src/tracing/json/json_tracing.cpp - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2023 Project CHIP Authors
  *    All rights reserved.
  *
  *    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
  *
  *        http://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.
  */

 #include <tracing/json/json_tracing.h>

 #include <lib/address_resolve/TracingStructs.h>
 #include <lib/core/ErrorStr.h>
 #include <lib/support/CHIPMem.h>
 #include <lib/support/StringBuilder.h>
 #include <lib/support/StringSplitter.h>
 #include <log_json/log_json_build_config.h>
 #include <tracing/metric_event.h>
 #include <transport/TracingStructs.h>

 #include <json/json.h>

 #include <errno.h>

 #include <sstream>
 #include <string>

 #if MATTER_LOG_JSON_DECODE_HEX
 #include <lib/support/BytesToHex.h> // nogncheck
 #endif

 #if MATTER_LOG_JSON_DECODE_FULL
 #include <lib/format/protocol_decoder.h> // nogncheck
 #include <tlv/meta/clusters_meta.h>      // nogncheck
 #include <tlv/meta/protocols_meta.h>     // nogncheck
 #endif

 namespace chip {
 namespace Tracing {
 namespace Json {

 namespace {

 using chip::StringBuilder;

 #if MATTER_LOG_JSON_DECODE_FULL

 using namespace chip::Decoders;

 using PayloadDecoderType = chip::Decoders::PayloadDecoder<64, 2048>;

 /// Figures out a unique name within a json object.
 ///
 /// Decoded keys may be duplicated, like list elements are denoted as "[]".
 /// The existing code does not attempt to encode lists and everything is an object,
 /// so this name builder attempts to find unique keys for elements inside a json.
 ///
 /// In particular a repeated "Anonymous<>", "Anonymous<>", ... will become "Anonymous<0>", ...
 class UniqueNameBuilder
 {
 public:
     UniqueNameBuilder(chip::StringBuilderBase & formatter) : mFormatter(formatter) {}
     const char * c_str() const { return mFormatter.c_str(); }

     // Figure out the next unique name in the given value
     //
     // After this returns, c_str() will return a name based on `baseName` that is
     // not a key of `value` (unless on overflows, which are just logged)
     void ComputeNextUniqueName(const char * baseName, ::Json::Value & value)
     {
         FirstName(baseName);
         while (value.isMember(mFormatter.c_str()))
         {
             NextName(baseName);
             if (!mFormatter.Fit())
             {
                 ChipLogError(Automation, "Potential data loss: insufficient space for unique keys in json");
                 return;
             }
         }
     }

 private:
     void FirstName(const char * baseName)
     {
         if (strcmp(baseName, "Anonymous<>") == 0)
         {
             mFormatter.Reset().Add("Anonymous<0>");
         }
         else
         {
             mFormatter.Reset().Add(baseName);
         }
     }

     void NextName(const char * baseName)
     {
         if (strcmp(baseName, "Anonymous<>") == 0)
         {
             mFormatter.Reset().Add("Anonymous<").Add(mUniqueIndex++).Add(">");
         }
         else
         {
             mFormatter.Reset().Add(baseName).Add("@").Add(mUniqueIndex++);
         }
     }

     chip::StringBuilderBase & mFormatter;
     int mUniqueIndex = 0;
 };

 // Gets the current value of the decoder until a NEST exit is returned
 ::Json::Value GetPayload(PayloadDecoderType & decoder)
 {
     ::Json::Value value;
     PayloadEntry entry;
     StringBuilder<128> formatter;
     UniqueNameBuilder nameBuilder(formatter);

