1 // Copyright 2020 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
15 // clang-format off
16 #include "pw_rpc/internal/log_config.h" // PW_LOG_* macros must be first.
17
18 #include "pw_rpc/internal/channel.h"
19 // clang-format on
20
21 #include "pw_bytes/span.h"
22 #include "pw_log/log.h"
23 #include "pw_protobuf/decoder.h"
24 #include "pw_rpc/internal/config.h"
25
26 namespace pw::rpc {
27 namespace {
28
29 // TODO(pwbug/615): Dynamically allocate this buffer if
30 // PW_RPC_DYNAMIC_ALLOCATION is enabled.
31 std::array<std::byte, cfg::kEncodingBufferSizeBytes> encoding_buffer
32 PW_GUARDED_BY(internal::rpc_lock());
33
34 } // namespace
35
ExtractChannelId(ConstByteSpan packet)36 Result<uint32_t> ExtractChannelId(ConstByteSpan packet) {
37 protobuf::Decoder decoder(packet);
38
39 while (decoder.Next().ok()) {
40 switch (static_cast<internal::RpcPacket::Fields>(decoder.FieldNumber())) {
41 case internal::RpcPacket::Fields::CHANNEL_ID: {
42 uint32_t channel_id;
43 PW_TRY(decoder.ReadUint32(&channel_id));
44 return channel_id;
45 }
46
47 default:
48 continue;
49 }
50 }
51
52 return Status::DataLoss();
53 }
54
55 namespace internal {
56
GetPayloadBuffer()57 ByteSpan GetPayloadBuffer() PW_EXCLUSIVE_LOCKS_REQUIRED(rpc_lock()) {
58 return ByteSpan(encoding_buffer)
59 .subspan(Packet::kMinEncodedSizeWithoutPayload);
60 }
61
Send(const Packet & packet)62 Status Channel::Send(const Packet& packet) {
63 Result encoded = packet.Encode(encoding_buffer);
64
65 if (!encoded.ok()) {
66 PW_LOG_ERROR(
67 "Failed to encode RPC packet type %u to channel %u buffer, status %u",
68 static_cast<unsigned>(packet.type()),
69 static_cast<unsigned>(id()),
70 encoded.status().code());
71 return Status::Internal();
72 }
73
74 Status sent = output().Send(encoded.value());
75
76 if (!sent.ok()) {
77 PW_LOG_DEBUG("Channel %u failed to send packet with status %u",
78 static_cast<unsigned>(id()),
79 sent.code());
80
81 return Status::Unknown();
82 }
83 return OkStatus();
84 }
85
86 } // namespace internal
87 } // namespace pw::rpc
88