The Tor Browser: widget/windows/IEnumFE.cpp@ac0c01689b40

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #include "IEnumFE.h"

     7 #include "nsAlgorithm.h"

     8 #include <algorithm>

    10 CEnumFormatEtc::CEnumFormatEtc() :

    11   mRefCnt(0),

    12   mCurrentIdx(0)

    13 {

    14 }

    16 // Constructor used by Clone()

    17 CEnumFormatEtc::CEnumFormatEtc(nsTArray<FormatEtc>& aArray) :

    18   mRefCnt(0),

    19   mCurrentIdx(0)

    20 {

    21   // a deep copy, calls FormatEtc's copy constructor on each

    22   mFormatList.AppendElements(aArray);

    23 }

    25 CEnumFormatEtc::~CEnumFormatEtc()

    26 {

    27 }

    29 /* IUnknown impl. */

    31 STDMETHODIMP

    32 CEnumFormatEtc::QueryInterface(REFIID riid, LPVOID *ppv)

    33 {

    34   *ppv = nullptr;

    36   if (IsEqualIID(riid, IID_IUnknown) ||

    37       IsEqualIID(riid, IID_IEnumFORMATETC))

    38       *ppv = (LPVOID)this;

    40   if (*ppv == nullptr)

    41       return E_NOINTERFACE;

    43   // AddRef any interface we'll return.

    44   ((LPUNKNOWN)*ppv)->AddRef();

    45   return S_OK;

    46 }

    48 STDMETHODIMP_(ULONG)

    49 CEnumFormatEtc::AddRef()

    50 {

    51   ++mRefCnt;

    52   NS_LOG_ADDREF(this, mRefCnt, "CEnumFormatEtc",sizeof(*this));

    53   return mRefCnt;

    54 }

    56 STDMETHODIMP_(ULONG)

    57 CEnumFormatEtc::Release()

    58 {

    59   uint32_t refReturn;

    61   refReturn = --mRefCnt;

    62   NS_LOG_RELEASE(this, mRefCnt, "CEnumFormatEtc");

    64   if (mRefCnt == 0)

    65       delete this;

    67   return refReturn;

    68 }

    70 /* IEnumFORMATETC impl. */

    72 STDMETHODIMP

    73 CEnumFormatEtc::Next(ULONG aMaxToFetch, FORMATETC *aResult, ULONG *aNumFetched)

    74 {

    75   // If the method retrieves the number of items requested, the return

    76   // value is S_OK. Otherwise, it is S_FALSE.

    78   if (aNumFetched)

    79       *aNumFetched = 0;

    81   // aNumFetched can be null if aMaxToFetch is 1

    82   if (!aNumFetched && aMaxToFetch > 1)

    83       return S_FALSE;

    85   if (!aResult)

    86       return S_FALSE;

    88   // We're done walking the list

    89   if (mCurrentIdx >= mFormatList.Length())

    90       return S_FALSE;

    92   uint32_t left = mFormatList.Length() - mCurrentIdx;

    94   if (!aMaxToFetch)

    95       return S_FALSE;

    97   uint32_t count = std::min(static_cast<uint32_t>(aMaxToFetch), left);

    99   uint32_t idx = 0;

   100   while (count > 0) {

   101       // Copy out to aResult

   102       mFormatList[mCurrentIdx++].CopyOut(&aResult[idx++]);

   103       count--;

   104   }

   106   if (aNumFetched)

   107       *aNumFetched = idx;

   109   return S_OK;

   110 }

   112 STDMETHODIMP

   113 CEnumFormatEtc::Skip(ULONG aSkipNum)

   114 {

   115   // If the method skips the number of items requested, the return value is S_OK.

   116   // Otherwise, it is S_FALSE.

   118   if ((mCurrentIdx + aSkipNum) >= mFormatList.Length())

   119       return S_FALSE;

   121   mCurrentIdx += aSkipNum;

   123   return S_OK;

   124 }

   126 STDMETHODIMP

   127 CEnumFormatEtc::Reset(void)

   128 {

   129   mCurrentIdx = 0;

   130   return S_OK;

   131 }

   133 STDMETHODIMP

   134 CEnumFormatEtc::Clone(LPENUMFORMATETC *aResult)

   135 {

   136   // Must return a new IEnumFORMATETC interface with the same iterative state.

   138   if (!aResult)

   139       return E_INVALIDARG;

   141   CEnumFormatEtc * pEnumObj = new CEnumFormatEtc(mFormatList);

   143   if (!pEnumObj)

   144       return E_OUTOFMEMORY;

   146   pEnumObj->AddRef();

   147   pEnumObj->SetIndex(mCurrentIdx);

   149   *aResult = pEnumObj;

   151   return S_OK;

   152 }

   154 /* utils */

   156 void

   157 CEnumFormatEtc::AddFormatEtc(LPFORMATETC aFormat)

   158 {

   159   if (!aFormat)

   160       return;

   161   FormatEtc * etc = mFormatList.AppendElement();

   162   // Make a copy of aFormat

   163   if (etc)

   164       etc->CopyIn(aFormat);

   165 }

   167 /* private */

   169 void

   170 CEnumFormatEtc::SetIndex(uint32_t aIdx)

   171 {

   172   mCurrentIdx = aIdx;

   173 }

The Tor Browser / file revision

widget/windows/IEnumFE.cpp@ac0c01689b40

widget/windows/IEnumFE.cpp