fs_merger.hh

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/* vim: set sw=4 sts=4 et foldmethod=syntax : */
 
/*
 * Copyright (c) 2007, 2008, 2009, 2010, 2011 Ciaran McCreesh
 *
 * This file is part of the Paludis package manager. Paludis is free software;
 * you can redistribute it and/or modify it under the terms of the GNU General
 * Public License version 2, as published by the Free Software Foundation.
 *
 * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
#ifndef PALUDIS_GUARD_PALUDIS_FS_MERGER_HH
#define PALUDIS_GUARD_PALUDIS_FS_MERGER_HH 1
 
#include <paludis/fs_merger-fwd.hh>
#include <paludis/util/exception.hh>
#include <paludis/util/options.hh>
#include <paludis/util/named_value.hh>
#include <paludis/util/timestamp.hh>
#include <paludis/merger_entry_type.hh>
#include <paludis/merger.hh>
#include <paludis/environment-fwd.hh>
#include <paludis/hook-fwd.hh>
#include <paludis/partitioning-fwd.hh>
#include <iosfwd>
#include <sys/stat.h>
#include <sys/types.h>
 
/** \file
 * Declarations for the FSMerger class, which can be used by Repository
 * implementations to perform to-filesystem merging.
 *
 * \ingroup g_repository
 *
 * \section Examples
 *
 * - None at this time.
 */
 
namespace paludis
{
    namespace n
    {
        typedef Name<struct name_environment> environment;
        typedef Name<struct name_fix_mtimes_before> fix_mtimes_before;
        typedef Name<struct name_fs_merger_options> fs_merger_options;
        typedef Name<struct name_get_new_ids_or_minus_one> get_new_ids_or_minus_one;
        typedef Name<struct name_image> image;
        typedef Name<struct name_install_under> install_under;
        typedef Name<struct name_maybe_output_manager> maybe_output_manager;
        typedef Name<struct name_merged_entries> merged_entries;
        typedef Name<struct name_no_chown> no_chown;
        typedef Name<struct name_options> options;
        typedef Name<struct name_parts> parts;
        typedef Name<struct name_permit_destination> permit_destination;
        typedef Name<struct name_root> root;
        typedef Name<struct name_should_merge> should_merge;
    }
 
    /**
     * Parameters for a basic FSMerger.
     *
     * \see Merger
     * \ingroup g_repository
     * \nosubgrouping
     * \since 0.30
     * \since 0.51 called FSMergerParams instead of MergerParams
     */
    struct FSMergerParams
    {
        NamedValue<n::environment, Environment *> environment;
 
        /**
         * Rewrite any mtimes that are before this time to this time, even if
         * preserving mtimes.
         *
         * \since 0.44
         */
        NamedValue<n::fix_mtimes_before, Timestamp> fix_mtimes_before;
 
        /**
         * Additional options not in MergerOptions.
         *
         * \since 0.71
         */
        NamedValue<n::fs_merger_options, FSMergerOptions> fs_merger_options;
 
        NamedValue<n::get_new_ids_or_minus_one, std::function<std::pair<uid_t, gid_t> (const FSPath &)> > get_new_ids_or_minus_one;
        NamedValue<n::image, FSPath> image;
        NamedValue<n::install_under, FSPath> install_under;
 
        NamedValue<n::maybe_output_manager, std::shared_ptr<OutputManager> > maybe_output_manager;
 
        /**
         * We record things we merged here.
         *
         * \since 0.41
         */
        NamedValue<n::merged_entries, std::shared_ptr<FSPathSet> > merged_entries;
 
        NamedValue<n::no_chown, bool> no_chown;
        NamedValue<n::options, MergerOptions> options;
 
        ///\since 1.1.0
        NamedValue<n::parts, std::shared_ptr<const Partitioning> > parts;
 
        ///\since 0.66
        NamedValue<n::permit_destination, PermitDestinationFn> permit_destination;
 
        NamedValue<n::root, FSPath> root;
 
        ///\since 1.99.0
        NamedValue<n::should_merge, std::function<bool(const FSPath &)>> should_merge;
    };
 
    /**
     * Thrown if an error occurs during an FSMerger operation.
     *
     * \ingroup g_repository
     * \ingroup g_exceptions
     * \nosubgrouping
     */
    class PALUDIS_VISIBLE FSMergerError :
        public MergerError
    {
        public:
            ///\name Basic operations
            ///\{
 
            FSMergerError(const std::string & msg) noexcept;
            FSMergerError(int error, const std::string & msg) noexcept;
 
            ///\}
    };
 
