Remove GrRedBlackTree

src/gpu/GrRedBlackTree.h

Index: src/gpu/GrRedBlackTree.h
diff --git a/src/gpu/GrRedBlackTree.h b/src/gpu/GrRedBlackTree.h
deleted file mode 100644
index c58ae2790042454a63dc720ae97581c9d969da26..0000000000000000000000000000000000000000
--- a/src/gpu/GrRedBlackTree.h
+++ /dev/null
@@ -1,948 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrRedBlackTree_DEFINED
-#define GrRedBlackTree_DEFINED
-
-#include "GrConfig.h"
-#include "SkTypes.h"
-
-template <typename T>
-class GrLess {
-public:
-    bool operator()(const T& a, const T& b) const { return a < b; }
-};
-
-template <typename T>
-class GrLess<T*> {
-public:
-    bool operator()(const T* a, const T* b) const { return *a < *b; }
-};
-
-class GrStrLess {
-public:
-    bool operator()(const char* a, const char* b) const { return strcmp(a,b) < 0; }
-};
-
-/**
- * In debug build this will cause full traversals of the tree when the validate
- * is called on insert and remove. Useful for debugging but very slow.
- */
-#define DEEP_VALIDATE 0
-
-/**
- * A sorted tree that uses the red-black tree algorithm. Allows duplicate
- * entries. Data is of type T and is compared using functor C. A single C object
- * will be created and used for all comparisons.
- */
-template <typename T, typename C = GrLess<T> >
-class GrRedBlackTree : SkNoncopyable {
-public:
-    /**
-     * Creates an empty tree.
-     */
-    GrRedBlackTree();
-    virtual ~GrRedBlackTree();
-
-    /**
-     * Class used to iterater through the tree. The valid range of the tree
-     * is given by [begin(), end()). It is legal to dereference begin() but not
-     * end(). The iterator has preincrement and predecrement operators, it is
-     * legal to decerement end() if the tree is not empty to get the last
-     * element. However, a last() helper is provided.
-     */
-    class Iter;
-
-    /**
-     * Add an element to the tree. Duplicates are allowed.
-     * @param t     the item to add.
-     * @return  an iterator to the item.
-     */
-    Iter insert(const T& t);
-
-    /**
-     * Removes all items in the tree.
-     */
-    void reset();
-
-    /**
-     * @return true if there are no items in the tree, false otherwise.
-     */
-    bool empty() const {return 0 == fCount;}
-
-    /**
-     * @return the number of items in the tree.
-     */
-    int  count() const {return fCount;}
-
-    /**
-     * @return  an iterator to the first item in sorted order, or end() if empty
-     */
-    Iter begin();
-    /**
-     * Gets the last valid iterator. This is always valid, even on an empty.
-     * However, it can never be dereferenced. Useful as a loop terminator.
-     * @return  an iterator that is just beyond the last item in sorted order.
-     */
-    Iter end();
-    /**
-     * @return  an iterator that to the last item in sorted order, or end() if
-     * empty.
-     */
-    Iter last();
-
-    /**
-     * Finds an occurrence of an item.
-     * @param t     the item to find.
-     * @return an iterator to a tree element equal to t or end() if none exists.
-     */
-    Iter find(const T& t);
-    /**
-     * Finds the first of an item in iterator order.
-     * @param t     the item to find.
-     * @return  an iterator to the first element equal to t or end() if
-     *          none exists.
-     */
-    Iter findFirst(const T& t);
-    /**
-     * Finds the last of an item in iterator order.
-     * @param t     the item to find.
-     * @return  an iterator to the last element equal to t or end() if
-     *          none exists.
-     */
-    Iter findLast(const T& t);
-    /**
-     * Gets the number of items in the tree equal to t.
-     * @param t     the item to count.
-     * @return  number of items equal to t in the tree
-     */
-    int countOf(const T& t) const;
-
-    /**
-     * Removes the item indicated by an iterator. The iterator will not be valid
-     * afterwards.
-     *
-     * @param iter      iterator of item to remove. Must be valid (not end()).
