xref: /f-stack/app/redis-5.0.5/src/sds.h (revision 572c4311)
1 /* SDSLib 2.0 -- A C dynamic strings library
2  *
3  * Copyright (c) 2006-2015, Salvatore Sanfilippo <antirez at gmail dot com>
4  * Copyright (c) 2015, Oran Agra
5  * Copyright (c) 2015, Redis Labs, Inc
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  *   * Redistributions of source code must retain the above copyright notice,
12  *     this list of conditions and the following disclaimer.
13  *   * Redistributions in binary form must reproduce the above copyright
14  *     notice, this list of conditions and the following disclaimer in the
15  *     documentation and/or other materials provided with the distribution.
16  *   * Neither the name of Redis nor the names of its contributors may be used
17  *     to endorse or promote products derived from this software without
18  *     specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #ifndef __SDS_H
34 #define __SDS_H
35 
36 #define SDS_MAX_PREALLOC (1024*1024)
37 const char *SDS_NOINIT;
38 
39 #include <sys/types.h>
40 #include <stdarg.h>
41 #include <stdint.h>
42 
43 typedef char *sds;
44 
45 /* Note: sdshdr5 is never used, we just access the flags byte directly.
46  * However is here to document the layout of type 5 SDS strings. */
47 struct __attribute__ ((__packed__)) sdshdr5 {
48     unsigned char flags; /* 3 lsb of type, and 5 msb of string length */
49     char buf[];
50 };
51 struct __attribute__ ((__packed__)) sdshdr8 {
52     uint8_t len; /* used */
53     uint8_t alloc; /* excluding the header and null terminator */
54     unsigned char flags; /* 3 lsb of type, 5 unused bits */
55     char buf[];
56 };
57 struct __attribute__ ((__packed__)) sdshdr16 {
58     uint16_t len; /* used */
59     uint16_t alloc; /* excluding the header and null terminator */
60     unsigned char flags; /* 3 lsb of type, 5 unused bits */
61     char buf[];
62 };
63 struct __attribute__ ((__packed__)) sdshdr32 {
64     uint32_t len; /* used */
65     uint32_t alloc; /* excluding the header and null terminator */
66     unsigned char flags; /* 3 lsb of type, 5 unused bits */
67     char buf[];
68 };
69 struct __attribute__ ((__packed__)) sdshdr64 {
70     uint64_t len; /* used */
71     uint64_t alloc; /* excluding the header and null terminator */
72     unsigned char flags; /* 3 lsb of type, 5 unused bits */
73     char buf[];
74 };
75 
76 #define SDS_TYPE_5  0
77 #define SDS_TYPE_8  1
78 #define SDS_TYPE_16 2
79 #define SDS_TYPE_32 3
80 #define SDS_TYPE_64 4
81 #define SDS_TYPE_MASK 7
82 #define SDS_TYPE_BITS 3
83 #define SDS_HDR_VAR(T,s) struct sdshdr##T *sh = (void*)((s)-(sizeof(struct sdshdr##T)));
84 #define SDS_HDR(T,s) ((struct sdshdr##T *)((s)-(sizeof(struct sdshdr##T))))
85 #define SDS_TYPE_5_LEN(f) ((f)>>SDS_TYPE_BITS)
86 
sdslen(const sds s)87 static inline size_t sdslen(const sds s) {
88     unsigned char flags = s[-1];
89     switch(flags&SDS_TYPE_MASK) {
90         case SDS_TYPE_5:
91             return SDS_TYPE_5_LEN(flags);
92         case SDS_TYPE_8:
93             return SDS_HDR(8,s)->len;
94         case SDS_TYPE_16:
95             return SDS_HDR(16,s)->len;
96         case SDS_TYPE_32:
97             return SDS_HDR(32,s)->len;
98         case SDS_TYPE_64:
99             return SDS_HDR(64,s)->len;
100     }
101     return 0;
102 }
103 
sdsavail(const sds s)104 static inline size_t sdsavail(const sds s) {
105     unsigned char flags = s[-1];
106     switch(flags&SDS_TYPE_MASK) {
107         case SDS_TYPE_5: {
108             return 0;
109         }
110         case SDS_TYPE_8: {
111             SDS_HDR_VAR(8,s);
112             return sh->alloc - sh->len;
113         }
114         case SDS_TYPE_16: {
115             SDS_HDR_VAR(16,s);
116             return sh->alloc - sh->len;
117         }
118         case SDS_TYPE_32: {
119             SDS_HDR_VAR(32,s);
120             return sh->alloc - sh->len;
121         }
122         case SDS_TYPE_64: {
123             SDS_HDR_VAR(64,s);
124             return sh->alloc - sh->len;
125         }
126     }
127     return 0;
128 }
129 
sdssetlen(sds s,size_t newlen)130 static inline void sdssetlen(sds s, size_t newlen) {
131     unsigned char flags = s[-1];
132     switch(flags&SDS_TYPE_MASK) {
133         case SDS_TYPE_5:
134             {
135                 unsigned char *fp = ((unsigned char*)s)-1;
136                 *fp = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS);
137             }
138             break;
139         case SDS_TYPE_8:
140             SDS_HDR(8,s)->len = newlen;
141             break;
142         case SDS_TYPE_16:
