Edinburgh Speech Tools 2.4-release
 
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EST_Chunk.h
1
2 /************************************************************************/
3 /* */
4 /* Centre for Speech Technology Research */
5 /* University of Edinburgh, UK */
6 /* Copyright (c) 1997 */
7 /* All Rights Reserved. */
8 /* */
9 /* Permission is hereby granted, free of charge, to use and distribute */
10 /* this software and its documentation without restriction, including */
11 /* without limitation the rights to use, copy, modify, merge, publish, */
12 /* distribute, sublicense, and/or sell copies of this work, and to */
13 /* permit persons to whom this work is furnished to do so, subject to */
14 /* the following conditions: */
15 /* 1. The code must retain the above copyright notice, this list of */
16 /* conditions and the following disclaimer. */
17 /* 2. Any modifications must be clearly marked as such. */
18 /* 3. Original authors' names are not deleted. */
19 /* 4. The authors' names are not used to endorse or promote products */
20 /* derived from this software without specific prior written */
21 /* permission. */
22 /* */
23 /* THE UNIVERSITY OF EDINBURGH AND THE CONTRIBUTORS TO THIS WORK */
24 /* DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING */
25 /* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT */
26 /* SHALL THE UNIVERSITY OF EDINBURGH NOR THE CONTRIBUTORS BE LIABLE */
27 /* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */
28 /* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN */
29 /* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, */
30 /* ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF */
31 /* THIS SOFTWARE. */
32 /* */
33 /************************************************************************/
34 /* */
35 /* Author: Richard Caley (rjc@cstr.ed.ac.uk) */
36 /* Date: February 1997 */
37 /* -------------------------------------------------------------------- */
38 /* */
39 /* Use counted memory chunks and smart pointers to them. */
40 /* */
41 /************************************************************************/
42
43#if ! defined(__EST_CHUNK_H__)
44#define __EST_CHUNK_H__
45
46#define HAVE_WALLOC_H (1)
47
48#include <iostream>
49using namespace std;
50#include <climits>
51#include <sys/types.h>
52
53// Warn when getting a writable version of a shared chunk --
54// useful for minimising copies.
55
56/* #define __INCLUDE_CHUNK_WARNINGS__ (1) */
57
58#if defined(__INCULDE_CHUNK_WARNINGS__)
59# define CHUNK_WARN(WHAT) do { cerr << "chunk: " <<WHAT << "\n";} while (0)
60#else
61# define CHUNK_WARN(WHAT) // empty
62#endif
63
64#define __CHUNK_INLINE_AGGRESSIVELY__ (1)
65
66#if defined(__CHUNK_INLINE_AGGRESSIVELY__)
67# define CII(BODY) BODY
68#else
69# define CII(BODY) /* empty */
70#endif
71
72#define __CHUNK_USE_WALLOC__ (1)
73
74#if __CHUNK_USE_WALLOC__
75
76#if HAVE_WALLOC_H
77
78# include "EST_walloc.h"
79
80#else
81
82# define walloc(T,N) ((T *)malloc(sizeof(T)*(N)))
83# define wfree(P) free(P)
84# define wrealloc(P,T,N) ((T *)realloc((P),sizeof(T)*(N)))
85
86#endif
87
88#endif
89
90 /************************************************************************/
91 /* */
92 /* EST_Chunk is a use-counted chunk of memory. You shouldn't be able */
93 /* to do anything to it except create it and manipulate it via */
94 /* EST_ChunkPtr. The private operator::new takes a placement argument */
95 /* which is actually the number of bytes of memory in the body of the */
96 /* chunk. */
97 /* */
98 /* If the use counter overflows, it sticks. Anything with more than */
99 /* SHRT_MAX references to it is probably permanent. */
100 /* */
101 /************************************************************************/
102
103class EST_ChunkPtr;
104
106 public:
107 typedef unsigned short use_counter;
108# define MAX_CHUNK_COUNT (USHRT_MAX)
109 typedef int EST_chunk_size;
110# define MAX_CHUNK_SIZE (INT_MAX)
111
112 private:
113 use_counter count;
114 EST_chunk_size size;
115 int malloc_flag; // set if this was got from malloc (rather than new)
116 char memory[1];
117
118 EST_Chunk(void);
119 ~EST_Chunk();
120
122 void *operator new (size_t size, int bytes);
