1 // Copyright 2022 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 #include <cstddef> 17 #include <cstdint> 18 #include <limits> 19 20 #include "pw_bytes/span.h" 21 #include "pw_transfer/handler.h" 22 #include "pw_transfer/internal/config.h" 23 #include "pw_transfer/internal/server_context.h" 24 #include "pw_transfer/transfer.raw_rpc.pb.h" 25 #include "pw_transfer/transfer_thread.h" 26 27 namespace pw::transfer { 28 namespace internal { 29 30 struct Chunk; 31 32 } // namespace internal 33 34 class TransferService : public pw_rpc::raw::Transfer::Service<TransferService> { 35 public: 36 // Initializes a TransferService that can be registered with an RPC server. 37 // 38 // The transfer service requires a work queue to perform deferred tasks, such 39 // as handling transfer timeouts and retries. This work queue does not need to 40 // be unique to the transfer service; it may be shared with other parts of the 41 // system. 42 // 43 // The provided buffer is used to stage data from transfer chunks before it is 44 // written out to the writer. The size of this buffer is the largest amount of 45 // data that can be sent in a single transfer chunk, excluding any transport 46 // layer overhead. 47 // 48 // max_pending_bytes is the maximum amount of data to ask for at a 49 // time during a write transfer, unless told a more restrictive amount by a 50 // transfer handler. This size can span multiple chunks. A larger value 51 // generally increases the efficiency of write transfers when sent over a 52 // reliable transport. However, if the underlying transport is unreliable, 53 // larger values could slow down a transfer in the event of repeated packet 54 // loss. 55 TransferService( 56 TransferThread& transfer_thread, 57 uint32_t max_pending_bytes, 58 chrono::SystemClock::duration chunk_timeout = cfg::kDefaultChunkTimeout, 59 uint8_t max_retries = cfg::kDefaultMaxRetries, 60 uint32_t extend_window_divisor = cfg::kDefaultExtendWindowDivisor) 61 : max_parameters_(max_pending_bytes, 62 transfer_thread.max_chunk_size(), 63 extend_window_divisor), 64 thread_(transfer_thread), 65 chunk_timeout_(chunk_timeout), 66 max_retries_(max_retries) {} 67 68 TransferService(const TransferService&) = delete; 69 TransferService(TransferService&&) = delete; 70 71 TransferService& operator=(const TransferService&) = delete; 72 TransferService& operator=(TransferService&&) = delete; 73 Read(RawServerReaderWriter & reader_writer)74 void Read(RawServerReaderWriter& reader_writer) { 75 reader_writer.set_on_next([this](ConstByteSpan message) { 76 HandleChunk(message, internal::TransferType::kTransmit); 77 }); 78 thread_.SetServerReadStream(reader_writer); 79 } 80 Write(RawServerReaderWriter & reader_writer)81 void Write(RawServerReaderWriter& reader_writer) { 82 reader_writer.set_on_next([this](ConstByteSpan message) { 83 HandleChunk(message, internal::TransferType::kReceive); 84 }); 85 thread_.SetServerWriteStream(reader_writer); 86 } 87 RegisterHandler(internal::Handler & handler)88 void RegisterHandler(internal::Handler& handler) { 89 thread_.AddTransferHandler(handler); 90 } 91 set_max_pending_bytes(uint32_t max_pending_bytes)92 void set_max_pending_bytes(uint32_t max_pending_bytes) { 93 max_parameters_.set_pending_bytes(max_pending_bytes); 94 } 95 96 // Sets the maximum size for the data in a pw_transfer chunk. Note that the 97 // max chunk size must always fit within the transfer thread's chunk buffer. set_max_chunk_size_bytes(uint32_t max_chunk_size_bytes)98 void set_max_chunk_size_bytes(uint32_t max_chunk_size_bytes) { 99 max_parameters_.set_max_chunk_size_bytes(max_chunk_size_bytes); 100 } 101 UnregisterHandler(internal::Handler & handler)102 void UnregisterHandler(internal::Handler& handler) { 103 thread_.RemoveTransferHandler(handler); 104 } 105 set_chunk_timeout(chrono::SystemClock::duration chunk_timeout)106 void set_chunk_timeout(chrono::SystemClock::duration chunk_timeout) { 107 chunk_timeout_ = chunk_timeout; 108 } 109 set_max_retries(uint8_t max_retries)110 void set_max_retries(uint8_t max_retries) { max_retries_ = max_retries; } 111 set_extend_window_divisor(uint32_t extend_window_divisor)112 Status set_extend_window_divisor(uint32_t extend_window_divisor) { 113 if (extend_window_divisor <= 1) { 114 return Status::InvalidArgument(); 115 } 116 117 max_parameters_.set_extend_window_divisor(extend_window_divisor); 118 return OkStatus(); 119 } 120 121 private: 122 void HandleChunk(ConstByteSpan message, internal::TransferType type); 123 124 internal::TransferParameters max_parameters_; 125 TransferThread& thread_; 126 127 chrono::SystemClock::duration chunk_timeout_; 128 uint8_t max_retries_; 129 }; 130 131 } // namespace pw::transfer 132