//===-- LockFileBase.cpp --------------------------------------------------===//

//

// 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 "lldb/Host/LockFileBase.h"

using namespace lldb;

using namespace lldb_private;

static Status AlreadyLocked() { return Status("Already locked"); }

static Status NotLocked() { return Status("Not locked"); }

LockFileBase::LockFileBase(int fd)

    : m_fd(fd), m_locked(false), m_start(0), m_len(0) {}

bool LockFileBase::IsLocked() const { return m_locked; }

Status LockFileBase::WriteLock(const uint64_t start, const uint64_t len) {

  return DoLock([&](const uint64_t start,

                    const uint64_t len) { return DoWriteLock(start, len); },

                start, len);

}

Status LockFileBase::TryWriteLock(const uint64_t start, const uint64_t len) {

  return DoLock([&](const uint64_t start,

                    const uint64_t len) { return DoTryWriteLock(start, len); },

                start, len);

}

Status LockFileBase::ReadLock(const uint64_t start, const uint64_t len) {

  return DoLock([&](const uint64_t start,

                    const uint64_t len) { return DoReadLock(start, len); },

                start, len);

}

Status LockFileBase::TryReadLock(const uint64_t start, const uint64_t len) {

  return DoLock([&](const uint64_t start,

                    const uint64_t len) { return DoTryReadLock(start, len); },

                start, len);

}

Status LockFileBase::Unlock() {

  if (!IsLocked())

    return NotLocked();

  const auto error = DoUnlock();

  if (error.Success()) {

    m_locked = false;

    m_start = 0;

    m_len = 0;

  }

  return error;

}

bool LockFileBase::IsValidFile() const { return m_fd != -1; }

Status LockFileBase::DoLock(const Locker &locker, const uint64_t start,

                            const uint64_t len) {

  if (!IsValidFile())

    return Status("File is invalid");

  if (IsLocked())

    return AlreadyLocked();

  const auto error = locker(start, len);

  if (error.Success()) {

    m_locked = true;

    m_start = start;

    m_len = len;

  }

  return error;

}