-     */
-    void remove(const Iter& iter) { deleteAtNode(iter.fN); }
-
-private:
-    enum Color {
-        kRed_Color,
-        kBlack_Color
-    };
-
-    enum Child {
-        kLeft_Child  = 0,
-        kRight_Child = 1
-    };
-
-    struct Node {
-        T       fItem;
-        Color   fColor;
-
-        Node*   fParent;
-        Node*   fChildren[2];
-    };
-
-    void rotateRight(Node* n);
-    void rotateLeft(Node* n);
-
-    static Node* SuccessorNode(Node* x);
-    static Node* PredecessorNode(Node* x);
-
-    void deleteAtNode(Node* x);
-    static void RecursiveDelete(Node* x);
-
-    int onCountOf(const Node* n, const T& t) const;
-
-#ifdef SK_DEBUG
-    void validate() const;
-    int checkNode(Node* n, int* blackHeight) const;
-    // checks relationship between a node and its children. allowRedRed means
-    // node may be in an intermediate state where a red parent has a red child.
-    bool validateChildRelations(const Node* n, bool allowRedRed) const;
-    // place to stick break point if validateChildRelations is failing.
-    bool validateChildRelationsFailed() const { return false; }
-#else
-    void validate() const {}
-#endif
-
-    int     fCount;
-    Node*   fRoot;
-    Node*   fFirst;
-    Node*   fLast;
-
-    const C fComp;
-};
-
-template <typename T, typename C>
-class GrRedBlackTree<T,C>::Iter {
-public:
-    Iter() {};
-    Iter(const Iter& i) {fN = i.fN; fTree = i.fTree;}
-    Iter& operator =(const Iter& i) {
-        fN = i.fN;
-        fTree = i.fTree;
-        return *this;
-    }
-    // altering the sort value of the item using this method will cause
-    // errors.
-    T& operator *() const { return fN->fItem; }
-    bool operator ==(const Iter& i) const {
-        return fN == i.fN && fTree == i.fTree;
-    }
-    bool operator !=(const Iter& i) const { return !(*this == i); }
-    Iter& operator ++() {
-        SkASSERT(*this != fTree->end());
-        fN = SuccessorNode(fN);
-        return *this;
-    }
-    Iter& operator --() {
-        SkASSERT(*this != fTree->begin());
-        if (fN) {
-            fN = PredecessorNode(fN);
-        } else {
-            *this = fTree->last();
-        }
-        return *this;
-    }
-
-private:
-    friend class GrRedBlackTree;
-    explicit Iter(Node* n, GrRedBlackTree* tree) {
-        fN = n;
-        fTree = tree;
-    }
-    Node* fN;
-    GrRedBlackTree* fTree;
-};
-
-template <typename T, typename C>
-GrRedBlackTree<T,C>::GrRedBlackTree() : fComp() {
-    fRoot = NULL;
-    fFirst = NULL;
-    fLast = NULL;
-    fCount = 0;
-    validate();
-}
-
-template <typename T, typename C>
-GrRedBlackTree<T,C>::~GrRedBlackTree() {
-    RecursiveDelete(fRoot);
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::begin() {
-    return Iter(fFirst, this);
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::end() {
-    return Iter(NULL, this);
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::last() {
-    return Iter(fLast, this);
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::find(const T& t) {
-    Node* n = fRoot;
-    while (n) {
-        if (fComp(t, n->fItem)) {
-            n = n->fChildren[kLeft_Child];
-        } else {
-            if (!fComp(n->fItem, t)) {
-                return Iter(n, this);
-            }
-            n = n->fChildren[kRight_Child];
-        }
-    }
-    return end();
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::findFirst(const T& t) {
-    Node* n = fRoot;
-    Node* leftMost = NULL;
-    while (n) {
-        if (fComp(t, n->fItem)) {
-            n = n->fChildren[kLeft_Child];
-        } else {
-            if (!fComp(n->fItem, t)) {
-                // found one. check if another in left subtree.