143             SDS_HDR(16,s)->len = newlen;
144             break;
145         case SDS_TYPE_32:
146             SDS_HDR(32,s)->len = newlen;
147             break;
148         case SDS_TYPE_64:
149             SDS_HDR(64,s)->len = newlen;
150             break;
151     }
152 }
153 
sdsinclen(sds s,size_t inc)154 static inline void sdsinclen(sds s, size_t inc) {
155     unsigned char flags = s[-1];
156     switch(flags&SDS_TYPE_MASK) {
157         case SDS_TYPE_5:
158             {
159                 unsigned char *fp = ((unsigned char*)s)-1;
160                 unsigned char newlen = SDS_TYPE_5_LEN(flags)+inc;
161                 *fp = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS);
162             }
163             break;
164         case SDS_TYPE_8:
165             SDS_HDR(8,s)->len += inc;
166             break;
167         case SDS_TYPE_16:
168             SDS_HDR(16,s)->len += inc;
169             break;
170         case SDS_TYPE_32:
171             SDS_HDR(32,s)->len += inc;
172             break;
173         case SDS_TYPE_64:
174             SDS_HDR(64,s)->len += inc;
175             break;
176     }
177 }
178 
179 /* sdsalloc() = sdsavail() + sdslen() */
sdsalloc(const sds s)180 static inline size_t sdsalloc(const sds s) {
181     unsigned char flags = s[-1];
182     switch(flags&SDS_TYPE_MASK) {
183         case SDS_TYPE_5:
184             return SDS_TYPE_5_LEN(flags);
185         case SDS_TYPE_8:
186             return SDS_HDR(8,s)->alloc;
187         case SDS_TYPE_16:
188             return SDS_HDR(16,s)->alloc;
189         case SDS_TYPE_32:
190             return SDS_HDR(32,s)->alloc;
191         case SDS_TYPE_64:
192             return SDS_HDR(64,s)->alloc;
193     }
194     return 0;
195 }
196 
sdssetalloc(sds s,size_t newlen)197 static inline void sdssetalloc(sds s, size_t newlen) {
198     unsigned char flags = s[-1];
199     switch(flags&SDS_TYPE_MASK) {
200         case SDS_TYPE_5:
201             /* Nothing to do, this type has no total allocation info. */
202             break;
203         case SDS_TYPE_8:
204             SDS_HDR(8,s)->alloc = newlen;
205             break;
206         case SDS_TYPE_16:
207             SDS_HDR(16,s)->alloc = newlen;
208             break;
209         case SDS_TYPE_32:
210             SDS_HDR(32,s)->alloc = newlen;
211             break;
212         case SDS_TYPE_64:
213             SDS_HDR(64,s)->alloc = newlen;
214             break;
215     }
216 }
217 
218 sds sdsnewlen(const void *init, size_t initlen);
219 sds sdsnew(const char *init);
220 sds sdsempty(void);
221 sds sdsdup(const sds s);
222 void sdsfree(sds s);
223 sds sdsgrowzero(sds s, size_t len);
224 sds sdscatlen(sds s, const void *t, size_t len);
225 sds sdscat(sds s, const char *t);
226 sds sdscatsds(sds s, const sds t);
227 sds sdscpylen(sds s, const char *t, size_t len);
228 sds sdscpy(sds s, const char *t);
229 
230 sds sdscatvprintf(sds s, const char *fmt, va_list ap);
231 #ifdef __GNUC__
232 sds sdscatprintf(sds s, const char *fmt, ...)
233     __attribute__((format(printf, 2, 3)));
234 #else
235 sds sdscatprintf(sds s, const char *fmt, ...);
236 #endif
237 
238 sds sdscatfmt(sds s, char const *fmt, ...);
239 sds sdstrim(sds s, const char *cset);
240 void sdsrange(sds s, ssize_t start, ssize_t end);
241 void sdsupdatelen(sds s);
242 void sdsclear(sds s);
243 int sdscmp(const sds s1, const sds s2);
244 sds *sdssplitlen(const char *s, ssize_t len, const char *sep, int seplen, int *count);
245 void sdsfreesplitres(sds *tokens, int count);
246 void sdstolower(sds s);
247 void sdstoupper(sds s);
248 sds sdsfromlonglong(long long value);
249 sds sdscatrepr(sds s, const char *p, size_t len);
250 sds *sdssplitargs(const char *line, int *argc);
251 sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen);
252 sds sdsjoin(char **argv, int argc, char *sep);
253 sds sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen);
254 
255 /* Low level functions exposed to the user API */
256 sds sdsMakeRoomFor(sds s, size_t addlen);
257 void sdsIncrLen(sds s, ssize_t incr);
258 sds sdsRemoveFreeSpace(sds s);
259 size_t sdsAllocSize(sds s);
260 void *sdsAllocPtr(sds s);
261 
262 /* Export the allocator used by SDS to the program using SDS.
263  * Sometimes the program SDS is linked to, may use a different set of
264  * allocators, but may want to allocate or free things that SDS will
265  * respectively free or allocate. */
266 void *sds_malloc(size_t size);
267 void *sds_realloc(void *ptr, size_t size);
268 void sds_free(void *ptr);
269 
270 #ifdef REDIS_TEST
271 int sdsTest(int argc, char *argv[]);
272 #endif
273 
274 #endif
275