include/file_case.h

   1 /*@ file_case: input file encapsulator
   2  *
   3  * Copyright (c) 2014 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   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   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
  33 public:
  34   // Flags for ctor / muxer()
  35   enum{
  36     fc_none = 0,
  37     fc_dont_close = 1<<0, // Don't close the file, if any
  38     fc_pipe = 1<<1,       // _file is not seekable
  39     fc_const_path = 1<<2, // Don't dup path, and don't a_delete it
  40     fc_take_path = 1<<3,  // Don't dup path, but a_delete it
  41     fc_have_stdio = 1<<4, // .file() may be used
  42     _fc_freebit = 5,
  43     fc_mask = (1<<_fc_freebit) - 1
  44   };
  45
  46   // Flags only for muxer()
  47   enum{
  48     mux_need_seek = 1<<(_fc_freebit+0),   // File must be seekable
  49     mux_need_binary = 1<<(_fc_freebit+1), // Need binary I/O
  50     mux_unpack = 1<<(_fc_freebit+2),      // Do auto-check for FILE{.gz,.bz2..}
  51     mux_no_unpack = 1<<(_fc_freebit+3),   // Do NOT auto-check
  52     mux_need_stdio = 1<<(_fc_freebit+4),  // Only then may .file() be used
  53     _mux_freebit = _fc_freebit + 5,
  54     mux_mask = ~fc_mask,
  55     mux_default = fc_none,
  56     // Defines the global default strategy for dealing with packed files in case
  57     // none of the above has been given explicitly by a callee
  58     _mux_unpack_default = mux_unpack
  59   };
  60
  61   enum seek_whence{
  62     seek_set,
  63     seek_cur,
  64     seek_end
  65   };
  66
  67   file_case(FILE *fp, char const *path, uint32_t flags=fc_none);
  68   ~file_case(void);
  69
  70   bool close(void);
  71   char const *path(void) const;
  72   FILE *file(void) const;
  73   bool is_pipe(void) const;
  74
  75   bool is_eof(void) const;
  76   int get_c(void);
  77   int unget_c(int c);
  78   char *get_line(char *buf, size_t buf_size);
  79   size_t get_buf(void *buf, size_t buf_size);
  80   void rewind(void);
  81   int seek(long offset, seek_whence whence=seek_set);
  82
  83   // Factory muxer; note that fc_take_path will be honoured even on failure
  84   // If path is NULL or "-" we'll go for stdin
  85   static file_case *muxer(char const *path=NULL, uint32_t flags=mux_default);
  86
  87   CLASS_DISABLE_COPY(file_case);
  88 };
  89
  90 inline
  91 file_case::file_case(FILE *fp, char const *path, uint32_t flags)
  92     : _path(path), _file(fp), _layer(NULL), _flags(flags){
  93   assert(!(flags & (fc_const_path | fc_take_path)) ||
  94       !(flags & fc_const_path) != !(flags & fc_take_path));
  95   assert(!(flags & ~fc_mask));
  96 }
  97
  98 inline
  99 file_case::~file_case(void){
 100   if(_file != NULL || _layer != NULL) // xxx (uintptr_t)a|(uintptr_t)b
 101     close();
 102 }
 103
 104 inline char const *
 105 file_case::path(void) const{
 106   return _path;
 107 }
 108
 109 inline FILE *
 110 file_case::file(void) const{
 111   assert(_flags & fc_have_stdio);
 112   return _file;
 113 }
 114
 115 inline bool
 116 file_case::is_pipe(void) const{
 117   return ((_flags & fc_pipe) != 0);
 118 }
 119
 120 #endif // _FILE_CASE_H
 121 // s-it2-mode