     while (decoder.Next(entry))
     {
         switch (entry.GetType())
         {
         case PayloadEntry::IMPayloadType::kNestingEnter:
             // PayloadEntry validity is only until any decoder calls are made,
             // because the entry Name/Value may point into a shared Decoder buffer.
             //
             // As such entry.GetName() is only valid here and would not be valid once
             // GetPayload() is called as GetPayload calls decoder.Next, which invalidates
             // internal name and value buffers (makes them point to the next element).
             //
             // TLDR: name MUST be used and saved before GetPayload is executed.
             nameBuilder.ComputeNextUniqueName(entry.GetName(), value);
             value[nameBuilder.c_str()] = GetPayload(decoder);
             break;
         case PayloadEntry::IMPayloadType::kNestingExit:
             return value;
         case PayloadEntry::IMPayloadType::kAttribute:
             value[formatter.Reset().AddFormat("ATTR(%u/%u)", entry.GetClusterId(), entry.GetAttributeId()).c_str()] =
                 "<NOT_DECODED>";
             break;
         case PayloadEntry::IMPayloadType::kCommand:
             value[formatter.Reset().AddFormat("CMD(%u/%u)", entry.GetClusterId(), entry.GetCommandId()).c_str()] = "<NOT_DECODED>";
             continue;
         case PayloadEntry::IMPayloadType::kEvent:
             value[formatter.Reset().AddFormat("EVNT(%u/%u)", entry.GetClusterId(), entry.GetEventId()).c_str()] = "<NOT_DECODED>";
             continue;
         default:
             nameBuilder.ComputeNextUniqueName(entry.GetName(), value);
             value[nameBuilder.c_str()] = entry.GetValueText();
             break;
         }
     }
     return value;
 }

 #endif

 void DecodePayloadHeader(::Json::Value & value, const PayloadHeader * payloadHeader)
 {

     value["exchangeFlags"] = payloadHeader->GetExchangeFlags();
     value["exchangeId"]    = payloadHeader->GetExchangeID();
     value["protocolId"]    = payloadHeader->GetProtocolID().ToFullyQualifiedSpecForm();
     value["messageType"]   = payloadHeader->GetMessageType();
     value["initiator"]     = payloadHeader->IsInitiator();
     value["needsAck"]      = payloadHeader->NeedsAck();

     const Optional<uint32_t> & acknowledgedMessageCounter = payloadHeader->GetAckMessageCounter();
     if (acknowledgedMessageCounter.HasValue())
     {
         value["ackMessageCounter"] = acknowledgedMessageCounter.Value();
     }
 }

 void DecodePacketHeader(::Json::Value & value, const PacketHeader * packetHeader)
 {
     value["msgCounter"]    = packetHeader->GetMessageCounter();
     value["sessionId"]     = packetHeader->GetSessionId();
     value["flags"]         = packetHeader->GetMessageFlags();
     value["securityFlags"] = packetHeader->GetSecurityFlags();

     {
         const Optional<NodeId> & nodeId = packetHeader->GetSourceNodeId();
         if (nodeId.HasValue())
         {
             value["sourceNodeId"] = nodeId.Value();
         }
     }

     {
         const Optional<NodeId> & nodeId = packetHeader->GetDestinationNodeId();
         if (nodeId.HasValue())
         {
             value["destinationNodeId"] = nodeId.Value();
         }
     }

     {
         const Optional<GroupId> & groupId = packetHeader->GetDestinationGroupId();
         if (groupId.HasValue())
         {
             value["groupId"] = groupId.Value();
         }
     }
 }

 void DecodePayloadData(::Json::Value & value, chip::ByteSpan payload, Protocols::Id protocolId, uint8_t messageType)
 {
     value["size"] = static_cast<::Json::Value::UInt>(payload.size());

 #if MATTER_LOG_JSON_DECODE_HEX
     char hex_buffer[4096];
     if (chip::Encoding::BytesToUppercaseHexString(payload.data(), payload.size(), hex_buffer, sizeof(hex_buffer)) == CHIP_NO_ERROR)
     {
         value["hex"] = hex_buffer;
     }
 #endif // MATTER_LOG_JSON_DECODE_HEX

