aboutsummaryrefslogtreecommitdiff
path: root/common/fs.h
blob: 271a0dc9eb9dad279e1dbef9bd2690c81b6f5e63 (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
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
273
274
275
276
277
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 */

#ifndef COMMON_FS_H
#define COMMON_FS_H

#include "common/array.h"
#include "common/str.h"

//namespace Common {

class FilesystemNode;
class AbstractFilesystemNode;

/**
 * List of multiple file system nodes. E.g. the contents of a given directory.
 * This is subclass instead of just a typedef so that we can use forward
 * declarations of it in other places.
 */
class FSList : public Common::Array<FilesystemNode> {};

/**
 * FilesystemNode provides an abstraction for file paths, allowing for portable
 * file system browsing. To this ends, multiple or single roots have to be supported
 * (compare Unix with a single root, Windows with multiple roots C:, D:, ...).
 *
 * To this end, we abstract away from paths; implementations can be based on
 * paths (and it's left to them whether / or \ or : is the path separator :-);
 * but it is also possible to use inodes or vrefs (MacOS 9) or anything else.
 *
 * NOTE: Backends still have to provide a way to extract a path from a FSIntern
 *
 * You may ask now: "isn't this cheating? Why do we go through all this when we use
 * a path in the end anyway?!?".
 * Well, for once as long as we don't provide our own file open/read/write API, we
 * still have to use fopen(). Since all our targets already support fopen(), it should
 * be possible to get a fopen() compatible string for any file system node.
 *
 * Secondly, with this abstraction layer, we still avoid a lot of complications based on
 * differences in FS roots, different path separators, or even systems with no real
 * paths (MacOS 9 doesn't even have the notion of a "current directory").
 * And if we ever want to support devices with no FS in the classical sense (Palm...),
 * we can build upon this.
 * 
 * This class acts as a wrapper around the AbstractFilesystemNode class defined in backends/fs. 
 */
class FilesystemNode {
private:
	int *_refCount;
	AbstractFilesystemNode *_realNode;
	FilesystemNode(AbstractFilesystemNode *realNode);

public:
	/**
	 * Flag to tell listDir() which kind of files to list.
	 */
	enum ListMode {
		kListFilesOnly = 1,
		kListDirectoriesOnly = 2,
		kListAll = 3
	};

	/**
	 * Create a new pathless FilesystemNode. Since there's no path associated
	 * with this node, path-related operations (i.e. exists(), isDirectory(), 
	 * getPath()) will always return false or raise an assertion.
	 */
	FilesystemNode();

	/**
	 * Create a new FilesystemNode referring to the specified path. This is
	 * the counterpart to the path() method.
	 *
	 * If path is empty or equals ".", then a node representing the "current
	 * directory" will be created. If that is not possible (since e.g. the
	 * operating system doesn't support the concept), some other directory is
	 * used (usually the root directory).
	 */
	FilesystemNode(const Common::String &path);

	/**
	 * Copy constructor.
	 */
	FilesystemNode(const FilesystemNode &node);
	
	/**
	 * Destructor.
	 */
	virtual ~FilesystemNode();

	/**
	 * Copy operator.
	 */
	FilesystemNode &operator= (const FilesystemNode &node);
	
	/**
	 * Compare the name of this node to the name of another. Directories
	 * go before normal files.
	 */
	bool operator<(const FilesystemNode& node) const;

	/**
	 * Indicates whether the object referred by this path exists in the filesystem or not.
	 * 
	 * @return bool true if the path exists, false otherwise.
	 */
	virtual bool exists() const;

	/**
	 * Fetch a child node of this node, with the given name. Only valid for
	 * directory nodes (an assertion is triggered otherwise).
	 * If no child node with the given name exists, an invalid node is returned.
	 */
	FilesystemNode getChild(const Common::String &name) const;
	
	/**
	 * Return a list of child nodes of this directory node. If called on a node
	 * that does not represent a directory, false is returned.
	 * 
	 * @return true if succesful, false otherwise (e.g. when the directory does not exist).
	 */
	virtual bool getChildren(FSList &fslist, ListMode mode = kListDirectoriesOnly, bool hidden = false) const;	

	/**
	 * Return a human readable string for this node, usable for display (e.g.
	 * in the GUI code). Do *not* rely on it being usable for anything else,
	 * like constructing paths!
	 * 
	 * @return the display name
	 */
	virtual Common::String getDisplayName() const;

