The Tor Browser: gfx/skia/trunk/src/core/SkMatrixClipStateMgr.cpp@97036ab72558 (annotated)

gfx/skia/trunk/src/core/SkMatrixClipStateMgr.cpp@97036ab72558 (annotated)

gfx/skia/trunk/src/core/SkMatrixClipStateMgr.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkMatrixClipStateMgr.h"
 #include "SkPictureRecord.h"
 bool SkMatrixClipStateMgr::MatrixClipState::ClipInfo::clipPath(SkPictureRecord* picRecord,
                                                                const SkPath& path,
                                                                SkRegion::Op op,
                                                                bool doAA,
                                                                int matrixID) {
     int pathID = picRecord->addPathToHeap(path);
     ClipOp* newClip = fClips.append();
     newClip->fClipType = kPath_ClipType;
     newClip->fGeom.fPathID = pathID;
     newClip->fOp = op;
     newClip->fDoAA = doAA;
     newClip->fMatrixID = matrixID;
     return false;
 }
 bool SkMatrixClipStateMgr::MatrixClipState::ClipInfo::clipRegion(SkPictureRecord* picRecord,
                                                                  int regionID,
                                                                  SkRegion::Op op,
                                                                  int matrixID) {
     ClipOp* newClip = fClips.append();
     newClip->fClipType = kRegion_ClipType;
     newClip->fGeom.fRegionID = regionID;
     newClip->fOp = op;
     newClip->fDoAA = true;      // not necessary but sanity preserving
     newClip->fMatrixID = matrixID;
     return false;
 }
 void SkMatrixClipStateMgr::writeDeltaMat(int currentMatID, int desiredMatID) {
     const SkMatrix& current = this->lookupMat(currentMatID);
     const SkMatrix& desired = this->lookupMat(desiredMatID);
     SkMatrix delta;
     bool result = current.invert(&delta);
     if (result) {
         delta.preConcat(desired);
     }
     fPicRecord->recordConcat(delta);
 }
 // Note: this only writes out the clips for the current save state. To get the
 // entire clip stack requires iterating of the entire matrix/clip stack.
 void SkMatrixClipStateMgr::MatrixClipState::ClipInfo::writeClip(int* curMatID,
                                                                 SkMatrixClipStateMgr* mgr) {
     for (int i = 0; i < fClips.count(); ++i) {
         ClipOp& curClip = fClips[i];
         // TODO: use the matrix ID to skip writing the identity matrix
         // over and over, i.e.:
         //  if (*curMatID != curClip.fMatrixID) {
         //      mgr->writeDeltaMat...
         //      *curMatID...
         //  }
         // Right now this optimization would throw off the testing harness.
         // TODO: right now we're writing out the delta matrix from the prior
         // matrix state. This is a side-effect of writing out the entire
         // clip stack and should be resolved when that is fixed.
         mgr->writeDeltaMat(*curMatID, curClip.fMatrixID);
         *curMatID = curClip.fMatrixID;
         int offset = 0;
         switch (curClip.fClipType) {
         case kRect_ClipType:
             offset = mgr->getPicRecord()->recordClipRect(curClip.fGeom.fRRect.rect(),
                                                          curClip.fOp, curClip.fDoAA);
             break;
         case kRRect_ClipType:
             offset = mgr->getPicRecord()->recordClipRRect(curClip.fGeom.fRRect, curClip.fOp,
                                                          curClip.fDoAA);
             break;
         case kPath_ClipType:
