view base/StorageAdviser.cpp @ 490:c3fb8258e34d

* Make it possible to import an entire session from an RDF document.
  However, at the moment the timings of events appear to be constrained
  by how far the audio decoder has got through its audio file at the
  time the event is queried -- need to investigate.

/* -*- 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>

//#define DEBUG_STORAGE_ADVISER 1

long StorageAdviser::m_discPlanned = 0;
long StorageAdviser::m_memoryPlanned = 0;

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

StorageAdviser::Recommendation
StorageAdviser::recommend(Criteria criteria,
			  int minimumSize,
			  int maximumSize)
{
#ifdef DEBUG_STORAGE_ADVISER
    std::cerr << "StorageAdviser::recommend: Criteria " << criteria 
              << ", minimumSize " << minimumSize
              << ", maximumSize " << maximumSize << std::endl;
#endif

    if (m_baseRecommendation != NoRecommendation) {
        return m_baseRecommendation; // for now
    }

    QString path = TempDirectory::getInstance()->getPath();
    int discFree = GetDiscSpaceMBAvailable(path.toLocal8Bit());
    int memoryFree, memoryTotal;
    GetRealMemoryMBAvailable(memoryFree, memoryTotal);

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

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

#ifdef DEBUG_STORAGE_ADVISER
    std::cerr << "Disc space: " << discFree << ", memory free: " << memoryFree << ", memory total: " << memoryTotal << ", min " << minimumSize << ", max " << maximumSize << std::endl;
#endif

    //!!! 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.

    enum StorageStatus {
        Unknown,
        Insufficient,
        Marginal,
        Sufficient
    };

    StorageStatus memoryStatus = Unknown;
    StorageStatus discStatus = Unknown;

    int minmb = minimumSize / 1024 + 1;
    int maxmb = maximumSize / 1024 + 1;

    if (memoryFree == -1) memoryStatus = Unknown;
    else if (memoryFree < memoryTotal / 3) 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;

#ifdef DEBUG_STORAGE_ADVISER
    std::cerr << "Memory status: " << memoryStatus << ", disc status "
              << discStatus << std::endl;
#endif

    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;
            }
        }
    }

    return Recommendation(recommendation);
}

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

void
StorageAdviser::notifyDoneAllocation(AllocationArea area, int 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;
    }
//    std::cerr << "storage planned down: memory: " << m_memoryPlanned << ", disc "
//              << m_discPlanned << std::endl;
}

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