headers/private/net/DynamicBuffer.h

   1 /*
   2  * Copyright 2009-2014, Haiku, Inc. All Rights Reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Bruno Albuquerque, bga@bug-br.org.br
   7  */
   8
   9 #ifndef _DYNAMIC_BUFFER_H
  10 #define _DYNAMIC_BUFFER_H
  11
  12 #include <DataIO.h>
  13 #include <SupportDefs.h>
  14
  15
  16 class DynamicBuffer : public BDataIO {
  17 public:
  18         DynamicBuffer(size_t initialSize = 0);
  19         ~DynamicBuffer();
  20
  21         DynamicBuffer(const DynamicBuffer& buffer);
  22
  23         // InitCheck() should be called to guarantee the object initialization
  24         // didn't fail. If it does not return B_OK, the initialization failed.
  25         status_t InitCheck() const;
  26
  27         // Insert data at the end of the buffer. The buffer will be increased to
  28         // accomodate the data if needed.
  29         virtual ssize_t Write(const void* data, size_t size);
  30
  31         // Remove data from the start of the buffer. Move the buffer start
  32         // pointer to point to the data following it.
  33         virtual ssize_t Read(void* data, size_t size);
  34
  35         // Return a pointer to the underlying buffer. Note this will not
  36         // necessarily be a pointer to the start of the allocated memory as the
  37         // initial data may be positioned at an offset inside the buffer. In other
  38         // words, this returns a pointer to the start of data inside the buffer.
  39         unsigned char* Data() const;
  40
  41         // Returns the actual buffer size. This is the amount of memory allocated
  42         // for the buffer.
  43         size_t Size() const;
  44
  45         // Number of bytes of data still present in the buffer that can be
  46         // extracted through calls to Remove().
  47         size_t BytesRemaining() const;
  48
  49         // Dump some buffer statistics to stdout.
  50         void PrintToStream();
  51
  52 private:
  53         status_t _GrowToFit(size_t size, bool exact = false);
  54
  55         unsigned char* fBuffer;
  56         size_t fBufferSize;
  57         size_t fDataStart;
  58         size_t fDataEnd;
  59
  60         status_t fInit;
  61 };
  62
  63 #endif  // _DYNAMIC_BUFFER_H