Quelle nsStringFlags.h Sprache: C

/* -*- 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 nsStringFlags_h
#define nsStringFlags_h

#include <stdint.h>
#include "mozilla/TypedEnumBits.h"

namespace mozilla {
namespace detail {
// NOTE: these flags are declared public _only_ for convenience inside
// the string implementation.  And they are outside of the string
// class so that the type is the same for both narrow and wide
// strings.

// bits for mDataFlags
enum class StringDataFlags : uint16_t {
  // Some terminology:
  //
  //   "dependent buffer"    A dependent buffer is one that the string class
  //                         does not own.  The string class relies on some
  //                         external code to ensure the lifetime of the
  //                         dependent buffer.
  //
  //   "refcounted buffer"   A refcounted buffer is one that the string class
  //                         allocates.  When it allocates a refcounted string
  //                         buffer, it allocates some additional space at
  //                         the beginning of the buffer for additional
  //                         fields, including a reference count and a
  //                         buffer length.  See nsStringHeader.
  //
  //   "adopted buffer"      An adopted buffer is a raw string buffer
  //                         allocated on the heap (using moz_xmalloc)
  //                         of which the string class subsumes ownership.
  //
  // Some comments about the string data flags:
  //
  //   REFCOUNTED, OWNED, and INLINE are all mutually exlusive.  They
  //   indicate the allocation type of mData.  If none of these flags
  //   are set, then the string buffer is dependent.
  //
  //   REFCOUNTED, OWNED, or INLINE imply TERMINATED.  This is because
  //   the string classes always allocate null-terminated buffers, and
  //   non-terminated substrings are always dependent.
  //
  //   VOIDED implies TERMINATED, and moreover it implies that mData
  //   points to char_traits::sEmptyBuffer.  Therefore, VOIDED is
  //   mutually exclusive with REFCOUNTED, OWNED, and INLINE.
  //
  //   INLINE requires StringClassFlags::INLINE to be set on the type.

  // IsTerminated returns true
  TERMINATED = 1 << 0,

  // IsVoid returns true
  VOIDED = 1 << 1,

  // mData points to a heap-allocated, shareable, refcounted buffer
  REFCOUNTED = 1 << 2,

  // mData points to a heap-allocated, raw buffer
  OWNED = 1 << 3,

  // mData points to a writable, inline buffer
  INLINE = 1 << 4,

  // mData points to a string literal; DataFlags::TERMINATED will also be set
  LITERAL = 1 << 5,

  // used to check for invalid flags -- all bits above the last item
  INVALID_MASK = (uint16_t) ~((LITERAL << 1) - 1)
};

// bits for mClassFlags
enum class StringClassFlags : uint16_t {
  // |this|'s buffer is inline, and requires the type to be binary-compatible
  // with nsTAutoStringN
  INLINE = 1 << 0,
  // |this| requires its buffer is null-terminated
  NULL_TERMINATED = 1 << 1,
  // used to check for invalid flags -- all bits above the last item
  INVALID_MASK = (uint16_t) ~((NULL_TERMINATED << 1) - 1)
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(StringDataFlags)
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(StringClassFlags)

}  // namespace detail
}  // namespace mozilla

#endif

quality100%

¤ Dauer der Verarbeitung: 0.27 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.