vfs_populate.cpp

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/* Copyright (c) 2012 Wildfire Games
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * populate VFS directories with files
 */

#include "precompiled.h"
#include "lib/file/vfs/vfs_populate.h"

#include "lib/file/archive/archive_zip.h"
#include "lib/file/vfs/vfs_tree.h"
#include "lib/file/vfs/vfs_lookup.h"
#include "lib/file/vfs/vfs.h"   // error codes


#define ENABLE_ARCHIVE_STATS 0
#if ENABLE_ARCHIVE_STATS
static std::vector<const VfsFile*> s_looseFiles;
static size_t s_numArchivedFiles;
#endif

struct CompareFileInfoByName
{
    bool operator()(const CFileInfo& a, const CFileInfo& b)
    {
        return a.Name() < b.Name();
    }
};

// helper class that allows breaking up the logic into sub-functions without
// always having to pass directory/realDirectory as parameters.
class PopulateHelper
{
    NONCOPYABLE(PopulateHelper);
public:
    PopulateHelper(VfsDirectory* directory, const PRealDirectory& realDirectory)
        : m_directory(directory), m_realDirectory(realDirectory)
    {
    }

    Status AddEntries() const
    {
#if ENABLE_ARCHIVE_STATS
        s_looseFiles.reserve(10000);
#endif

        CFileInfos files; files.reserve(500);
        DirectoryNames subdirectoryNames; subdirectoryNames.reserve(50);
        RETURN_STATUS_IF_ERR(GetDirectoryEntries(m_realDirectory->Path(), &files, &subdirectoryNames));

        // to support .DELETED files inside archives safely, we need to load
        // archives and loose files in a deterministic order in case they add
        // and then delete the same file (or vice versa, depending on loading
        // order). GetDirectoryEntries has undefined order so sort its output
        std::sort(files.begin(), files.end(), CompareFileInfoByName());
        std::sort(subdirectoryNames.begin(), subdirectoryNames.end());

        RETURN_STATUS_IF_ERR(AddFiles(files));
        AddSubdirectories(subdirectoryNames);

        return INFO::OK;
    }

private:
    void AddFile(const CFileInfo& fileInfo) const
    {
        const VfsPath name = fileInfo.Name();
        if(name.Extension() == L".DELETED")
        {
            m_directory->RemoveFile(name.Basename());
            if(!(m_realDirectory->Flags() & VFS_MOUNT_KEEP_DELETED))
                return;
        }

        const VfsFile file(name, (size_t)fileInfo.Size(), fileInfo.MTime(), m_realDirectory->Priority(), m_realDirectory);
        const VfsFile* pfile = m_directory->AddFile(file);

#if ENABLE_ARCHIVE_STATS
        // notify archive builder that this file could be archived but
        // currently isn't; if there are too many of these, archive will
        // be rebuilt.
        // note: check if archivable to exclude stuff like screenshots
        // from counting towards the threshold.
        if(m_realDirectory->Flags() & VFS_MOUNT_ARCHIVABLE)
            s_looseFiles.push_back(pfile);
#else
        UNUSED2(pfile);
#endif
    }

    static void AddArchiveFile(const VfsPath& pathname, const CFileInfo& fileInfo, PIArchiveFile archiveFile, uintptr_t cbData)
    {
        PopulateHelper* this_ = (PopulateHelper*)cbData;

        // (we have to create missing subdirectoryNames because archivers
        // don't always place directory entries before their files)
        const size_t flags = VFS_LOOKUP_ADD|VFS_LOOKUP_SKIP_POPULATE;
        VfsDirectory* directory;
        WARN_IF_ERR(vfs_Lookup(pathname, this_->m_directory, directory, 0, flags));

        const VfsPath name = fileInfo.Name();
        if(name.Extension() == L".DELETED")
        {
            directory->RemoveFile(name.Basename());
            if(!(this_->m_realDirectory->Flags() & VFS_MOUNT_KEEP_DELETED))
                return;
        }

        const VfsFile file(name, (size_t)fileInfo.Size(), fileInfo.MTime(), this_->m_realDirectory->Priority(), archiveFile);
        directory->AddFile(file);
#if ENABLE_ARCHIVE_STATS
        s_numArchivedFiles++;
#endif
    }

    Status AddFiles(const CFileInfos& files) const
    {
        const OsPath path(m_realDirectory->Path());

        for(size_t i = 0; i < files.size(); i++)
        {
            const OsPath pathname = path / files[i].Name();
            if(pathname.Extension() == L".zip")
            {
                PIArchiveReader archiveReader = CreateArchiveReader_Zip(pathname);
                // archiveReader == nullptr if file could not be opened (e.g. because
                // archive is currently open in another program)
                if(archiveReader)
                    RETURN_STATUS_IF_ERR(archiveReader->ReadEntries(AddArchiveFile, (uintptr_t)this));
            }
            else    // regular (non-archive) file
                AddFile(files[i]);
        }

        return INFO::OK;
    }

    void AddSubdirectories(const DirectoryNames& subdirectoryNames) const
    {
        for(size_t i = 0; i < subdirectoryNames.size(); i++)
        {
            // skip version control directories - this avoids cluttering the
            // VFS with hundreds of irrelevant files.
            if(subdirectoryNames[i] == L".svn")
                continue;

            VfsDirectory* subdirectory = m_directory->AddSubdirectory(subdirectoryNames[i]);
            PRealDirectory realDirectory = CreateRealSubdirectory(m_realDirectory, subdirectoryNames[i]);
            vfs_Attach(subdirectory, realDirectory);
        }
    }

    VfsDirectory* const m_directory;
    PRealDirectory m_realDirectory;
};


Status vfs_Populate(VfsDirectory* directory)
{
    if(!directory->ShouldPopulate())
        return INFO::OK;

    const PRealDirectory& realDirectory = directory->AssociatedDirectory();

    if(realDirectory->Flags() & VFS_MOUNT_WATCH)
        realDirectory->Watch();

    PopulateHelper helper(directory, realDirectory);
    RETURN_STATUS_IF_ERR(helper.AddEntries());

    return INFO::OK;
}


Status vfs_Attach(VfsDirectory* directory, const PRealDirectory& realDirectory)
{
    RETURN_STATUS_IF_ERR(vfs_Populate(directory));
    directory->SetAssociatedDirectory(realDirectory);
    return INFO::OK;
}