xref: /aosp_15_r20/external/pigweed/pw_trace_tokenized/trace_buffer.cc (revision 61c4878ac05f98d0ceed94b57d316916de578985)
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 //
16 #include "pw_trace_tokenized/trace_buffer.h"
17 
18 #include "pw_ring_buffer/prefixed_entry_ring_buffer.h"
19 #include "pw_span/span.h"
20 #include "pw_trace_tokenized/trace_callback.h"
21 
22 namespace pw {
23 namespace trace {
24 namespace {
25 
26 class TraceBuffer {
27  public:
TraceBuffer(Callbacks & callbacks)28   TraceBuffer(Callbacks& callbacks) : callbacks_(callbacks) {
29     ring_buffer_.SetBuffer(raw_buffer_)
30         .IgnoreError();  // TODO: b/242598609 - Handle Status properly
31     callbacks_
32         .RegisterSink(
33             TraceSinkStartBlock, TraceSinkAddBytes, TraceSinkEndBlock, this)
34         .IgnoreError();  // TODO: b/242598609 - Handle Status properly
35   }
36 
TraceSinkStartBlock(void * user_data,size_t size)37   static void TraceSinkStartBlock(void* user_data, size_t size) {
38     TraceBuffer* buffer = reinterpret_cast<TraceBuffer*>(user_data);
39     if (size > PW_TRACE_BUFFER_MAX_BLOCK_SIZE_BYTES) {
40       buffer->block_size_ = 0;  // Skip this block
41       return;
42     }
43     buffer->block_size_ = static_cast<uint16_t>(size);
44     buffer->block_idx_ = 0;
45   }
46 
TraceSinkAddBytes(void * user_data,const void * bytes,size_t size)47   static void TraceSinkAddBytes(void* user_data,
48                                 const void* bytes,
49                                 size_t size) {
50     TraceBuffer* buffer = reinterpret_cast<TraceBuffer*>(user_data);
51     if (buffer->block_size_ == 0 ||
52         buffer->block_idx_ + size > buffer->block_size_) {
53       return;  // Block is too large, skipping.
54     }
55     memcpy(&buffer->current_block_[buffer->block_idx_], bytes, size);
56     buffer->block_idx_ += size;
57   }
58 
TraceSinkEndBlock(void * user_data)59   static void TraceSinkEndBlock(void* user_data) {
60     TraceBuffer* buffer = reinterpret_cast<TraceBuffer*>(user_data);
61     if (buffer->block_idx_ != buffer->block_size_) {
62       return;  // Block is too large, skipping.
63     }
64     buffer->ring_buffer_
65         .PushBack(span<const std::byte>(&buffer->current_block_[0],
66                                         buffer->block_size_))
67         .IgnoreError();  // TODO: b/242598609 - Handle Status properly
68   }
69 
RingBuffer()70   pw::ring_buffer::PrefixedEntryRingBuffer& RingBuffer() {
71     return ring_buffer_;
72   }
73 
DeringAndViewRawBuffer()74   ConstByteSpan DeringAndViewRawBuffer() {
75     ring_buffer_.Dering()
76         .IgnoreError();  // TODO: b/242598609 - Handle Status properly
77     return ByteSpan(raw_buffer_, ring_buffer_.TotalUsedBytes());
78   }
79 
80  private:
81   Callbacks& callbacks_;
82   uint16_t block_size_ = 0;
83   uint16_t block_idx_ = 0;
84   std::byte current_block_[PW_TRACE_BUFFER_MAX_BLOCK_SIZE_BYTES];
85   std::byte raw_buffer_[PW_TRACE_BUFFER_SIZE_BYTES];
86   pw::ring_buffer::PrefixedEntryRingBuffer ring_buffer_{false};
87 };
88 
89 #if PW_TRACE_BUFFER_SIZE_BYTES > 0
90 TraceBuffer trace_buffer_instance(GetCallbacks());
91 #endif  // PW_TRACE_BUFFER_SIZE_BYTES > 0
92 
93 }  // namespace
94 
ClearBuffer()95 void ClearBuffer() { trace_buffer_instance.RingBuffer().Clear(); }
96 
GetBuffer()97 pw::ring_buffer::PrefixedEntryRingBuffer* GetBuffer() {
98   return &trace_buffer_instance.RingBuffer();
99 }
100 
DeringAndViewRawBuffer()101 ConstByteSpan DeringAndViewRawBuffer() {
102   return trace_buffer_instance.DeringAndViewRawBuffer();
103 }
104 
105 }  // namespace trace
106 }  // namespace pw
107