1 #ifndef libjmmcg_core_file_hpp
2 #define libjmmcg_core_file_hpp
3
4 /******************************************************************************
5 ** $Header: svn+ssh://jmmcg@svn.code.sf.net/p/libjmmcg/code/trunk/libjmmcg/core/file.hpp 2055 2017-05-13 19:35:47Z jmmcg $
6 **
7 ** Copyright (C) 2002 by J.M.McGuiness, coder@hussar.me.uk
8 **
9 ** This library is free software; you can redistribute it and/or
10 ** modify it under the terms of the GNU Lesser General Public
11 ** License as published by the Free Software Foundation; either
12 ** version 2.1 of the License, or (at your option) any later version.
13 **
14 ** This library is distributed in the hope that it will be useful,
15 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 ** Lesser General Public License for more details.
18 **
19 ** You should have received a copy of the GNU Lesser General Public
20 ** License along with this library; if not, write to the Free Software
21 ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23
24 /*
25 Wrap up into a class creating a file, so that it is deleted upon object
26 destruction. This class is completely ANSI.
27 */
28
29 #include "exception.hpp"
30 #include <cassert>
31 #include <fstream>
32 #include <string>
33
34 namespace jmmcg {
35
36 typedef std::basic_fstream<tchar> tfstream;
37 typedef std::basic_ifstream<tchar> tifstream;
38 typedef std::basic_ofstream<tchar> tofstream;
39
40 /**
41 This templating is done to generalise this class. Why? There are ASCII mode files and binary ones. ASCII mode translates the CR/LF combinations. Binary does not. Also it allows this class to manage Unicode character sets. (One that use double bytes for the character set.)
42 */
43 template <typename basic_file_type,ppd::generic_traits::api_type API_,typename Mdl_>
44 class file : public basic_file_type, protected non_copyable {
45 public:
46 typedef basic_file_type file_type;
47 typedef jmmcg::crt_exception<API_,Mdl_> exception_type;
48
49 file(const tstring &, const std::ios_base::openmode,const bool =true);
50 virtual ~file(void);
51 file &operator=(const file &);
52 // Why is "false" always returned? That's because comparing two files
53 // is non obvious: Do I compare the file names & the contents? What
54 // about the path to the two files? One may be relative, the other
55 // may be absolute. Even if they are the *same* file, but created with
56 // the names with these different paths they'll compare different,
57 // unless I do somethig very tricky with the path situation.
58 // Why am I going on about this? Well what if you want to create a set
59 // (or map) of these "File<...>" objects you could fall foul of the
60 // fact that they require "operator<(...)" to be defined. This in turn
61 // implies that "operator==(...)" is defined to do something sensible.
62 // If you don't like this, derive from this class and override the
63 // function.
64 virtual const bool operator==(const file &) const noexcept(true) {
65 return false;
66 }
67
68 const tstring &name(void) const noexcept(true) {
69 return fname;
70 }
71
72 private:
73 bool auto_delete;
74 tstring fname;
75 std::ios_base::openmode mode;
76
77 void check_open(void);
78 void remove(void);
79
80 // I don't allow copying.
81 // Why? Well I need the file name for the current object to put the
82 // data from the input file object. How do I pass in this file name
83 // when the copy constructor only takes one parameter, and there's
84 // no way to pass in the destination file name. That's why I don't
85 // allow this.
86 explicit file(const tstring &) noexcept(true);
87 };
88
89 template<typename basic_file_type,ppd::generic_traits::api_type API_,typename Mdl_> inline
90 file<basic_file_type,API_,Mdl_>::file(const tstring &nm, const std::ios_base::openmode flags,const bool ad)
91 : basic_file_type(nm.c_str(), flags), auto_delete(ad), fname(nm), mode(flags) {
92 check_open();
93 }
94
95 template<typename basic_file_type,ppd::generic_traits::api_type API_,typename Mdl_> inline
96 file<basic_file_type,API_,Mdl_>::~file(void) {
97 if (auto_delete) {
98 remove();
99 }
100 }
101
102 template<typename basic_file_type,ppd::generic_traits::api_type API_,typename Mdl_> inline file<basic_file_type,API_,Mdl_> &
103 file<basic_file_type,API_,Mdl_>::operator=(const file<basic_file_type,API_,Mdl_> &tf) {
104 remove();
105 open(tf.fname,mode|=std::ios_base::out);
106 check_open();
107 file_type::operator<<(tf.rdbuf());
108 return *this;
109 }
110
111 template<typename basic_file_type,ppd::generic_traits::api_type API_,typename Mdl_> inline void
112 file<basic_file_type,API_,Mdl_>::check_open(void) noexcept(false) {
113 if (!file_type::is_open()) {
114 jmmcg::info::function desc(__LINE__,__PRETTY_FUNCTION__,typeid(&file<basic_file_type,API_,Mdl_>::check_open),info::function::argument(_T("file name"),fname));
115 desc.add_arg(info::function::argument(_T("open mode"), mode));
116 throw exception(_T("Failed to open the specified file."), desc, JMMCG_REVISION_HDR(_T("$Header: svn+ssh://jmmcg@svn.code.sf.net/p/libjmmcg/code/trunk/libjmmcg/core/file.hpp 2055 2017-05-13 19:35:47Z jmmcg $")));
117 }
118 }
119
120 template<typename basic_file_type,ppd::generic_traits::api_type API_,typename Mdl_> inline void
121 file<basic_file_type,API_,Mdl_>::remove(void) noexcept(false) {
122 file_type::close();
123 if (::remove(fname.c_str())) {
124 throw exception(_T("Failed to delete the specified file."), jmmcg::info::function(__LINE__,__PRETTY_FUNCTION__,typeid(&file<basic_file_type,API_,Mdl_>::remove), info::function::argument(_T("file name"), fname)), JMMCG_REVISION_HDR(_T("$Header: svn+ssh://jmmcg@svn.code.sf.net/p/libjmmcg/code/trunk/libjmmcg/core/file.hpp 2055 2017-05-13 19:35:47Z jmmcg $")));
125 }
126 }
127
128 }
129
130 #endif