket will fail after that.
+      input_for_remote_.reset();
       closed_ = true;
     }
   }
@@ -111,24 +110,42 @@ class SocketBase {
     return input_ != nullptr;
   }
 
-  class InvalidInputStream : public InputStream {
+  class InputProxyStream : public InputStream {
    public:
+    explicit InputProxyStream(SocketBase* socket) : socket_(socket) {}
     ExceptionOr<ByteArray> Read(std::int64_t size) override {
-      return ExceptionOr<ByteArray>(Exception::kIo);
+      if (!socket_->IsConnected()) {
+        return ExceptionOr<ByteArray>(Exception::kIo);
+      }
+      return socket_->input_->Read(size);
     }
     ExceptionOr<size_t> Skip(size_t offset) override {
-      return ExceptionOr<size_t>(Exception::kIo);
+      if (!socket_->IsConnected()) {
+        return ExceptionOr<size_t>(Exception::kIo);
+      }
+      return socket_->input_->Skip(offset);
+    }
+    Exception Close() override {
+      if (!socket_->IsConnected()) {
+        return {Exception::kIo};
+      }
+      return socket_->input_->Close();
     }
-    Exception Close() override { return {Exception::kIo}; }
-  };
-  // Returned to the caller if the remote socket is destroyed.
-  InvalidInputStream invalid_input_stream_;
 
-  // Output pipe is initialized by constructor, it remains always valid, until
-  // it is closed. it represents output part of a local socket. Input part of a
-  // local socket comes from the peer socket, after connection.
-  std::shared_ptr<Pipe> output_{new Pipe};
-  std::shared_ptr<Pipe> input_;
+   private:
+    SocketBase* socket_;
+  };
+  InputProxyStream input_proxy_{this};
+
+  // Output stream is initialized by constructor, it remains always valid. It
+  // represents output part of a local socket. Input stream of a local socket
+  // comes from the peer socket, after connection.
+  std::unique_ptr<OutputStream> output_;
+  std::unique_ptr<InputStream> input_;
+  // `input_for_remote_` is the other end of the pipe formed with `output_`. We
+  // give this stream to the remote socket when they connect to us, and it
+  // becomes their `input_` stream.
+  std::unique_ptr<InputStream> input_for_remote_;
   SocketBase* remote_socket_ ABSL_GUARDED_BY(mutex_) = nullptr;
   bool closed_ ABSL_GUARDED_BY(mutex_) = false;
 };

internal/platform/implementation/g3/wifi_direct.cc

@@ -16,15 +16,21 @@
 
 #include <iostream>
 #include <memory>
-#include <optional>
 #include <string>
 #include <utility>
 
+#include "absl/log/check.h"
+#include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
+#include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
+#include "internal/platform/cancellation_flag.h"
+#include "internal/platform/exception.h"
 #include "internal/platform/implementation/wifi_direct.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/medium_environment.h"
+#include "internal/platform/prng.h"
+#include "internal/platform/wifi_credential.h"
 
 namespace nearby {
 namespace g3 {

internal/platform/implementation/g3/wifi_direct.h

@@ -22,7 +22,6 @@
 
 #include "absl/synchronization/mutex.h"
 #include "internal/platform/implementation/g3/multi_thread_executor.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/implementation/g3/socket_base.h"
 #include "internal/platform/implementation/wifi_direct.h"
 #include "internal/platform/input_stream.h"

internal/platform/implementation/g3/wifi_hotspot.cc

@@ -16,16 +16,22 @@
 
 #include <iostream>
 #include <memory>
-#include <optional>
 #include <string>
 #include <utility>
 
+#include "absl/log/check.h"
+#include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
+#include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
+#include "internal/platform/cancellation_flag.h"
 #include "internal/platform/cancellation_flag_listener.h"
+#include "internal/platform/exception.h"
 #include "internal/platform/implementation/wifi_hotspot.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/medium_environment.h"
+#include "internal/platform/prng.h"
+#include "internal/platform/wifi_credential.h"
 
 namespace nearby {
 namespace g3 {

internal/platform/implementation/g3/wifi_hotspot.h

@@ -23,7 +23,6 @@
 #include "absl/synchronization/mutex.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/implementation/g3/multi_thread_executor.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/implementation/g3/socket_base.h"
 #include "internal/platform/implementation/wifi_hotspot.h"
 #include "internal/platform/input_stream.h"

internal/platform/implementation/g3/wifi_lan.cc

@@ -19,10 +19,13 @@
 #include <string>
 #include <utility>
 
-#include "absl/strings/escaping.h"
+#include "absl/log/check.h"
+#include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
 #include "absl/synchronization/mutex.h"
+#include "internal/platform/cancellation_flag.h"
 #include "internal/platform/cancellation_flag_listener.h"
+#include "internal/platform/exception.h"
 #include "internal/platform/implementation/wifi_lan.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/medium_environment.h"

internal/platform/implementation/g3/wifi_lan.h

@@ -24,7 +24,6 @@
 #include "absl/synchronization/mutex.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/implementation/g3/multi_thread_executor.h"
-#include "internal/platform/implementation/g3/pipe.h"
 #include "internal/platform/implementation/g3/socket_base.h"
 #include "internal/platform/implementation/wifi_lan.h"
 #include "internal/platform/input_stream.h"