 #if MATTER_LOG_JSON_DECODE_FULL

     // As PayloadDecoder is quite large (large strings buffers), we place it in heap
     auto decoder = chip::Platform::MakeUnique<PayloadDecoderType>(PayloadDecoderInitParams()
                                                                       .SetProtocolDecodeTree(chip::TLVMeta::protocols_meta)
                                                                       .SetClusterDecodeTree(chip::TLVMeta::clusters_meta)
                                                                       .SetProtocol(protocolId)
                                                                       .SetMessageType(messageType));

     decoder->StartDecoding(payload);

     value["decoded"] = GetPayload(*decoder);
 #endif // MATTER_LOG_JSON_DECODE_FULL
 }

 } // namespace

 JsonBackend::~JsonBackend()
 {
     CloseFile();
 }

 void JsonBackend::TraceBegin(const char * label, const char * group)
 {
     ::Json::Value value;

     value["event"] = "TraceBegin";
     value["label"] = label;
     value["group"] = group;
     OutputValue(value);
 }

 void JsonBackend::TraceEnd(const char * label, const char * group)
 {
     ::Json::Value value;
     value["event"] = "TraceEnd";
     value["label"] = label;
     value["group"] = group;
     OutputValue(value);
 }

 void JsonBackend::TraceInstant(const char * label, const char * group)
 {
     ::Json::Value value;
     value["event"] = "TraceInstant";
     value["label"] = label;
     value["group"] = group;
     OutputValue(value);
 }

 void JsonBackend::TraceCounter(const char * label)
 {
     std::string counterId = std::string(label);
     if (mCounters.find(counterId) == mCounters.end())
     {
         mCounters[counterId] = 1;
     }
     else
     {
         mCounters[counterId]++;
     }
     ::Json::Value value;
     value["event"] = "TraceCounter";
     value["label"] = label;
     value["count"] = mCounters[counterId];

     // Output the counter event
     OutputValue(value);
 }

 void JsonBackend::LogMetricEvent(const MetricEvent & event)
 {
     ::Json::Value value;

     value["label"] = event.key();

     using ValueType = MetricEvent::Value::Type;
     switch (event.ValueType())
     {
     case ValueType::kInt32:
         value["value"] = event.ValueInt32();
         break;
     case ValueType::kUInt32:
         value["value"] = event.ValueUInt32();
         break;
     case ValueType::kChipErrorCode:
         value["value"] = event.ValueErrorCode();
         break;
     case ValueType::kUndefined:
         value["value"] = ::Json::Value();
         break;
     default:
         value["value"] = "UNKNOWN";
         break;
     }

     OutputValue(value);
 }

 void JsonBackend::LogMessageSend(MessageSendInfo & info)
 {
     ::Json::Value value;

     value["event"] = "MessageSend";

     switch (info.messageType)
     {
     case OutgoingMessageType::kGroupMessage:
         value["messageType"] = "Group";
         break;
     case OutgoingMessageType::kSecureSession:
         value["messageType"] = "Secure";
         break;
     case OutgoingMessageType::kUnauthenticated:
         value["messageType"] = "Unauthenticated";
         break;
     }

     DecodePayloadHeader(value["payloadHeader"], info.payloadHeader);
     DecodePacketHeader(value["packetHeader"], info.packetHeader);
     DecodePayloadData(value["payload"], info.payload, info.payloadHeader->GetProtocolID(), info.payloadHeader->GetMessageType());

     OutputValue(value);
 }

 void JsonBackend::LogMessageReceived(MessageReceivedInfo & info)
 {
     ::Json::Value value;

     value["event"] = "MessageReceived";

     switch (info.messageType)
     {
     case IncomingMessageType::kGroupMessage:
         value["messageType"] = "Group";
         break;
     case IncomingMessageType::kSecureUnicast:
         value["messageType"] = "Secure";
         break;
     case IncomingMessageType::kUnauthenticated:
         value["messageType"] = "Unauthenticated";
         break;
     }

     DecodePayloadHeader(value["payloadHeader"], info.payloadHeader);
     DecodePacketHeader(value["packetHeader"], info.packetHeader);
     DecodePayloadData(value["payload"], info.payload, info.payloadHeader->GetProtocolID(), info.payloadHeader->GetMessageType());

