summaryrefslogtreecommitdiff
path: root/indra/llvfs/lldiriterator.cpp
blob: f57bf4ebc60afb37bf5c1794ceb6dcad2c4d99d4 (plain)
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
/**
 * @file lldiriterator.cpp
 * @brief Iterator through directory entries matching the search pattern.
 *
 * $LicenseInfo:firstyear=2010&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * 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;
 * version 2.1 of the License only.
 *
 * 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 Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "lldiriterator.h"

#include "fix_macros.h"
#include "llregex.h"
#include <boost/filesystem.hpp>

namespace fs = boost::filesystem;

static std::string glob_to_regex(const std::string& glob);

class LLDirIterator::Impl
{
public:
	Impl(const std::string &dirname, const std::string &mask);
	~Impl();

	bool next(std::string &fname);

private:
	boost::regex			mFilterExp;
	fs::directory_iterator	mIter;
	bool					mIsValid;
};

LLDirIterator::Impl::Impl(const std::string &dirname, const std::string &mask)
	: mIsValid(false)
{
#ifdef LL_WINDOWS // or BOOST_WINDOWS_API
	fs::path dir_path(utf8str_to_utf16str(dirname));
#else
	fs::path dir_path(dirname);
#endif

	bool is_dir = false;

	// Check if path is a directory.
	try
	{
		is_dir = fs::is_directory(dir_path);
	}
	catch (const fs::filesystem_error& e)
	{
		LL_WARNS() << e.what() << LL_ENDL;
		return;
	}

	if (!is_dir)
	{
		LL_WARNS() << "Invalid path: \"" << dir_path.string() << "\"" << LL_ENDL;
		return;
	}

	// Initialize the directory iterator for the given path.
	try
	{
		mIter = fs::directory_iterator(dir_path);
	}
	catch (const fs::filesystem_error& e)
	{
		LL_WARNS() << e.what() << LL_ENDL;
		return;
	}

	// Convert the glob mask to a regular expression
	std::string exp = glob_to_regex(mask);

	// Initialize boost::regex with the expression converted from
	// the glob mask.
	// An exception is thrown if the expression is not valid.
	try
	{
		mFilterExp.assign(exp);
	}
	catch (boost::regex_error& e)
	{
		LL_WARNS() << "\"" << exp << "\" is not a valid regular expression: "
				<< e.what() << LL_ENDL;
		return;
	}

	mIsValid = true;
}

LLDirIterator::Impl::~Impl()
{
}

bool LLDirIterator::Impl::next(std::string &fname)
{
	fname = "";

	if (!mIsValid)
	{
		LL_WARNS() << "The iterator is not correctly initialized." << LL_ENDL;
		return false;
	}

	fs::directory_iterator end_itr; // default construction yields past-the-end
	bool found = false;

	// Check if path is a directory.
	try
	{
		while (mIter != end_itr && !found)
		{
			boost::smatch match;
			std::string name = mIter->path().filename().string();
			found = ll_regex_match(name, match, mFilterExp);
			if (found)
			{
				fname = name;
			}

			++mIter;
		}
	}
	catch (const fs::filesystem_error& e)
	{
		LL_WARNS() << e.what() << LL_ENDL;
	}

	return found;
}

/**
Converts the incoming glob into a regex. This involves
converting incoming glob expressions to regex equivilents and
at the same time, escaping any regex meaningful characters which
do not have glob meaning, i.e.
            .()+|^$ 
in the input.
*/
std::string glob_to_regex(const std::string& glob)
{
	std::string regex;
	regex.reserve(glob.size()<<1);
	S32 braces = 0;
	bool escaped = false;
	bool square_brace_open = false;

	for (std::string::const_iterator i = glob.begin(); i != glob.end(); ++i)
	{
		char c = *i;

		switch (c)
		{
			case '*':
				if (glob.begin() == i)
				{
					regex+="[^.].*";
				}
				else
				{
					regex+= escaped ? "*" : ".*";
				}
				break;
			case '?':
				regex+= escaped ? '?' : '.';
				break;
			case '{':
				braces++;
				regex+='(';
				break;
			case '}':
				if (!braces)
				{
					LL_ERRS() << "glob_to_regex: Closing brace without an equivalent opening brace: " << glob << LL_ENDL;
				}

				regex+=')';
				braces--;
				break;
			case ',':
				regex+= braces ? '|' : c;
				break;
			case '!':
				regex+= square_brace_open ? '^' : c;
				break;
			case '.': // This collection have different regex meaning
			case '^': // and so need escaping.
			case '(': 
			case ')':
			case '+':
			case '|':
			case '$':
				regex += '\\'; 
			default:
				regex += c;
				break;
		}

		escaped = ('\\' == c);
		square_brace_open = ('[' == c);
	}

	if (braces)
	{
		LL_ERRS() << "glob_to_regex: Unterminated brace expression: " << glob << LL_ENDL;
	}

	return regex;
}

LLDirIterator::LLDirIterator(const std::string &dirname, const std::string &mask)
{
	mImpl = new Impl(dirname, mask);
}

LLDirIterator::~LLDirIterator()
{
	delete mImpl;
}

bool LLDirIterator::next(std::string &fname)
{
	return mImpl->next(fname);
}