annotate base/StorageAdviser.cpp @ 1752:6d09d68165a4 by-id

Further review of ById: make IDs only available when adding a model to the ById store, not by querying the item directly. This means any id encountered in the wild must have been added to the store at some point (even if later released), which simplifies reasoning about lifecycles

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 QMUL.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "StorageAdviser.h"

#include "Exceptions.h"
#include "TempDirectory.h"

#include "system/System.h"

#include <iostream>

QString
StorageAdviser::criteriaToString(int criteria)
{
    QStringList labels;
    if (criteria & SpeedCritical) labels.push_back("SpeedCritical");
    if (criteria & PrecisionCritical) labels.push_back("PrecisionCritical");
    if (criteria & LongRetentionLikely) labels.push_back("LongRetentionLikely");
    if (criteria & FrequentLookupLikely) labels.push_back("FrequentLookupLikely");
    if (labels.empty()) return "None";
    else return labels.join("+");
}

QString
StorageAdviser::recommendationToString(int recommendation)
{
    QStringList labels;
    if (recommendation & UseMemory) labels.push_back("UseMemory");
    if (recommendation & PreferMemory) labels.push_back("PreferMemory");
    if (recommendation & PreferDisc) labels.push_back("PreferDisc");
    if (recommendation & UseDisc) labels.push_back("UseDisc");
    if (recommendation & ConserveSpace) labels.push_back("ConserveSpace");
    if (recommendation & UseAsMuchAsYouLike) labels.push_back("UseAsMuchAsYouLike");
    if (labels.empty()) return "None";
    else return labels.join("+");
}

QString
StorageAdviser::storageStatusToString(StorageStatus status)
{
    if (status == Insufficient) return "Insufficient";
    if (status == Marginal) return "Marginal";
    if (status == Sufficient) return "Sufficient";
    return "Unknown";
}

size_t StorageAdviser::m_discPlanned = 0;
size_t StorageAdviser::m_memoryPlanned = 0;

StorageAdviser::Recommendation
StorageAdviser::m_baseRecommendation = StorageAdviser::NoRecommendation;

StorageAdviser::Recommendation
StorageAdviser::recommend(Criteria criteria,
                          size_t minimumSize,
                          size_t maximumSize)
{
    SVDEBUG << "StorageAdviser::recommend: criteria " << criteria
            << " (" + criteriaToString(criteria) + ")"
            << ", minimumSize " << minimumSize
            << ", maximumSize " << maximumSize << endl;

    if (m_baseRecommendation != NoRecommendation) {
        SVDEBUG << "StorageAdviser::recommend: Returning fixed recommendation "
                << m_baseRecommendation << " ("
                << recommendationToString(m_baseRecommendation) << ")" << endl;
        return m_baseRecommendation; // for now
    }

    QString path;
    try {
        path = TempDirectory::getInstance()->getPath();
    } catch (const std::exception &e) {
        SVDEBUG << "StorageAdviser::recommend: ERROR: Failed to get temporary directory path: " << e.what() << endl;
        int r = UseMemory | ConserveSpace;
        SVDEBUG << "StorageAdviser: returning fallback " << r
                << " (" << recommendationToString(r) << ")" << endl;
        return Recommendation(r);
    }
    ssize_t discFree = GetDiscSpaceMBAvailable(path.toLocal8Bit());
    ssize_t memoryFree, memoryTotal;
    GetRealMemoryMBAvailable(memoryFree, memoryTotal);

    SVDEBUG << "StorageAdviser: disc space: " << discFree
            << "M, memory free: " << memoryFree
            << "M, memory total: " << memoryTotal << "M" << endl;

    // In 32-bit addressing mode we can't address more than 4Gb.
    // If the total memory is reported as more than 4Gb, we should
    // reduce the available amount by the difference between 4Gb
    // and the total. This won't give us an accurate idea of the
    // amount of memory available any more, but it should be enough
    // to prevent us from trying to allocate more for our own use
    // than can be addressed at all!
    if (sizeof(void *) < 8) {
        if (memoryTotal > 4096) {
            ssize_t excess = memoryTotal - 4096;
            if (memoryFree > excess) {
                memoryFree -= excess;
            } else {
                memoryFree = 0;
            }
            SVDEBUG << "StorageAdviser: more real memory found than we "
                    << "can address in a 32-bit process, reducing free "
                    << "estimate to " << memoryFree << "M accordingly" << endl;
        }
    }

    SVDEBUG << "StorageAdviser: disc planned: " << (m_discPlanned / 1024)
            << "K, memory planned: " << (m_memoryPlanned / 1024) << "K" << endl;
    SVDEBUG << "StorageAdviser: min requested: " << minimumSize
            << "K, max requested: " << maximumSize << "K" << endl;

    if (discFree > ssize_t(m_discPlanned / 1024 + 1)) {
        discFree -= m_discPlanned / 1024 + 1;
    } else if (discFree > 0) { // can also be -1 for unknown
        discFree = 0;
    }

    if (memoryFree > ssize_t(m_memoryPlanned / 1024 + 1)) {
        memoryFree -= m_memoryPlanned / 1024 + 1;
    } else if (memoryFree > 0) { // can also be -1 for unknown
        memoryFree = 0;
    }

    //!!! We have a potentially serious problem here if multiple
    //recommendations are made in advance of any of the resulting
    //allocations, as the allocations that have been recommended for
    //won't be taken into account in subsequent recommendations.

