archive.h

   1 /*
   2  * Copyright (c) 2001, Robert Collins.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by Robert Collins  <rbtcollins@hotmail.com>
  13  *
  14  */
  15
  16 #ifndef SETUP_ARCHIVE_H
  17 #define SETUP_ARCHIVE_H
  18
  19 /* this is the parent class for all archive IO operations. */
  20
  21 /* The read/write the archive stream to get the archive data is flawed.
  22  * The problem is that you then need a *different* gzip etc class to be able
  23  * to ungzip a gzip from within an archive.
  24  * The correct way is to
  25  * 1) retrieve the file name.
  26  * 2) the user creates their own output object.
  27  * 3) the user calls extract_file (output strea,).
  28  */
  29
  30 typedef enum
  31 {
  32   ARCHIVE_FILE_INVALID,
  33   ARCHIVE_FILE_REGULAR,
  34   ARCHIVE_FILE_HARDLINK,
  35   ARCHIVE_FILE_SYMLINK,
  36   ARCHIVE_FILE_DIRECTORY
  37 }
  38 archive_file_t;
  39
  40
  41 class archive:public io_stream
  42 {
  43 public:
  44   enum extract_results
  45   {
  46     extract_inuse = 7,          /* Arbitrary number != 1 */
  47     extract_ok = 0,
  48     extract_other = 9
  49   };
  50   /* get an archive child class from an io_stream */
  51   static archive *extract (io_stream *);
  52   /* get an ouput stream for the next files from the archive.
  53    * returns NULL on failure.
  54    * The stream is not taken over - it will not be automatically deleted
  55    */
  56   virtual io_stream *extract_file () = 0;
  57   /* extract the next file to the given prefixURL+Path in one step, and name it with the
  58    * given suffix.
  59    * returns 1 on failure.
  60    */
  61   static extract_results extract_file (archive *, const std::string&,
  62                                        const std::string&,
  63                                        const std::string = std::string());
  64
  65   /*
  66    * To create a stream that will be compressed, you should open the url, and then get a new stream
  67    * from compress::compress.
  68    */
  69   /* read data - not valid for archives (duh!)
  70    * Could be made valid via the read-child-directly model
  71    */
  72
  73   virtual off_t seek (off_t offset, io_stream_seek_t whence) = 0;
  74
  75   /* Find out the next stream name -
  76    * ie for foo.tar.gz, at offset 0, next_file_name = foo.tar
  77    * for foobar that is an compress, next_file_name is the next
  78    * extractable filename.
  79    * The way this works is that when read returns 0, you are at the end of *a* file.
  80    * next_file_name will allow read to be called again, if it returns !NULL
  81    */
  82   virtual const std::string next_file_name () = 0;
  83   virtual archive_file_t next_file_type () = 0;
  84   virtual const std::string linktarget () = 0;
  85   virtual int skip_file () = 0;
  86   virtual ~archive() = 0;
  87 protected:
  88   void operator= (const archive &);
  89   archive () {};
  90   archive (const archive &);
  91 };
  92
  93 #endif /* SETUP_ARCHIVE_H */