             offset = mgr->getPicRecord()->recordClipPath(curClip.fGeom.fPathID, curClip.fOp,
                                                          curClip.fDoAA);
             break;
         case kRegion_ClipType: {
             const SkRegion* region = mgr->lookupRegion(curClip.fGeom.fRegionID);
             offset = mgr->getPicRecord()->recordClipRegion(*region, curClip.fOp);
             break;
         }
         default:
             SkASSERT(0);
         }
         mgr->addClipOffset(offset);
     }
 }
 SkMatrixClipStateMgr::SkMatrixClipStateMgr()
     : fPicRecord(NULL)
     , fMatrixClipStack(sizeof(MatrixClipState),
                        fMatrixClipStackStorage,
                        sizeof(fMatrixClipStackStorage))
     , fCurOpenStateID(kIdentityWideOpenStateID) {
     fSkipOffsets = SkNEW(SkTDArray<int>);
     // The first slot in the matrix dictionary is reserved for the identity matrix
     fMatrixDict.append()->reset();
     fCurMCState = (MatrixClipState*)fMatrixClipStack.push_back();
     new (fCurMCState) MatrixClipState(NULL, 0);    // balanced in restore()
 #ifdef SK_DEBUG
     fActualDepth = 0;
 #endif
 }
 SkMatrixClipStateMgr::~SkMatrixClipStateMgr() {
     for (int i = 0; i < fRegionDict.count(); ++i) {
         SkDELETE(fRegionDict[i]);
     }
     SkDELETE(fSkipOffsets);
 }
 int SkMatrixClipStateMgr::MCStackPush(SkCanvas::SaveFlags flags) {
     MatrixClipState* newTop = (MatrixClipState*)fMatrixClipStack.push_back();
     new (newTop) MatrixClipState(fCurMCState, flags); // balanced in restore()
     fCurMCState = newTop;
     SkDEBUGCODE(this->validate();)
     return fMatrixClipStack.count();
 }
 int SkMatrixClipStateMgr::save(SkCanvas::SaveFlags flags) {
     SkDEBUGCODE(this->validate();)
     return this->MCStackPush(flags);
 }
 int SkMatrixClipStateMgr::saveLayer(const SkRect* bounds, const SkPaint* paint,
                                     SkCanvas::SaveFlags flags) {
 #ifdef SK_DEBUG
     if (fCurMCState->fIsSaveLayer) {
         SkASSERT(0 == fSkipOffsets->count());
     }
 #endif
     // Since the saveLayer call draws something we need to potentially dump
     // out the MC state
     SkDEBUGCODE(bool saved =) this->call(kOther_CallType);
     int result = this->MCStackPush(flags);
     ++fCurMCState->fLayerID;
     fCurMCState->fIsSaveLayer = true;
 #ifdef SK_DEBUG
     if (saved) {
         fCurMCState->fExpectedDepth++; // 1 for nesting save
     }
     fCurMCState->fExpectedDepth++;   // 1 for saveLayer
 #endif
     *fStateIDStack.append() = fCurOpenStateID;
     fCurMCState->fSavedSkipOffsets = fSkipOffsets;
     // TODO: recycle these rather then new & deleting them on every saveLayer/
     // restore
     fSkipOffsets = SkNEW(SkTDArray<int>);
     fPicRecord->recordSaveLayer(bounds, paint,
                                 (SkCanvas::SaveFlags)(flags| SkCanvas::kMatrixClip_SaveFlag));
 #ifdef SK_DEBUG
     fActualDepth++;
 #endif
     return result;
 }
 void SkMatrixClipStateMgr::restore() {
     SkDEBUGCODE(this->validate();)
     if (fCurMCState->fIsSaveLayer) {
         if (fCurMCState->fHasOpen) {
             fCurMCState->fHasOpen = false;
             fPicRecord->recordRestore(); // Close the open block inside the saveLayer
 #ifdef SK_DEBUG
             SkASSERT(fActualDepth > 0);
             fActualDepth--;
 #endif
         } else {
             SkASSERT(0 == fSkipOffsets->count());
         }
         // The saveLayer's don't carry any matrix or clip state in the
         // new scheme so make sure the saveLayer's recordRestore doesn't
         // try to finalize them (i.e., fill in their skip offsets).
