src/include/file_case.h

   1 /*@ file_case: input file encapsulator
   2  *
   3  * Copyright (c) 2014 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 "lib.h"
  21
  22 #include <assert.h>
  23 #include <stdio.h>
  24
  25 class file_case
  26 {
  27   char const  *_path;
  28   FILE        *_file;       // fc_have_stdio
  29   void        *_layer;      // E.g., gzFile
  30   uint32_t    _flags;
  31   uint8_t     _dummy[4];
  32 public:
  33   // Flags for ctor / muxer()
  34   enum {
  35     fc_none       = 0,
  36     fc_dont_close = 1<<0,   // Don't close the file, if any
  37     fc_pipe       = 1<<1,   // _file is not seekable
  38     fc_const_path = 1<<2,   // Don't dup path, and don't a_delete it
  39     fc_take_path  = 1<<3,   // Don't dup path, but a_delete it
  40     fc_have_stdio = 1<<4,   // .file() may be used
  41     _fc_freebit   = 5,
  42     fc_mask       = (1<<_fc_freebit) - 1
  43   };
  44
  45   // Flags only for muxer()
  46   enum {
  47     mux_need_seek   = 1<<(_fc_freebit+0), // File must be seekable
  48     mux_need_binary = 1<<(_fc_freebit+1), // Need binary I/O
  49     mux_unpack      = 1<<(_fc_freebit+2), // Do auto-check for FILE{.gz,.bz2..}
  50     mux_no_unpack   = 1<<(_fc_freebit+3), // Do NOT auto-check
  51     mux_need_stdio  = 1<<(_fc_freebit+4), // Only then may .file() be used
  52     _mux_freebit    = _fc_freebit + 5,
  53     mux_mask        = ~fc_mask,
  54     mux_default     = fc_none,
  55     // Defines the global default strategy for dealing with packed files in case
  56     // none of the above has been given explicitly by a callee
  57     _mux_unpack_default = mux_unpack
  58   };
  59
  60   enum seek_whence {
  61     seek_set,
  62     seek_cur,
  63     seek_end
  64   };
  65
  66   file_case(FILE *fp, char const *path, uint32_t flags=fc_none);
  67   ~file_case(void);
  68
  69   bool          close(void);
  70   char const *  path(void) const;
  71   FILE *        file(void) const;
  72   bool          is_pipe(void) const;
  73
  74   bool          is_eof(void) const;
  75   int           get_c(void);
  76   int           unget_c(int c);
  77   char *        get_line(char *buf, size_t buf_size);
  78   size_t        get_buf(void *buf, size_t buf_size);
  79   void          rewind(void);
  80   int           seek(long offset, seek_whence whence=seek_set);
  81
  82   // Factory muxer; note that fc_take_path will be honoured even on failure
  83   // If path is NULL or "-" we'll go for stdin
  84   static file_case *  muxer(char const *path=NULL, uint32_t flags=mux_default);
  85
  86   CLASS_DISABLE_COPY(file_case);
  87 };
  88
  89 inline
  90 file_case::file_case(FILE *fp, char const *path, uint32_t flags)
  91 :
  92   _path(path), _file(fp), _layer(NULL), _flags(flags)
  93 {
  94   assert(!(flags & (fc_const_path | fc_take_path)) ||
  95       !(flags & fc_const_path) != !(flags & fc_take_path));
  96   assert(!(flags & ~fc_mask));
  97 }
  98
  99 inline
 100 file_case::~file_case(void)
 101 {
 102   if (_file != NULL || _layer != NULL) // xxx (uintptr_t)a|(uintptr_t)b
 103     close();
 104 }
 105
 106 inline char const *
 107 file_case::path(void) const
 108 {
 109   return _path;
 110 }
 111
 112 inline FILE *
 113 file_case::file(void) const
 114 {
 115   assert(_flags & fc_have_stdio);
 116   return _file;
 117 }
 118
 119 inline bool
 120 file_case::is_pipe(void) const
 121 {
 122   return ((_flags & fc_pipe) != 0);
 123 }
 124
 125 #endif
 126 /* s-it2-mode */