-                leftMost = n;
-                n = n->fChildren[kLeft_Child];
-            } else {
-                n = n->fChildren[kRight_Child];
-            }
-        }
-    }
-    return Iter(leftMost, this);
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::findLast(const T& t) {
-    Node* n = fRoot;
-    Node* rightMost = NULL;
-    while (n) {
-        if (fComp(t, n->fItem)) {
-            n = n->fChildren[kLeft_Child];
-        } else {
-            if (!fComp(n->fItem, t)) {
-                // found one. check if another in right subtree.
-                rightMost = n;
-            }
-            n = n->fChildren[kRight_Child];
-        }
-    }
-    return Iter(rightMost, this);
-}
-
-template <typename T, typename C>
-int GrRedBlackTree<T,C>::countOf(const T& t) const {
-    return onCountOf(fRoot, t);
-}
-
-template <typename T, typename C>
-int GrRedBlackTree<T,C>::onCountOf(const Node* n, const T& t) const {
-    // this is count*log(n) :(
-    while (n) {
-        if (fComp(t, n->fItem)) {
-            n = n->fChildren[kLeft_Child];
-        } else {
-            if (!fComp(n->fItem, t)) {
-                int count = 1;
-                count += onCountOf(n->fChildren[kLeft_Child], t);
-                count += onCountOf(n->fChildren[kRight_Child], t);
-                return count;
-            }
-            n = n->fChildren[kRight_Child];
-        }
-    }
-    return 0;
-
-}
-
-template <typename T, typename C>
-void GrRedBlackTree<T,C>::reset() {
-    RecursiveDelete(fRoot);
-    fRoot = NULL;
-    fFirst = NULL;
-    fLast = NULL;
-    fCount = 0;
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::insert(const T& t) {
-    validate();
-
-    ++fCount;
-
-    Node* x = SkNEW(Node);
-    x->fChildren[kLeft_Child] = NULL;
-    x->fChildren[kRight_Child] = NULL;
-    x->fItem = t;
-
-    Node* returnNode = x;
-
-    Node* gp = NULL;
-    Node* p = NULL;
-    Node* n = fRoot;
-    Child pc = kLeft_Child; // suppress uninit warning
-    Child gpc = kLeft_Child;
-
-    bool first = true;
-    bool last = true;
-    while (n) {
-        gpc = pc;
-        pc = fComp(x->fItem, n->fItem) ? kLeft_Child : kRight_Child;
-        first = first && kLeft_Child == pc;
-        last = last && kRight_Child == pc;
-        gp = p;
-        p = n;
-        n = p->fChildren[pc];
-    }
-    if (last) {
-        fLast = x;
-    }
-    if (first) {
-        fFirst = x;
-    }
-
-    if (NULL == p) {
-        fRoot = x;
-        x->fColor = kBlack_Color;
-        x->fParent = NULL;
-        SkASSERT(1 == fCount);
-        return Iter(returnNode, this);
-    }
-    p->fChildren[pc] = x;
-    x->fColor = kRed_Color;
-    x->fParent = p;
-
-    do {
-        // assumptions at loop start.
-        SkASSERT(x);
-        SkASSERT(kRed_Color == x->fColor);
-        // can't have a grandparent but no parent.
-        SkASSERT(!(gp && NULL == p));
-        // make sure pc and gpc are correct
-        SkASSERT(NULL == p  || p->fChildren[pc] == x);
-        SkASSERT(NULL == gp || gp->fChildren[gpc] == p);
-
-        // if x's parent is black then we didn't violate any of the
-        // red/black properties when we added x as red.
-        if (kBlack_Color == p->fColor) {
-            return Iter(returnNode, this);
-        }
-        // gp must be valid because if p was the root then it is black
-        SkASSERT(gp);
-        // gp must be black since it's child, p, is red.
-        SkASSERT(kBlack_Color == gp->fColor);
-
-
-        // x and its parent are red, violating red-black property.
-        Node* u = gp->fChildren[1-gpc];
-        // if x's uncle (p's sibling) is also red then we can flip
-        // p and u to black and make gp red. But then we have to recurse
-        // up to gp since it's parent may also be red.
