src/system/boot/loader/net/ChainBuffer.cpp

   1 /*
   2  * Copyright 2005, Ingo Weinhold <bonefish@cs.tu-berlin.de>.
   3  * All rights reserved. Distributed under the terms of the MIT License.
   4  */
   5
   6 #include <boot/net/ChainBuffer.h>
   7
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 #include <util/kernel_cpp.h>
  12
  13 // constructor
  14 ChainBuffer::ChainBuffer(void *data, uint32 size, ChainBuffer *next,
  15         bool freeData)
  16 {
  17         _Init(data, size, next,
  18                 CHAIN_BUFFER_ON_STACK | (freeData ? CHAIN_BUFFER_FREE_DATA : 0));
  19 }
  20
  21 // destructor
  22 ChainBuffer::~ChainBuffer()
  23 {
  24         _Destroy();
  25 }
  26
  27 // DetachNext
  28 ChainBuffer *
  29 ChainBuffer::DetachNext()
  30 {
  31         if (!fNext)
  32                 return NULL;
  33
  34         ChainBuffer *next = fNext;
  35
  36         fNext = NULL;
  37         next->fFlags |= CHAIN_BUFFER_HEAD;
  38         fTotalSize = fSize;
  39
  40         return next;
  41 }
  42
  43 // Append
  44 void
  45 ChainBuffer::Append(ChainBuffer *next)
  46 {
  47         if (!next)
  48                 return;
  49
  50         if (fNext)
  51                 fNext->Append(next);
  52         else
  53                 fNext = next;
  54
  55         fTotalSize = fSize + fNext->fTotalSize;
  56 }
  57
  58 // Flatten
  59 void
  60 ChainBuffer::Flatten(void *_buffer) const
  61 {
  62         if (uint8 *buffer = (uint8*)_buffer) {
  63                 if (fData && fSize > 0) {
  64                         memcpy(buffer, fData, fSize);
  65                         buffer += fSize;
  66                 }
  67
  68                 if (fNext)
  69                         fNext->Flatten(buffer);
  70         }
  71 }
  72
  73 // _Init
  74 void
  75 ChainBuffer::_Init(void *data, uint32 size, ChainBuffer *next, uint32 flags)
  76 {
  77         fFlags = flags | CHAIN_BUFFER_HEAD;
  78         fSize = size;
  79         fTotalSize = fSize;
  80         fData = data;
  81         fNext = NULL;
  82         Append(next);
  83 }
  84
  85 // _Destroy
  86 void
  87 ChainBuffer::_Destroy()
  88 {
  89         ChainBuffer *next = fNext;
  90         fNext = NULL;
  91         if ((fFlags & CHAIN_BUFFER_FREE_DATA) && fData) {
  92                 free(fData);
  93                 fData = NULL;
  94         }
  95
  96         if (!(fFlags & CHAIN_BUFFER_EMBEDDED_DATA))
  97                 fSize = 0;
  98         fTotalSize = fSize;
  99
 100         if (next) {
 101                 if (next->fFlags & CHAIN_BUFFER_ON_STACK)
 102                         next->_Destroy();
 103                 else
 104                         delete next;
 105         }
 106 }