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
|
/* 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.
*
*/
#include "sherlock/resources.h"
#include "sherlock/decompress.h"
#include "common/debug.h"
namespace Sherlock {
Cache::Cache() {
}
/**
* Returns true if a given file is currently being cached
*/
bool Cache::isCached(const Common::String &filename) const {
return _resources.contains(filename);
}
/**
* Loads a file into the cache if it's not already present, and returns it.
* If the file is LZW compressed, automatically decompresses it and loads
* the uncompressed version into memory
*/
void Cache::load(const Common::String &filename) {
// First check if the entry already exists
if (_resources.contains(filename))
return;
// Allocate a new cache entry
_resources[filename] = CacheEntry();
CacheEntry &cacheEntry = _resources[filename];
// Open the file for reading
Common::File f;
if (!f.open(filename))
error("Could not read file - %s", filename.c_str());
// Check whether the file is compressed
const char LZW_HEADER[5] = { "LZV\x1a" };
char header[5];
f.read(header, 5);
bool isCompressed = !strncmp(header, LZW_HEADER, 5);
f.seek(0);
if (isCompressed) {
// It's compressed, so decompress the file and store it's data in the cache entry
Common::SeekableReadStream *decompressed = decompressLZ(f);
cacheEntry.resize(decompressed->size());
decompressed->read(&cacheEntry[0], decompressed->size());
delete decompressed;
} else {
// It's not, so read the raw data of the file into the cache entry
cacheEntry.resize(f.size());
f.read(&cacheEntry[0], f.size());
}
f.close();
}
Common::SeekableReadStream *Cache::get(const Common::String &filename) const {
// Return a memory stream that encapsulates the data
const CacheEntry &cacheEntry = _resources[filename];
return new Common::MemoryReadStream(&cacheEntry[0], cacheEntry.size());
}
/*----------------------------------------------------------------*/
Resources::Resources() {
_resourceIndex = -1;
addToCache("vgs.lib");
addToCache("talk.lib");
addToCache("sequence.txt");
addToCache("journal.txt");
addToCache("portrait.lib");
}
/**
* Adds the specified file to the cache. If it's a library file, takes care of
* loading it's index for future use
*/
void Resources::addToCache(const Common::String &filename) {
_cache.load(filename);
// Check to see if the file is a library
Common::SeekableReadStream *stream = load(filename);
uint32 header = stream->readUint32BE();
if (header == MKTAG('L', 'I', 'B', 26))
loadLibraryIndex(filename, stream);
delete stream;
}
Common::SeekableReadStream *Resources::load(const Common::String &filename) {
// First check if the file is directly in the cache
if (_cache.isCached(filename))
return _cache.get(filename);
// Secondly, iterate through any loaded library file looking for a resource
// that has the same name
LibraryIndexes::iterator i;
for (i = _indexes.begin(); i != _indexes.end(); ++i) {
if ((*i)._value.contains(filename)) {
// Get a stream reference to the given library file
Common::SeekableReadStream *stream = load((*i)._key);
LibraryEntry &entry = (*i)._value[filename];
_resourceIndex = entry._index;
stream->seek(entry._offset);
Common::SeekableReadStream *resStream = stream->readStream(entry._size);
delete stream;
return resStream;
}
}
// At this point, fall back on a physical file with the given name
Common::File f;
if (!f.open(filename))
error("Could not load file - %s", filename.c_str());
Common::SeekableReadStream *stream = f.readStream(f.size());
f.close();
return stream;
}
/**
* Loads a specific resource from a given library file
*/
Common::SeekableReadStream *Resources::load(const Common::String &filename, const Common::String &libraryFile) {
// Open up the library for access
Common::SeekableReadStream *libStream = load(libraryFile);
// Check if the library has already had it's index read, and if not, load it
if (!_indexes.contains(libraryFile))
loadLibraryIndex(libraryFile, libStream);
// Extract the data for the specified resource and return it
LibraryEntry &entry = _indexes[libraryFile][filename];
libStream->seek(entry._offset);
Common::SeekableReadStream *stream = libStream->readStream(entry._size);
delete libStream;
return stream;
}
/**
* Reads in the index from a library file, and caches it's index for later use
*/
void Resources::loadLibraryIndex(const Common::String &libFilename,
Common::SeekableReadStream *stream) {
uint32 offset, nextOffset;
// Create an index entry
_indexes[libFilename] = LibraryIndex();
LibraryIndex &index = _indexes[libFilename];
// Read in the number of resources
stream->seek(4);
int count = stream->readUint16LE();
// Loop through reading in the entries
for (int idx = 0; idx < count; ++idx) {
// Read the name of the resource
char resName[13];
stream->read(resName, 13);
resName[12] = '\0';
// Read the offset
offset = stream->readUint32LE();
if (idx == (count - 1)) {
nextOffset = stream->size();
} else {
// Read the size by jumping forward to read the next entry's offset
stream->seek(13, SEEK_CUR);
nextOffset = stream->readUint32LE();
stream->seek(-17, SEEK_CUR);
}
// Add the entry to the index
index[resName] = LibraryEntry(idx, offset, nextOffset - offset);
}
}
/**
* Returns the index of the last loaded resource in it's given library file.
* This will be used primarily when loading talk files, so the engine can
* update the given conversation number in the journal
*/
int Resources::resourceIndex() const {
return _resourceIndex;
}
} // End of namespace Sherlock
|
