Simplify path allocation, clean up resources correctly

src/gpu/gl/GrGLNameAllocator.h

-
-/*
- * Copyright 2014 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrGLNameAllocator_DEFINED
-#define GrGLNameAllocator_DEFINED
-
-#include "SkRefCnt.h"
-#include "gl/GrGLTypes.h"
-
-/**
- * This class assumes ownership of an explicit range of OpenGL object names and
- * manages allocations within that range. This allows the app to generate new
- * objects on the client side without making round trips to the GL server.
- */
-class GrGLNameAllocator {
-public:
-    /**
-     * Constructs a name allocator that produces names within the explicit
-     * half-open range [firstName, end). Note that the caller will most likely
-     * need to call glGen* beforehand to reserve a range within the GL driver,
-     * and then invoke this constructor with that range.
-     *
-     * @param firstName The first name in the range owned by this class. Must be
-                        greater than zero.
-     * @param endName   The first past-the-end name beyond the range owned by
-                        this class. Must be >= firstName.
-     */
-    GrGLNameAllocator(GrGLuint firstName, GrGLuint endName);
-
-    /**
-     * Destructs the name allocator. The caller is responsible for calling the
-     * appropriate glDelete* on the range if necessary.
-     */
-    ~GrGLNameAllocator();
-
-    /**
-     * Return the beginning of this class's range.
-     *
-     * @return The first name in the range owned by this class.
-     */
-    GrGLuint firstName() const { return fFirstName; }
-
-    /**
-     * Return the end of this class's range. Note that endName() is not owned by
-     * this class.
-     *
-     * @return One plus the final name in the range owned by this class.
-     */
-    GrGLuint endName() const { return fEndName; }
-
-    /**
-     * Allocate an OpenGL object name from within this class's range.
-     *
-     * @return The name if one was available,
-               0 if all the names in the range were already in use.
-     */
-    GrGLuint allocateName();
-
-    /**
-     * Free an OpenGL object name, allowing it to be returned by a future call
-     * to allocateName(). Note that the caller should most likely redefine the
-     * object as empty to deallocate any underlying GPU memory before calling
-     * this method (but not call glDelete*, since that would free up the name
-     * within the driver itself).
-     *
-     * @param name The object name to free. Not-allocated names are silently
-     *             ignored the same way they are in the OpenGL spec.
-     */
-    void free(GrGLuint name);
-
-private:
-    class SparseNameRange;
-    class SparseNameTree;
-    class ContiguousNameRange;
-
-    const GrGLuint fFirstName;
-    const GrGLuint fEndName;
-    SkAutoTUnref<SparseNameRange> fAllocatedNames;
-};
-
-#endif