         fPicRecord->recordRestore(false); // close of saveLayer
 #ifdef SK_DEBUG
         SkASSERT(fActualDepth > 0);
         fActualDepth--;
 #endif
         SkASSERT(fStateIDStack.count() >= 1);
         fCurOpenStateID = fStateIDStack[fStateIDStack.count()-1];
         fStateIDStack.pop();
         SkASSERT(0 == fSkipOffsets->count());
         SkASSERT(NULL != fCurMCState->fSavedSkipOffsets);
         SkDELETE(fSkipOffsets);
         fSkipOffsets = fCurMCState->fSavedSkipOffsets;
     }
     bool prevHadOpen = fCurMCState->fHasOpen;
     bool prevWasSaveLayer = fCurMCState->fIsSaveLayer;
     fCurMCState->~MatrixClipState();       // balanced in save()
     fMatrixClipStack.pop_back();
     fCurMCState = (MatrixClipState*)fMatrixClipStack.back();
     if (!prevWasSaveLayer) {
         fCurMCState->fHasOpen = prevHadOpen;
     }
     if (fCurMCState->fIsSaveLayer) {
         if (0 != fSkipOffsets->count()) {
             SkASSERT(fCurMCState->fHasOpen);
         }
     }
     SkDEBUGCODE(this->validate();)
 }
 // kIdentityWideOpenStateID (0) is reserved for the identity/wide-open clip state
 int32_t SkMatrixClipStateMgr::NewMCStateID() {
     // TODO: guard against wrap around
     // TODO: make uint32_t
     static int32_t gMCStateID = kIdentityWideOpenStateID;
     ++gMCStateID;
     return gMCStateID;
 }
 bool SkMatrixClipStateMgr::isNestingMCState(int stateID) {
     return fStateIDStack.count() > 0 && fStateIDStack[fStateIDStack.count()-1] == fCurOpenStateID;
 }
 bool SkMatrixClipStateMgr::call(CallType callType) {
     SkDEBUGCODE(this->validate();)
     if (kMatrix_CallType == callType || kClip_CallType == callType) {
         fCurMCState->fMCStateID = NewMCStateID();
         SkDEBUGCODE(this->validate();)
         return false;
     }
     SkASSERT(kOther_CallType == callType);
     if (fCurMCState->fMCStateID == fCurOpenStateID) {
         // Required MC state is already active one - nothing to do
         SkDEBUGCODE(this->validate();)
         return false;
     }
     if (kIdentityWideOpenStateID != fCurOpenStateID &&
         !this->isNestingMCState(fCurOpenStateID)) {
         // Don't write a restore if the open state is one in which a saveLayer
         // is nested. The save after the saveLayer's restore will close it.
         fPicRecord->recordRestore();    // Close the open block
         fCurMCState->fHasOpen = false;
 #ifdef SK_DEBUG
         SkASSERT(fActualDepth > 0);
         fActualDepth--;
 #endif
     }
     // Install the required MC state as the active one
     fCurOpenStateID = fCurMCState->fMCStateID;
     if (kIdentityWideOpenStateID == fCurOpenStateID) {
         SkASSERT(0 == fActualDepth);
         SkASSERT(!fCurMCState->fHasOpen);
         SkASSERT(0 == fSkipOffsets->count());
         return false;
     }
     SkASSERT(!fCurMCState->fHasOpen);
     SkASSERT(0 == fSkipOffsets->count());
     fCurMCState->fHasOpen = true;
     fPicRecord->recordSave(SkCanvas::kMatrixClip_SaveFlag);
 #ifdef SK_DEBUG
     fActualDepth++;
     SkASSERT(fActualDepth == fCurMCState->fExpectedDepth);
 #endif
     // write out clips
     SkDeque::Iter iter(fMatrixClipStack, SkDeque::Iter::kBack_IterStart);
     const MatrixClipState* state;
     // Loop back across the MC states until the last saveLayer. The MC
     // state in front of the saveLayer has already been written out.
     for (state = (const MatrixClipState*) iter.prev();
          state != NULL;
          state = (const MatrixClipState*) iter.prev()) {
         if (state->fIsSaveLayer) {
             break;
         }
     }
     int curMatID;
     if (NULL == state) {
         // There was no saveLayer in the MC stack so we need to output them all
         iter.reset(fMatrixClipStack, SkDeque::Iter::kFront_IterStart);
         state = (const MatrixClipState*) iter.next();
         curMatID = kIdentityMatID;
     } else {
         // SkDeque's iterators actually return the previous location so we
         // need to reverse and go forward one to get back on track.
         iter.next();
         SkDEBUGCODE(const MatrixClipState* test = (const MatrixClipState*)) iter.next();
         SkASSERT(test == state);
         curMatID = state->fMatrixInfo->getID(this);
         // TODO: this assumes that, in the case of Save|SaveLayer when the SaveLayer
         // doesn't save the clip, that the SaveLayer doesn't add any additional clip state.