-        if (u && kRed_Color == u->fColor) {
-            p->fColor = kBlack_Color;
-            u->fColor = kBlack_Color;
-            gp->fColor = kRed_Color;
-            x = gp;
-            p = x->fParent;
-            if (NULL == p) {
-                // x (prev gp) is the root, color it black and be done.
-                SkASSERT(fRoot == x);
-                x->fColor = kBlack_Color;
-                validate();
-                return Iter(returnNode, this);
-            }
-            gp = p->fParent;
-            pc = (p->fChildren[kLeft_Child] == x) ? kLeft_Child :
-                                                    kRight_Child;
-            if (gp) {
-                gpc = (gp->fChildren[kLeft_Child] == p) ? kLeft_Child :
-                                                          kRight_Child;
-            }
-            continue;
-        } break;
-    } while (true);
-    // Here p is red but u is black and we still have to resolve the fact
-    // that x and p are both red.
-    SkASSERT(NULL == gp->fChildren[1-gpc] || kBlack_Color == gp->fChildren[1-gpc]->fColor);
-    SkASSERT(kRed_Color == x->fColor);
-    SkASSERT(kRed_Color == p->fColor);
-    SkASSERT(kBlack_Color == gp->fColor);
-
-    // make x be on the same side of p as p is of gp. If it isn't already
-    // the case then rotate x up to p and swap their labels.
-    if (pc != gpc) {
-        if (kRight_Child == pc) {
-            rotateLeft(p);
-            Node* temp = p;
-            p = x;
-            x = temp;
-            pc = kLeft_Child;
-        } else {
-            rotateRight(p);
-            Node* temp = p;
-            p = x;
-            x = temp;
-            pc = kRight_Child;
-        }
-    }
-    // we now rotate gp down, pulling up p to be it's new parent.
-    // gp's child, u, that is not affected we know to be black. gp's new
-    // child is p's previous child (x's pre-rotation sibling) which must be
-    // black since p is red.
-    SkASSERT(NULL == p->fChildren[1-pc] ||
-             kBlack_Color == p->fChildren[1-pc]->fColor);
-    // Since gp's two children are black it can become red if p is made
-    // black. This leaves the black-height of both of p's new subtrees
-    // preserved and removes the red/red parent child relationship.
-    p->fColor = kBlack_Color;
-    gp->fColor = kRed_Color;
-    if (kLeft_Child == pc) {
-        rotateRight(gp);
-    } else {
-        rotateLeft(gp);
-    }
-    validate();
-    return Iter(returnNode, this);
-}
-
-
-template <typename T, typename C>
-void GrRedBlackTree<T,C>::rotateRight(Node* n) {
-    /*            d?              d?
-     *           /               /
-     *          n               s
-     *         / \     --->    / \
-     *        s   a?          c?  n
-     *       / \                 / \
-     *      c?  b?              b?  a?
-     */
-    Node* d = n->fParent;
-    Node* s = n->fChildren[kLeft_Child];
-    SkASSERT(s);
-    Node* b = s->fChildren[kRight_Child];
-
-    if (d) {
-        Child c = d->fChildren[kLeft_Child] == n ? kLeft_Child :
-                                             kRight_Child;
-        d->fChildren[c] = s;
-    } else {
-        SkASSERT(fRoot == n);
-        fRoot = s;
-    }
-    s->fParent = d;
-    s->fChildren[kRight_Child] = n;
-    n->fParent = s;
-    n->fChildren[kLeft_Child] = b;
-    if (b) {
-        b->fParent = n;
-    }
-
-    GR_DEBUGASSERT(validateChildRelations(d, true));
-    GR_DEBUGASSERT(validateChildRelations(s, true));
-    GR_DEBUGASSERT(validateChildRelations(n, false));
-    GR_DEBUGASSERT(validateChildRelations(n->fChildren[kRight_Child], true));
-    GR_DEBUGASSERT(validateChildRelations(b, true));
-    GR_DEBUGASSERT(validateChildRelations(s->fChildren[kLeft_Child], true));
-}
-
-template <typename T, typename C>
-void GrRedBlackTree<T,C>::rotateLeft(Node* n) {
-
-    Node* d = n->fParent;
-    Node* s = n->fChildren[kRight_Child];
