104 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // vim: set sts=2 ts=8 sw=2 tw=99 et:
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| //
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| // Copyright (C) 2012-2014 AlliedModders LLC, David Anderson
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| //
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| // This file is part of SourcePawn.
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| //
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| // SourcePawn is free software: you can redistribute it and/or modify it under
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| // the terms of the GNU General Public License as published by the Free
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| // Software Foundation, either version 3 of the License, or (at your option)
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| // any later version.
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| // 
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| // SourcePawn is distributed in the hope that it will be useful, but WITHOUT ANY
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| // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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| // FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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| //
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| // You should have received a copy of the GNU General Public License along with
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| // SourcePawn. If not, see http://www.gnu.org/licenses/.
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| #ifndef _include_sp_memory_buffer_h_
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| #define _include_sp_memory_buffer_h_
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| 
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| #include <stdio.h>
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| #include <am-utility.h>
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| #include "smx-builder.h"
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| 
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| // Interface for SmxBuilder to blit bytes.
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| class ISmxBuffer
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| {
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|  public:
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|   virtual bool write(const void *bytes, size_t len) = 0;
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|   virtual size_t pos() const = 0;
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| };
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| 
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| // An in-memory buffer for SmxBuilder.
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| class MemoryBuffer : public ISmxBuffer
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| {
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|   static const size_t kDefaultSize = 4096;
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| 
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|  public:
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|   MemoryBuffer() {
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|     buffer_ = (uint8_t *)calloc(kDefaultSize, 1);
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|     pos_ = buffer_;
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|     end_ = buffer_ + kDefaultSize;
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|   }
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|   ~MemoryBuffer() {
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|     free(buffer_);
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|   }
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| 
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|   bool write(const void *bytes, size_t len) KE_OVERRIDE {
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|     if (pos_ + len > end_)
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|       grow(len);
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|     memcpy(pos_, bytes, len);
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|     pos_ += len;
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|     return true;
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|   }
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| 
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|   size_t pos() const KE_OVERRIDE {
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|     return pos_ - buffer_;
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|   }
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| 
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|   uint8_t *bytes() const {
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|     return buffer_;
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|   }
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|   size_t size() const {
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|     return pos();
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|   }
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|   void rewind(size_t newpos) {
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|     assert(newpos < pos());
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|     pos_ = buffer_ + newpos;
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|   }
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| 
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|  private:
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|   void grow(size_t len) {
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|     if (!ke::IsUintPtrAddSafe(pos(), len)) {
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|       fprintf(stderr, "Allocation overflow!\n");
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|       abort();
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|     }
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| 
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|     size_t new_maxsize = end_ - buffer_;
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|     while (pos() + len > new_maxsize) {
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|       if (!ke::IsUintPtrMultiplySafe(new_maxsize, 2)) {
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|         fprintf(stderr, "Allocation overflow!\n");
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|         abort();
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|       }
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|       new_maxsize *= 2;
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|     }
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| 
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|     uint8_t *newbuffer = (uint8_t *)realloc(buffer_, new_maxsize);
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|     if (!newbuffer) {
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|       fprintf(stderr, "Out of memory!\n");
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|       abort();
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|     }
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|     pos_ = newbuffer + (pos_ - buffer_);
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|     end_ = newbuffer + new_maxsize;
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|     buffer_ = newbuffer;
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|   }
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| 
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|  private:
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|   uint8_t *buffer_;
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|   uint8_t *pos_;
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|   uint8_t *end_;
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| };
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| 
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| #endif // _include_sp_memory_buffer_h_
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