#ifndef __XRDNETCACHE_HH__
#define __XRDNETCACHE_HH__
/******************************************************************************/
/* */
/* X r d N e t C a c h e . h h */
/* */
/* (c) 2013 by the Board of Trustees of the Leland Stanford, Jr., University */
/* All Rights Reserved */
/* Produced by Andrew Hanushevsky for Stanford University under contract */
/* DE-AC02-76-SFO0515 with the Department of Energy */
/* */
/* This file is part of the XRootD software suite. */
/* */
/* XRootD is free software: you can redistribute it and/or modify it under */
/* the terms of the GNU Lesser General Public License as published by the */
/* Free Software Foundation, either version 3 of the License, or (at your */
/* option) any later version. */
/* */
/* XRootD is distributed in the hope that it will be useful, but WITHOUT */
/* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or */
/* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public */
/* License for more details. */
/* */
/* You should have received a copy of the GNU Lesser General Public License */
/* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */
/* COPYING (GPL license). If not, see . */
/* */
/* The copyright holder's institutional names and contributor's names may not */
/* be used to endorse or promote products derived from this software without */
/* specific prior written permission of the institution or contributor. */
/******************************************************************************/
#include
#include
#include
#include "XrdSys/XrdSysPthread.hh"
class XrdNetAddrInfo;
class XrdNetCache
{
public:
//------------------------------------------------------------------------------
//! Add an address-hostname association to the cache. The address must be an
//! INET family address; otherwise it is not added.
//!
//! @param hAddr points to the address of the name.
//! @param hName points to the name to be associated with the address.
//------------------------------------------------------------------------------
void Add(XrdNetAddrInfo *hAddr, const char *hName);
//------------------------------------------------------------------------------
//! Locate an address-hostname association in the cache.
//!
//! @param hAddr points to the address of the name.
//!
//! @return Success: an strdup'd string of the corresponding name.
//! Failure: 0;
//------------------------------------------------------------------------------
char *Find(XrdNetAddrInfo *hAddr);
//------------------------------------------------------------------------------
//! Set the default keep time for entries in the cache during initialization.
//!
//! @param ktVal the number of seconds to keep an entry in the cache.
//------------------------------------------------------------------------------
static
void SetKT(int ktval) {keepTime = ktval;}
//------------------------------------------------------------------------------
//! Constructor. When allocateing a new hash, two adjacent Fibonocci numbers.
//! The series is simply n[j] = n[j-1] + n[j-2].
//!
//! @param psize the correct Fibonocci antecedent to csize.
//! @param csize the initial size of the table.
//------------------------------------------------------------------------------
XrdNetCache(int psize = 987, int csize = 1597);
//------------------------------------------------------------------------------
//! Destructor. The XrdNetCache object is not designed to be deleted. Doing
//! so will cause memory to be lost.
//------------------------------------------------------------------------------
~XrdNetCache() {} // Never gets deleted
private:
static const int LoadMax = 80;
struct anItem
{union {long long aV6[2];
int aV4[4];
char aVal[16]; // Enough for IPV4 or IPV6
};
anItem *Next;
char *hName;
time_t expTime; // Expiration time
unsigned int aHash; // Hash value
int aLen; // Actual length 4 or 16
inline int operator!=(const anItem &oth)
{return aLen != oth.aLen || aHash != oth.aHash
|| memcmp(aVal, oth.aVal, aLen);
}
anItem() : Next(0), hName(0), aLen(0) {}
anItem(anItem &Item, const char *hn, int kt)
: Next(0), hName(strdup(hn)), expTime(time(0)+kt),
aHash(Item.aHash), aLen(Item.aLen)
{memcpy(aVal, Item.aVal, Item.aLen);}
~anItem() {if (hName) free(hName);}
};
void Expand();
int GenKey(anItem &Item, XrdNetAddrInfo *hAddr);
anItem *Locate(anItem &Item);
static int keepTime;
XrdSysMutex myMutex;
anItem **nashtable;
int prevtablesize;
int nashtablesize;
int nashnum;
int Threshold;
};
#endif