//===--- CachingUtils.h -----------------------------------------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#ifndef SWIFT_FRONTEND_CACHINGUTILS_H
#define SWIFT_FRONTEND_CACHINGUTILS_H

#include "swift/Frontend/CASOutputBackends.h"
#include "swift/Frontend/CachedDiagnostics.h"
#include "swift/Frontend/FrontendInputsAndOutputs.h"
#include "swift/Frontend/FrontendOptions.h"
#include "clang/CAS/CASOptions.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/CAS/ActionCache.h"
#include "llvm/CAS/CASReference.h"
#include "llvm/CAS/ObjectStore.h"
#include "llvm/Support/PrefixMapper.h"
#include "llvm/Support/VirtualFileSystem.h"
#include "llvm/Support/VirtualOutputBackend.h"
#include <memory>

namespace swift {

class DiagnosticHelper;

/// Create a swift caching output backend that stores the output from
/// compiler into a CAS.
llvm::IntrusiveRefCntPtr<cas::SwiftCASOutputBackend>
createSwiftCachingOutputBackend(
    llvm::cas::ObjectStore &CAS, llvm::cas::ActionCache &Cache,
    llvm::cas::ObjectRef BaseKey,
    const FrontendInputsAndOutputs &InputsAndOutputs,
    const FrontendOptions &Opts, FrontendOptions::ActionType Action);

/// Replay the output of the compilation from cache.
/// Return true if outputs are replayed, false otherwise.
bool replayCachedCompilerOutputs(llvm::cas::ObjectStore &CAS,
                                 llvm::cas::ActionCache &Cache,
                                 llvm::cas::ObjectRef BaseKey,
                                 DiagnosticEngine &Diag,
                                 const FrontendOptions &Opts,
                                 CachingDiagnosticsProcessor &CDP,
                                 bool CacheRemarks, bool UseCASBackend);

/// Replay the output of the compilation from cache for one input file.
/// Return true if outputs are replayed, false otherwise.
bool replayCachedCompilerOutputsForInput(llvm::cas::ObjectStore &CAS,
                                         llvm::cas::ObjectRef OutputRef,
                                         const InputFile &Input,
                                         unsigned InputIndex,
                                         DiagnosticEngine &Diag,
                                         DiagnosticHelper &DiagHelper,
                                         llvm::vfs::OutputBackend &OutBackend,
                                         const FrontendOptions &Opts,
                                         CachingDiagnosticsProcessor &CDP,
                                         bool CacheRemarks, bool UseCASBackend);

/// Load the cached compile result from cache.
std::unique_ptr<llvm::MemoryBuffer> loadCachedCompileResultFromCacheKey(
    llvm::cas::ObjectStore &CAS, llvm::cas::ActionCache &Cache,
    DiagnosticEngine &Diag, llvm::StringRef CacheKey, file_types::ID Type,
    llvm::StringRef Filename = "");

llvm::Expected<llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>>
createCASFileSystem(llvm::cas::ObjectStore &CAS,
                    const std::string &IncludeTreeRoot,
                    const std::string &IncludeTreeFileList);

std::vector<std::string> remapPathsFromCommandLine(
    ArrayRef<std::string> Args,
    llvm::function_ref<std::string(StringRef)> RemapCallback);

namespace cas {
class CachedResultLoader {
public:
  CachedResultLoader(llvm::cas::ObjectStore &CAS,
                     llvm::cas::ObjectRef OutputRef)
      : CAS(CAS), OutputRef(OutputRef) {}

  using CallbackTy =
      llvm::function_ref<llvm::Error(file_types::ID, llvm::cas::ObjectRef)>;

  /// Replay the cached result.
  llvm::Error replay(CallbackTy Callback);

private:
  llvm::cas::ObjectStore &CAS;
  llvm::cas::ObjectRef OutputRef;
};
} // end namespace cas
} // end namespace swift

#endif