C++ Vector::remove方法代码示例

void TilesManager::discardTexturesVector(unsigned long long sparedDrawCount,
                                         WTF::Vector<TileTexture*>& textures,
                                         bool deallocateGLTextures)
{
    const unsigned int max = textures.size();
    int dealloc = 0;
    WTF::Vector<int> discardedIndex;
    for (unsigned int i = 0; i < max; i++) {
        TextureOwner* owner = textures[i]->owner();
        if (!owner || owner->drawCount() < sparedDrawCount) {
            if (deallocateGLTextures) {
                // deallocate textures' gl memory
                textures[i]->discardGLTexture();
                discardedIndex.append(i);
            } else if (owner) {
                // simply detach textures from owner
                static_cast<Tile*>(owner)->discardTextures();
            }
            dealloc++;
        }
    }

    bool base = textures == m_textures;
    // Clean up the vector of TileTextures and reset the max texture count.
    if (discardedIndex.size()) {
        android::Mutex::Autolock lock(m_texturesLock);
        for (int i = discardedIndex.size() - 1; i >= 0; i--)
            textures.remove(discardedIndex[i]);

        int remainedTextureNumber = textures.size();
        int* countPtr = base ? &m_currentTextureCount : &m_currentLayerTextureCount;
        if (remainedTextureNumber < *countPtr) {
            ALOGV("reset currentTextureCount for %s tiles from %d to %d",
                  base ? "base" : "layer", *countPtr, remainedTextureNumber);
            *countPtr = remainedTextureNumber;
        }

    }

    ALOGV("Discarded %d %s textures (out of %d %s tiles)",
          dealloc, (deallocateGLTextures ? "gl" : ""),
          max, base ? "base" : "layer");
}

static void WebHistoryClose(JNIEnv* env, jobject obj, jint frame)
{
    LOG_ASSERT(frame, "Close needs a valid Frame pointer!");
    WebCore::Frame* pFrame = (WebCore::Frame*)frame;

    WebCore::BackForwardList* list = pFrame->page()->backForwardList();
    RefPtr<WebCore::HistoryItem> current = list->currentItem();
    // Remove each item instead of using close(). close() is intended to be used
    // right before the list is deleted.
    WebCore::HistoryItemVector& entries = list->entries();
    int size = entries.size();
    for (int i = size - 1; i >= 0; --i)
        list->removeItem(entries[i].get());
    // Add the current item back to the list.
    if (current) {
        current->setBridge(0);
        // addItem will update the children to match the newly created bridge
        list->addItem(current);

        /*
         * The Grand Prix site uses anchor navigations to change the display.
         * WebKit tries to be smart and not load child frames that have the
         * same history urls during an anchor navigation. This means that the
         * current history item stored in the child frame's loader does not
         * match the item found in the history tree. If we remove all the
         * entries in the back/foward list, we have to restore the entire tree
         * or else a HistoryItem might have a deleted parent.
         *
         * In order to restore the history tree correctly, we have to look up
         * all the frames first and then look up the history item. We do this
         * because the history item in the tree may be null at this point.
         * Unfortunately, a HistoryItem can only search its immediately
         * children so we do a breadth-first rebuild of the tree.
         */

        // Keep a small list of child frames to traverse.
        WTF::Vector<WebCore::Frame*> frameQueue;
        // Fix the top-level item.
        pFrame->loader()->history()->setCurrentItem(current.get());
        WebCore::Frame* child = pFrame->tree()->firstChild();
        // Remember the parent history item so we can search for a child item.
        RefPtr<WebCore::HistoryItem> parent = current;
        while (child) {
            // Use the old history item since the current one may have a
            // deleted parent.
            WebCore::HistoryItem* item = parent->childItemWithTarget(child->tree()->name());
            child->loader()->history()->setCurrentItem(item);
            // Append the first child to the queue if it exists. If there is no
            // item, then we do not need to traverse the children since there
            // will be no parent history item.
            WebCore::Frame* firstChild;
            if (item && (firstChild = child->tree()->firstChild()))
                frameQueue.append(firstChild);
            child = child->tree()->nextSibling();
            // If we don't have a sibling for this frame and the queue isn't
            // empty, use the next entry in the queue.
            if (!child && !frameQueue.isEmpty()) {
                child = frameQueue.at(0);
                frameQueue.remove(0);
                // Figure out the parent history item used when searching for
                // the history item to use.
                parent = child->tree()->parent()->loader()->history()->currentItem();
            }
        }
    }
}

BaseTileTexture* TilesManager::getAvailableTexture(BaseTile* owner)
{
    android::Mutex::Autolock lock(m_texturesLock);

    // Sanity check that the tile does not already own a texture
    if (owner->backTexture() && owner->backTexture()->owner() == owner) {
        XLOG("same owner (%d, %d), getAvailableBackTexture(%x) => texture %x",
             owner->x(), owner->y(), owner, owner->backTexture());
        if (owner->isLayerTile())
            m_availableTilesTextures.remove(m_availableTilesTextures.find(owner->backTexture()));
        else
            m_availableTextures.remove(m_availableTextures.find(owner->backTexture()));
        return owner->backTexture();
    }

    WTF::Vector<BaseTileTexture*>* availableTexturePool;
    if (owner->isLayerTile()) {
        availableTexturePool = &m_availableTilesTextures;
    } else {
        availableTexturePool = &m_availableTextures;
    }

    // The heuristic for selecting a texture is as follows:
    //  1. Skip textures currently being painted, they can't be painted while
    //         busy anyway
    //  2. If a tile isn't owned, break with that one
    //  3. Don't let tiles acquire their front textures
    //  4. If we find a tile in the same page with a different scale,
    //         it's old and not visible. Break with that one
    //  5. Otherwise, use the least recently prepared tile, but ignoring tiles
    //         drawn in the last frame to avoid flickering

