Merge pull request #997 from iamemilio/slog-2.0

Slog 2.0

Author: nr-swilloughby

v3/integrations/logcontext-v2/nrslog/attributes.go

@@ -0,0 +1,97 @@
+package nrslog
+
+import (
+	"log/slog"
+	"maps"
+	"strings"
+)
+
+type attributeCache struct {
+	preCompiledAttributes map[string]interface{}
+	prefix                string
+}
+
+func newAttributeCache() *attributeCache {
+	return &attributeCache{
+		preCompiledAttributes: make(map[string]interface{}),
+		prefix:                "",
+	}
+}
+
+func (c *attributeCache) clone() *attributeCache {
+	return &attributeCache{
+		preCompiledAttributes: maps.Clone(c.preCompiledAttributes),
+		prefix:                c.prefix,
+	}
+}
+
+func (c *attributeCache) copyPreCompiledAttributes() map[string]interface{} {
+	return maps.Clone(c.preCompiledAttributes)
+}
+
+func (c *attributeCache) getPrefix() string {
+	return c.prefix
+}
+
+// precompileGroup sets the group prefix for the cache created by a handler
+// precompileGroup call. This is used to avoid re-computing the group prefix
+// and should only ever be called on newly created caches and handlers.
+func (c *attributeCache) precompileGroup(group string) {
+	if c.prefix != "" {
+		c.prefix += "."
+	}
+	c.prefix += group
+}
+
+// precompileAttributes appends attributes to the cache created by a handler
+// WithAttrs call. This is used to avoid re-computing the with Attrs attributes
+// and should only ever be called on newly created caches and handlers.
+func (c *attributeCache) precompileAttributes(attrs []slog.Attr) {
+	if len(attrs) == 0 {
+		return
+	}
+
+	for _, a := range attrs {
+		c.appendAttr(c.preCompiledAttributes, a, c.prefix)
+	}
+}
+
+func (c *attributeCache) appendAttr(nrAttrs map[string]interface{}, a slog.Attr, groupPrefix string) {
+	// Resolve the Attr's value before doing anything else.
+	a.Value = a.Value.Resolve()
+	// Ignore empty Attrs.
+	if a.Equal(slog.Attr{}) {
+		return
+	}
+
+	// majority of runtime spent allocating and copying strings
+	group := strings.Builder{}
+	group.Grow(len(groupPrefix) + len(a.Key) + 1)
+	group.WriteString(groupPrefix)
+
+	if a.Key != "" {
+		if group.Len() > 0 {
+			group.WriteByte('.')
+		}
+		group.WriteString(a.Key)
+	}
+
+	key := group.String()
+
+	// If the Attr is a group, append its attributes
+	if a.Value.Kind() == slog.KindGroup {
+		attrs := a.Value.Group()
+		// Ignore empty groups.
+		if len(attrs) == 0 {
+			return
+		}
+
+		for _, ga := range attrs {
+			c.appendAttr(nrAttrs, ga, key)
+		}
+		return
+	}
+
+	// attr is an attribute
+	nrAttrs[key] = a.Value.Any()
+}

v3/integrations/logcontext-v2/nrslog/config.go

@@ -0,0 +1,80 @@
+package nrslog
+
+import (
+	"time"
+
+	"github.com/newrelic/go-agent/v3/newrelic"
+)
+
+const updateFrequency = 1 * time.Minute // check infrequently because the go agent config is not expected to change --> cost 50-100 uS
+
+// 44% faster than checking the config on every log message
+type configCache struct {
+	lastCheck time.Time
+
+	// true if we have successfully gotten the config at least once to verify the agent is connected
+	gotStartupConfig bool
+	// true if the logs in context feature is enabled as well as either local decorating or forwarding
+	enabled     bool
+	enrichLogs  bool
+	forwardLogs bool
+}
+
+func newConfigCache() *configCache {
+	return &configCache{}
+}
+
+func (c *configCache) clone() *configCache {
+	return &configCache{
+		lastCheck:        c.lastCheck,
+		gotStartupConfig: c.gotStartupConfig,
+		enabled:          c.enabled,
+		enrichLogs:       c.enrichLogs,
+		forwardLogs:      c.forwardLogs,
+	}
+}
+
+func (c *configCache) shouldEnrichLog(app *newrelic.Application) bool {
+	c.update(app)
+	return c.enrichLogs
+}
+
+func (c *configCache) shouldForwardLogs(app *newrelic.Application) bool {
+	c.update(app)
+	return c.forwardLogs
+}
+
+// isEnabled returns true if the logs in context feature is enabled
+// as well as either local decorating or forwarding.
+func (c *configCache) isEnabled(app *newrelic.Application) bool {
+	c.update(app)
+	return c.enabled
+}
+
+// Note: this has a data race in async use cases, but it does not
+// cause logical errors, only cache misses. This is acceptable in
+// comparison to the cost of synchronization.
+func (c *configCache) update(app *newrelic.Application) {
+	// do not get the config from agent if we have successfully gotten it before
+	// and it has been less than updateFrequency since the last check. This is
+	// because on startup, the agent will return a dummy config until it has
+	// connected and received the real config.
+	if c.gotStartupConfig && time.Since(c.lastCheck) < updateFrequency {
+		return
+	}
+
+	config, ok := app.Config()
+	if !ok {
+		c.enrichLogs = false
+		c.forwardLogs = false
+		c.enabled = false
+		return
+	}
+
+	c.gotStartupConfig = true
+	c.enrichLogs = config.ApplicationLogging.LocalDecorating.Enabled && config.ApplicationLogging.Enabled
+	c.forwardLogs = config.ApplicationLogging.Forwarding.Enabled && config.ApplicationLogging.Enabled
+	c.enabled = config.ApplicationLogging.Enabled && (c.enrichLogs || c.forwardLogs)
+
+	c.lastCheck = time.Now()
+}

v3/integrations/logcontext-v2/nrslog/go.mod

@@ -4,5 +4,4 @@ go 1.21
 
 require github.com/newrelic/go-agent/v3 v3.36.0
 
-
 replace github.com/newrelic/go-agent/v3 => ../../..