100 lines
3.2 KiB
C
100 lines
3.2 KiB
C
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/*
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* IRandom.h
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef FLOW_IRANDOM_H
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#define FLOW_IRANDOM_H
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#pragma once
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#include "Platform.h"
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#include <stdint.h>
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#if (defined(__APPLE__))
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#include <ext/hash_map>
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#else
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#include <unordered_map>
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#endif
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class UID {
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uint64_t part[2];
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public:
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UID() { part[0] = part[1] = 0; }
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UID( uint64_t a, uint64_t b ) { part[0]=a; part[1]=b; }
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std::string toString() const;
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std::string shortString() const;
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bool isValid() const { return part[0] || part[1]; }
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bool operator == ( const UID& r ) const { return part[0]==r.part[0] && part[1]==r.part[1]; }
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bool operator != ( const UID& r ) const { return part[0]!=r.part[0] || part[1]!=r.part[1]; }
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bool operator < ( const UID& r ) const { return part[0] < r.part[0] || (part[0] == r.part[0] && part[1] < r.part[1]); }
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uint64_t hash() const { return first(); }
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uint64_t first() const { return part[0]; }
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uint64_t second() const { return part[1]; }
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static UID fromString( std::string const& );
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template <class Ar>
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void serialize_unversioned(Ar& ar) { // Changing this serialization format will affect key definitions, so can't simply be versioned!
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ar & part[0] & part[1];
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}
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};
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template <class Ar> void load( Ar& ar, UID& uid ) { uid.serialize_unversioned(ar); }
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template <class Ar> void save( Ar& ar, UID const& uid ) { const_cast<UID&>(uid).serialize_unversioned(ar); }
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namespace std {
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template <>
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class hash<UID> : public unary_function<UID,size_t> {
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public:
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size_t operator()(UID const& u) const { return u.hash(); }
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};
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}
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class IRandom {
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public:
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virtual double random01() = 0;
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virtual int randomInt(int min, int maxPlusOne) = 0;
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virtual int64_t randomInt64(int64_t min, int64_t maxPlusOne) = 0;
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virtual uint32_t randomUInt32() = 0;
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virtual UID randomUniqueID() = 0;
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virtual char randomAlphaNumeric() = 0;
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virtual std::string randomAlphaNumeric( int length ) = 0;
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virtual uint64_t peek() const = 0; // returns something that is probably different for different random states. Deterministic (and idempotent) for a deterministic generator.
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// The following functions have fixed implementations for now:
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template <class C>
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decltype((fake<const C>()[0])) randomChoice( const C& c ) { return c[randomInt(0,(int)c.size())]; }
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template <class C>
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void randomShuffle( C& container ) {
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int s = (int)container.size();
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for(int i=0; i<s; i++)
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std::swap( container[i], container[ randomInt( i, s ) ] );
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}
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bool coinflip() { return (this->random01() < 0.5); }
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};
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extern IRandom* g_random;
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extern IRandom* g_nondeterministic_random;
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extern IRandom* g_debug_random;
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extern FILE* randLog;
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#endif
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