MemoryPoolSettings.h

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// Copyright Onix Solutions Limited [OnixS]. All rights reserved.
//
// This software owned by Onix Solutions Limited [OnixS] and is
// protected by copyright law and international copyright treaties.
//
// Access to and use of the software is governed by the terms of the applicable
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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/MDH/String.h>

ONIXS_CMEMDH_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.
class ONIXS_CMEMDH_LTWT MemoryPoolSettings
{
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;
    }

private:
    size_t blockIncrease_;

    size_t increaseQty_;

    size_t chunkSize_;

    size_t chunkScaling_;
};

/// Serializes memory pool settings into a string.
ONIXS_CMEMDH_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_CMEMDH_NAMESPACE_END