    StorageStatus memoryStatus = Unknown;
    StorageStatus discStatus = Unknown;

    ssize_t minmb = ssize_t(minimumSize / 1024 + 1);
    ssize_t maxmb = ssize_t(maximumSize / 1024 + 1);

    if (memoryFree == -1) memoryStatus = Unknown;
    else if (memoryFree < memoryTotal / 3 && memoryFree < 512) memoryStatus = Insufficient;
    else if (minmb > (memoryFree * 3) / 4) memoryStatus = Insufficient;
    else if (maxmb > (memoryFree * 3) / 4) memoryStatus = Marginal;
    else if (minmb > (memoryFree / 3)) memoryStatus = Marginal;
    else if (memoryTotal == -1 ||
             minmb > (memoryTotal / 10)) memoryStatus = Marginal;
    else memoryStatus = Sufficient;

    if (discFree == -1) discStatus = Unknown;
    else if (minmb > (discFree * 3) / 4) discStatus = Insufficient;
    else if (maxmb > (discFree / 4)) discStatus = Marginal;
    else if (minmb > (discFree / 10)) discStatus = Marginal;
    else discStatus = Sufficient;

    SVDEBUG << "StorageAdviser: memory status: " << memoryStatus
            << " (" << storageStatusToString(memoryStatus) << ")"
            << ", disc status " << discStatus
            << " (" << storageStatusToString(discStatus) << ")" << endl;

    int recommendation = NoRecommendation;

    if (memoryStatus == Insufficient || memoryStatus == Unknown) {

        recommendation |= UseDisc;

        if (discStatus == Insufficient && minmb > discFree) {
            throw InsufficientDiscSpace(path, minmb, discFree);
        }

        if (discStatus == Insufficient || discStatus == Marginal) {
            recommendation |= ConserveSpace;
        } else if (discStatus == Unknown && !(criteria & PrecisionCritical)) {
            recommendation |= ConserveSpace;
        } else {
            recommendation |= UseAsMuchAsYouLike;
        }

    } else if (memoryStatus == Marginal) {

        if (((criteria & SpeedCritical) ||
             (criteria & FrequentLookupLikely)) &&
            !(criteria & PrecisionCritical) &&
            !(criteria & LongRetentionLikely)) {

            // requirements suggest a preference for memory

            if (discStatus != Insufficient) {
                recommendation |= PreferMemory;
            } else {
                recommendation |= UseMemory;
            }

            recommendation |= ConserveSpace;

        } else {

            if (discStatus == Insufficient) {
                recommendation |= (UseMemory | ConserveSpace);
            } else if (discStatus == Marginal) {
                recommendation |= (PreferMemory | ConserveSpace);
            } else if (discStatus == Unknown) {
                recommendation |= (PreferDisc | ConserveSpace);
            } else {
                recommendation |= (UseDisc | UseAsMuchAsYouLike);
            }
        }    

    } else {

        if (discStatus == Insufficient) {
            recommendation |= (UseMemory | ConserveSpace);
        } else if (discStatus != Sufficient) {
            recommendation |= (PreferMemory | ConserveSpace);
        } else {

            if ((criteria & SpeedCritical) ||
                (criteria & FrequentLookupLikely)) {
                recommendation |= PreferMemory;
                if (criteria & PrecisionCritical) {
                    recommendation |= UseAsMuchAsYouLike;
                } else {
                    recommendation |= ConserveSpace;
                }
            } else {
                recommendation |= PreferDisc;
                recommendation |= UseAsMuchAsYouLike;
            }
        }
    }

    SVDEBUG << "StorageAdviser: returning recommendation " << recommendation
            << " (" << recommendationToString(recommendation) << ")" << endl;
    
    return Recommendation(recommendation);
}

void
StorageAdviser::notifyPlannedAllocation(AllocationArea area, size_t size)
{
    if (area == MemoryAllocation) m_memoryPlanned += size;
    else if (area == DiscAllocation) m_discPlanned += size;
    SVDEBUG << "StorageAdviser: storage planned up: now memory: " << m_memoryPlanned << ", disc "
            << m_discPlanned << endl;
}

void
StorageAdviser::notifyDoneAllocation(AllocationArea area, size_t size)
{
    if (area == MemoryAllocation) {
        if (m_memoryPlanned > size) m_memoryPlanned -= size;
        else m_memoryPlanned = 0;
    } else if (area == DiscAllocation) {
        if (m_discPlanned > size) m_discPlanned -= size; 
        else m_discPlanned = 0;
    }
    SVDEBUG << "StorageAdviser: storage planned down: now memory: " << m_memoryPlanned << ", disc "
            << m_discPlanned << endl;
}

void
StorageAdviser::setFixedRecommendation(Recommendation recommendation)
{
    m_baseRecommendation = recommendation;
}