tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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Utils.h (3770B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef mozilla_mscom_Utils_h
      8 #define mozilla_mscom_Utils_h
      9 
     10 #if defined(MOZILLA_INTERNAL_API)
     11 #  include "nsString.h"
     12 #endif  // defined(MOZILLA_INTERNAL_API)
     13 
     14 #include "mozilla/Attributes.h"
     15 #include <guiddef.h>
     16 #include <stdint.h>
     17 
     18 struct IStream;
     19 struct IUnknown;
     20 
     21 namespace mozilla {
     22 namespace mscom {
     23 namespace detail {
     24 
     25 enum class GuidType {
     26  CLSID,
     27  AppID,
     28 };
     29 
     30 long BuildRegGuidPath(REFGUID aGuid, const GuidType aGuidType, wchar_t* aBuf,
     31                      const size_t aBufLen);
     32 
     33 }  // namespace detail
     34 
     35 bool IsCOMInitializedOnCurrentThread();
     36 bool IsCurrentThreadMTA();
     37 bool IsCurrentThreadExplicitMTA();
     38 bool IsCurrentThreadImplicitMTA();
     39 #if defined(MOZILLA_INTERNAL_API)
     40 bool IsCurrentThreadNonMainMTA();
     41 #endif  // defined(MOZILLA_INTERNAL_API)
     42 bool IsProxy(IUnknown* aUnknown);
     43 bool IsValidGUID(REFGUID aCheckGuid);
     44 uintptr_t GetContainingModuleHandle();
     45 
     46 template <size_t N>
     47 inline long BuildAppidPath(REFGUID aAppId, wchar_t (&aPath)[N]) {
     48  return detail::BuildRegGuidPath(aAppId, detail::GuidType::AppID, aPath, N);
     49 }
     50 
     51 template <size_t N>
     52 inline long BuildClsidPath(REFCLSID aClsid, wchar_t (&aPath)[N]) {
     53  return detail::BuildRegGuidPath(aClsid, detail::GuidType::CLSID, aPath, N);
     54 }
     55 
     56 /**
     57 * Given a buffer, create a new IStream object.
     58 * @param aBuf Buffer containing data to initialize the stream. This parameter
     59 *             may be nullptr, causing the stream to be created with aBufLen
     60 *             bytes of uninitialized data.
     61 * @param aBufLen Length of data in aBuf, or desired stream size if aBuf is
     62 *                nullptr.
     63 * @param aOutStream Outparam to receive the newly created stream.
     64 * @return HRESULT error code.
     65 */
     66 long CreateStream(const uint8_t* aBuf, const uint32_t aBufLen,
     67                  IStream** aOutStream);
     68 
     69 /**
     70 * Length of a stringified GUID as formatted for the registry, i.e. including
     71 * curly-braces and dashes.
     72 */
     73 constexpr size_t kGuidRegFormatCharLenInclNul = 39;
     74 
     75 #if defined(MOZILLA_INTERNAL_API)
     76 void GUIDToString(REFGUID aGuid, nsAString& aOutString);
     77 
     78 /**
     79 * Converts an IID to a human-readable string for the purposes of diagnostic
     80 * tools such as the profiler. For some special cases, we output a friendly
     81 * string that describes the purpose of the interface. If no such description
     82 * exists, we simply fall back to outputting the IID as a string formatted by
     83 * GUIDToString().
     84 */
     85 void DiagnosticNameForIID(REFIID aIid, nsACString& aOutString);
     86 #else
     87 void GUIDToString(REFGUID aGuid,
     88                  wchar_t (&aOutBuf)[kGuidRegFormatCharLenInclNul]);
     89 #endif  // defined(MOZILLA_INTERNAL_API)
     90 
     91 /**
     92 * Execute cleanup code when going out of scope if a condition is met.
     93 * This is useful when, for example, particular cleanup needs to be performed
     94 * whenever a call returns a failure HRESULT.
     95 * Both the condition and cleanup code are provided as functions (usually
     96 * lambdas).
     97 */
     98 template <typename CondFnT, typename ExeFnT>
     99 class MOZ_RAII ExecuteWhen final {
    100 public:
    101  ExecuteWhen(CondFnT& aCondFn, ExeFnT& aExeFn)
    102      : mCondFn(aCondFn), mExeFn(aExeFn) {}
    103 
    104  ~ExecuteWhen() {
    105    if (mCondFn()) {
    106      mExeFn();
    107    }
    108  }
    109 
    110  ExecuteWhen(const ExecuteWhen&) = delete;
    111  ExecuteWhen(ExecuteWhen&&) = delete;
    112  ExecuteWhen& operator=(const ExecuteWhen&) = delete;
    113  ExecuteWhen& operator=(ExecuteWhen&&) = delete;
    114 
    115 private:
    116  CondFnT& mCondFn;
    117  ExeFnT& mExeFn;
    118 };
    119 
    120 }  // namespace mscom
    121 }  // namespace mozilla
    122 
    123 #endif  // mozilla_mscom_Utils_h