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127 lines
2.8 KiB
127 lines
2.8 KiB
/*
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ISC License
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Copyright (c) 2019, Antonio SJ Musumeci <trapexit@spawn.link>
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Permission to use, copy, modify, and/or distribute this software for any
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purpose with or without fee is hereby granted, provided that the above
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copyright notice and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#pragma once
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// This uses a hashed key to limit the size of the data
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// structure. This could lead to choosing the wrong value but given
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// its usecase that really isn't a big deal.
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#include "nonstd/optional.hpp"
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#include "boost/unordered/concurrent_flat_map.hpp"
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#include "boost/flyweight.hpp"
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#include "boost/flyweight/no_tracking.hpp"
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#include "wyhash.h"
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#include "strpool.h"
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#include "fmt/core.h"
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#include <cstdint>
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#include <string>
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class PolicyCache
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{
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public:
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typedef uint64_t Key;
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typedef boost::flyweight<std::string,boost::flyweights::no_tracking> Val;
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typedef boost::concurrent_flat_map<Key,Val> Map;
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public:
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PolicyCache(unsigned const max_size_ = 256)
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: _max_size(max_size_)
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{
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}
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~PolicyCache()
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{
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}
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public:
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Val
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insert(char const *key_,
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size_t const keylen_,
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std::string const &val_)
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{
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Val val;
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uint64_t hash;
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val = val_;
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hash = wyhash(key_,keylen_,0xdeadbeef,_wyp);
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_cache.insert_or_assign(hash,val_);
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fmt::print("insert {}={}\n",
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key_,
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val.get());
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return val;
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}
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Val
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insert(char const *key_,
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std::string const &val_)
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{
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return insert(key_,
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strlen(key_),
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val_);
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}
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Val
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insert(std::string const &key_,
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std::string const &val_)
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{
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return insert(key_.c_str(),
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key_.size(),
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val_);
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}
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Val
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find(std::string const &key_) const
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{
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Val rv;
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uint64_t hash;
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hash = wyhash(key_.c_str(),key_.size(),0xdeadbeef,_wyp);
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_cache.cvisit(hash,
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[&](Map::value_type const &v_)
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{
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fmt::print("get {}={}\n",
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key_,
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v_.second.get());
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rv = v_.second;
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});
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return rv;
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}
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void
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erase(std::string const &key_)
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{
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uint64_t hash;
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hash = wyhash(key_.c_str(),key_.size(),0xdeadbeef,_wyp);
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_cache.erase(hash);
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}
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private:
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unsigned _max_size;
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Map _cache;
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};
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