     OutputValue(value);
 }

 void JsonBackend::LogNodeLookup(NodeLookupInfo & info)
 {
     ::Json::Value value;

     value["event"]                = "LogNodeLookup";
     value["node_id"]              = info.request->GetPeerId().GetNodeId();
     value["compressed_fabric_id"] = info.request->GetPeerId().GetCompressedFabricId();
     value["min_lookup_time_ms"]   = info.request->GetMinLookupTime().count();
     value["max_lookup_time_ms"]   = info.request->GetMaxLookupTime().count();

     OutputValue(value);
 }

 void JsonBackend::LogNodeDiscovered(NodeDiscoveredInfo & info)
 {
     ::Json::Value value;
     value["event"] = "LogNodeDiscovered";

     value["node_id"]              = info.peerId->GetNodeId();
     value["compressed_fabric_id"] = info.peerId->GetCompressedFabricId();

     switch (info.type)
     {
     case chip::Tracing::DiscoveryInfoType::kIntermediateResult:
         value["type"] = "intermediate";
         break;
     case chip::Tracing::DiscoveryInfoType::kResolutionDone:
         value["type"] = "done";
         break;
     case chip::Tracing::DiscoveryInfoType::kRetryDifferent:
         value["type"] = "retry-different";
         break;
     }

     {
         ::Json::Value result;

         char address_buff[chip::Transport::PeerAddress::kMaxToStringSize];

         info.result->address.ToString(address_buff);

         result["supports_tcp_client"] = info.result->supportsTcpClient;
         result["supports_tcp_server"] = info.result->supportsTcpServer;
         result["address"]             = address_buff;

         result["mrp"]["idle_retransmit_timeout_ms"]   = info.result->mrpRemoteConfig.mIdleRetransTimeout.count();
         result["mrp"]["active_retransmit_timeout_ms"] = info.result->mrpRemoteConfig.mActiveRetransTimeout.count();
         result["mrp"]["active_threshold_time_ms"]     = info.result->mrpRemoteConfig.mActiveThresholdTime.count();

         result["isICDOperatingAsLIT"] = info.result->isICDOperatingAsLIT;

         value["result"] = result;
     }

     OutputValue(value);
 }

 void JsonBackend::LogNodeDiscoveryFailed(NodeDiscoveryFailedInfo & info)
 {
     ::Json::Value value;

     value["event"]                = "LogNodeDiscoveryFailed";
     value["node_id"]              = info.peerId->GetNodeId();
     value["compressed_fabric_id"] = info.peerId->GetCompressedFabricId();
     value["error"]                = chip::ErrorStr(info.error);

     OutputValue(value);
 }

 void JsonBackend::CloseFile()
 {
     if (!mOutputFile.is_open())
     {
         return;
     }

     mOutputFile << "]\n";

     mOutputFile.close();
 }

 CHIP_ERROR JsonBackend::OpenFile(const char * path)
 {
     CloseFile();
     mOutputFile.open(path, std::ios_base::out);

     if (!mOutputFile)
     {
         return CHIP_ERROR_POSIX(errno);
     }

     mOutputFile << "[\n";
     mFirstRecord = true;

     return CHIP_NO_ERROR;
 }

 void JsonBackend::OutputValue(::Json::Value & value)
 {
     ::Json::StreamWriterBuilder builder;
     std::unique_ptr<::Json::StreamWriter> writer(builder.newStreamWriter());

     if (mOutputFile.is_open())
     {
         if (!mFirstRecord)
         {
             mOutputFile << ",\n";
         }
         else
         {
             mFirstRecord = false;
         }
         value["time_ms"] = chip::System::SystemClock().GetMonotonicTimestamp().count();
         writer->write(value, &mOutputFile);
         mOutputFile.flush();
     }
     else
     {
         std::stringstream output;
         writer->write(value, &output);
         // For pretty-printing, output each log line individually.
         std::string data_string = output.str();
         chip::StringSplitter splitter(data_string.c_str(), '\n');

         chip::CharSpan line;
         while (splitter.Next(line))
         {
             ChipLogProgress(Automation, "%.*s", static_cast<int>(line.size()), line.data());
         }
     }
 }