-    SkASSERT(s);
-    Node* b = s->fChildren[kLeft_Child];
-
-    if (d) {
-        Child c = d->fChildren[kRight_Child] == n ? kRight_Child :
-                                                   kLeft_Child;
-        d->fChildren[c] = s;
-    } else {
-        SkASSERT(fRoot == n);
-        fRoot = s;
-    }
-    s->fParent = d;
-    s->fChildren[kLeft_Child] = n;
-    n->fParent = s;
-    n->fChildren[kRight_Child] = b;
-    if (b) {
-        b->fParent = n;
-    }
-
-    GR_DEBUGASSERT(validateChildRelations(d, true));
-    GR_DEBUGASSERT(validateChildRelations(s, true));
-    GR_DEBUGASSERT(validateChildRelations(n, true));
-    GR_DEBUGASSERT(validateChildRelations(n->fChildren[kLeft_Child], true));
-    GR_DEBUGASSERT(validateChildRelations(b, true));
-    GR_DEBUGASSERT(validateChildRelations(s->fChildren[kRight_Child], true));
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Node* GrRedBlackTree<T,C>::SuccessorNode(Node* x) {
-    SkASSERT(x);
-    if (x->fChildren[kRight_Child]) {
-        x = x->fChildren[kRight_Child];
-        while (x->fChildren[kLeft_Child]) {
-            x = x->fChildren[kLeft_Child];
-        }
-        return x;
-    }
-    while (x->fParent && x == x->fParent->fChildren[kRight_Child]) {
-        x = x->fParent;
-    }
-    return x->fParent;
-}
-
-template <typename T, typename C>
-typename GrRedBlackTree<T,C>::Node* GrRedBlackTree<T,C>::PredecessorNode(Node* x) {
-    SkASSERT(x);
-    if (x->fChildren[kLeft_Child]) {
-        x = x->fChildren[kLeft_Child];
-        while (x->fChildren[kRight_Child]) {
-            x = x->fChildren[kRight_Child];
-        }
-        return x;
-    }
-    while (x->fParent && x == x->fParent->fChildren[kLeft_Child]) {
-        x = x->fParent;
-    }
-    return x->fParent;
-}
-
-template <typename T, typename C>
-void GrRedBlackTree<T,C>::deleteAtNode(Node* x) {
-    SkASSERT(x);
-    validate();
-    --fCount;
-
-    bool hasLeft =  SkToBool(x->fChildren[kLeft_Child]);
-    bool hasRight = SkToBool(x->fChildren[kRight_Child]);
-    Child c = hasLeft ? kLeft_Child : kRight_Child;
-
-    if (hasLeft && hasRight) {
-        // first and last can't have two children.
-        SkASSERT(fFirst != x);
-        SkASSERT(fLast != x);
-        // if x is an interior node then we find it's successor
-        // and swap them.
-        Node* s = x->fChildren[kRight_Child];
-        while (s->fChildren[kLeft_Child]) {
-            s = s->fChildren[kLeft_Child];
-        }
-        SkASSERT(s);
-        // this might be expensive relative to swapping node ptrs around.
-        // depends on T.
-        x->fItem = s->fItem;
-        x = s;
-        c = kRight_Child;
-    } else if (NULL == x->fParent) {
-        // if x was the root we just replace it with its child and make
-        // the new root (if the tree is not empty) black.
-        SkASSERT(fRoot == x);
-        fRoot = x->fChildren[c];
-        if (fRoot) {
-            fRoot->fParent = NULL;
-            fRoot->fColor = kBlack_Color;
-            if (x == fLast) {
-                SkASSERT(c == kLeft_Child);
-                fLast = fRoot;
-            } else if (x == fFirst) {
-                SkASSERT(c == kRight_Child);
-                fFirst = fRoot;
-            }
-        } else {
-            SkASSERT(fFirst == fLast && x == fFirst);
-            fFirst = NULL;
-            fLast = NULL;
-            SkASSERT(0 == fCount);
-        }
-        delete x;
-        validate();
-        return;
-    }
-
-    Child pc;
-    Node* p = x->fParent;
-    pc = p->fChildren[kLeft_Child] == x ? kLeft_Child : kRight_Child;
-
-    if (NULL == x->fChildren[c]) {
-        if (fLast == x) {
-            fLast = p;
-            SkASSERT(p == PredecessorNode(x));
-        } else if (fFirst == x) {
-            fFirst = p;
-            SkASSERT(p == SuccessorNode(x));
-        }
-        // x has two implicit black children.
