func newTracer()

in tracer.go [447:557]
106 lines of code
5 McCabe index (conditional complexity)

func newTracer(opts TracerOptions) *Tracer {
	t := &Tracer{
		transport: opts.Transport,
		service: makeService(
			opts.ServiceName,
			opts.ServiceVersion,
			opts.ServiceEnvironment,
		),
		process:           &currentProcess,
		system:            &localSystem,
		closing:           make(chan struct{}),
		closed:            make(chan struct{}),
		forceFlush:        make(chan chan<- struct{}),
		forceSendMetrics:  make(chan chan<- struct{}),
		configCommands:    make(chan tracerConfigCommand),
		configWatcher:     make(chan apmconfig.Watcher),
		events:            make(chan tracerEvent, tracerEventChannelCap),
		active:            1,
		breakdownMetrics:  newBreakdownMetrics(),
		stats:             &TracerStats{},
		bufferSize:        opts.bufferSize,
		metricsBufferSize: opts.metricsBufferSize,
		profileSender:     opts.profileSender,
		versionGetter:     opts.versionGetter,
		instrumentationConfigInternal: &instrumentationConfig{
			local: make(map[string]func(*instrumentationConfigValues)),
		},
		globalLabels: opts.globalLabels,
	}
	t.breakdownMetrics.enabled = opts.breakdownMetrics
	// Initialise local transaction config.
	t.setLocalInstrumentationConfig(envRecording, func(cfg *instrumentationConfigValues) {
		cfg.recording = opts.recording
	})
	t.setLocalInstrumentationConfig(envCaptureBody, func(cfg *instrumentationConfigValues) {
		cfg.captureBody = opts.captureBody
	})
	t.setLocalInstrumentationConfig(envCaptureHeaders, func(cfg *instrumentationConfigValues) {
		cfg.captureHeaders = opts.captureHeaders
	})
	t.setLocalInstrumentationConfig(envMaxSpans, func(cfg *instrumentationConfigValues) {
		cfg.maxSpans = opts.maxSpans
	})
	t.setLocalInstrumentationConfig(envSpanCompressionEnabled, func(cfg *instrumentationConfigValues) {
		cfg.compressionOptions.enabled = opts.compressionOptions.enabled
	})
	t.setLocalInstrumentationConfig(envSpanCompressionExactMatchMaxDuration, func(cfg *instrumentationConfigValues) {
		cfg.compressionOptions.exactMatchMaxDuration = opts.compressionOptions.exactMatchMaxDuration
	})
	t.setLocalInstrumentationConfig(envSpanCompressionSameKindMaxDuration, func(cfg *instrumentationConfigValues) {
		cfg.compressionOptions.sameKindMaxDuration = opts.compressionOptions.sameKindMaxDuration
	})
	t.setLocalInstrumentationConfig(envTransactionSampleRate, func(cfg *instrumentationConfigValues) {
		cfg.sampler = opts.sampler
	})
	t.setLocalInstrumentationConfig(envSpanStackTraceMinDuration, func(cfg *instrumentationConfigValues) {
		cfg.spanStackTraceMinDuration = opts.spanStackTraceMinDuration
	})
	t.setLocalInstrumentationConfig(envStackTraceLimit, func(cfg *instrumentationConfigValues) {
		cfg.stackTraceLimit = opts.stackTraceLimit
	})
	t.setLocalInstrumentationConfig(envUseElasticTraceparentHeader, func(cfg *instrumentationConfigValues) {
		cfg.propagateLegacyHeader = opts.propagateLegacyHeader
	})
	t.setLocalInstrumentationConfig(envSanitizeFieldNames, func(cfg *instrumentationConfigValues) {
		cfg.sanitizedFieldNames = opts.sanitizedFieldNames
	})
	t.setLocalInstrumentationConfig(envIgnoreURLs, func(cfg *instrumentationConfigValues) {
		cfg.ignoreTransactionURLs = opts.ignoreTransactionURLs
	})
	t.setLocalInstrumentationConfig(envExitSpanMinDuration, func(cfg *instrumentationConfigValues) {
		cfg.exitSpanMinDuration = opts.exitSpanMinDuration
	})
	t.setLocalInstrumentationConfig(envContinuationStrategy, func(cfg *instrumentationConfigValues) {
		cfg.continuationStrategy = opts.continuationStrategy
	})
	if logger := apmlog.DefaultLogger(); logger != nil {
		defaultLogLevel := logger.Level()
		t.setLocalInstrumentationConfig(apmlog.EnvLogLevel, func(cfg *instrumentationConfigValues) {
			// Revert to the original, local, log level when
			// the centrally defined log level is removed.
			logger.SetLevel(defaultLogLevel)
		})
	}

	if !opts.active {
		t.active = 0
		close(t.closed)
		return t
	}

	go t.loop()
	t.configCommands <- func(cfg *tracerConfig) {
		cfg.recording = opts.recording
		cfg.cpuProfileInterval = opts.cpuProfileInterval
		cfg.cpuProfileDuration = opts.cpuProfileDuration
		cfg.heapProfileInterval = opts.heapProfileInterval
		cfg.metricsInterval = opts.metricsInterval
		cfg.requestDuration = opts.requestDuration
		cfg.requestSize = opts.requestSize
		cfg.disabledMetrics = opts.disabledMetrics
		cfg.metricsGatherers = []MetricsGatherer{newBuiltinMetricsGatherer(t)}
		if logger := apmlog.DefaultLogger(); logger != nil {
			cfg.logger = logger
		}
	}
	if opts.configWatcher != nil {
		t.configWatcher <- opts.configWatcher
	}
	return t
}