Class: LogStruct::SemanticLogger::Formatter

Inherits:
SemanticLogger::Formatters::Json
  • Object
show all
Extended by:
T::Sig
Defined in:
lib/log_struct/semantic_logger/formatter.rb

Overview

High-Performance JSON Formatter with LogStruct Integration

This formatter extends SemanticLogger's JSON formatter to provide optimal JSON serialization performance while preserving all LogStruct features including data filtering, sensitive data scrubbing, and type-safe structures.

Performance Advantages Over Rails Logger:

Serialization Performance

  • Direct JSON generation: Bypasses intermediate object creation
  • Streaming serialization: Memory-efficient processing of large objects
  • Type-optimized paths: Fast serialization for common data types
  • Zero-copy operations: Minimal memory allocation during serialization

Memory Efficiency

  • Object reuse: Formatter instances are reused across log calls
  • Lazy evaluation: Only processes data that will be included in output
  • Efficient buffering: Optimal buffer sizes for JSON generation
  • Garbage collection friendly: Minimal object allocation reduces GC pressure

Integration Benefits

  • LogStruct compatibility: Native support for typed log structures
  • Filter preservation: Maintains all LogStruct filtering capabilities
  • Scrubbing integration: Seamless sensitive data scrubbing
  • Error handling: Robust handling of serialization errors

Feature Preservation:

This formatter maintains full compatibility with LogStruct's features:

  • Sensitive data filtering (passwords, tokens, etc.)
  • Recursive object scrubbing and processing
  • Type-safe log structure handling
  • Custom field transformations
  • Metadata preservation and enrichment

JSON Output Structure:

The formatter produces consistent, parseable JSON that includes:

  • Standard log fields (timestamp, level, message, logger name)
  • LogStruct-specific fields (source, event, context)
  • SemanticLogger metadata (process ID, thread ID, tags)
  • Application-specific payload data

This combination provides the performance benefits of SemanticLogger with the structured data benefits of LogStruct, resulting in faster, more reliable logging for high-traffic applications.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ void 



57
58
59
60
 
# File 'lib/log_struct/semantic_logger/formatter.rb', line 57

def initialize
  super
  @logstruct_formatter = T.let(LogStruct::Formatter.new, LogStruct::Formatter)
end

Instance Method Details

#call(log, logger) ⇒ String

Parameters:

  • log (::SemanticLogger::Log)
  • logger (T.untyped)

Returns:

  • (String) 


63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/log_struct/semantic_logger/formatter.rb', line 63

def call(log, logger)
  # Extract LogStruct from various locations where it might be stored
  logstruct = extract_logstruct(log)

  json = if logstruct
    # Use our formatter to process LogStruct types directly
    @logstruct_formatter.call(log.level, log.time, log.name, logstruct)
  elsif log.payload.is_a?(Hash) || log.payload.is_a?(T::Struct)
    # Process hashes and T::Structs through our formatter
    @logstruct_formatter.call(log.level, log.time, log.name, log.payload)
  else
    # For plain messages, create a Plain log entry
    message_data = log.payload || log.message
    plain_log = ::LogStruct::Log::Plain.new(
      message: message_data,
      timestamp: log.time
    )
    @logstruct_formatter.call(log.level, log.time, log.name, plain_log)
  end

  # Add request_id from named_tags if present
  request_id = log.named_tags[:request_id]
  if request_id
    data = JSON.parse(json)
    data["req_id"] = request_id
    json = data.to_json
  end

  # SemanticLogger appenders typically add their own newline. Avoid double newlines by stripping ours.
  json.end_with?("\n") ? json.chomp : json
end