// Walk down the free list calling f() on the in-range portions, until // f() returns true or we run out of free space. Return true iff f() returned true func (s *Space) walkFree(r address.Range, f func(address.Range) bool) bool { if r.Start >= r.End { // degenerate case return false } for i := 0; i < len(s.free); i += 2 { chunk := address.Range{Start: s.free[i], End: s.free[i+1]} if chunk.End <= r.Start { // this chunk comes before the range continue } if chunk.Start >= r.End { // all remaining free space is completely after range break } // at this point we know chunk.End>chunk.Start && // chunk.End>r.Start && r.End>chunk.Start && r.End>r.Start // therefore max(start, r.Start) < min(end, r.End) // Restrict this block of free space to be in range if chunk.Start < r.Start { chunk.Start = r.Start } if chunk.End > r.End { chunk.End = r.End } // at this point we know start<end if f(chunk) { return true } } return false }