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// Copyright (C) 2010 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
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
#include <map>
#include <set>
#include <vector>
#include <base/macros.h>
#include "update_engine/update_metadata.pb.h"
// An ExtentRanges object represents an unordered collection of extents (and
// therefore blocks). Such an object may be modified by adding or subtracting
// blocks (think: set addition or set subtraction). Note that ExtentRanges
// ignores sparse hole extents mostly to avoid confusion between extending a
// sparse hole range vs. set addition but also to ensure that the delta
// generator doesn't use sparse holes as scratch space.
namespace chromeos_update_engine {
struct ExtentLess {
bool operator()(const Extent& x, const Extent& y) const {
return x.start_block() < y.start_block();
Extent ExtentForRange(uint64_t start_block, uint64_t num_blocks);
Extent ExtentForBytes(uint64_t block_size,
uint64_t start_bytes,
uint64_t size_bytes);
class ExtentRanges {
typedef std::set<Extent, ExtentLess> ExtentSet;
ExtentRanges() : blocks_(0) {}
void AddBlock(uint64_t block);
void SubtractBlock(uint64_t block);
void AddExtent(Extent extent);
void SubtractExtent(const Extent& extent);
void AddExtents(const std::vector<Extent>& extents);
void SubtractExtents(const std::vector<Extent>& extents);
void AddRepeatedExtents(
const ::google::protobuf::RepeatedPtrField<Extent>& exts);
void SubtractRepeatedExtents(
const ::google::protobuf::RepeatedPtrField<Extent>& exts);
void AddRanges(const ExtentRanges& ranges);
void SubtractRanges(const ExtentRanges& ranges);
// Returns whether the block |block| is in this ExtentRange.
bool ContainsBlock(uint64_t block) const;
static bool ExtentsOverlapOrTouch(const Extent& a, const Extent& b);
static bool ExtentsOverlap(const Extent& a, const Extent& b);
// Dumps contents to the log file. Useful for debugging.
void Dump() const;
uint64_t blocks() const { return blocks_; }
const ExtentSet& extent_set() const { return extent_set_; }
// Returns an ordered vector of extents for |count| blocks,
// using extents in extent_set_. The returned extents are not
// removed from extent_set_. |count| must be less than or equal to
// the number of blocks in this extent set.
std::vector<Extent> GetExtentsForBlockCount(uint64_t count) const;
ExtentSet extent_set_;
uint64_t blocks_;
// Filters out from the passed list of extents |extents| all the blocks in the
// ExtentRanges set. Note that the order of the blocks in |extents| is preserved
// omitting blocks present in the ExtentRanges |ranges|.
std::vector<Extent> FilterExtentRanges(const std::vector<Extent>& extents,
const ExtentRanges& ranges);
} // namespace chromeos_update_engine