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   /* get an archive child class from an io_stream */
  45   static archive *extract (io_stream *);
  46   /* get an ouput stream for the next files from the archive.
  47    * returns NULL on failure.
  48    * The stream is not taken over - it will not be automatically deleted
  49    */
  50   virtual io_stream *extract_file () = 0;
  51   /* extract the next file to the given prefixURL+Path in one step, and name it with the
  52    * given suffix.
  53    * returns 1 on failure.
  54    */
  55   static int extract_file (archive *, const std::string&, const std::string&,
  56                            const std::string = std::string());
  57
  58   /*
  59    * To create a stream that will be compressed, you should open the url, and then get a new stream
  60    * from compress::compress.
  61    */
  62   /* read data - not valid for archives (duh!)
  63    * Could be made valid via the read-child-directly model
  64    */
  65 //  virtual ssize_t read(void *buffer, size_t len) {return -1;};
  66   /* provide data to (double duh!) */
  67 //  virtual ssize_t write(void *buffer, size_t len) { return -1;};
  68   /* read data without removing it from the class's internal buffer */
  69 //  virtual ssize_t peek(void *buffer, size_t len);
  70 //  virtual long tell ();
  71   /* try guessing this one */
  72 //  virtual int error ();
  73   /* Find out the next stream name -
  74    * ie for foo.tar.gz, at offset 0, next_file_name = foo.tar
  75    * for foobar that is an compress, next_file_name is the next
  76    * extractable filename.
  77    * The way this works is that when read returns 0, you are at the end of *a* file.
  78    * next_file_name will allow read to be called again, if it returns !NULL
  79    */
  80   virtual const std::string next_file_name () = 0;
  81   virtual archive_file_t next_file_type () = 0;
  82   virtual const std::string linktarget () = 0;
  83   virtual int skip_file () = 0;
  84   /* if you are still needing these hints... give up now! */
  85   virtual ~archive() = 0;
  86 protected:
  87   void operator= (const archive &);
  88   archive () {};
  89   archive (const archive &);
  90 private:
  91 //  archive () {};
  92 };
  93
  94 #endif /* SETUP_ARCHIVE_H */