aboutsummaryrefslogtreecommitdiff
path: root/common/str.cpp
blob: ad2367fb416401d7db9ad7d9d08eac0ebbad3fa4 (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
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002-2006 The ScummVM project
 *
 * 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.
 *
 * $URL$
 * $Id$
 */

#include "common/stdafx.h"

#include "common/str.h"
#include "common/hash-str.h"
#include "common/util.h"

#include <ctype.h>

namespace Common {

#if !(defined(PALMOS_ARM) || defined(PALMOS_DEBUG) || defined(__GP32__))
const String String::emptyString;
#else
const char *String::emptyString = "";
#endif

static int computeCapacity(int len) {
	// By default, for the capacity we use the nearest multiple of 32
	// that leaves at least 16 chars of extra space (in case the string
	// grows a bit).
	// Finally, we subtract 1 to compensate for the trailing zero byte.
	len += 16;
	return ((len + 32 - 1) & ~0x1F) - 1;
}

String::String(const char *str, uint32 len)
: _len(0), _str(_storage) {

	// Init _storage member explicitly (ie. without calling its constructor)
	// for GCC 2.95.x compatibility (see also tracker item #1602879).
	_storage[0] = 0;

	if (str && *str) {
		const uint32 tmp = strlen(str);
		assert(len <= tmp);
		if (len <= 0)
			len = tmp;
		_len = len;
		
		if (len >= _builtinCapacity) {
			// Not enough internal storage, so allocate more
			_extern._capacity = computeCapacity(len);
			_extern._refCount = 0;
			_str = (char *)malloc(_extern._capacity+1);
			assert(_str != 0);
		}
		
		// Copy the string into the storage area
		memcpy(_str, str, len);
		_str[len] = 0;
	}
}

String::String(const String &str)
 : _len(str._len), _str(str.isStorageIntern() ? _storage : str._str) {
	if (str.isStorageIntern()) {
		// String in internal storage: just copy it
		memcpy(_storage, str._storage, _builtinCapacity);
	} else {
		// String in external storage: use refcount mechanism
		str.incRefCount();
		_extern._refCount = str._extern._refCount;
		_extern._capacity = str._extern._capacity;
	}
	assert(_str != 0);
}
	
String::~String() {
	decRefCount(_extern._refCount);
}

void String::incRefCount() const {
	assert(!isStorageIntern());
	if (_extern._refCount == 0) {
		_extern._refCount = new int(2);
	} else {
		++(*_extern._refCount);
	}
}

void String::decRefCount(int *oldRefCount) {
	if (isStorageIntern())
		return;

	if (oldRefCount) {
		--(*oldRefCount);
	}
	if (!oldRefCount || *oldRefCount <= 0) {
		// The ref count reached zero, so we free the string storage
		// and the ref count storage.
		delete oldRefCount;
		free(_str);

		// Even though _str points to a freed memory block now,
		// we do not change its value, because any code that calls
		// decRefCount will have to do this afterwards anyway.
	}
}

String& String::operator  =(const char *str) {
	uint32 len = strlen(str);
	ensureCapacity(len, false);
	_len = len;
	memcpy(_str, str, len + 1);
	return *this;
}

String &String::operator  =(const String &str) {
	if (str.isStorageIntern()) {
		decRefCount(_extern._refCount);
		_len = str._len;
		_str = _storage;
		memcpy(_str, str._str, _len + 1);
	} else {
		str.incRefCount();
		decRefCount(_extern._refCount);
	
		_extern._refCount = str._extern._refCount;
		_extern._capacity = str._extern._capacity;
		_len = str._len;
		_str = str._str;
	}

	return *this;
}

String& String::operator  =(char c) {
	ensureCapacity(1, false);
	_len = 1;
	_str[0] = c;
	_str[1] = 0;
	return *this;
}

String &String::operator +=(const char *str) {
	int len = strlen(str);
	if (len > 0) {
		ensureCapacity(_len + len, true);

		memcpy(_str + _len, str, len + 1);
		_len += len;
	}
	return *this;
}

String &String::operator +=(const String &str) {
	int len = str._len;
	if (len > 0) {
		ensureCapacity(_len + len, true);

		memcpy(_str + _len, str._str, len + 1);
		_len += len;
	}
	return *this;
}

String &String::operator +=(char c) {
	ensureCapacity(_len + 1, true);

	_str[_len++] = c;
	_str[_len] = 0;

	return *this;
}

bool String::hasPrefix(const char *x) const {
	assert(x != 0);
	// Compare x with the start of _str.
	const char *y = c_str();
	while (*x && *x == *y) {
		++x;
		++y;
	}
	// It's a prefix, if and only if all letters in x are 'used up' before
	// _str ends.
	return *x == 0;
}

bool String::hasSuffix(const char *x) const {
	assert(x != 0);
	// Compare x with the end of _str.
	const uint32 x_len = strlen(x);
	if (x_len > _len)
		return false;
	const char *y = c_str() + _len - x_len;
	while (*x && *x == *y) {
		++x;
		++y;
	}
	// It's a suffix, if and only if all letters in x are 'used up' before
	// _str ends.
	return *x == 0;
}

void String::deleteLastChar() {
	deleteChar(_len - 1);
}

void String::deleteChar(uint32 p) {
	assert(p < _len);