 } // namespace Json
 } // namespace Tracing
 } // namespace chip
	/*
	*
	* Copyright (c) 2023 Project CHIP Authors
	* All rights reserved.
	*
	* 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
	*
	* http://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.
	*/

	#include <tracing/json/json_tracing.h>

	#include <lib/address_resolve/TracingStructs.h>
	#include <lib/core/ErrorStr.h>
	#include <lib/support/CHIPMem.h>
	#include <lib/support/StringBuilder.h>
	#include <lib/support/StringSplitter.h>
	#include <log_json/log_json_build_config.h>
	#include <tracing/metric_event.h>
	#include <transport/TracingStructs.h>

	#include <json/json.h>

	#include <errno.h>

	#include <sstream>
	#include <string>

	#if MATTER_LOG_JSON_DECODE_HEX
	#include <lib/support/BytesToHex.h> // nogncheck
	#endif

	#if MATTER_LOG_JSON_DECODE_FULL
	#include <lib/format/protocol_decoder.h> // nogncheck
	#include <tlv/meta/clusters_meta.h> // nogncheck
	#include <tlv/meta/protocols_meta.h> // nogncheck
	#endif

	namespace chip {
	namespace Tracing {
	namespace Json {

	namespace {

	using chip::StringBuilder;

	#if MATTER_LOG_JSON_DECODE_FULL

	using namespace chip::Decoders;

	using PayloadDecoderType = chip::Decoders::PayloadDecoder<64, 2048>;

	/// Figures out a unique name within a json object.
	///
	/// Decoded keys may be duplicated, like list elements are denoted as "[]".
	/// The existing code does not attempt to encode lists and everything is an object,
	/// so this name builder attempts to find unique keys for elements inside a json.
	///
	/// In particular a repeated "Anonymous<>", "Anonymous<>", ... will become "Anonymous<0>", ...
	class UniqueNameBuilder
	{
	public:
	UniqueNameBuilder(chip::StringBuilderBase & formatter) : mFormatter(formatter) {}
	const char * c_str() const { return mFormatter.c_str(); }

	// Figure out the next unique name in the given value
	//
	// After this returns, c_str() will return a name based on `baseName` that is
	// not a key of `value` (unless on overflows, which are just logged)
	void ComputeNextUniqueName(const char * baseName, ::Json::Value & value)
	{
	FirstName(baseName);
	while (value.isMember(mFormatter.c_str()))
	{
	NextName(baseName);
	if (!mFormatter.Fit())
	{
	ChipLogError(Automation, "Potential data loss: insufficient space for unique keys in json");
	return;
	}
	}
	}

	private:
	void FirstName(const char * baseName)
	{
	if (strcmp(baseName, "Anonymous<>") == 0)
	{
	mFormatter.Reset().Add("Anonymous<0>");
	}
	else
	{
	mFormatter.Reset().Add(baseName);
	}
	}

	void NextName(const char * baseName)
	{
	if (strcmp(baseName, "Anonymous<>") == 0)
	{
	mFormatter.Reset().Add("Anonymous<").Add(mUniqueIndex++).Add(">");
	}
	else
	{
	mFormatter.Reset().Add(baseName).Add("@").Add(mUniqueIndex++);
	}
	}

	chip::StringBuilderBase & mFormatter;
	int mUniqueIndex = 0;
	};

	// Gets the current value of the decoder until a NEST exit is returned
	::Json::Value GetPayload(PayloadDecoderType & decoder)
	{
	::Json::Value value;
	PayloadEntry entry;
	StringBuilder<128> formatter;
	UniqueNameBuilder nameBuilder(formatter);