    /**
     * Handles merging an image to a live filesystem.
     *
     * \ingroup g_exceptions
     * \ingroup g_repository
     * \nosubgrouping
     * \since 0.51 called FSMerger instead of Merger
     */
    class PALUDIS_VISIBLE FSMerger :
        public Merger
    {
        private:
            void track_renamed_dir_recursive(const FSPath &);
            void relabel_dir_recursive(const FSPath &, const FSPath &);
            void try_to_copy_xattrs(const FSPath &, int, FSMergerStatusFlags &);
 
            Pimp<FSMerger> _imp;
 
        protected:
            ///\name Basic operations
            ///\{
 
            FSMerger(const FSMergerParams &);
 
            ///\}
 
            Hook extend_hook(const Hook &) override;
 
            ///\name Track and record merges
            ///\{
 
            void track_install_file(const FSPath &, const FSPath &, const std::string &, const FSMergerStatusFlags &);
            void track_install_dir(const FSPath &, const FSPath &, const FSMergerStatusFlags &);
            void track_install_under_dir(const FSPath &, const FSMergerStatusFlags &);
            void track_install_sym(const FSPath &, const FSPath &, const FSMergerStatusFlags &);
 
            ///\}
 
            ///\name Handle filesystem entry things
            ///\{
 
            void on_file_main(bool is_check, const FSPath & src, const FSPath & dst) override;
            virtual void on_file_over_nothing(bool is_check, const FSPath &, const FSPath &);
            virtual void on_file_over_file(bool is_check, const FSPath &, const FSPath &);
            virtual void on_file_over_dir(bool is_check, const FSPath &, const FSPath &);
            virtual void on_file_over_sym(bool is_check, const FSPath &, const FSPath &);
            virtual void on_file_over_misc(bool is_check, const FSPath &, const FSPath &);
 
            virtual FSMergerStatusFlags install_file(const FSPath &, const FSPath &, const std::string &) PALUDIS_ATTRIBUTE((warn_unused_result));
            virtual void unlink_file(FSPath);
            virtual void record_install_file(const FSPath &, const FSPath &, const std::string &, const FSMergerStatusFlags &) = 0;
 
            void on_enter_dir(bool is_check, const FSPath) override;
 
            void on_dir_main(bool is_check, const FSPath & src, const FSPath & dst) override;
            virtual void on_dir_over_nothing(bool is_check, const FSPath &, const FSPath &);
            virtual void on_dir_over_file(bool is_check, const FSPath &, const FSPath &);
            virtual void on_dir_over_dir(bool is_check, const FSPath &, const FSPath &);
            virtual void on_dir_over_sym(bool is_check, const FSPath &, const FSPath &);
            virtual void on_dir_over_misc(bool is_check, const FSPath &, const FSPath &);
 
            virtual FSMergerStatusFlags install_dir(const FSPath &, const FSPath &) PALUDIS_ATTRIBUTE((warn_unused_result));
            virtual void unlink_dir(FSPath);
            virtual void record_install_dir(const FSPath &, const FSPath &, const FSMergerStatusFlags &) = 0;
            virtual void record_install_under_dir(const FSPath &, const FSMergerStatusFlags &) = 0;
 
            void on_sym_main(bool is_check, const FSPath & src, const FSPath & dst) override;
            virtual void on_sym_over_nothing(bool is_check, const FSPath &, const FSPath &);
            virtual void on_sym_over_file(bool is_check, const FSPath &, const FSPath &);
            virtual void on_sym_over_dir(bool is_check, const FSPath &, const FSPath &);
            virtual void on_sym_over_sym(bool is_check, const FSPath &, const FSPath &);
            virtual void on_sym_over_misc(bool is_check, const FSPath &, const FSPath &);
 
            virtual FSMergerStatusFlags install_sym(const FSPath &, const FSPath &) PALUDIS_ATTRIBUTE((warn_unused_result));
            virtual void unlink_sym(FSPath);
            virtual void record_install_sym(const FSPath &, const FSPath &, const FSMergerStatusFlags &) = 0;
 
            virtual void unlink_misc(FSPath);
 
            void prepare_install_under() override;
 
            FSPath canonicalise_root_path(const FSPath & f) override;
 
            void do_dir_recursive(bool is_check, const FSPath &, const FSPath &) override;
 
            ///\}
 
            ///\name Configuration protection
            ///\{
 
            virtual bool config_protected(const FSPath &, const FSPath &) = 0;
            virtual std::string make_config_protect_name(const FSPath &, const FSPath &) = 0;
 
            ///\}
 
            virtual std::string make_arrows(const FSMergerStatusFlags & flags) const;
            virtual void display_merge(const EntryType &, const FSPath &,
                                       const FSMergerStatusFlags &,
                                       const std::string & = "") const;
 
        public:
            ///\name Basic operations
            ///\{
 
            virtual ~FSMerger();
 
            FSMerger(const FSMerger &) = delete;
            FSMerger & operator= (const FSMerger &) = delete;
 
            ///\}
 
            void merge() override;
    };
 
}
 
#endif