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<DIV>Hi, Alex</DIV>
<DIV> </DIV>
<DIV>Is it possible for ns3::ndn::cs::lfu/lru? </DIV>
<DIV> </DIV>
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<DIV><SPAN>Aaron</SPAN></DIV>
<DIV> </DIV>
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<DIV><B>From:</B> <A href="mailto:alexander.afanasyev@ucla.edu">Alex
Afanasyev</A></DIV>
<DIV><B>Date:</B> 2013-05-10 09:20</DIV>
<DIV><B>To:</B> <A href="mailto:aaronishere@qq.com">Aaron</A></DIV>
<DIV><B>CC:</B> <A href="mailto:ndnsim@lists.cs.ucla.edu">ndnsim</A></DIV>
<DIV><B>Subject:</B> Re: Question</DIV></DIV></DIV>
<DIV>
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<DIV>Hi Aaron,</DIV>
<DIV><BR></DIV>
<DIV>Hmm... Again, in general there is no notion of beginning or ending in PIT.
It is just a complex tree-like structure, where items are stored until
they are explicitly removed (interest gets satisfied or timed out).</DIV>
<DIV><BR></DIV>
<DIV>The default implementation of PIT in
ndnSIM (ns3::ndn::pit::Persistent) has "persistent" item replace
policy, meaning that if there is a limit on number of entires and this
limit is reached, new entries will be rejected.</DIV>
<DIV><BR></DIV>
<DIV>The behavior similar to what you described is happening with
ns3::ndn::pit::Lru, where "item in the beginning" is the oldest PIT entry.
Is it what you're asking? If yes, then you can "remove" second-old,
third-old, or older items like this:</DIV>
<DIV style="FONT-FAMILY: sans-serif; OVERFLOW: auto"><PRE style="Z-INDEX: auto; POSITION: static; BACKGROUND-COLOR: rgb(241,240,240)"><PRE><SPAN style="COLOR: rgb(64,0,0); FONT-WEIGHT: bold">typename</SPAN> policy_container<SPAN style="COLOR: rgb(128,96,48)">::</SPAN><SPAN style="COLOR: rgb(128,0,64)">iterator</SPAN> item <SPAN style="COLOR: rgb(128,96,48)">=</SPAN> policy_container<SPAN style="COLOR: rgb(128,96,48)">::</SPAN>begin <SPAN style="COLOR: rgb(128,96,48)">(</SPAN><SPAN style="COLOR: rgb(128,96,48)">)</SPAN><SPAN style="COLOR: rgb(128,96,48)">;</SPAN>
<SPAN style="COLOR: rgb(0,221,221)">std</SPAN><SPAN style="COLOR: rgb(128,96,48)">::</SPAN>advance <SPAN style="COLOR: rgb(128,96,48)">(</SPAN>item<SPAN style="COLOR: rgb(128,96,48)">,</SPAN> <SPAN style="COLOR: rgb(192,0,0)">2</SPAN><SPAN style="COLOR: rgb(128,96,48)">)</SPAN><SPAN style="COLOR: rgb(128,96,48)">;</SPAN>
<SPAN style="COLOR: rgb(64,0,0); FONT-WEIGHT: bold">if</SPAN> <SPAN style="COLOR: rgb(128,96,48)">(</SPAN>item <SPAN style="COLOR: rgb(128,96,48)">!</SPAN><SPAN style="COLOR: rgb(128,96,48)">=</SPAN> policy_container<SPAN style="COLOR: rgb(128,96,48)">::</SPAN>end <SPAN style="COLOR: rgb(128,96,48)">(</SPAN><SPAN style="COLOR: rgb(128,96,48)">)</SPAN><SPAN style="COLOR: rgb(128,96,48)">)</SPAN>
<SPAN style="COLOR: rgb(128,96,48)">{</SPAN>
base_<SPAN style="COLOR: rgb(128,96,48)">.</SPAN>erase <SPAN style="COLOR: rgb(128,96,48)">(</SPAN><SPAN style="COLOR: rgb(128,96,48)">&</SPAN><SPAN style="COLOR: rgb(128,96,48)">(</SPAN><SPAN style="COLOR: rgb(128,96,48)">*</SPAN>item<SPAN style="COLOR: rgb(128,96,48)">)</SPAN><SPAN style="COLOR: rgb(128,96,48)">)</SPAN><SPAN style="COLOR: rgb(128,96,48)">;</SPAN>