    BaseTileTexture* farthestTexture = 0;
    unsigned long long oldestDrawCount = getDrawGLCount() - 1;
    const unsigned int max = availableTexturePool->size();
    for (unsigned int i = 0; i < max; i++) {
        BaseTileTexture* texture = (*availableTexturePool)[i];
        BaseTile* currentOwner = static_cast<BaseTile*>(texture->owner());

        if (texture->busy()) {
            // don't bother, since the acquire() will likely fail
            continue;
        }

        if (!currentOwner) {
            // unused texture! take it!
            farthestTexture = texture;
            break;
        }

        if (currentOwner == owner) {
            // Don't let a tile acquire its own front texture, as the
            // acquisition logic doesn't handle that
            continue;
        }

        if (currentOwner->painter() == owner->painter() && texture->scale() != owner->scale()) {
            // if we render the back page with one scale, then another while
            // still zooming, we recycle the tiles with the old scale instead of
            // taking ones from the front page
            farthestTexture = texture;
            break;
        }

        unsigned long long textureDrawCount = currentOwner->drawCount();
        if (oldestDrawCount > textureDrawCount) {
            farthestTexture = texture;
            oldestDrawCount = textureDrawCount;
        }
    }

    if (farthestTexture) {
        BaseTile* previousOwner = static_cast<BaseTile*>(farthestTexture->owner());
        if (farthestTexture->acquire(owner)) {
            if (previousOwner) {
                previousOwner->removeTexture(farthestTexture);

                XLOG("%s texture %p stolen from tile %d, %d for %d, %d, drawCount was %llu (now %llu)",
                     owner->isLayerTile() ? "LAYER" : "BASE",
                     farthestTexture, previousOwner->x(), previousOwner->y(),
                     owner->x(), owner->y(),
                     oldestDrawCount, getDrawGLCount());
            }

            availableTexturePool->remove(availableTexturePool->find(farthestTexture));
            return farthestTexture;
        }
    } else {
        if (owner->isLayerTile()) {
            // couldn't find a tile for a layer, layers shouldn't request redraw
            // TODO: once we do layer prefetching, don't set this for those
            // tiles
            m_layerTexturesRemain = false;
        }
    }

    XLOG("Couldn't find an available texture for %s tile %x (%d, %d) out of %d available",
          owner->isLayerTile() ? "LAYER" : "BASE",
          owner, owner->x(), owner->y(), max);
#ifdef DEBUG
//.........这里部分代码省略.........

TileTexture* TilesManager::getAvailableTexture(Tile* owner)
{
    android::Mutex::Autolock lock(m_texturesLock);

    WTF::Vector<TileTexture*>* availableTexturePool;
    if (owner->isLayerTile())
        availableTexturePool = &m_availableTilesTextures;
    else
        availableTexturePool = &m_availableTextures;

    // Sanity check that the tile does not already own a texture
    if (owner->backTexture() && owner->backTexture()->owner() == owner) {
        int removeIndex = availableTexturePool->find(owner->backTexture());

        // TODO: investigate why texture isn't found
        if (removeIndex >= 0)
            availableTexturePool->remove(removeIndex);
        return owner->backTexture();
    }

    // The heuristic for selecting a texture is as follows:
    //  1. Skip textures currently being painted, they can't be painted while
    //         busy anyway
    //  2. If a tile isn't owned, break with that one
    //  3. Don't let tiles acquire their front textures
    //  4. Otherwise, use the least recently prepared tile, but ignoring tiles
    //         drawn in the last frame to avoid flickering

    TileTexture* farthestTexture = 0;
    unsigned long long oldestDrawCount = getDrawGLCount() - 1;
    const unsigned int max = availableTexturePool->size();
    for (unsigned int i = 0; i < max; i++) {
        TileTexture* texture = (*availableTexturePool)[i];
        Tile* currentOwner = static_cast<Tile*>(texture->owner());
        if (!currentOwner) {
            // unused texture! take it!
            farthestTexture = texture;
            break;
        }

        if (currentOwner == owner) {
            // Don't let a tile acquire its own front texture, as the
            // acquisition logic doesn't handle that
            continue;
        }

        unsigned long long textureDrawCount = currentOwner->drawCount();
        if (oldestDrawCount > textureDrawCount) {
            farthestTexture = texture;
            oldestDrawCount = textureDrawCount;
        }
    }

    if (farthestTexture) {
        Tile* previousOwner = static_cast<Tile*>(farthestTexture->owner());
        if (farthestTexture->acquire(owner)) {
            if (previousOwner) {
                previousOwner->removeTexture(farthestTexture);

                ALOGV("%s texture %p stolen from tile %d, %d for %d, %d, drawCount was %llu (now %llu)",
                      owner->isLayerTile() ? "LAYER" : "BASE",
                      farthestTexture, previousOwner->x(), previousOwner->y(),
                      owner->x(), owner->y(),
                      oldestDrawCount, getDrawGLCount());
            }

            availableTexturePool->remove(availableTexturePool->find(farthestTexture));
            return farthestTexture;
        }
    } else {
        if (owner->isLayerTile()) {
            // couldn't find a tile for a layer, layers shouldn't request redraw
            // TODO: once we do layer prefetching, don't set this for those
            // tiles
            m_layerTexturesRemain = false;
        }
    }

    ALOGV("Couldn't find an available texture for %s tile %x (%d, %d) out of %d available",
          owner->isLayerTile() ? "LAYER" : "BASE",
          owner, owner->x(), owner->y(), max);
#ifdef DEBUG
    printTextures();
#endif // DEBUG
    return 0;
}