| // Copyright 2022 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 <cstddef> |
| #include <cstdint> |
| #include <limits> |
| |
| #include "pw_bytes/span.h" |
| #include "pw_transfer/handler.h" |
| #include "pw_transfer/internal/config.h" |
| #include "pw_transfer/internal/server_context.h" |
| #include "pw_transfer/transfer.raw_rpc.pb.h" |
| #include "pw_transfer/transfer_thread.h" |
| |
| namespace pw::transfer { |
| namespace internal { |
| |
| class Chunk; |
| |
| } // namespace internal |
| |
| class TransferService : public pw_rpc::raw::Transfer::Service<TransferService> { |
| public: |
| // Initializes a TransferService that can be registered with an RPC server. |
| // |
| // The transfer service requires a work queue to perform deferred tasks, such |
| // as handling transfer timeouts and retries. This work queue does not need to |
| // be unique to the transfer service; it may be shared with other parts of the |
| // system. |
| // |
| // The provided buffer is used to stage data from transfer chunks before it is |
| // written out to the writer. The size of this buffer is the largest amount of |
| // data that can be sent in a single transfer chunk, excluding any transport |
| // layer overhead. |
| // |
| // max_pending_bytes is the maximum amount of data to ask for at a |
| // time during a write transfer, unless told a more restrictive amount by a |
| // transfer handler. This size can span multiple chunks. A larger value |
| // generally increases the efficiency of write transfers when sent over a |
| // reliable transport. However, if the underlying transport is unreliable, |
| // larger values could slow down a transfer in the event of repeated packet |
| // loss. |
| TransferService( |
| TransferThread& transfer_thread, |
| uint32_t max_pending_bytes, |
| chrono::SystemClock::duration chunk_timeout = cfg::kDefaultChunkTimeout, |
| uint8_t max_retries = cfg::kDefaultMaxRetries, |
| uint32_t extend_window_divisor = cfg::kDefaultExtendWindowDivisor) |
| : max_parameters_(max_pending_bytes, |
| transfer_thread.max_chunk_size(), |
| extend_window_divisor), |
| thread_(transfer_thread), |
| chunk_timeout_(chunk_timeout), |
| max_retries_(max_retries), |
| next_session_id_(1) {} |
| |
| TransferService(const TransferService&) = delete; |
| TransferService(TransferService&&) = delete; |
| |
| TransferService& operator=(const TransferService&) = delete; |
| TransferService& operator=(TransferService&&) = delete; |
| |
| void Read(RawServerReaderWriter& reader_writer) { |
| reader_writer.set_on_next([this](ConstByteSpan message) { |
| HandleChunk(message, internal::TransferType::kTransmit); |
| }); |
| thread_.SetServerReadStream(reader_writer); |
| } |
| |
| void Write(RawServerReaderWriter& reader_writer) { |
| reader_writer.set_on_next([this](ConstByteSpan message) { |
| HandleChunk(message, internal::TransferType::kReceive); |
| }); |
| thread_.SetServerWriteStream(reader_writer); |
| } |
| |
| void RegisterHandler(internal::Handler& handler) { |
| thread_.AddTransferHandler(handler); |
| } |
| |
| void set_max_pending_bytes(uint32_t max_pending_bytes) { |
| max_parameters_.set_pending_bytes(max_pending_bytes); |
| } |
| |
| // Sets the maximum size for the data in a pw_transfer chunk. Note that the |
| // max chunk size must always fit within the transfer thread's chunk buffer. |
| void set_max_chunk_size_bytes(uint32_t max_chunk_size_bytes) { |
| max_parameters_.set_max_chunk_size_bytes(max_chunk_size_bytes); |
| } |
| |
| void UnregisterHandler(internal::Handler& handler) { |
| thread_.RemoveTransferHandler(handler); |
| } |
| |
| void set_chunk_timeout(chrono::SystemClock::duration chunk_timeout) { |
| chunk_timeout_ = chunk_timeout; |
| } |
| |
| void set_max_retries(uint8_t max_retries) { max_retries_ = max_retries; } |
| |
| Status set_extend_window_divisor(uint32_t extend_window_divisor) { |
| if (extend_window_divisor <= 1) { |
| return Status::InvalidArgument(); |
| } |
| |
| max_parameters_.set_extend_window_divisor(extend_window_divisor); |
| return OkStatus(); |
| } |
| |
| private: |
| void HandleChunk(ConstByteSpan message, internal::TransferType type); |
| |
| // TODO(frolv): This could be more sophisticated and less predictable. |
| uint32_t GenerateNewSessionId() { return next_session_id_++; } |
| |
| internal::TransferParameters max_parameters_; |
| TransferThread& thread_; |
| |
| chrono::SystemClock::duration chunk_timeout_; |
| uint8_t max_retries_; |
| |
| uint32_t next_session_id_; |
| }; |
| |
| } // namespace pw::transfer |