src/mem_node.cc

   1
   2 /*
   3  * DEBUG: section 19    Store Memory Primitives
   4  * AUTHOR: Robert Collins
   5  *
   6  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   7  * ----------------------------------------------------------
   8  *
   9  *  Squid is the result of efforts by numerous individuals from
  10  *  the Internet community; see the CONTRIBUTORS file for full
  11  *  details.   Many organizations have provided support for Squid's
  12  *  development; see the SPONSORS file for full details.  Squid is
  13  *  Copyrighted (C) 2001 by the Regents of the University of
  14  *  California; see the COPYRIGHT file for full details.  Squid
  15  *  incorporates software developed and/or copyrighted by other
  16  *  sources; see the CREDITS file for full details.
  17  *
  18  *  This program is free software; you can redistribute it and/or modify
  19  *  it under the terms of the GNU General Public License as published by
  20  *  the Free Software Foundation; either version 2 of the License, or
  21  *  (at your option) any later version.
  22  *
  23  *  This program is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  29  *  along with this program; if not, write to the Free Software
  30  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  31  *
  32  */
  33
  34 #include "squid.h"
  35 #include "mem_node.h"
  36
  37 static ptrdiff_t makeMemNodeDataOffset();
  38
  39 static ptrdiff_t _mem_node_data_offset = makeMemNodeDataOffset();
  40
  41 /*
  42  * Calculate the offset between the start of a mem_node and
  43  * its 'data' member
  44  */
  45 static ptrdiff_t
  46 makeMemNodeDataOffset()
  47 {
  48     mem_node *p = 0L;
  49     return ptrdiff_t(&p->data);
  50 }
  51
  52 /*
  53  * This is the callback when storeIOWrite() is done.  We need to
  54  * clear the write_pending flag for the mem_node.  First we have
  55  * to calculate the start of the mem_node based on the character
  56  * buffer that we wrote.  ick.
  57  */
  58 void
  59 memNodeWriteComplete(void* d)
  60 {
  61     mem_node* n = (mem_node*)((char*)d - _mem_node_data_offset);
  62     assert(n->write_pending);
  63     n->write_pending = false;
  64 }
  65
  66 mem_node::mem_node(int64_t offset) :
  67         nodeBuffer(0,offset,data),
  68         write_pending(false)
  69 {
  70     *data = 0;
  71 }
  72
  73 mem_node::~mem_node()
  74 {}
  75
  76 size_t
  77 mem_node::InUseCount()
  78 {
  79     return Pool().inUseCount();
  80 }
  81
  82 size_t
  83 mem_node::StoreMemSize()
  84 {
  85     return InUseCount() * SM_PAGE_SIZE;
  86 }
  87
  88 int64_t
  89 mem_node::start() const
  90 {
  91     assert (nodeBuffer.offset >= 0);
  92     return nodeBuffer.offset;
  93 }
  94
  95 int64_t
  96 mem_node::end() const
  97 {
  98     return nodeBuffer.offset + nodeBuffer.length;
  99 }
 100
 101 Range<int64_t>
 102 mem_node::dataRange() const
 103 {
 104     return Range<int64_t> (start(), end());
 105 }
 106
 107 size_t
 108 mem_node::space() const
 109 {
 110     return SM_PAGE_SIZE - nodeBuffer.length;
 111 }
 112
 113 bool
 114 mem_node::contains (int64_t const &location) const
 115 {
 116     if (start() <= location && end() > location)
 117         return true;
 118
 119     return false;
 120 }
 121
 122 /* nodes can not be sparse */
 123 bool
 124 mem_node::canAccept (int64_t const &location) const
 125 {
 126     if (location == end() && space() > 0)
 127         return true;
 128
 129     return false;
 130 }
 131
 132 bool
 133 mem_node::operator < (mem_node const & rhs) const
 134 {
 135     return start() < rhs.start();
 136 }