	while (decoder.Next(entry))
	{
	switch (entry.GetType())
	{
	case PayloadEntry::IMPayloadType::kNestingEnter:
	// PayloadEntry validity is only until any decoder calls are made,
	// because the entry Name/Value may point into a shared Decoder buffer.
	//
	// As such entry.GetName() is only valid here and would not be valid once
	// GetPayload() is called as GetPayload calls decoder.Next, which invalidates
	// internal name and value buffers (makes them point to the next element).
	//
	// TLDR: name MUST be used and saved before GetPayload is executed.
	nameBuilder.ComputeNextUniqueName(entry.GetName(), value);
	value[nameBuilder.c_str()] = GetPayload(decoder);
	break;
	case PayloadEntry::IMPayloadType::kNestingExit:
	return value;
	case PayloadEntry::IMPayloadType::kAttribute:
	value[formatter.Reset().AddFormat("ATTR(%u/%u)", entry.GetClusterId(), entry.GetAttributeId()).c_str()] =
	"<NOT_DECODED>";
	break;
	case PayloadEntry::IMPayloadType::kCommand:
	value[formatter.Reset().AddFormat("CMD(%u/%u)", entry.GetClusterId(), entry.GetCommandId()).c_str()] = "<NOT_DECODED>";
	continue;
	case PayloadEntry::IMPayloadType::kEvent:
	value[formatter.Reset().AddFormat("EVNT(%u/%u)", entry.GetClusterId(), entry.GetEventId()).c_str()] = "<NOT_DECODED>";
	continue;
	default:
	nameBuilder.ComputeNextUniqueName(entry.GetName(), value);
	value[nameBuilder.c_str()] = entry.GetValueText();
	break;
	}
	}
	return value;
	}

	#endif

	void DecodePayloadHeader(::Json::Value & value, const PayloadHeader * payloadHeader)
	{

	value["exchangeFlags"] = payloadHeader->GetExchangeFlags();
	value["exchangeId"] = payloadHeader->GetExchangeID();
	value["protocolId"] = payloadHeader->GetProtocolID().ToFullyQualifiedSpecForm();
	value["messageType"] = payloadHeader->GetMessageType();
	value["initiator"] = payloadHeader->IsInitiator();
	value["needsAck"] = payloadHeader->NeedsAck();

	const Optional<uint32_t> & acknowledgedMessageCounter = payloadHeader->GetAckMessageCounter();
	if (acknowledgedMessageCounter.HasValue())
	{
	value["ackMessageCounter"] = acknowledgedMessageCounter.Value();
	}
	}

	void DecodePacketHeader(::Json::Value & value, const PacketHeader * packetHeader)
	{
	value["msgCounter"] = packetHeader->GetMessageCounter();
	value["sessionId"] = packetHeader->GetSessionId();
	value["flags"] = packetHeader->GetMessageFlags();
	value["securityFlags"] = packetHeader->GetSecurityFlags();

	{
	const Optional<NodeId> & nodeId = packetHeader->GetSourceNodeId();
	if (nodeId.HasValue())
	{
	value["sourceNodeId"] = nodeId.Value();
	}
	}

	{
	const Optional<NodeId> & nodeId = packetHeader->GetDestinationNodeId();
	if (nodeId.HasValue())
	{
	value["destinationNodeId"] = nodeId.Value();
	}
	}

	{
	const Optional<GroupId> & groupId = packetHeader->GetDestinationGroupId();
	if (groupId.HasValue())
	{
	value["groupId"] = groupId.Value();
	}
	}
	}

	void DecodePayloadData(::Json::Value & value, chip::ByteSpan payload, Protocols::Id protocolId, uint8_t messageType)
	{
	value["size"] = static_cast<::Json::Value::UInt>(payload.size());

	#if MATTER_LOG_JSON_DECODE_HEX
	char hex_buffer[4096];
	if (chip::Encoding::BytesToUppercaseHexString(payload.data(), payload.size(), hex_buffer, sizeof(hex_buffer)) == CHIP_NO_ERROR)
	{
	value["hex"] = hex_buffer;
	}
	#endif // MATTER_LOG_JSON_DECODE_HEX