         // This assumption will be removed when we explicitly store the clip state in
         // self-contained objects. It is valid for the small set of skps.
         if (NULL != state->fPrev && state->fClipInfo == state->fPrev->fClipInfo) {
             // By the above assumption the SaveLayer's MC state has already been
             // written out by the prior Save so don't output it again.
             state = (const MatrixClipState*) iter.next();
         }
     }
     for ( ; state != NULL; state = (const MatrixClipState*) iter.next()) {
          state->fClipInfo->writeClip(&curMatID, this);
     }
     // write out matrix
     // TODO: this test isn't quite right. It should be:
     //   if (curMatID != fCurMCState->fMatrixInfo->getID(this)) {
     // but right now the testing harness always expects a matrix if
     // the matrices are non-I
     if (kIdentityMatID != fCurMCState->fMatrixInfo->getID(this)) {
         // TODO: writing out the delta matrix here is an artifact of the writing
         // out of the entire clip stack (with its matrices). Ultimately we will
         // write out the CTM here when the clip state is collapsed to a single path.
         this->writeDeltaMat(curMatID, fCurMCState->fMatrixInfo->getID(this));
     }
     SkDEBUGCODE(this->validate();)
     return true;
 }
 // Fill in the skip offsets for all the clips written in the current block
 void SkMatrixClipStateMgr::fillInSkips(SkWriter32* writer, int32_t restoreOffset) {
     for (int i = 0; i < fSkipOffsets->count(); ++i) {
         SkDEBUGCODE(int32_t peek = writer->readTAt<int32_t>((*fSkipOffsets)[i]);)
         SkASSERT(-1 == peek);
         writer->overwriteTAt<int32_t>((*fSkipOffsets)[i], restoreOffset);
     }
     fSkipOffsets->rewind();
     SkASSERT(0 == fSkipOffsets->count());
 }
 void SkMatrixClipStateMgr::finish() {
     if (kIdentityWideOpenStateID != fCurOpenStateID) {
         fPicRecord->recordRestore();    // Close the open block
         fCurMCState->fHasOpen = false;
 #ifdef SK_DEBUG
         SkASSERT(fActualDepth > 0);
         fActualDepth--;
 #endif
         fCurOpenStateID = kIdentityWideOpenStateID;
         SkASSERT(!fCurMCState->fHasOpen);
     }
 }
 #ifdef SK_DEBUG
 void SkMatrixClipStateMgr::validate() {
     if (fCurOpenStateID == fCurMCState->fMCStateID && !this->isNestingMCState(fCurOpenStateID)) {
         // The current state is the active one so it should have a skip
         // offset for each clip
         SkDeque::Iter iter(fMatrixClipStack, SkDeque::Iter::kBack_IterStart);
         int clipCount = 0;
         for (const MatrixClipState* state = (const MatrixClipState*) iter.prev();
              state != NULL;
              state = (const MatrixClipState*) iter.prev()) {
             if (NULL == state->fPrev || state->fPrev->fClipInfo != state->fClipInfo) {
                 clipCount += state->fClipInfo->numClips();
             }
             if (state->fIsSaveLayer) {
                 break;
             }
         }
         SkASSERT(fSkipOffsets->count() == clipCount);
     }
 }
 #endif
 int SkMatrixClipStateMgr::addRegionToDict(const SkRegion& region) {
     int index = fRegionDict.count();
     *fRegionDict.append() = SkNEW(SkRegion(region));
     return index;
 }
 int SkMatrixClipStateMgr::addMatToDict(const SkMatrix& mat) {
     if (mat.isIdentity()) {
         return kIdentityMatID;
     }
     *fMatrixDict.append() = mat;
     return fMatrixDict.count()-1;
 }

The Tor Browser / annotate

gfx/skia/trunk/src/core/SkMatrixClipStateMgr.cpp@97036ab72558 (annotated)

gfx/skia/trunk/src/core/SkMatrixClipStateMgr.cpp