//===- InMemoryModuleCache.cpp - Cache for loaded memory buffers ----------===//

//

// 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

//

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

#include "clang/Serialization/InMemoryModuleCache.h"

#include "llvm/Support/MemoryBuffer.h"

using namespace clang;

InMemoryModuleCache::State

InMemoryModuleCache::getPCMState(llvm::StringRef Filename) const {

  auto I = PCMs.find(Filename);

  if (I == PCMs.end())

    return Unknown;

  if (I->second.IsFinal)

    return Final;

  return I->second.Buffer ? Tentative : ToBuild;

}

llvm::MemoryBuffer &

InMemoryModuleCache::addPCM(llvm::StringRef Filename,

                            std::unique_ptr<llvm::MemoryBuffer> Buffer) {

  auto Insertion = PCMs.insert(std::make_pair(Filename, std::move(Buffer)));

  assert(Insertion.second && "Already has a PCM");

  return *Insertion.first->second.Buffer;

}

llvm::MemoryBuffer &

InMemoryModuleCache::addBuiltPCM(llvm::StringRef Filename,

                                 std::unique_ptr<llvm::MemoryBuffer> Buffer) {

  auto &PCM = PCMs[Filename];

  assert(!PCM.IsFinal && "Trying to override finalized PCM?");

  assert(!PCM.Buffer && "Trying to override tentative PCM?");

  PCM.Buffer = std::move(Buffer);

  PCM.IsFinal = true;

  return *PCM.Buffer;

}

llvm::MemoryBuffer *

InMemoryModuleCache::lookupPCM(llvm::StringRef Filename) const {

  auto I = PCMs.find(Filename);

  if (I == PCMs.end())

    return nullptr;

  return I->second.Buffer.get();

}

bool InMemoryModuleCache::isPCMFinal(llvm::StringRef Filename) const {

  return getPCMState(Filename) == Final;

}

bool InMemoryModuleCache::shouldBuildPCM(llvm::StringRef Filename) const {

  return getPCMState(Filename) == ToBuild;

}

bool InMemoryModuleCache::tryToDropPCM(llvm::StringRef Filename) {

  auto I = PCMs.find(Filename);

  assert(I != PCMs.end() && "PCM to remove is unknown...");

  auto &PCM = I->second;

  assert(PCM.Buffer && "PCM to remove is scheduled to be built...");

  if (PCM.IsFinal)

    return true;

  PCM.Buffer.reset();

  return false;

}

void InMemoryModuleCache::finalizePCM(llvm::StringRef Filename) {

  auto I = PCMs.find(Filename);

  assert(I != PCMs.end() && "PCM to finalize is unknown...");

  auto &PCM = I->second;

  assert(PCM.Buffer && "Trying to finalize a dropped PCM...");

  PCM.IsFinal = true;

}