123 void operator delete (void *it);
124
125 void operator ++ ()
126 CII({if (count < MAX_CHUNK_COUNT) ++count; });
127
128 void operator -- ()
129 CII({if (count < MAX_CHUNK_COUNT) if (--count == 0) delete this;});
130
131 public:
132 friend class EST_ChunkPtr;
133
134 friend EST_ChunkPtr chunk_allocate(int bytes);
135 friend EST_ChunkPtr chunk_allocate(int bytes, const char *initial, int initial_len);
136 friend EST_ChunkPtr chunk_allocate(int bytes, const EST_ChunkPtr &initial, int initial_start, int initial_len);
137
138 friend void cp_make_updatable(EST_ChunkPtr &shared, EST_chunk_size inuse);
139 friend void cp_make_updatable(EST_ChunkPtr &shared);
140
141 friend void grow_chunk(EST_ChunkPtr &shared, EST_chunk_size inuse, EST_chunk_size newsize);
142 friend void grow_chunk(EST_ChunkPtr &shared, EST_chunk_size newsize);
143
144 friend ostream &operator << (ostream &s, const EST_Chunk &chp);
145 friend void tester(void);
146};
147
148 /************************************************************************/
149 /* */
150 /* Pointers to chunks. Initialising them and assigning them around */
151 /* keeps track of use counts. We allow them to be cast to char * as a */
152 /* way of letting people work on them with standard functions, */
153 /* however it is bad voodoo to hold on to such a cast chunk for more */
154 /* than a trivial amount of time. */
155 /* */
156 /************************************************************************/
157
159 private:
160 EST_Chunk *ptr;
161
163 if ((ptr=chp))
164 ++ *ptr;
165 });
166 public:
167 EST_ChunkPtr(void) { ptr = (EST_Chunk *)NULL; };
168
169 EST_ChunkPtr(const EST_ChunkPtr &cp) CII({
170 ptr=cp.ptr;
171 if (ptr)
172 ++ *ptr;
173 });
174
175 ~EST_ChunkPtr(void) CII({ if (ptr) -- *ptr; });
176
177 int size(void) const { return ptr?ptr->size:0; };
178 int shareing(void) const { return ptr?(ptr->count >1):0; };
179 int count(void) const { return ptr?(ptr->count):-1; };
180
182 // doing it in this order means self assignment is safe.
183 if (cp.ptr)
184 ++ *(cp.ptr);
185 if (ptr)
186 -- *ptr;
187 ptr=cp.ptr;
188 return *this;
189 });
190
191 // If they manage to get hold of one...
192 // Actually usually used to assign NULL and so (possibly) deallocate
193 // the chunk currently pointed to.
195 // doing it in this order means self assignment is safe.
196 if (chp)
197 ++ *chp;
198 if (ptr)
199 -- *ptr;
200 ptr=chp;
201 return *this;
202 });
203
204 // Casting to a non-const pointer causes a
205 // warning to stderr if the chunk is shared.
206 operator char*() CII({
207 if (ptr && ptr->count > 1)
208 {
209 CHUNK_WARN("getting writable version of shared chunk\n");
210 cp_make_updatable(*this);
211 }
212 return ptr?&(ptr->memory[0]):(char *)NULL;
213 });
214 operator const char*() const CII({
215 return ptr?&(ptr->memory[0]):(const char *)NULL;
216 });
217 operator const char*() CII({
218 return ptr?&(ptr->memory[0]):(const char *)NULL;
219 });
220
221
222 const char operator [] (int i) const { return ptr->memory[i]; };
223 char &operator () (int i) CII({
224 if (ptr->count>1)
225 {
226 CHUNK_WARN("getting writable version of shared chunk\n");
227 cp_make_updatable(*this);
228 }
229 return ptr->memory[i];
230 });
231
232 // Creating a new one
233 friend EST_ChunkPtr chunk_allocate(int size);
234 friend EST_ChunkPtr chunk_allocate(int bytes, const char *initial, int initial_len);
235 friend EST_ChunkPtr chunk_allocate(int bytes, const EST_ChunkPtr &initial, int initial_start, int initial_len);
236
237 // Make sure the memory isn`t shared.
238 friend void cp_make_updatable(EST_ChunkPtr &shared, EST_Chunk::EST_chunk_size inuse);
239 friend void cp_make_updatable(EST_ChunkPtr &shared);
240
241 // Make sure there is enough room (also makes updatable)
242 friend void grow_chunk(EST_ChunkPtr &shared, EST_Chunk::EST_chunk_size inuse, EST_Chunk::EST_chunk_size newsize);
243 friend void grow_chunk(EST_ChunkPtr &shared, EST_Chunk::EST_chunk_size newsize);
244
245 // we print it by just printing the chunk
246 friend ostream &operator << (ostream &s, const EST_ChunkPtr &cp) { return (s<< *cp.ptr); };
247
248 friend void tester(void);
249};
250
251#endif