	#if MATTER_LOG_JSON_DECODE_FULL

	// As PayloadDecoder is quite large (large strings buffers), we place it in heap
	auto decoder = chip::Platform::MakeUnique<PayloadDecoderType>(PayloadDecoderInitParams()
	.SetProtocolDecodeTree(chip::TLVMeta::protocols_meta)
	.SetClusterDecodeTree(chip::TLVMeta::clusters_meta)
	.SetProtocol(protocolId)
	.SetMessageType(messageType));

	decoder->StartDecoding(payload);

	value["decoded"] = GetPayload(*decoder);
	#endif // MATTER_LOG_JSON_DECODE_FULL
	}

	} // namespace

	JsonBackend::~JsonBackend()
	{
	CloseFile();
	}

	void JsonBackend::TraceBegin(const char * label, const char * group)
	{
	::Json::Value value;

	value["event"] = "TraceBegin";
	value["label"] = label;
	value["group"] = group;
	OutputValue(value);
	}

	void JsonBackend::TraceEnd(const char * label, const char * group)
	{
	::Json::Value value;
	value["event"] = "TraceEnd";
	value["label"] = label;
	value["group"] = group;
	OutputValue(value);
	}

	void JsonBackend::TraceInstant(const char * label, const char * group)
	{
	::Json::Value value;
	value["event"] = "TraceInstant";
	value["label"] = label;
	value["group"] = group;
	OutputValue(value);
	}

	void JsonBackend::TraceCounter(const char * label)
	{
	std::string counterId = std::string(label);
	if (mCounters.find(counterId) == mCounters.end())
	{
	mCounters[counterId] = 1;
	}
	else
	{
	mCounters[counterId]++;
	}
	::Json::Value value;
	value["event"] = "TraceCounter";
	value["label"] = label;
	value["count"] = mCounters[counterId];

	// Output the counter event
	OutputValue(value);
	}

	void JsonBackend::LogMetricEvent(const MetricEvent & event)
	{
	::Json::Value value;

	value["label"] = event.key();

	using ValueType = MetricEvent::Value::Type;
	switch (event.ValueType())
	{
	case ValueType::kInt32:
	value["value"] = event.ValueInt32();
	break;
	case ValueType::kUInt32:
	value["value"] = event.ValueUInt32();
	break;
	case ValueType::kChipErrorCode:
	value["value"] = event.ValueErrorCode();
	break;
	case ValueType::kUndefined:
	value["value"] = ::Json::Value();
	break;
	default:
	value["value"] = "UNKNOWN";
	break;
	}

	OutputValue(value);
	}

	void JsonBackend::LogMessageSend(MessageSendInfo & info)
	{
	::Json::Value value;

	value["event"] = "MessageSend";

	switch (info.messageType)
	{
	case OutgoingMessageType::kGroupMessage:
	value["messageType"] = "Group";
	break;
	case OutgoingMessageType::kSecureSession:
	value["messageType"] = "Secure";
	break;
	case OutgoingMessageType::kUnauthenticated:
	value["messageType"] = "Unauthenticated";
	break;
	}

	DecodePayloadHeader(value["payloadHeader"], info.payloadHeader);
	DecodePacketHeader(value["packetHeader"], info.packetHeader);
	DecodePayloadData(value["payload"], info.payload, info.payloadHeader->GetProtocolID(), info.payloadHeader->GetMessageType());

	OutputValue(value);
	}

	void JsonBackend::LogMessageReceived(MessageReceivedInfo & info)
	{
	::Json::Value value;

	value["event"] = "MessageReceived";

	switch (info.messageType)
	{
	case IncomingMessageType::kGroupMessage:
	value["messageType"] = "Group";
	break;
	case IncomingMessageType::kSecureUnicast:
	value["messageType"] = "Secure";
	break;
	case IncomingMessageType::kUnauthenticated:
	value["messageType"] = "Unauthenticated";
	break;
	}

	DecodePayloadHeader(value["payloadHeader"], info.payloadHeader);
	DecodePacketHeader(value["packetHeader"], info.packetHeader);
	DecodePayloadData(value["payload"], info.payload, info.payloadHeader->GetProtocolID(), info.payloadHeader->GetMessageType());

