Replace single allocations in fbx loader by block allocation

code/Common/StackAllocator.cpp

@@ -0,0 +1,84 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2022, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#include "StackAllocator.h"
+#include <assimp/ai_assert.h>
+
+using namespace Assimp;
+
+
+StackAllocator::StackAllocator() {
+}
+
+StackAllocator::~StackAllocator() {
+    FreeAll();
+}
+
+void *StackAllocator::Allocate(size_t byteSize) {
+    if (m_subIndex + byteSize > m_blockAllocationSize) // start a new block
+    {
+        // double block size every time, up to maximum of g_maxBytesPerBlock.
+        // Block size must be at least as large as byteSize, but we want to use this for small allocations anyway.
+        m_blockAllocationSize = std::max(std::min(m_blockAllocationSize * 2, g_maxBytesPerBlock), byteSize);
+        uint8_t *data = (uint8_t *)malloc(m_blockAllocationSize);
+        m_storageBlocks.push_back(data);
+        m_subIndex = byteSize;
+        return data;
+    }
+
+    uint8_t *data = m_storageBlocks.back();
+    data += m_subIndex;
+    m_subIndex += byteSize;
+
+    return data;
+}
+
+void StackAllocator::FreeAll() {
+    for (size_t i = 0; i < m_storageBlocks.size(); i++) {
+        free(m_storageBlocks[i]);
+    }
+    std::deque<uint8_t *> empty;
+    m_storageBlocks.swap(empty);
+    // start over:
+    m_blockAllocationSize = g_startBytesPerBlock;
+    m_subIndex = g_maxBytesPerBlock;
+}

code/Common/StackAllocator.h

@@ -0,0 +1,89 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2022, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  StackAllocator.h
+ *  @brief A very bare-bone allocator class that is suitable when
+ *      allocating many small objects, e.g. during parsing.
+ *      Individual objects are not freed, instead only the whole memory
+ *      can be deallocated.
+ */
+#ifndef AI_STACK_ALLOCATOR_H_INC
+#define AI_STACK_ALLOCATOR_H_INC
+
+
+#include <deque>
+
+namespace Assimp
+{
+
+/** @brief A very bare-bone allocator class that is suitable when
+ *      allocating many small objects, e.g. during parsing.
+ *      Individual objects are not freed, instead only the whole memory
+ *      can be deallocated.
+*/
+class StackAllocator {
+public:
+    // Constructs the allocator
+    StackAllocator();
+    // Destructs the allocator and frees all memory
+    ~StackAllocator();
+
+    // Returns a pointer to byteSize bytes of heap memory that persists
+    // for the lifetime of the allocator (or until FreeAll is called).
+    void *Allocate(size_t byteSize);
+
+    // Releases all the memory owned by this allocator.
+    // Memory provided through function Allocate is not valid anymore after this function has been called.
+    void FreeAll();
+
+private:
+    constexpr const static size_t g_maxBytesPerBlock = 64 * 1024 * 1024; // The maximum size (in bytes) of a block
+    constexpr const static size_t g_startBytesPerBlock = 16 * 1024;  // Size of the first block. Next blocks will double in size until maximum size of g_maxBytesPerBlock
+    size_t m_blockAllocationSize = g_startBytesPerBlock; // Block size of the current block
+    size_t m_subIndex = g_maxBytesPerBlock; // The current byte offset in the current block
+    std::deque<uint8_t *> m_storageBlocks;  // A list of blocks
+};
+
+
+} // namespace Assimp
+
+#endif // include guard