balancer_policy.h

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// @file balancer_policy.h

#ifndef S_BALANCER_POLICY_HEADER
#define S_BALANCER_POLICY_HEADER

#include "../pch.h"

namespace mongo {

    class BalancerPolicy {
    public:
        struct ChunkInfo;

        typedef map< string,BSONObj > ShardToLimitsMap;
        typedef map< string,vector<BSONObj> > ShardToChunksMap;
        static ChunkInfo* balance( const string& ns, const ShardToLimitsMap& shardToLimitsMap,
                                   const ShardToChunksMap& shardToChunksMap, int balancedLastTime );

        // below exposed for testing purposes only -- treat it as private --

        static BSONObj pickChunk( const vector<BSONObj>& from, const vector<BSONObj>& to );

        static bool isSizeMaxed( BSONObj shardLimits );

        static bool isDraining( BSONObj shardLimits );

        static bool hasOpsQueued( BSONObj shardLimits );

    private:
        // Convenience types
        typedef ShardToChunksMap::const_iterator ShardToChunksIter;
        typedef ShardToLimitsMap::const_iterator ShardToLimitsIter;

    };

    struct BalancerPolicy::ChunkInfo {
        const string ns;
        const string to;
        const string from;
        const BSONObj chunk;

        ChunkInfo( const string& a_ns , const string& a_to , const string& a_from , const BSONObj& a_chunk )
            : ns( a_ns ) , to( a_to ) , from( a_from ), chunk( a_chunk ) {}
    };

    struct LimitsFields {
        // we use 'draining' and 'maxSize' from the 'shards' collection plus the following
        static BSONField<long long> currSize; // currently used disk space in bytes
        static BSONField<bool> hasOpsQueued;  // writeback queue is not empty?
    };

}  // namespace mongo

#endif  // S_BALANCER_POLICY_HEADER

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mongodb
Author(s): Nate Koenig
autogenerated on Fri Jan 11 12:15:18 2013