webengine/osswebengine/WebCore/rendering/RenderArena.cpp
changeset 0 dd21522fd290
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/osswebengine/WebCore/rendering/RenderArena.cpp	Mon Mar 30 12:54:55 2009 +0300
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2003 Apple Computer, Inc.
+ *
+ * Portions are Copyright (C) 1998 Netscape Communications Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Alternatively, the contents of this file may be used under the terms
+ * of either the Mozilla Public License Version 1.1, found at
+ * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
+ * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
+ * (the "GPL"), in which case the provisions of the MPL or the GPL are
+ * applicable instead of those above.  If you wish to allow use of your
+ * version of this file only under the terms of one of those two
+ * licenses (the MPL or the GPL) and not to allow others to use your
+ * version of this file under the LGPL, indicate your decision by
+ * deletingthe provisions above and replace them with the notice and
+ * other provisions required by the MPL or the GPL, as the case may be.
+ * If you do not delete the provisions above, a recipient may use your
+ * version of this file under any of the LGPL, the MPL or the GPL.
+ */
+
+#include "config.h"
+#include "RenderArena.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <wtf/Assertions.h>
+
+#define ROUNDUP(x,y) ((((x)+((y)-1))/(y))*(y))
+
+namespace WebCore {
+
+#ifndef NDEBUG
+
+const int signature = 0xDBA00AEA;
+const int signatureDead = 0xDBA00AED;
+
+typedef struct {
+    RenderArena* arena;
+    size_t size;
+    int signature;
+} RenderArenaDebugHeader;
+
+#endif
+
+RenderArena::RenderArena(unsigned arenaSize)
+{
+    // Initialize the arena pool
+    INIT_ARENA_POOL(&m_pool, "RenderArena", arenaSize);
+
+    // Zero out the recyclers array
+    memset(m_recyclers, 0, sizeof(m_recyclers));
+}
+
+RenderArena::~RenderArena()
+{
+    FinishArenaPool(&m_pool);
+}
+
+void* RenderArena::allocate(size_t size)
+{
+#ifndef NDEBUG
+    // Use standard malloc so that memory debugging tools work.
+    ASSERT(this);
+    void* block = ::malloc(sizeof(RenderArenaDebugHeader) + size);
+    RenderArenaDebugHeader* header = (RenderArenaDebugHeader*)block;
+    header->arena = this;
+    header->size = size;
+    header->signature = signature;
+    return header + 1;
+#else
+    void* result = 0;
+
+    // Ensure we have correct alignment for pointers.  Important for Tru64
+    size = ROUNDUP(size, sizeof(void*));
+
+    // Check recyclers first
+    if (size < gMaxRecycledSize) {
+        const int index = size >> 2;
+
+        result = m_recyclers[index];
+        if (result) {
+            // Need to move to the next object
+            void* next = *((void**)result);
+            m_recyclers[index] = next;
+        }
+    }
+
+    if (!result) {
+        // Allocate a new chunk from the arena
+        ARENA_ALLOCATE(result, &m_pool, size);
+    }
+
+    return result;
+#endif
+}
+
+void RenderArena::free(size_t size, void* ptr)
+{
+#ifndef NDEBUG
+    // Use standard free so that memory debugging tools work.
+    RenderArenaDebugHeader* header = (RenderArenaDebugHeader*)ptr - 1;
+    ASSERT(header->signature == signature);
+    ASSERT(header->size == size);
+    ASSERT(header->arena == this);
+    header->signature = signatureDead;
+    ::free(header);
+#else
+    // Ensure we have correct alignment for pointers.  Important for Tru64
+    size = ROUNDUP(size, sizeof(void*));
+
+    // See if it's a size that we recycle
+    if (size < gMaxRecycledSize) {
+        const int index = size >> 2;
+        void* currentTop = m_recyclers[index];
+        m_recyclers[index] = ptr;
+        *((void**)ptr) = currentTop;
+    }
+#endif
+}
+
+} // namespace WebCore