//===- llvm/Support/StringSaver.h -------------------------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_STRINGSAVER_H

#define LLVM_SUPPORT_STRINGSAVER_H

#include "llvm/ADT/DenseSet.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/ADT/Twine.h"

#include "llvm/Support/Allocator.h"

namespace llvm {

/// Saves strings in the provided stable storage and returns a

/// StringRef with a stable character pointer.

class StringSaver final {

  BumpPtrAllocator &Alloc;

public:

  StringSaver(BumpPtrAllocator &Alloc) : Alloc(Alloc) {}

  // All returned strings are null-terminated: *save(S).end() == 0.

  StringRef save(const char *S) { return save(StringRef(S)); }

  StringRef save(StringRef S);

  StringRef save(const Twine &S) { return save(StringRef(S.str())); }

  StringRef save(const std::string &S) { return save(StringRef(S)); }

};

/// Saves strings in the provided stable storage and returns a StringRef with a

/// stable character pointer. Saving the same string yields the same StringRef.

///

/// Compared to StringSaver, it does more work but avoids saving the same string

/// multiple times.

///

/// Compared to StringPool, it performs fewer allocations but doesn't support

/// refcounting/deletion.

class UniqueStringSaver final {

  StringSaver Strings;

  llvm::DenseSet<llvm::StringRef> Unique;

public:

  UniqueStringSaver(BumpPtrAllocator &Alloc) : Strings(Alloc) {}

  // All returned strings are null-terminated: *save(S).end() == 0.

  StringRef save(const char *S) { return save(StringRef(S)); }

  StringRef save(StringRef S);

  StringRef save(const Twine &S) { return save(StringRef(S.str())); }

  StringRef save(const std::string &S) { return save(StringRef(S)); }

};

}

#endif