	OutputValue(value);
	}

	void JsonBackend::LogNodeLookup(NodeLookupInfo & info)
	{
	::Json::Value value;

	value["event"] = "LogNodeLookup";
	value["node_id"] = info.request->GetPeerId().GetNodeId();
	value["compressed_fabric_id"] = info.request->GetPeerId().GetCompressedFabricId();
	value["min_lookup_time_ms"] = info.request->GetMinLookupTime().count();
	value["max_lookup_time_ms"] = info.request->GetMaxLookupTime().count();

	OutputValue(value);
	}

	void JsonBackend::LogNodeDiscovered(NodeDiscoveredInfo & info)
	{
	::Json::Value value;
	value["event"] = "LogNodeDiscovered";

	value["node_id"] = info.peerId->GetNodeId();
	value["compressed_fabric_id"] = info.peerId->GetCompressedFabricId();

	switch (info.type)
	{
	case chip::Tracing::DiscoveryInfoType::kIntermediateResult:
	value["type"] = "intermediate";
	break;
	case chip::Tracing::DiscoveryInfoType::kResolutionDone:
	value["type"] = "done";
	break;
	case chip::Tracing::DiscoveryInfoType::kRetryDifferent:
	value["type"] = "retry-different";
	break;
	}

	{
	::Json::Value result;

	char address_buff[chip::Transport::PeerAddress::kMaxToStringSize];

	info.result->address.ToString(address_buff);

	result["supports_tcp_client"] = info.result->supportsTcpClient;
	result["supports_tcp_server"] = info.result->supportsTcpServer;
	result["address"] = address_buff;

	result["mrp"]["idle_retransmit_timeout_ms"] = info.result->mrpRemoteConfig.mIdleRetransTimeout.count();
	result["mrp"]["active_retransmit_timeout_ms"] = info.result->mrpRemoteConfig.mActiveRetransTimeout.count();
	result["mrp"]["active_threshold_time_ms"] = info.result->mrpRemoteConfig.mActiveThresholdTime.count();

	result["isICDOperatingAsLIT"] = info.result->isICDOperatingAsLIT;

	value["result"] = result;
	}

	OutputValue(value);
	}

	void JsonBackend::LogNodeDiscoveryFailed(NodeDiscoveryFailedInfo & info)
	{
	::Json::Value value;

	value["event"] = "LogNodeDiscoveryFailed";
	value["node_id"] = info.peerId->GetNodeId();
	value["compressed_fabric_id"] = info.peerId->GetCompressedFabricId();
	value["error"] = chip::ErrorStr(info.error);

	OutputValue(value);
	}

	void JsonBackend::CloseFile()
	{
	if (!mOutputFile.is_open())
	{
	return;
	}

	mOutputFile << "]\n";

	mOutputFile.close();
	}

	CHIP_ERROR JsonBackend::OpenFile(const char * path)
	{
	CloseFile();
	mOutputFile.open(path, std::ios_base::out);

	if (!mOutputFile)
	{
	return CHIP_ERROR_POSIX(errno);
	}

	mOutputFile << "[\n";
	mFirstRecord = true;

	return CHIP_NO_ERROR;
	}

	void JsonBackend::OutputValue(::Json::Value & value)
	{
	::Json::StreamWriterBuilder builder;
	std::unique_ptr<::Json::StreamWriter> writer(builder.newStreamWriter());

	if (mOutputFile.is_open())
	{
	if (!mFirstRecord)
	{
	mOutputFile << ",\n";
	}
	else
	{
	mFirstRecord = false;
	}
	value["time_ms"] = chip::System::SystemClock().GetMonotonicTimestamp().count();
	writer->write(value, &mOutputFile);
	mOutputFile.flush();
	}
	else
	{
	std::stringstream output;
	writer->write(value, &output);
	// For pretty-printing, output each log line individually.
	std::string data_string = output.str();
	chip::StringSplitter splitter(data_string.c_str(), '\n');

	chip::CharSpan line;
	while (splitter.Next(line))
	{
	ChipLogProgress(Automation, "%.*s", static_cast<int>(line.size()), line.data());
	}
	}
	}

	} // namespace Json
	} // namespace Tracing
	} // namespace chip