-        Color xcolor = x->fColor;
-        p->fChildren[pc] = NULL;
-        delete x;
-        x = NULL;
-        // when x is red it can be with an implicit black leaf without
-        // violating any of the red-black tree properties.
-        if (kRed_Color == xcolor) {
-            validate();
-            return;
-        }
-        // s is p's other child (x's sibling)
-        Node* s = p->fChildren[1-pc];
-
-        //s cannot be an implicit black node because the original
-        // black-height at x was >= 2 and s's black-height must equal the
-        // initial black height of x.
-        SkASSERT(s);
-        SkASSERT(p == s->fParent);
-
-        // assigned in loop
-        Node* sl;
-        Node* sr;
-        bool slRed;
-        bool srRed;
-
-        do {
-            // When we start this loop x may already be deleted it is/was
-            // p's child on its pc side. x's children are/were black. The
-            // first time through the loop they are implict children.
-            // On later passes we will be walking up the tree and they will
-            // be real nodes.
-            // The x side of p has a black-height that is one less than the
-            // s side. It must be rebalanced.
-            SkASSERT(s);
-            SkASSERT(p == s->fParent);
-            SkASSERT(NULL == x || x->fParent == p);
-
-            //sl and sr are s's children, which may be implicit.
-            sl = s->fChildren[kLeft_Child];
-            sr = s->fChildren[kRight_Child];
-
-            // if the s is red we will rotate s and p, swap their colors so
-            // that x's new sibling is black
-            if (kRed_Color == s->fColor) {
-                // if s is red then it's parent must be black.
-                SkASSERT(kBlack_Color == p->fColor);
-                // s's children must also be black since s is red. They can't
-                // be implicit since s is red and it's black-height is >= 2.
-                SkASSERT(sl && kBlack_Color == sl->fColor);
-                SkASSERT(sr && kBlack_Color == sr->fColor);
-                p->fColor = kRed_Color;
-                s->fColor = kBlack_Color;
-                if (kLeft_Child == pc) {
-                    rotateLeft(p);
-                    s = sl;
-                } else {
-                    rotateRight(p);
-                    s = sr;
-                }
-                sl = s->fChildren[kLeft_Child];
-                sr = s->fChildren[kRight_Child];
-            }
-            // x and s are now both black.
-            SkASSERT(kBlack_Color == s->fColor);
-            SkASSERT(NULL == x || kBlack_Color == x->fColor);
-            SkASSERT(p == s->fParent);
-            SkASSERT(NULL == x || p == x->fParent);
-
-            // when x is deleted its subtree will have reduced black-height.
-            slRed = (sl && kRed_Color == sl->fColor);
-            srRed = (sr && kRed_Color == sr->fColor);
-            if (!slRed && !srRed) {
-                // if s can be made red that will balance out x's removal
-                // to make both subtrees of p have the same black-height.
-                if (kBlack_Color == p->fColor) {
-                    s->fColor = kRed_Color;
-                    // now subtree at p has black-height of one less than
-                    // p's parent's other child's subtree. We move x up to
-                    // p and go through the loop again. At the top of loop
-                    // we assumed x and x's children are black, which holds
-                    // by above ifs.
-                    // if p is the root there is no other subtree to balance
-                    // against.
