mfbt/Range.h
author Jim Chen <nchen@mozilla.com>
Wed, 20 Jun 2018 16:46:20 -0400
changeset 423113 2806729c61eaac199ad4670788c4008079a99f34
parent 350727 261772d7198542e9cf1f0577a55446785a2c189d
child 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1469683 - 1. Fix crash tests; r=esawin Specify individual sessions in crash tests (i.e. "mainSession.waitUntilCalled" instead of "sessionRule.waitUntilCalled"), so that the tests assert behavior on the correct session, and not inadvertently on the cached session. Also, under x86 debug builds, Gecko installs an "ah_crap_handler" for SIGSEGV that waits for a long time, which causes our crash tests to time out. Therefore, ignore crash tests under x86 debug. MozReview-Commit-ID: DdtmRBLmPGp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_Range_h
#define mozilla_Range_h

#include "mozilla/RangedPtr.h"
#include "mozilla/TypeTraits.h"
#include "mozilla/Span.h"

#include <stddef.h>

namespace mozilla {

// Range<T> is a tuple containing a pointer and a length.
template <typename T>
class Range
{
  const RangedPtr<T> mStart;
  const RangedPtr<T> mEnd;

public:
  Range() : mStart(nullptr, 0), mEnd(nullptr, 0) {}
  Range(T* aPtr, size_t aLength)
    : mStart(aPtr, aPtr, aPtr + aLength),
      mEnd(aPtr + aLength, aPtr, aPtr + aLength)
  {}
  Range(const RangedPtr<T>& aStart, const RangedPtr<T>& aEnd)
    : mStart(aStart.get(), aStart.get(), aEnd.get()),
      mEnd(aEnd.get(), aStart.get(), aEnd.get())
  {
    // Only accept two RangedPtrs within the same range.
    aStart.checkIdenticalRange(aEnd);
    MOZ_ASSERT(aStart <= aEnd);
  }

  template<typename U,
           class = typename EnableIf<IsConvertible<U (*)[], T (*)[]>::value,
                                     int>::Type>
  MOZ_IMPLICIT Range(const Range<U>& aOther)
    : mStart(aOther.mStart),
      mEnd(aOther.mEnd)
  {}

  MOZ_IMPLICIT Range(Span<T> aSpan)
    : Range(aSpan.Elements(), aSpan.Length())
  {
  }

  template<typename U,
           class = typename EnableIf<IsConvertible<U (*)[], T (*)[]>::value,
                                     int>::Type>
  MOZ_IMPLICIT Range(const Span<U>& aSpan)
    : Range(aSpan.Elements(), aSpan.Length())
  {
  }

  RangedPtr<T> begin() const { return mStart; }
  RangedPtr<T> end() const { return mEnd; }
  size_t length() const { return mEnd - mStart; }

  T& operator[](size_t aOffset) const { return mStart[aOffset]; }

  explicit operator bool() const { return mStart != nullptr; }

  operator Span<T>() { return Span<T>(mStart.get(), length()); }

  operator Span<const T>() const { return Span<T>(mStart.get(), length()); }
};

template<class T>
Span<T>
MakeSpan(Range<T>& aRange)
{
  return aRange;
}

template<class T>
Span<const T>
MakeSpan(const Range<T>& aRange)
{
  return aRange;
}

} // namespace mozilla

#endif /* mozilla_Range_h */