libcruft-util/io.hpp

/*
 * This file is part of libgim.
 *
 * libgim 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 3 of the License, or (at your option) any later
 * version.
 *
 * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright 2010-2012 Danny Robson <danny@nerdcruft.net>
 */

#ifndef __UTIL_IO_HPP
#define __UTIL_IO_HPP

#include "annotations.hpp"
#include "types.hpp"
#include "memory.hpp"

#include <cstdio>
#include <cstdint>
#include <memory>
#include <boost/filesystem/path.hpp>


namespace util {
    /// Specifies bitwise combinations of IO access rights.
    enum access_t {
        ACCESS_READ      = 1 << 0,
        ACCESS_WRITE     = 1 << 1,
        ACCESS_READWRITE = ACCESS_READ | ACCESS_WRITE
    };


    /// Reads an entire file into memory. Caller frees the result. Guarantees a
    /// null trailing byte.
    std::unique_ptr<char []>
    slurp (const boost::filesystem::path&) mustuse;

    /// A simple RAII wrapper for file descriptors
    struct fd_ref {
        public:
            int fd;

            explicit fd_ref  (int _fd);
            explicit fd_ref  (const boost::filesystem::path &);
            ~fd_ref ();

            operator int (void) const;
    };


    class indenter : public std::streambuf
    {
    protected:
        std::streambuf* m_dest;
        bool            m_line_start;
        std::string     m_indent;
        std::ostream*   m_owner;

    protected:
        virtual int overflow (int ch);

    public:
        explicit indenter (std::streambuf* _dest, size_t _indent = 4);
        explicit indenter (std::ostream&   _dest, size_t _indent = 4);

        virtual ~indenter ();
    };



#if defined(HAVE_MMAP)
    /// Wraps a mechanism to map a file into memory. Read only.
    class mapped_file {
        protected:
            fd_ref   m_fd;
            uint8_t *m_data;
            size_t   m_size;

            void load_fd (void);

        public:
            mapped_file (const char                    *path);
            mapped_file (const std::string             &path);
            mapped_file (const boost::filesystem::path &path);

            mapped_file (const mapped_file             &rhs);
            mapped_file& operator =(const mapped_file  &rhs);

            ~mapped_file ();

            const uint8_t* data (void) const;
            size_t         size (void) const;
    };
#endif

    class path_error : public std::runtime_error {
        public:
            path_error (const boost::filesystem::path &path):
                runtime_error ("Invalid path " + path.string ())
            { ; }
    };
}

#endif