-                    x = p;
-                    p = x->fParent;
-                    if (NULL == p) {
-                        SkASSERT(fRoot == x);
-                        validate();
-                        return;
-                    } else {
-                        pc = p->fChildren[kLeft_Child] == x ? kLeft_Child :
-                                                              kRight_Child;
-
-                    }
-                    s = p->fChildren[1-pc];
-                    SkASSERT(s);
-                    SkASSERT(p == s->fParent);
-                    continue;
-                } else if (kRed_Color == p->fColor) {
-                    // we can make p black and s red. This balance out p's
-                    // two subtrees and keep the same black-height as it was
-                    // before the delete.
-                    s->fColor = kRed_Color;
-                    p->fColor = kBlack_Color;
-                    validate();
-                    return;
-                }
-            }
-            break;
-        } while (true);
-        // if we made it here one or both of sl and sr is red.
-        // s and x are black. We make sure that a red child is on
-        // the same side of s as s is of p.
-        SkASSERT(slRed || srRed);
-        if (kLeft_Child == pc && !srRed) {
-            s->fColor = kRed_Color;
-            sl->fColor = kBlack_Color;
-            rotateRight(s);
-            sr = s;
-            s = sl;
-            //sl = s->fChildren[kLeft_Child]; don't need this
-        } else if (kRight_Child == pc && !slRed) {
-            s->fColor = kRed_Color;
-            sr->fColor = kBlack_Color;
-            rotateLeft(s);
-            sl = s;
-            s = sr;
-            //sr = s->fChildren[kRight_Child]; don't need this
-        }
-        // now p is either red or black, x and s are red and s's 1-pc
-        // child is red.
-        // We rotate p towards x, pulling s up to replace p. We make
-        // p be black and s takes p's old color.
-        // Whether p was red or black, we've increased its pc subtree
-        // rooted at x by 1 (balancing the imbalance at the start) and
-        // we've also its subtree rooted at s's black-height by 1. This
-        // can be balanced by making s's red child be black.
-        s->fColor = p->fColor;
-        p->fColor = kBlack_Color;
-        if (kLeft_Child == pc) {
-            SkASSERT(sr && kRed_Color == sr->fColor);
-            sr->fColor = kBlack_Color;
-            rotateLeft(p);
-        } else {
-            SkASSERT(sl && kRed_Color == sl->fColor);
-            sl->fColor = kBlack_Color;
-            rotateRight(p);
-        }
-    }
-    else {
-        // x has exactly one implicit black child. x cannot be red.
-        // Proof by contradiction: Assume X is red. Let c0 be x's implicit
-        // child and c1 be its non-implicit child. c1 must be black because
-        // red nodes always have two black children. Then the two subtrees
-        // of x rooted at c0 and c1 will have different black-heights.
-        SkASSERT(kBlack_Color == x->fColor);
-        // So we know x is black and has one implicit black child, c0. c1
-        // must be red, otherwise the subtree at c1 will have a different
-        // black-height than the subtree rooted at c0.
-        SkASSERT(kRed_Color == x->fChildren[c]->fColor);
-        // replace x with c1, making c1 black, preserves all red-black tree
-        // props.
