zap_helpers.go

package log

import (
	"context"
)

type ctxKeyType struct{}

var ctxKey ctxKeyType

// Inject stores the logger in the context.
func Inject(ctx context.Context, log *Logger) context.Context {
	return context.WithValue(ctx, ctxKey, log)
}

// FromContext extracts a logger from the context or returns false, if log is not found.
func FromContext(ctx context.Context) (*Logger, bool) {
	var log, ok = ctx.Value(ctxKey).(*Logger)
	return log, ok
}

// FromContextOr extracts a logger from the context or returns the provided alternative (from the `or` parameter).
func FromContextOr(ctx context.Context, or *Logger) *Logger {
	var log, ok = FromContext(ctx)
	if !ok {
		return or
	}
	return log
}

// Named extracts logger from context or uses the provided default, names it and returns context with named logger.
func Named(ctx context.Context, name string, def *Logger) (context.Context, *Logger) {
	var lg = FromContextOr(ctx, def).Named(name)
	return Inject(ctx, lg), lg
}

// MustFromContext return a non-nil logger from the context or panic if the logger is not found.
func MustFromContext(ctx context.Context) *Logger {
	var log, _ = ctx.Value(ctxKey).(*Logger)
	if log == nil {
		panic("[log.MustFromContext] logger is not found in the context")
	}
	return log
}