package context import ( "time" "golang.org/x/net/context" ) // Since looks up key, which should be a time.Time, and returns the duration // since that time. If the key is not found, the value returned will be zero. // This is helpful when inferring metrics related to context execution times. func Since(ctx context.Context, key interface{}) time.Duration { startedAtI := ctx.Value(key) if startedAtI != nil { if startedAt, ok := startedAtI.(time.Time); ok { return time.Since(startedAt) } } return 0 } // GetStringValue returns a string value from the context. The empty string // will be returned if not found. func GetStringValue(ctx context.Context, key string) (value string) { stringi := ctx.Value(key) if stringi != nil { if valuev, ok := stringi.(string); ok { value = valuev } } return value }