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//===- ContinuousRangeMap.h - Map with int range as key ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ContinuousRangeMap class, which is a highly
// specialized container used by serialization.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_SERIALIZATION_CONTINUOUSRANGEMAP_H
#define LLVM_CLANG_SERIALIZATION_CONTINUOUSRANGEMAP_H
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include <algorithm>
#include <cassert>
#include <utility>
namespace clang {
/// A map from continuous integer ranges to some value, with a very
/// specialized interface.
///
/// CRM maps from integer ranges to values. The ranges are continuous, i.e.
/// where one ends, the next one begins. So if the map contains the stops I0-3,
/// the first range is from I0 to I1, the second from I1 to I2, the third from
/// I2 to I3 and the last from I3 to infinity.
///
/// Ranges must be inserted in order. Inserting a new stop I4 into the map will
/// shrink the fourth range to I3 to I4 and add the new range I4 to inf.
template <typename Int, typename V, unsigned InitialCapacity>
class ContinuousRangeMap {
public:
using value_type = std::pair<Int, V>;
using reference = value_type &;
using const_reference = const value_type &;
using pointer = value_type *;
using const_pointer = const value_type *;
private:
using Representation = SmallVector<value_type, InitialCapacity>;
Representation Rep;
struct Compare {
bool operator ()(const_reference L, Int R) const {
return L.first < R;
}
bool operator ()(Int L, const_reference R) const {
return L < R.first;
}
bool operator ()(Int L, Int R) const {
return L < R;
}
bool operator ()(const_reference L, const_reference R) const {
return L.first < R.first;
}
};
public:
void insert(const value_type &Val) {
if (!Rep.empty() && Rep.back() == Val)
return;
assert((Rep.empty() || Rep.back().first < Val.first) &&
"Must insert keys in order.");
Rep.push_back(Val);
}
void insertOrReplace(const value_type &Val) {
iterator I = std::lower_bound(Rep.begin(), Rep.end(), Val, Compare());
if (I != Rep.end() && I->first == Val.first) {
I->second = Val.second;
return;
}
Rep.insert(I, Val);
}
using iterator = typename Representation::iterator;
using const_iterator = typename Representation::const_iterator;
iterator begin() { return Rep.begin(); }
iterator end() { return Rep.end(); }
const_iterator begin() const { return Rep.begin(); }
const_iterator end() const { return Rep.end(); }
iterator find(Int K) {
iterator I = std::upper_bound(Rep.begin(), Rep.end(), K, Compare());
// I points to the first entry with a key > K, which is the range that
// follows the one containing K.
if (I == Rep.begin())
return Rep.end();
--I;
return I;
}
const_iterator find(Int K) const {
return const_cast<ContinuousRangeMap*>(this)->find(K);
}
reference back() { return Rep.back(); }
const_reference back() const { return Rep.back(); }
/// An object that helps properly build a continuous range map
/// from a set of values.
class Builder {
ContinuousRangeMap &Self;
public:
explicit Builder(ContinuousRangeMap &Self) : Self(Self) {}
Builder(const Builder&) = delete;
Builder &operator=(const Builder&) = delete;
~Builder() {
llvm::sort(Self.Rep.begin(), Self.Rep.end(), Compare());
std::unique(Self.Rep.begin(), Self.Rep.end(),
[](const_reference A, const_reference B) {
// FIXME: we should not allow any duplicate keys, but there are a lot of
// duplicate 0 -> 0 mappings to remove first.
assert((A == B || A.first != B.first) &&
"ContinuousRangeMap::Builder given non-unique keys");
return A == B;
});
}
void insert(const value_type &Val) {
Self.Rep.push_back(Val);
}
};
friend class Builder;
};
} // namespace clang
#endif // LLVM_CLANG_SERIALIZATION_CONTINUOUSRANGEMAP_H