File: dbfile.cpp

package info (click to toggle)
mapnik 2.2.0%2Bds1-7
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd
  • size: 30,288 kB
  • ctags: 18,382
  • sloc: cpp: 115,128; python: 9,298; xml: 5,692; ansic: 3,726; makefile: 160; sh: 159; lisp: 13
file content (272 lines) | stat: -rw-r--r-- 6,936 bytes parent folder | download | duplicates (2)
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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2011 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/
// mapnik
#include <mapnik/value_types.hpp>
#include <mapnik/global.hpp>
#include <mapnik/utils.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/util/trim.hpp>

#include "dbfile.hpp"

// boost
#include <boost/spirit/include/qi.hpp>
#include <boost/cstdint.hpp> // for int16_t and int32_t
#include <mapnik/mapped_memory_cache.hpp>

// stl
#include <string>
#include <stdexcept>

using mapnik::mapped_memory_cache;

dbf_file::dbf_file()
    : num_records_(0),
      num_fields_(0),
      record_length_(0),
      record_(0) {}

dbf_file::dbf_file(std::string const& file_name)
    :num_records_(0),
     num_fields_(0),
     record_length_(0),
#ifdef SHAPE_MEMORY_MAPPED_FILE
     file_(),
#elif defined(_WINDOWS)
     file_(mapnik::utf8_to_utf16(file_name), std::ios::in | std::ios::binary),
#else
     file_(file_name.c_str() ,std::ios::in | std::ios::binary),
#endif
     record_(0)
{

#ifdef SHAPE_MEMORY_MAPPED_FILE
    boost::optional<mapnik::mapped_region_ptr> memory = mapped_memory_cache::instance().find(file_name,true);
    if (memory)
    {
        mapped_region_ = *memory;
        file_.buffer(static_cast<char*>((*memory)->get_address()),(*memory)->get_size());
    }
    else
    {
        throw std::runtime_error("could not create file mapping for "+file_name);
    }
#endif
    if (file_)
    {
        read_header();
    }
}


dbf_file::~dbf_file()
{
    ::operator delete(record_);
}


bool dbf_file::is_open()
{
#ifdef SHAPE_MEMORY_MAPPED_FILE
    return (file_.buffer().second > 0);
#else
    return file_.is_open();
#endif
}

int dbf_file::num_records() const
{
    return num_records_;
}


int dbf_file::num_fields() const
{
    return num_fields_;
}


void dbf_file::move_to(int index)
{
    if (index>0 && index<=num_records_)
    {
        std::streampos pos=(num_fields_<<5)+34+(index-1)*(record_length_+1);
        file_.seekg(pos,std::ios::beg);
        file_.read(record_,record_length_);
    }
}


std::string dbf_file::string_value(int col) const
{
    if (col>=0 && col<num_fields_)
    {
        return std::string(record_+fields_[col].offset_,fields_[col].length_);
    }
    return "";
}


const field_descriptor& dbf_file::descriptor(int col) const
{
    assert(col>=0 && col<num_fields_);
    return fields_[col];
}


void dbf_file::add_attribute(int col, mapnik::transcoder const& tr, mapnik::feature_impl & f) const throw()
{
    using namespace boost::spirit;

    if (col>=0 && col<num_fields_)
    {
        std::string const& name=fields_[col].name_;

        switch (fields_[col].type_)
        {
        case 'C':
        case 'D':
        {
            // FIXME - avoid constructing std::string on stack
            std::string str(record_+fields_[col].offset_,fields_[col].length_);
            mapnik::util::trim(str);
            f.put(name,tr.transcode(str.c_str()));
            break;
        }
        case 'L':
        {
            char ch = record_[fields_[col].offset_];
            if ( ch == '1' || ch == 't' || ch == 'T' || ch == 'y' || ch == 'Y')
            {
                f.put(name,true);
            }
            else
            {
                // NOTE: null logical fields use '?'
                f.put(name,false);
            }
            break;
        }
        case 'N':
        {
            if (record_[fields_[col].offset_] == '*')
            {
                // NOTE: we intentionally do not store null here
                // since it is equivalent to the attribute not existing
                break;
            }
            if ( fields_[col].dec_>0 )
            {
                double val = 0.0;
                const char *itr = record_+fields_[col].offset_;
                const char *end = itr + fields_[col].length_;
                ascii::space_type space;
                qi::double_type double_;
                if (qi::phrase_parse(itr,end,double_,space,val))
                {
                    f.put(name,val);
                }
            }
            else
            {
                mapnik::value_integer val = 0;
                const char *itr = record_+fields_[col].offset_;
                const char *end = itr + fields_[col].length_;
                ascii::space_type space;
                qi::int_type int_;
                if (qi::phrase_parse(itr,end,int_,space,val))
                {
                    f.put(name,val);
                }
            }
            break;
        }
        }
    }
}

void dbf_file::read_header()
{
    char c=file_.get();
    if (c=='\3' || c=='\131')
    {
        skip(3);
        num_records_=read_int();
        assert(num_records_>=0);
        num_fields_=read_short();
        assert(num_fields_>0);
        num_fields_=(num_fields_-33)/32;
        skip(22);
        std::streampos offset=0;
        char name[11];
        memset(&name,0,11);
        fields_.reserve(num_fields_);
        for (int i=0;i<num_fields_;++i)
        {
            field_descriptor desc;
            desc.index_=i;
            file_.read(name,10);
            desc.name_=name;
            // TODO - when is this trim needed?
            mapnik::util::trim(desc.name_);
            skip(1);
            desc.type_=file_.get();
            skip(4);
            desc.length_=file_.get();
            desc.dec_=file_.get();
            skip(14);
            desc.offset_=offset;
            offset+=desc.length_;
            fields_.push_back(desc);
        }
        record_length_=offset;
        if (record_length_>0)
        {
            record_=static_cast<char*>(::operator new (sizeof(char)*record_length_));
        }
    }
}


int dbf_file::read_short()
{
    char b[2];
    file_.read(b,2);
    boost::int16_t val;
    mapnik::read_int16_ndr(b,val);
    return val;
}


int dbf_file::read_int()
{
    char b[4];
    file_.read(b,4);
    boost::int32_t val;
    mapnik::read_int32_ndr(b,val);
    return val;
}

void dbf_file::skip(int bytes)
{
    file_.seekg(bytes,std::ios::cur);
}