summaryrefslogtreecommitdiff
path: root/Build/source/libs/icu/icu-4.4/common/cmemory.h
blob: 0c525d08adcfc49e8741923f5d51140d9315c3ee (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
/*
******************************************************************************
*
*   Copyright (C) 1997-2010, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
******************************************************************************
*
* File CMEMORY.H
*
*  Contains stdlib.h/string.h memory functions
*
* @author       Bertrand A. Damiba
*
* Modification History:
*
*   Date        Name        Description
*   6/20/98     Bertrand    Created.
*  05/03/99     stephen     Changed from functions to macros.
*
******************************************************************************
*/

#ifndef CMEMORY_H
#define CMEMORY_H

#include "unicode/utypes.h"
#include "unicode/localpointer.h"
#include <stddef.h>
#include <string.h>


#define uprv_memcpy(dst, src, size) U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size)
#define uprv_memmove(dst, src, size) U_STANDARD_CPP_NAMESPACE memmove(dst, src, size)
#define uprv_memset(buffer, mark, size) U_STANDARD_CPP_NAMESPACE memset(buffer, mark, size)
#define uprv_memcmp(buffer1, buffer2, size) U_STANDARD_CPP_NAMESPACE memcmp(buffer1, buffer2,size)

U_CAPI void * U_EXPORT2
uprv_malloc(size_t s);

U_CAPI void * U_EXPORT2
uprv_realloc(void *mem, size_t size);

U_CAPI void U_EXPORT2
uprv_free(void *mem);

/**
 * This should align the memory properly on any machine.
 * This is very useful for the safeClone functions.
 */
typedef union {
    long    t1;
    double  t2;
    void   *t3;
} UAlignedMemory;

/**
 * Get the least significant bits of a pointer (a memory address).
 * For example, with a mask of 3, the macro gets the 2 least significant bits,
 * which will be 0 if the pointer is 32-bit (4-byte) aligned.
 *
 * ptrdiff_t is the most appropriate integer type to cast to.
 * size_t should work too, since on most (or all?) platforms it has the same
 * width as ptrdiff_t.
 */
#define U_POINTER_MASK_LSB(ptr, mask) (((ptrdiff_t)(char *)(ptr)) & (mask))

/**
 * Get the amount of bytes that a pointer is off by from
 * the previous UAlignedMemory-aligned pointer.
 */
#define U_ALIGNMENT_OFFSET(ptr) U_POINTER_MASK_LSB(ptr, sizeof(UAlignedMemory) - 1)

/**
 * Get the amount of bytes to add to a pointer
 * in order to get the next UAlignedMemory-aligned address.
 */
#define U_ALIGNMENT_OFFSET_UP(ptr) (sizeof(UAlignedMemory) - U_ALIGNMENT_OFFSET(ptr))

/**
  *  Indicate whether the ICU allocation functions have been used.
  *  This is used to determine whether ICU is in an initial, unused state.
  */
U_CFUNC UBool 
cmemory_inUse(void);

/**
  *  Heap clean up function, called from u_cleanup()
  *    Clears any user heap functions from u_setMemoryFunctions()
  *    Does NOT deallocate any remaining allocated memory.
  */
U_CFUNC UBool 
cmemory_cleanup(void);

