MemoryPoolSettings.h

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// Copyright Onix Solutions Limited [OnixS]. All rights reserved.
//
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// protected by copyright law and international copyright treaties.
//
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// agreements granting a non-assignable, non-transferable and non-exclusive license 
// to use the software for it's own data processing purposes under the terms defined 
// in the Agreement.
//
// Except as otherwise granted within the terms of the Agreement, copying or 
// reproduction of any part of this source code or associated reference material 
// to any other location for further reproduction or redistribution, and any 
// amendments to this copyright notice, are expressly prohibited.
//
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//

#pragma once

#include <string>
#include <stdexcept>

#include <OnixS/CME/ConflatedUDP/String.h>

ONIXS_CONFLATEDUDP_NAMESPACE_BEGIN

/// Raises exception on zero parameter value. 
inline
void
throwZeroParameter(
    const Char* parameter)
{
    std::string reason;

    reason += "Non-zero value is expected for '";
    reason += parameter ? parameter : "<unknown>";
    reason += "' parameter. ";

    throw std::out_of_range(reason);
}

/// Memory pool settings. 
///
/// Control parameters affecting behavior of memory 
/// pool used by Handler while processing market data. 
ONIXS_CONFLATEDUDP_LTWT_CLASS MemoryPoolSettings 
{
    size_t blockIncrease_;

    size_t increaseQty_;

    size_t chunkSize_;

    size_t chunkScaling_;

public:
    /// Initializes parameters with default values. 
    MemoryPoolSettings()
      : blockIncrease_(48)
      , increaseQty_(32)
      , chunkSize_(20)
      , chunkScaling_(2)
    {
    }

    /// Initializes as a copy. 
    MemoryPoolSettings(
        const MemoryPoolSettings& other)
        : blockIncrease_(
            other.blockIncrease_)
        , increaseQty_(
            other.increaseQty_)
        , chunkSize_(
            other.chunkSize_)
        , chunkScaling_(
            other.chunkScaling_)
    {
    }

    /// Finalizes the instance.
    ~MemoryPoolSettings()
    {
    }

    /// Memory block increase value. 
    /// 
    /// Memory pool allocates blocks 
    /// divisible by given value. 
    size_t 
    blockIncrease() const
    {
        return blockIncrease_;
    }

    /// Updates memory block increase value. 
    /// 
    /// Memory pool allocates blocks 
    /// divisible by given value. 
    void 
    blockIncrease(
        size_t increase) 
    {
        const Char* 
        const name = 
            "BlockIncrease";

        if (0 < increase)
        {
            blockIncrease_ = increase;
        }
        else
        {
            throwZeroParameter(name);
        }
    }

    /// Limits number of increases memory pool does. 
    ///
    /// Memory pool allocates blocks divisible by 
    /// 'blockIncrease' value. Efficient allocation 
    /// is performed for blocks whose size doesn't 
    /// exceeds multiplication of 'blockIncrease' 
    /// and 'increaseQty' values. Other blocks are 
    /// allocated upon request without caching. 
    size_t 
    increaseQty() const
    {
        return increaseQty_;
    }

    /// Limits number of increases memory pool does. 
    ///
    /// Memory pool allocates blocks divisible by 
    /// 'blockIncrease' value. Efficient allocation 
    /// is performed for blocks whose size doesn't 
    /// exceeds multiplication of 'blockIncrease' 
    /// and 'increaseQty' values. Other blocks are 
    /// allocated upon request without caching. 
    void 
    increaseQty(
        size_t qty) 
    {
        const Char* 
        const name = 
            "IncreaseQty";

        if (0 < qty)
        {
            increaseQty_ = qty;
        }
        else
        {
            throwZeroParameter(name);
        }
    }

    /// Number of blocks per chunk. 
    ///
    /// Memory pool allocates chunks of blocks 
    /// thus reducing number of actual allocations. 
    /// Given parameter specifies number of memory 
    /// blocks of same size allocated at once if 
    /// pool is empty. 
    size_t 
    chunkSize() const
    {
        return chunkSize_;
    }

    /// Number of blocks per chunk. 
    ///
    /// Memory pool allocates chunks of blocks 
    /// thus reducing number of actual allocations. 
    /// Given parameter specifies number of memory 
    /// blocks of same size allocated at once if 
    /// pool is empty. 
    void 
    chunkSize(
        size_t size) 
    {
        const Char* 
        const name = 
            "ChunkSize";

        if (0 < size)
        {
            chunkSize_ = size;
        }
        else
        {
            throwZeroParameter(name);
        }
    }

    /// Defines chunk scale factor. 
    ///
    /// Each time memory pool allocates a new chunk 
    /// of blocks, its size is scaled by given factor. 
    size_t 
    chunkScaling() const
    {
        return chunkScaling_;
    }

    /// Defines chunk scale factor. 
    ///
    /// Each time memory pool allocates a new chunk 
    /// of blocks, its size is scaled by given factor. 
    void
    chunkScaling(
        size_t factor)
    {
        const Char* 
        const name = 
            "ChunkScaling";

        if (0 < factor)
        {
            chunkScaling_ = factor;
        }
        else
        {
            throwZeroParameter(name);
        }
    }

    /// Initializes as a copy. 
    MemoryPoolSettings&
    operator =(
        const MemoryPoolSettings& other)
    {
        blockIncrease_ = 
            other.blockIncrease_;

        increaseQty_ = 
            other.increaseQty_;

        chunkSize_ = 
            other.chunkSize_;

        chunkScaling_ = 
            other.chunkScaling_;

        return *this;
    }
};

/// Serializes memory pool settings into a string. 
ONIXS_CONFLATEDUDP_EXPORTED
void
toStr(
    std::string&,
    const 
    MemoryPoolSettings&);

/// Serializes memory pool settings into a string. 
inline
std::string
toStr(
    const 
    MemoryPoolSettings& settings)
{
    std::string str;

    toStr(str, settings);

    return str;
}

ONIXS_CONFLATEDUDP_NAMESPACE_END