include/file_case.h

   1 /*@ file_case: input file encapsulator
   2  *
   3  * Copyright (c) 2014 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #ifndef _FILE_CASE_H
  18 #define _FILE_CASE_H
  19
  20 #include "config.h"
  21 #include "lib.h"
  22
  23 #include <assert.h>
  24 #include <stdio.h>
  25
  26 class file_case
  27 {
  28   char const  *_path;
  29   FILE        *_file;       // fc_have_stdio
  30   void        *_layer;      // E.g., gzFile
  31   uint32_t    _flags;
  32   uint8_t     _dummy[4];
  33
  34 public:
  35   // Flags for ctor / muxer()
  36   enum {
  37     fc_none       = 0,
  38     fc_dont_close = 1<<0,   // Don't close the file, if any
  39     fc_pipe       = 1<<1,   // _file is not seekable
  40     fc_const_path = 1<<2,   // Don't dup path, and don't a_delete it
  41     fc_take_path  = 1<<3,   // Don't dup path, but a_delete it
  42     fc_have_stdio = 1<<4,   // .file() may be used
  43     _fc_freebit   = 5,
  44     fc_mask       = (1<<_fc_freebit) - 1
  45   };
  46
  47   // Flags only for muxer()
  48   enum {
  49     mux_need_seek   = 1<<(_fc_freebit+0), // File must be seekable
  50     mux_need_binary = 1<<(_fc_freebit+1), // Need binary I/O
  51     mux_unpack      = 1<<(_fc_freebit+2), // Do auto-check for FILE{.gz,.bz2..}
  52     mux_no_unpack   = 1<<(_fc_freebit+3), // Do NOT auto-check
  53     mux_need_stdio  = 1<<(_fc_freebit+4), // Only then may .file() be used
  54     _mux_freebit    = _fc_freebit + 5,
  55     mux_mask        = ~fc_mask,
  56     mux_default     = fc_none,
  57     // Defines the global default strategy for dealing with packed files in case
  58     // none of the above has been given explicitly by a callee
  59     _mux_unpack_default = mux_unpack
  60   };
  61
  62   enum seek_whence {
  63     seek_set,
  64     seek_cur,
  65     seek_end
  66   };
  67
  68   file_case(FILE *fp, char const *path, uint32_t flags=fc_none);
  69   ~file_case(void);
  70
  71   bool          close(void);
  72   char const *  path(void) const;
  73   FILE *        file(void) const;
  74   bool          is_pipe(void) const;
  75
  76   bool          is_eof(void) const;
  77   int           get_c(void);
  78   int           unget_c(int c);
  79   char *        get_line(char *buf, size_t buf_size);
  80   size_t        get_buf(void *buf, size_t buf_size);
  81   void          rewind(void);
  82   int           seek(long offset, seek_whence whence=seek_set);
  83
  84   // Factory muxer; note that fc_take_path will be honoured even on failure
  85   // If path is NULL or "-" we'll go for stdin
  86   static file_case *  muxer(char const *path=NULL, uint32_t flags=mux_default);
  87
  88   CLASS_DISABLE_COPY(file_case);
  89 };
  90
  91 inline
  92 file_case::file_case(FILE *fp, char const *path, uint32_t flags)
  93 :
  94   _path(path), _file(fp), _layer(NULL), _flags(flags)
  95 {
  96   assert(!(flags & (fc_const_path | fc_take_path)) ||
  97       !(flags & fc_const_path) != !(flags & fc_take_path));
  98   assert(!(flags & ~fc_mask));
  99 }
 100
 101 inline
 102 file_case::~file_case(void)
 103 {
 104   if (_file != NULL || _layer != NULL) // xxx (uintptr_t)a|(uintptr_t)b
 105     close();
 106 }
 107
 108 inline char const *
 109 file_case::path(void) const
 110 {
 111   return _path;
 112 }
 113
 114 inline FILE *
 115 file_case::file(void) const
 116 {
 117   assert(_flags & fc_have_stdio);
 118   return _file;
 119 }
 120
 121 inline bool
 122 file_case::is_pipe(void) const
 123 {
 124   return ((_flags & fc_pipe) != 0);
 125 }
 126
 127 #endif // _FILE_CASE_H
 128 // s-it2-mode