#ifdef XP_CPLUSPLUS

U_NAMESPACE_BEGIN

/**
 * "Smart pointer" class, deletes memory via uprv_free().
 * For most methods see the LocalPointerBase base class.
 * Adds operator[] for array item access.
 *
 * @see LocalPointerBase
 */
template<typename T>
class LocalMemory : public LocalPointerBase<T> {
public:
    /**
     * Constructor takes ownership.
     * @param p simple pointer to an array of T items that is adopted
     */
    explicit LocalMemory(T *p=NULL) : LocalPointerBase<T>(p) {}
    /**
     * Destructor deletes the memory it owns.
     */
    ~LocalMemory() {
        uprv_free(LocalPointerBase<T>::ptr);
    }
    /**
     * Deletes the array it owns,
     * and adopts (takes ownership of) the one passed in.
     * @param p simple pointer to an array of T items that is adopted
     */
    void adoptInstead(T *p) {
        uprv_free(LocalPointerBase<T>::ptr);
        LocalPointerBase<T>::ptr=p;
    }
    /**
     * Deletes the array it owns, allocates a new one and reset its bytes to 0.
     * Returns the new array pointer.
     * If the allocation fails, then the current array is unchanged and
     * this method returns NULL.
     * @param newCapacity must be >0
     * @return the allocated array pointer, or NULL if the allocation failed
     */
    inline T *allocateInsteadAndReset(int32_t newCapacity=1);
    /**
     * Deletes the array it owns and allocates a new one, copying length T items.
     * Returns the new array pointer.
     * If the allocation fails, then the current array is unchanged and
     * this method returns NULL.
     * @param newCapacity must be >0
     * @param length number of T items to be copied from the old array to the new one;
     *               must be no more than the capacity of the old array,
     *               which the caller must track because the LocalMemory does not track it
     * @return the allocated array pointer, or NULL if the allocation failed
     */
    inline T *allocateInsteadAndCopy(int32_t newCapacity=1, int32_t length=0);
    /**
     * Array item access (writable).
     * No index bounds check.
     * @param i array index
     * @return reference to the array item
     */
    T &operator[](ptrdiff_t i) const { return LocalPointerBase<T>::ptr[i]; }
};

/**
 * Simple array/buffer management class using uprv_malloc() and uprv_free().
 * Provides an internal array with fixed capacity. Can alias another array
 * or allocate one.
 * Unlike LocalMemory and LocalArray, this class never adopts
 * (takes ownership of) another array.
 */
template<typename T, int32_t stackCapacity>
class MaybeStackArray {
public:
    /**
     * Default constructor initializes with internal T[stackCapacity] buffer.
     */
    MaybeStackArray() : needToRelease(FALSE), capacity(stackCapacity), ptr(stackArray) {}
    /**
     * Destructor deletes the array (if owned).
     */
    ~MaybeStackArray() { releaseArray(); }
    /**
     * Returns the array capacity (number of T items).
     * @return array capacity
     */
    int32_t getCapacity() const { return capacity; }
    /**
     * Access without ownership change.
     * @return the array pointer
     */
    T *getAlias() const { return ptr; }
    /**
     * Returns the array limit. Simple convenience method.
     * @return getAlias()+getCapacity()
     */
    T *getArrayLimit() const { return getAlias()+capacity; }
    /**
     * Access without ownership change. Same as getAlias().
     * A class instance can be used directly in expressions that take a T *.
     * @return the array pointer
     */
    operator T *() const { return ptr; }
    /**
     * Array item access (writable).
     * No index bounds check.
     * @param i array index
     * @return reference to the array item
     */
    T &operator[](ptrdiff_t i) { return ptr[i]; }
    /**
     * Deletes the array (if owned) and aliases another one, no transfer of ownership.
     * If the arguments are illegal, then the current array is unchanged.
     * @param otherArray must not be NULL
     * @param otherCapacity must be >0
     */
    void aliasInstead(T *otherArray, int32_t otherCapacity) {
        if(otherArray!=NULL && otherCapacity>0) {
            releaseArray();
            ptr=otherArray;
            capacity=otherCapacity;
            needToRelease=FALSE;
        }
    };
    /**
     * Deletes the array (if owned) and allocates a new one, copying length T items.
     * Returns the new array pointer.
     * If the allocation fails, then the current array is unchanged and
     * this method returns NULL.
     * @param newCapacity can be less than or greater than the current capacity;
     *                    must be >0
     * @param length number of T items to be copied from the old array to the new one
     * @return the allocated array pointer, or NULL if the allocation failed
     */
    inline T *resize(int32_t newCapacity, int32_t length=0);
    /**
     * Gives up ownership of the array if owned, or else clones it,
     * copying length T items; resets itself to the internal stack array.
     * Returns NULL if the allocation failed.
     * @param length number of T items to copy when cloning,
     *        and capacity of the clone when cloning
     * @param resultCapacity will be set to the returned array's capacity (output-only)
     * @return the array pointer;
     *         caller becomes responsible for deleting the array
     * @draft ICU 4.4
     */
    inline T *orphanOrClone(int32_t length, int32_t &resultCapacity);
private:
    UBool needToRelease;
    int32_t capacity;
    T *ptr;
    T stackArray[stackCapacity];
    void releaseArray() {
        if(needToRelease) {
            uprv_free(ptr);
        }
    }
    /* No comparison operators with other MaybeStackArray's. */
    bool operator==(const MaybeStackArray & /*other*/) {return FALSE;};
    bool operator!=(const MaybeStackArray & /*other*/) {return TRUE;};
    /* No ownership transfer: No copy constructor, no assignment operator. */
    MaybeStackArray(const MaybeStackArray & /*other*/) {};
    void operator=(const MaybeStackArray & /*other*/) {};

