1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2003-2007 Jonathan Turkanis
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
// See http://www.boost.org/libs/iostreams for documentation.
#ifndef BOOST_IOSTREAMS_AGGREGATE_FILTER_HPP_INCLUDED
#define BOOST_IOSTREAMS_AGGREGATE_FILTER_HPP_INCLUDED
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <algorithm> // copy, min.
#include <boost/assert.hpp>
#include <iterator> // back_inserter
#include <vector>
#include <boost/iostreams/constants.hpp> // default_device_buffer_size
#include <boost/iostreams/categories.hpp>
#include <boost/iostreams/detail/char_traits.hpp>
#include <boost/iostreams/detail/ios.hpp> // openmode, streamsize.
#include <boost/iostreams/pipeline.hpp>
#include <boost/iostreams/read.hpp> // check_eof
#include <boost/iostreams/write.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/type_traits/is_convertible.hpp>
// Must come last.
#include <boost/iostreams/detail/config/disable_warnings.hpp> // MSVC.
namespace boost { namespace iostreams {
//
// Template name: aggregate_filter.
// Template paramters:
// Ch - The character type.
// Alloc - The allocator type.
// Description: Utility for defining DualUseFilters which filter an
// entire stream at once. To use, override the protected virtual
// member do_filter.
// Note: This filter should not be copied while it is in use.
//
template<typename Ch, typename Alloc = std::allocator<Ch> >
class aggregate_filter {
public:
typedef Ch char_type;
struct category
: dual_use,
filter_tag,
multichar_tag,
closable_tag
{ };
aggregate_filter() : ptr_(0), state_(0) { }
virtual ~aggregate_filter() { }
template<typename Source>
std::streamsize read(Source& src, char_type* s, std::streamsize n)
{
using namespace std;
BOOST_ASSERT(!(state_ & f_write));
state_ |= f_read;
if (!(state_ & f_eof))
do_read(src);
std::streamsize amt =
(std::min)(n, static_cast<std::streamsize>(data_.size() - ptr_));
if (amt) {
BOOST_IOSTREAMS_CHAR_TRAITS(char_type)::copy(s, &data_[ptr_], amt);
ptr_ += amt;
}
return detail::check_eof(amt);
}
template<typename Sink>
std::streamsize write(Sink&, const char_type* s, std::streamsize n)
{
BOOST_ASSERT(!(state_ & f_read));
state_ |= f_write;
data_.insert(data_.end(), s, s + n);
return n;
}
template<typename Sink>
void close(Sink& sink, BOOST_IOS::openmode which)
{
if ((state_ & f_read) != 0 && which == BOOST_IOS::in)
close_impl();
if ((state_ & f_write) != 0 && which == BOOST_IOS::out) {
try {
vector_type filtered;
do_filter(data_, filtered);
do_write(
sink, &filtered[0],
static_cast<std::streamsize>(filtered.size())
);
} catch (...) {
close_impl();
throw;
}
close_impl();
}
}
protected:
typedef std::vector<Ch, Alloc> vector_type;
typedef typename vector_type::size_type size_type;
private:
virtual void do_filter(const vector_type& src, vector_type& dest) = 0;
virtual void do_close() { }
template<typename Source>
void do_read(Source& src)
{
using std::streamsize;
vector_type data;
while (true) {
const std::streamsize size = default_device_buffer_size;
Ch buf[size];
std::streamsize amt;
if ((amt = boost::iostreams::read(src, buf, size)) == -1)
break;
data.insert(data.end(), buf, buf + amt);
}
do_filter(data, data_);
state_ |= f_eof;
}
template<typename Sink>
void do_write(Sink& sink, const char_type* s, std::streamsize n)
{
typedef typename iostreams::category_of<Sink>::type category;
typedef is_convertible<category, output> can_write;
do_write(sink, s, n, can_write());
}
template<typename Sink>
void do_write(Sink& sink, const char_type* s, std::streamsize n, mpl::true_)
{ iostreams::write(sink, s, n); }
template<typename Sink>
void do_write(Sink&, const char_type*, std::streamsize, mpl::false_) { }
void close_impl()
{
data_.clear();
ptr_ = 0;
state_ = 0;
do_close();
}
enum flag_type {
f_read = 1,
f_write = f_read << 1,
f_eof = f_write << 1
};
// Note: typically will not be copied while vector contains data.
vector_type data_;
size_type ptr_;
int state_;
};
BOOST_IOSTREAMS_PIPABLE(aggregate_filter, 1)
} } // End namespaces iostreams, boost.
#include <boost/iostreams/detail/config/enable_warnings.hpp> // MSVC.
#endif // #ifndef BOOST_IOSTREAMS_AGGREGATE_FILTER_HPP_INCLUDED
|
