pkg/tarsum/builder_context.go

package tarsum

// This interface extends TarSum by adding the Remove method.  In general
// there was concern about adding this method to TarSum itself so instead
// it is being added just to "BuilderContext" which will then only be used
// during the .dockerignore file processing - see builder/evaluator.go
type BuilderContext interface {
	TarSum
	Remove(string)
}

func (bc *tarSum) Remove(filename string) {
	for i, fis := range bc.sums {
		if fis.Name() == filename {
			bc.sums = append(bc.sums[:i], bc.sums[i+1:]...)
			// Note, we don't just return because there could be
			// more than one with this name
		}
	}
}