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** Copyright (C) 2018 The Qt Company Ltd.
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**
** This file is part of Qt Creator.
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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#include "builddependenciesprovider.h"

#include "builddependenciesstorageinterface.h"
#include "modifiedtimecheckerinterface.h"
#include "builddependencygeneratorinterface.h"

#include <sqlitetransaction.h>

#include <algorithm>

namespace ClangBackEnd {

template<class OutputContainer,
         class InputContainer1,
         class InputContainer2>
OutputContainer setUnion(InputContainer1 &&input1,
                         InputContainer2 &&input2)
{
    OutputContainer results;
    results.reserve(input1.size() + input2.size());

    std::set_union(std::begin(input1),
                   std::end(input1),
                   std::begin(input2),
                   std::end(input2),
                   std::back_inserter(results));

    return results;
}

BuildDependency BuildDependenciesProvider::create(const ProjectPartContainer &projectPart)
{
    m_ensureAliveMessageIsSentCallback();

    auto sourcesAndProjectPart = createSourceEntriesFromStorage(projectPart.sourcePathIds,
                                                                projectPart.projectPartId);

    if (!m_modifiedTimeChecker.isUpToDate(sourcesAndProjectPart.first)) {
        BuildDependency buildDependency = m_generator.create(projectPart);

        storeBuildDependency(buildDependency, sourcesAndProjectPart.second);

        return buildDependency;
    }

    return createBuildDependencyFromStorage(
        std::move(sourcesAndProjectPart.first));
}

BuildDependency BuildDependenciesProvider::createBuildDependencyFromStorage(
    SourceEntries &&includes) const
{
    BuildDependency buildDependency;

    buildDependency.usedMacros = createUsedMacrosFromStorage(includes);
    buildDependency.sources = std::move(includes);

    return buildDependency;
}

UsedMacros BuildDependenciesProvider::createUsedMacrosFromStorage(const SourceEntries &includes) const
{
    UsedMacros usedMacros;
    usedMacros.reserve(1024);

    Sqlite::DeferredTransaction transaction(m_transactionBackend);

    for (const SourceEntry &entry : includes) {
        UsedMacros macros = m_storage.fetchUsedMacros(entry.sourceId);
        std::sort(macros.begin(), macros.end());
        usedMacros.insert(usedMacros.end(),
                          std::make_move_iterator(macros.begin()),
                          std::make_move_iterator(macros.end()));
    }

    transaction.commit();

    return usedMacros;
}

std::pair<SourceEntries, ProjectPartId> BuildDependenciesProvider::createSourceEntriesFromStorage(
    const FilePathIds &sourcePathIds, ProjectPartId projectPartId) const
{
    SourceEntries includes;

    Sqlite::DeferredTransaction transaction(m_transactionBackend);

    for (FilePathId sourcePathId : sourcePathIds) {
        SourceEntries entries = m_storage.fetchDependSources(sourcePathId, projectPartId);
        SourceEntries mergedEntries = setUnion<SourceEntries>(includes, entries);

        includes = std::move(mergedEntries);
    }

    transaction.commit();

    return {includes, projectPartId};
}

void BuildDependenciesProvider::storeBuildDependency(const BuildDependency &buildDependency,
                                                     ProjectPartId projectPartId)
{
    Sqlite::ImmediateTransaction transaction(m_transactionBackend);
    m_storage.insertOrUpdateSources(buildDependency.sources, projectPartId);
    m_storage.insertOrUpdateFileStatuses(buildDependency.fileStatuses);
    m_storage.insertOrUpdateSourceDependencies(buildDependency.sourceDependencies);
    m_storage.insertOrUpdateUsedMacros(buildDependency.usedMacros);

    transaction.commit();
}

} // namespace ClangBackEnd