	// Call ensureCapacity to make sure we actually *own* the storage
	// to which _str points to -- we wouldn't want to modify a storage
	// which other string objects are sharing, after all.
	ensureCapacity(_len, true);
	while (p++ < _len)
		_str[p-1] = _str[p];
	_len--;
}

void String::clear() {
	decRefCount(_extern._refCount);

	_len = 0;
	_str = _storage;
	_storage[0] = 0;
}

void String::insertChar(char c, uint32 p) {
	assert(p <= _len);

	ensureCapacity(_len + 1, true);
	_len++;
	for (uint32 i = _len; i > p; --i)
		_str[i] = _str[i-1];
	_str[p] = c;
}

void String::toLowercase() {
	ensureCapacity(_len, true);
	for (uint32 i = 0; i < _len; ++i)
		_str[i] = tolower(_str[i]);
}

void String::toUppercase() {
	ensureCapacity(_len, true);
	for (uint32 i = 0; i < _len; ++i)
		_str[i] = toupper(_str[i]);
}

/**
 * Ensure that enough storage is available to store at least new_len
 * characters plus a null byte. In addition, if we currently share
 * the storage with another string, unshare it, so that we can safely
 * write to the storage.
 */
void String::ensureCapacity(uint32 new_len, bool keep_old) {
	bool isShared;
	uint32 curCapacity, newCapacity;
	char *newStorage;
	int *oldRefCount = _extern._refCount;
	
	if (isStorageIntern()) {
		isShared = false;
		curCapacity = _builtinCapacity - 1;
	} else {
		isShared = (oldRefCount && *oldRefCount > 1);
		curCapacity = _extern._capacity;
	}
	
	// Special case: If there is enough space, and we do not share
	// the storage, then there is nothing to do.
	if (!isShared && new_len <= curCapacity)
		return;

	if (isShared && new_len <= _builtinCapacity - 1) {
		// We share the storage, but there is enough internal storage: Use that.
		newStorage = _storage;
		newCapacity = _builtinCapacity - 1;
	} else {
		// We need to allocate storage on the heap!

		// Compute a suitable new capacity limit
		newCapacity = computeCapacity(new_len);

		// Allocate new storage
		newStorage = (char *)malloc(newCapacity+1);
		assert(newStorage);
	}

	// Copy old data if needed, elsewise reset the new storage.
	if (keep_old) {
		assert(_len <= newCapacity);
		memcpy(newStorage, _str, _len + 1);
	} else {
		_len = 0;
		newStorage[0] = 0;
	}

	// Release hold on the old storage ...
	decRefCount(oldRefCount);

	// ... in favor of the new storage
	_str = newStorage;

	if (!isStorageIntern()) {
		// Set the ref count & capacity if we use an external storage.
		// It is important to do this *after* copying any old content,
		// else we would override data that has not yet been copied!
		_extern._refCount = 0;
		_extern._capacity = newCapacity;
	}
}

uint String::hash() const {
	return hashit(c_str());
}
	
#pragma mark -

bool String::operator ==(const String &x) const {
	return equals(x);
}

bool String::operator ==(const char *x) const {
	assert(x != 0);
	return equals(x);
}

bool String::operator !=(const String &x) const {
	return !equals(x);
}

bool String::operator !=(const char *x) const {
	assert(x != 0);
	return !equals(x);
}

bool String::operator < (const String &x) const {
	return compareTo(x) < 0;
}

bool String::operator <= (const String &x) const {
	return compareTo(x) <= 0;
}

bool String::operator > (const String &x) const {
	return compareTo(x) > 0;
}

bool String::operator >= (const String &x) const {
	return compareTo(x) >= 0;
}

#pragma mark -

bool operator == (const char* y, const String &x) {
	return (x == y);
}

bool operator != (const char* y, const String &x) {
	return x != y;
}

#pragma mark -

bool String::equals(const String &x) const {
	return (0 == compareTo(x));
}

bool String::equals(const char *x) const {
	assert(x != 0);
	return (0 == compareTo(x));
}

bool String::equalsIgnoreCase(const String &x) const {
	return (0 == compareToIgnoreCase(x));
}

bool String::equalsIgnoreCase(const char *x) const {
	assert(x != 0);
	return (0 == compareToIgnoreCase(x));
}

int String::compareTo(const String &x) const {
	return compareTo(x.c_str());
}

int String::compareTo(const char *x) const {
	assert(x != 0);
	return strcmp(c_str(), x);
}

int String::compareToIgnoreCase(const String &x) const {
	return compareToIgnoreCase(x.c_str());
}

int String::compareToIgnoreCase(const char *x) const {
	assert(x != 0);
	return scumm_stricmp(c_str(), x);
}

#pragma mark -

String operator +(const String &x, const String &y) {
	String temp(x);
	temp += y;
	return temp;
}

String operator +(const char *x, const String &y) {
	String temp(x);
	temp += y;
	return temp;
}

String operator +(const String &x, const char *y) {
	String temp(x);
	temp += y;
	return temp;
}


}	// End of namespace Common