| // Copyright 2020 The Pigweed Authors |
| // |
| // 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. |
| #pragma once |
| |
| #include <cstdint> |
| #include <span> |
| |
| #include "pw_assert/assert.h" |
| #include "pw_status/status.h" |
| |
| namespace pw::rpc { |
| namespace internal { |
| |
| class BaseServerWriter; |
| |
| } // namespace internal |
| |
| class ChannelOutput { |
| public: |
| // Creates a channel output with the provided name. The name is used for |
| // logging only. |
| constexpr ChannelOutput(const char* name) : name_(name) {} |
| |
| virtual ~ChannelOutput() = default; |
| |
| constexpr const char* name() const { return name_; } |
| |
| // Acquire a buffer into which to write an outgoing RPC packet. |
| virtual std::span<std::byte> AcquireBuffer() = 0; |
| |
| // Sends the contents of the buffer from AcquireBuffer(). |
| virtual void SendAndReleaseBuffer(size_t size) = 0; |
| |
| private: |
| const char* name_; |
| }; |
| |
| class Channel { |
| public: |
| static constexpr uint32_t kUnassignedChannelId = 0; |
| |
| // Creates a dynamically assignable channel without a set ID or output. |
| constexpr Channel() : id_(kUnassignedChannelId), output_(nullptr) {} |
| |
| // Creates a channel with a static ID. The channel's output can also be |
| // static, or it can set to null to allow dynamically opening connections |
| // through the channel. |
| template <uint32_t id> |
| constexpr static Channel Create(ChannelOutput* output) { |
| static_assert(id != kUnassignedChannelId, "Channel ID cannot be 0"); |
| return Channel(id, output); |
| } |
| |
| constexpr uint32_t id() const { return id_; } |
| constexpr bool assigned() const { return id_ != kUnassignedChannelId; } |
| |
| protected: |
| constexpr Channel(uint32_t id, ChannelOutput* output) |
| : id_(id), output_(output) { |
| PW_CHECK_UINT_NE(id, kUnassignedChannelId); |
| } |
| |
| ChannelOutput& output() const { |
| PW_CHECK_NOTNULL(output_); |
| return *output_; |
| } |
| |
| private: |
| uint32_t id_; |
| ChannelOutput* output_; |
| }; |
| |
| } // namespace pw::rpc |