<SPAN style="COLOR: rgb(128,96,48)">}</SPAN></PRE></PRE></DIV>
<DIV><BR></DIV>
<DIV>std::advance operation is not very efficient (it has linear complexity),
but if you don't go too far away from the beginning, it should work reasonably
well.</DIV>
<DIV><BR></DIV>
<DIV>---</DIV>
<DIV>Alex</DIV><BR>
<DIV>
<DIV>On May 9, 2013, at 6:02 PM, "Aaron" <<A
href="mailto:aaronishere@qq.com">aaronishere@qq.com</A>> wrote:</DIV><BR
class=Apple-interchange-newline>
<BLOCKQUOTE
type="cite">hi, Alex<BR>since the insert function always erase the item in the beginning. if it's possible to delete the first several items something like when A comes, erases the beginning, then B comes，erases the second，C erases the third. Say we only replace the first five item, then when F comes, re-erases the beginning<BR>
<DIV></DIV>
<DIV>
<DIV
style="PADDING-BOTTOM: 2px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-FAMILY: Arial Narrow; FONT-SIZE: 12px; PADDING-TOP: 2px">------------------ 原始邮件 ------------------</DIV>
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<DIV><B>发件人:</B> "alexander.afanasyev"<<A
href="mailto:alexander.afanasyev@ucla.edu">alexander.afanasyev@ucla.edu</A>><WBR></DIV>
<DIV><B>发送时间:</B> 2013年5月10日(星期五) 上午7:42</DIV>
<DIV><B>收件人:</B> "aaronishere"<<A
href="mailto:aaronishere@qq.com">aaronishere@qq.com</A>>;</DIV>
<DIV><B>抄送:</B> "<A
href="mailto:ndnsim@lists.cs.ucla.edu">ndnsim@lists.cs.ucla.edu</A>"<<A
href="mailto:ndnsim@lists.cs.ucla.edu">ndnsim@lists.cs.ucla.edu</A>>;</DIV>
<DIV><B>主题:</B> Re: Question</DIV></DIV></DIV>
<DIV>Hi Aaron,</DIV>
<DIV><BR></DIV>It is almost impossible to get a position number of an item,
since the PIT data structure is a recursive hash-based container. Is
there any specific use case why you want to get this number? If you
really need such functionality, the custom PIT policy can track PIT item
positions.
<DIV><BR></DIV>
<DIV>To iterate over all elements of PIT you can do the following:</DIV>
<DIV><BR></DIV>
<DIV>Ptr<ndn::Pit> pit = ?;</DIV>
<DIV>for (Ptr<pit::Entry> entry = pit->Begin (); entry != pit->End
(); entry = pit->Next (entry))</DIV>
<DIV>{</DIV>
<DIV>...</DIV>
<DIV>}</DIV>
<DIV><BR></DIV>
<DIV>---</DIV>
<DIV>Alex<BR>
<DIV><BR>
<DIV>
<DIV>On May 9, 2013, at 4:35 PM, aaronishere <<A
href="mailto:aaronishere@qq.com">aaronishere@qq.com</A>> wrote:</DIV><BR
class=Apple-interchange-newline>
<BLOCKQUOTE type="cite">
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<DIV>Hi, Alex</DIV>
<DIV> </DIV>
<DIV> Is there some way to get the position number of item in the
*-policy.h, such as the lookuped item is the 5th item in the
container?</DIV>
<DIV> </DIV>
<DIV>Another is how to loop of all pit-entry, such as</DIV>
<DIV>for ( pitentry::begin, pitentry::end, Next( ) )</DIV>
<DIV>{</DIV>
<DIV>......</DIV>
<DIV>},</DIV>
<DIV>I'm not clear abou it.</DIV>
<DIV> </DIV>
<DIV>Thanks!!</DIV>
<DIV> </DIV>
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<DIV><SPAN>Aaron</SPAN></DIV></DIV></BLOCKQUOTE></DIV><BR></DIV></DIV></BLOCKQUOTE></DIV><BR></DIV></DIV></BODY></HTML>