1 files changed, 131 insertions, 0 deletions
diff --git a/gfx/angle/src/libANGLE/HandleAllocator.cpp b/gfx/angle/src/libANGLE/HandleAllocator.cpp
new file mode 100755
index 000000000..c090b3dfc
--- /dev/null
+++ b/gfx/angle/src/libANGLE/HandleAllocator.cpp
@@ -0,0 +1,131 @@
+//
+// Copyright (c) 2002-2011 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+// HandleAllocator.cpp: Implements the gl::HandleAllocator class, which is used
+// to allocate GL handles.
+
+#include "libANGLE/HandleAllocator.h"
+
+#include <algorithm>
+
+#include "common/debug.h"
+
+namespace gl
+{
+
+struct HandleAllocator::HandleRangeComparator
+{
+    bool operator()(const HandleRange &range, GLuint handle) const
+    {
+        return (range.end < handle);
+    }
+};
+
+HandleAllocator::HandleAllocator() : mBaseValue(1), mNextValue(1)
+{
+    mUnallocatedList.push_back(HandleRange(1, std::numeric_limits<GLuint>::max()));
+}
+
+HandleAllocator::HandleAllocator(GLuint maximumHandleValue) : mBaseValue(1), mNextValue(1)
+{
+    mUnallocatedList.push_back(HandleRange(1, maximumHandleValue));
+}
+
+HandleAllocator::~HandleAllocator()
+{
+}
+
+void HandleAllocator::setBaseHandle(GLuint value)
+{
+    ASSERT(mBaseValue == mNextValue);
+    mBaseValue = value;
+    mNextValue = value;
+}
+
+GLuint HandleAllocator::allocate()
+{
+    ASSERT(!mUnallocatedList.empty() || !mReleasedList.empty());
+
+    // Allocate from released list, constant time.
+    if (!mReleasedList.empty())
+    {
+        GLuint reusedHandle = mReleasedList.back();
+        mReleasedList.pop_back();
+        return reusedHandle;
+    }
+
+    // Allocate from unallocated list, constant time.
+    auto listIt = mUnallocatedList.begin();
+
+    GLuint freeListHandle = listIt->begin;
+    ASSERT(freeListHandle > 0);
+
+    if (listIt->begin == listIt->end)
+    {
+        mUnallocatedList.erase(listIt);
+    }
+    else
+    {
+        listIt->begin++;
+    }
+
+    return freeListHandle;
+}
+
+void HandleAllocator::release(GLuint handle)
+{
+    // Add to released list, constant time.
+    mReleasedList.push_back(handle);
+}
+
+void HandleAllocator::reserve(GLuint handle)
+{
+    // Clear from released list -- might be a slow operation.
+    if (!mReleasedList.empty())
+    {
+        auto releasedIt = std::find(mReleasedList.begin(), mReleasedList.end(), handle);
+        if (releasedIt != mReleasedList.end())
+        {
+            mReleasedList.erase(releasedIt);
+            return;
+        }
+    }
+
+    // Not in released list, reserve in the unallocated list.
+    auto boundIt = std::lower_bound(mUnallocatedList.begin(), mUnallocatedList.end(), handle, HandleRangeComparator());
+
+    ASSERT(boundIt != mUnallocatedList.end());
+
+    GLuint begin = boundIt->begin;
+    GLuint end = boundIt->end;
+
+    if (handle == begin || handle == end)
+    {
+        if (begin == end)
+        {
+            mUnallocatedList.erase(boundIt);
+        }
+        else if (handle == begin)
+        {
+            boundIt->begin++;
+        }
+        else
+        {
+            ASSERT(handle == end);
+            boundIt->end--;
+        }
+        return;
+    }
+
+    ASSERT(begin < handle && handle < end);
+
+    // need to split the range
+    auto placementIt = mUnallocatedList.erase(boundIt);
+    placementIt      = mUnallocatedList.insert(placementIt, HandleRange(handle + 1, end));
+    mUnallocatedList.insert(placementIt, HandleRange(begin, handle - 1));
+}
+
+}  // namespace gl