    // No heap allocation. Use only on the stack.
    //   (Declaring these functions private triggers a cascade of problems:
    //      MSVC insists on exporting an instantiation of MaybeStackArray, which
    //      requires that all functions be defined.
    //      An empty implementation of new() is rejected, it must return a value.
    //      Returning NULL is rejected by gcc for operator new.
    //      The expedient thing is just not to override operator new.
    //      While relatively pointless, heap allocated instances will function.
    // static void * U_EXPORT2 operator new(size_t size); 
    // static void * U_EXPORT2 operator new[](size_t size);
#if U_HAVE_PLACEMENT_NEW
    // static void * U_EXPORT2 operator new(size_t, void *ptr);
#endif
};

template<typename T>
inline T *LocalMemory<T>::allocateInsteadAndReset(int32_t newCapacity) {
    if(newCapacity>0) {
        T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
        if(p!=NULL) {
            uprv_memset(p, 0, newCapacity*sizeof(T));
            uprv_free(LocalPointerBase<T>::ptr);
            LocalPointerBase<T>::ptr=p;
        }
        return p;
    } else {
        return NULL;
    }
}


template<typename T>
inline T *LocalMemory<T>::allocateInsteadAndCopy(int32_t newCapacity, int32_t length) {
    if(newCapacity>0) {
        T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
        if(p!=NULL) {
            if(length>0) {
                if(length>newCapacity) {
                    length=newCapacity;
                }
                uprv_memcpy(p, LocalPointerBase<T>::ptr, length*sizeof(T));
            }
            uprv_free(LocalPointerBase<T>::ptr);
            LocalPointerBase<T>::ptr=p;
        }
        return p;
    } else {
        return NULL;
    }
}

template<typename T, int32_t stackCapacity>
inline T *MaybeStackArray<T, stackCapacity>::resize(int32_t newCapacity, int32_t length) {
    if(newCapacity>0) {
        T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
        if(p!=NULL) {
            if(length>0) {
                if(length>capacity) {
                    length=capacity;
                }
                if(length>newCapacity) {
                    length=newCapacity;
                }
                uprv_memcpy(p, ptr, length*sizeof(T));
            }
            releaseArray();
            ptr=p;
            capacity=newCapacity;
            needToRelease=TRUE;
        }
        return p;
    } else {
        return NULL;
    }
}

template<typename T, int32_t stackCapacity>
inline T *MaybeStackArray<T, stackCapacity>::orphanOrClone(int32_t length, int32_t &resultCapacity) {
    T *p;
    if(needToRelease) {
        p=ptr;
    } else if(length<=0) {
        return NULL;
    } else {
        if(length>capacity) {
            length=capacity;
        }
        p=(T *)uprv_malloc(length*sizeof(T));
        if(p==NULL) {
            return NULL;
        }
        uprv_memcpy(p, ptr, length*sizeof(T));
    }
    resultCapacity=length;
    ptr=stackArray;
    capacity=stackCapacity;
    needToRelease=FALSE;
    return p;
}

U_NAMESPACE_END

#endif  /* XP_CPLUSPLUS */
#endif  /* CMEMORY_H */