| // Copyright (C) 2015 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package memory |
| |
| import ( |
| "fmt" |
| |
| "android.googlesource.com/platform/tools/gpu/binary" |
| "android.googlesource.com/platform/tools/gpu/interval" |
| ) |
| |
| func min(a, b uint64) uint64 { |
| if a < b { |
| return a |
| } else { |
| return b |
| } |
| } |
| |
| func max(a, b uint64) uint64 { |
| if a > b { |
| return a |
| } else { |
| return b |
| } |
| } |
| |
| // Range represents a region of memory. |
| type Range struct { |
| binary.Generate |
| Base Pointer // A pointer to the first byte in the memory range. |
| Size uint64 // The size in bytes of the memory range. |
| } |
| |
| // Expand returns a new Range that is grown to include the pointer p. |
| func (i Range) Expand(p Pointer) Range { |
| if i.Base > p { |
| i.Base = p |
| } |
| if i.Last() < p { |
| i.Size += uint64(p - i.Last()) |
| } |
| return i |
| } |
| |
| // Contains returns true if the pointer p is within the Range. |
| func (i Range) Contains(p Pointer) bool { |
| return i.First() <= p && p <= i.Last() |
| } |
| |
| // Overlaps returns true if other overlaps this memory range. |
| func (i Range) Overlaps(other Range) bool { |
| a, b := i.Span(), other.Span() |
| s, e := max(a.Start, b.Start), min(a.End, b.End) |
| return s < e |
| } |
| |
| // Intersect returns the Range that is common between this Range and other. |
| // If the two memory ranges do not intersect, then this function panics. |
| func (i Range) Intersect(other Range) Range { |
| a, b := i.Span(), other.Span() |
| s, e := max(a.Start, b.Start), min(a.End, b.End) |
| if e < s { |
| panic(fmt.Errorf("Intervals %v and %v do not intersect", i, other)) |
| } |
| return Range{Base: Pointer(s), Size: e - s} |
| } |
| |
| // First returns a Pointer to the first byte in the Range. |
| func (i Range) First() Pointer { |
| return i.Base |
| } |
| |
| // Last returns a Pointer to the last byte in the Range. |
| func (i Range) Last() Pointer { |
| return i.End() - 1 |
| } |
| |
| // End returns a Pointer to one byte beyond the end of the Range. |
| func (i Range) End() Pointer { |
| return i.Base + Pointer(i.Size) |
| } |
| |
| // Span returns the Range as a U64Span. |
| func (i Range) Span() interval.U64Span { |
| return interval.U64Span{ |
| Start: uint64(i.Base), |
| End: uint64(i.Base) + i.Size, |
| } |
| } |
| |
| func (i Range) String() string { |
| return fmt.Sprintf("[%v-%v]", i.First(), i.Last()) |
| } |