-        Node* c1 = x->fChildren[c];
-        if (x == fFirst) {
-            SkASSERT(c == kRight_Child);
-            fFirst = c1;
-            while (fFirst->fChildren[kLeft_Child]) {
-                fFirst = fFirst->fChildren[kLeft_Child];
-            }
-            SkASSERT(fFirst == SuccessorNode(x));
-        } else if (x == fLast) {
-            SkASSERT(c == kLeft_Child);
-            fLast = c1;
-            while (fLast->fChildren[kRight_Child]) {
-                fLast = fLast->fChildren[kRight_Child];
-            }
-            SkASSERT(fLast == PredecessorNode(x));
-        }
-        c1->fParent = p;
-        p->fChildren[pc] = c1;
-        c1->fColor = kBlack_Color;
-        delete x;
-        validate();
-    }
-    validate();
-}
-
-template <typename T, typename C>
-void GrRedBlackTree<T,C>::RecursiveDelete(Node* x) {
-    if (x) {
-        RecursiveDelete(x->fChildren[kLeft_Child]);
-        RecursiveDelete(x->fChildren[kRight_Child]);
-        delete x;
-    }
-}
-
-#ifdef SK_DEBUG
-template <typename T, typename C>
-void GrRedBlackTree<T,C>::validate() const {
-    if (fCount) {
-        SkASSERT(NULL == fRoot->fParent);
-        SkASSERT(fFirst);
-        SkASSERT(fLast);
-
-        SkASSERT(kBlack_Color == fRoot->fColor);
-        if (1 == fCount) {
-            SkASSERT(fFirst == fRoot);
-            SkASSERT(fLast == fRoot);
-            SkASSERT(0 == fRoot->fChildren[kLeft_Child]);
-            SkASSERT(0 == fRoot->fChildren[kRight_Child]);
-        }
-    } else {
-        SkASSERT(NULL == fRoot);
-        SkASSERT(NULL == fFirst);
-        SkASSERT(NULL == fLast);
-    }
-#if DEEP_VALIDATE
-    int bh;
-    int count = checkNode(fRoot, &bh);
-    SkASSERT(count == fCount);
-#endif
-}
-
-template <typename T, typename C>
-int GrRedBlackTree<T,C>::checkNode(Node* n, int* bh) const {
-    if (n) {
-        SkASSERT(validateChildRelations(n, false));
-        if (kBlack_Color == n->fColor) {
-            *bh += 1;
-        }
-        SkASSERT(!fComp(n->fItem, fFirst->fItem));
-        SkASSERT(!fComp(fLast->fItem, n->fItem));
-        int leftBh = *bh;
-        int rightBh = *bh;
-        int cl = checkNode(n->fChildren[kLeft_Child], &leftBh);
-        int cr = checkNode(n->fChildren[kRight_Child], &rightBh);
-        SkASSERT(leftBh == rightBh);
-        *bh = leftBh;
-        return 1 + cl + cr;
-    }
-    return 0;
-}
-
-template <typename T, typename C>
-bool GrRedBlackTree<T,C>::validateChildRelations(const Node* n,
-                                                 bool allowRedRed) const {
-    if (n) {
-        if (n->fChildren[kLeft_Child] ||
-            n->fChildren[kRight_Child]) {
-            if (n->fChildren[kLeft_Child] == n->fChildren[kRight_Child]) {
-                return validateChildRelationsFailed();
-            }
-            if (n->fChildren[kLeft_Child] == n->fParent &&
-                n->fParent) {
-                return validateChildRelationsFailed();
-            }
-            if (n->fChildren[kRight_Child] == n->fParent &&
-                n->fParent) {
-                return validateChildRelationsFailed();
-            }
-            if (n->fChildren[kLeft_Child]) {
-                if (!allowRedRed &&
-                    kRed_Color == n->fChildren[kLeft_Child]->fColor &&
-                    kRed_Color == n->fColor) {
-                    return validateChildRelationsFailed();
-                }
-                if (n->fChildren[kLeft_Child]->fParent != n) {
-                    return validateChildRelationsFailed();
-                }
-                if (!(fComp(n->fChildren[kLeft_Child]->fItem, n->fItem) ||
-                      (!fComp(n->fChildren[kLeft_Child]->fItem, n->fItem) &&
-                       !fComp(n->fItem, n->fChildren[kLeft_Child]->fItem)))) {
-                    return validateChildRelationsFailed();
-                }
-            }
-            if (n->fChildren[kRight_Child]) {
-                if (!allowRedRed &&
-                    kRed_Color == n->fChildren[kRight_Child]->fColor &&
-                    kRed_Color == n->fColor) {
-                    return validateChildRelationsFailed();
-                }
-                if (n->fChildren[kRight_Child]->fParent != n) {
-                    return validateChildRelationsFailed();
-                }
-                if (!(fComp(n->fItem, n->fChildren[kRight_Child]->fItem) ||
-                      (!fComp(n->fChildren[kRight_Child]->fItem, n->fItem) &&
-                       !fComp(n->fItem, n->fChildren[kRight_Child]->fItem)))) {
-                    return validateChildRelationsFailed();
-                }
-            }
-        }
-    }
-    return true;
-}
-#endif
-
-#endif