src/mem_node.cc

   1
   2 /*
   3  * $Id$
   4  *
   5  * DEBUG: section 19    Store Memory Primitives
   6  * AUTHOR: Robert Collins
   7  *
   8  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   9  * ----------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from
  12  *  the Internet community; see the CONTRIBUTORS file for full
  13  *  details.   Many organizations have provided support for Squid's
  14  *  development; see the SPONSORS file for full details.  Squid is
  15  *  Copyrighted (C) 2001 by the Regents of the University of
  16  *  California; see the COPYRIGHT file for full details.  Squid
  17  *  incorporates software developed and/or copyrighted by other
  18  *  sources; see the CREDITS file for full details.
  19  *
  20  *  This program is free software; you can redistribute it and/or modify
  21  *  it under the terms of the GNU General Public License as published by
  22  *  the Free Software Foundation; either version 2 of the License, or
  23  *  (at your option) any later version.
  24  *
  25  *  This program is distributed in the hope that it will be useful,
  26  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  *  GNU General Public License for more details.
  29  *
  30  *  You should have received a copy of the GNU General Public License
  31  *  along with this program; if not, write to the Free Software
  32  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  33  *
  34  */
  35
  36 #include "squid-old.h"
  37 #include "mem_node.h"
  38
  39 static ptrdiff_t makeMemNodeDataOffset();
  40
  41 static ptrdiff_t _mem_node_data_offset = makeMemNodeDataOffset();
  42
  43 /*
  44  * Calculate the offset between the start of a mem_node and
  45  * its 'data' member
  46  */
  47 static ptrdiff_t
  48 makeMemNodeDataOffset()
  49 {
  50     mem_node *p = 0L;
  51     return ptrdiff_t(&p->data);
  52 }
  53
  54 /*
  55  * This is the callback when storeIOWrite() is done.  We need to
  56  * clear the write_pending flag for the mem_node.  First we have
  57  * to calculate the start of the mem_node based on the character
  58  * buffer that we wrote.  ick.
  59  */
  60 void
  61 memNodeWriteComplete(void* d)
  62 {
  63     mem_node* n = (mem_node*)((char*)d - _mem_node_data_offset);
  64     assert(n->write_pending);
  65     n->write_pending = 0;
  66 }
  67
  68 mem_node::mem_node(int64_t offset):nodeBuffer(0,offset,data)
  69 {}
  70
  71 mem_node::~mem_node()
  72 {}
  73
  74 size_t
  75 mem_node::InUseCount()
  76 {
  77     return Pool().inUseCount();
  78 }
  79
  80 size_t
  81 mem_node::StoreMemSize()
  82 {
  83     return InUseCount() * SM_PAGE_SIZE;
  84 }
  85
  86 int64_t
  87 mem_node::start() const
  88 {
  89     assert (nodeBuffer.offset >= 0);
  90     return nodeBuffer.offset;
  91 }
  92
  93 int64_t
  94 mem_node::end() const
  95 {
  96     return nodeBuffer.offset + nodeBuffer.length;
  97 }
  98
  99 Range<int64_t>
 100 mem_node::dataRange() const
 101 {
 102     return Range<int64_t> (start(), end());
 103 }
 104
 105 size_t
 106 mem_node::space() const
 107 {
 108     return SM_PAGE_SIZE - nodeBuffer.length;
 109 }
 110
 111 bool
 112 mem_node::contains (int64_t const &location) const
 113 {
 114     if (start() <= location && end() > location)
 115         return true;
 116
 117     return false;
 118 }
 119
 120 /* nodes can not be sparse */
 121 bool
 122 mem_node::canAccept (int64_t const &location) const
 123 {
 124     if (location == end() && space() > 0)
 125         return true;
 126
 127     return false;
 128 }
 129
 130 bool
 131 mem_node::operator < (mem_node const & rhs) const
 132 {
 133     return start() < rhs.start();
 134 }