	/**
	 * Return a string representation of the name of the file. This is can be
	 * used e.g. by detection code that relies on matching the name of a given
	 * file. But it is *not* suitable for use with fopen / File::open, nor
	 * should it be archived.
	 *
	 * @return the file name
	 */
	virtual Common::String getName() const;

	/**
	 * Return a string representation of the file which can be passed to fopen(),
	 * and is suitable for archiving (i.e. writing to the config file).
	 * This will usually be a 'path' (hence the name of the method), but can
	 * be anything that fulfills the above criterions.
	 *
	 * @note Do not assume that this string contains (back)slashes or any
	 *       other kind of 'path separators'.
	 *
	 * @return the 'path' represented by this filesystem node
	 */
	virtual Common::String getPath() const;
	
	/**
	 * Get the parent node of this node. If this node has no parent node,
	 * then it returns a duplicate of this node.
	 */
	FilesystemNode getParent() const;

	/**
	 * Indicates whether the path refers to a directory or not.
	 * 
	 * @todo Currently we assume that a node that is not a directory
	 * automatically is a file (ignoring things like symlinks or pipes).
	 * That might actually be OK... but we could still add an isFile method.
	 * Or even replace isDirectory by a getType() method that can return values like
	 * kDirNodeType, kFileNodeType, kInvalidNodeType.
	 */
	virtual bool isDirectory() const;
	
	/**
	 * Indicates whether the object referred by this path can be read from or not.
	 * 
	 * If the path refers to a directory, readability implies being able to read 
	 * and list the directory entries.
	 * 
	 * If the path refers to a file, readability implies being able to read the 
	 * contents of the file.
	 * 
	 * @return bool true if the object can be read, false otherwise.
	 */
	virtual bool isReadable() const;
	
	/**
	 * Indicates whether the object referred by this path can be written to or not.
	 * 
	 * If the path refers to a directory, writability implies being able to modify
	 * the directory entry (i.e. rename the directory, remove it or write files inside of it).
	 * 
	 * If the path refers to a file, writability implies being able to write data
	 * to the file.
	 * 
	 * @return bool true if the object can be written to, false otherwise.
	 */
	virtual bool isWritable() const;
	
	/**
	 * Searches recursively for a filename inside the given directories.
	 * 
	 * For each directory in the directory list a breadth-first search is performed,
	 * that is, the current directory entries are scanned before going into subdirectories.
	 * 
	 * @param results List to put the matches in.
	 * @param fslist List of directories to search within.
	 * @param pattern Pattern of the files to look for.
	 * @param hidden Whether to search hidden files or not.
	 * @param exhaustive Whether to continue searching after one match has been found.
	 * 
	 * @return true if matches could be found, false otherwise.
	 */
	virtual bool lookupFile(FSList &results, FSList &fslist, Common::String &pattern, bool hidden, bool exhaustive) const;
	
	/**
	 * Searches recursively for a filename inside this directory.
	 * 
	 * The search is performed breadth-first, that is, the current directory entries
	 * are scanned before going into subdirectories.
	 * 
	 * @param results List to put the matches in.
	 * @param pattern Pattern of the files to look for.
	 * @param hidden Whether to search hidden files or not.
	 * @param exhaustive Whether to continue searching after one match has been found.
	 * 
	 * @return true if matches could be found, false otherwise.
	 */
	virtual bool lookupFile(FSList &results, Common::String &pattern, bool hidden, bool exhaustive) const;

protected:
	/**
	 * Decreases the reference count to the FilesystemNode, and if necessary,
	 * deletes the corresponding underlying references.
	 */
	void decRefCount();
	
	/**
	 * Searches recursively for a filename inside the given directory.
	 * 
	 * The search is performed breadth-first, that is, the current directory entries
	 * are scanned before going into subdirectories.
	 * 
	 * @param results List to put the matches in.
	 * @param dir Directory to search within.
	 * @param pattern Pattern of the files to look for.
	 * @param hidden Whether to search hidden files or not.
	 * @param exhaustive Whether to continue searching after one match has been found.
	 * 
	 * @return The number of matches found.
	 */
	int lookupFileRec(FSList &results, FilesystemNode &dir, Common::String &pattern, bool hidden, bool exhaustive) const;
};

//} // End of namespace Common

#endif //COMMON_FS_H