text: // MIT License
  
  // Copyright (c) 2019 Erin Catto
  
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  
  // The above copyright notice and this permission notice shall be included in all
  // copies or substantial portions of the Software.
  
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  // SOFTWARE.
  
  #ifndef B2_STACK_ALLOCATOR_H
  #define B2_STACK_ALLOCATOR_H
  
  #include "b2_settings.h"
  
  const int32 b2_stackSize = 100 * 1024;	// 100k
  const int32 b2_maxStackEntries = 32;
  
  struct b2StackEntry
  {
  	char* data;
  	int32 size;
  	bool usedMalloc;
  };
  
  // This is a stack allocator used for fast per step allocations.
  // You must nest allocate/free pairs. The code will assert
  // if you try to interleave multiple allocate/free pairs.
  class b2StackAllocator
  {
  public:
  	b2StackAllocator();
  	~b2StackAllocator();
  
  	void* Allocate(int32 size);
  	void Free(void* p);
  
  	int32 GetMaxAllocation() const;
  
  private:
  
  	char m_data[b2_stackSize];
  	int32 m_index;
  
  	int32 m_allocation;
  	int32 m_maxAllocation;
  
  	b2StackEntry m_entries[b2_maxStackEntries];
  	int32 m_entryCount;
  };
  
  #endif
  