Sat, 30 Apr 2022 08:30:51 +0200
#170 add cxBufferClear test
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
29 #include "cx/buffer.h"
30 #include "cx/utils.h"
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <string.h>
36 int cxBufferInit(
37 CxBuffer *buffer,
38 void *space,
39 size_t capacity,
40 CxAllocator const *allocator,
41 int flags
42 ) {
43 buffer->allocator = allocator;
44 buffer->flags = flags;
45 if (!space) {
46 buffer->bytes = cxMalloc(allocator, capacity);
47 if (buffer->bytes == NULL) {
48 return 1;
49 }
50 buffer->flags |= CX_BUFFER_FREE_CONTENTS;
51 } else {
52 buffer->bytes = space;
53 }
54 buffer->capacity = capacity;
55 buffer->size = 0;
57 buffer->pos = 0;
59 return 0;
60 }
62 void cxBufferDestroy(CxBuffer *buffer) {
63 if ((buffer->flags & CX_BUFFER_FREE_CONTENTS) == CX_BUFFER_FREE_CONTENTS) {
64 cxFree(buffer->allocator, buffer->bytes);
65 }
66 }
68 int cxBufferSeek(
69 CxBuffer *buffer,
70 off_t offset,
71 int whence
72 ) {
73 size_t npos;
74 switch (whence) {
75 case SEEK_CUR:
76 npos = buffer->pos;
77 break;
78 case SEEK_END:
79 npos = buffer->size;
80 break;
81 case SEEK_SET:
82 npos = 0;
83 break;
84 default:
85 return -1;
86 }
88 size_t opos = npos;
89 npos += offset;
91 if ((offset > 0 && npos < opos) || (offset < 0 && npos > opos)) {
92 return -1;
93 }
95 if (npos >= buffer->size) {
96 return -1;
97 } else {
98 buffer->pos = npos;
99 return 0;
100 }
102 }
104 void cxBufferClear(CxBuffer *buffer) {
105 memset(buffer->bytes, 0, buffer->size);
106 buffer->size = 0;
107 buffer->pos = 0;
108 }
110 int cxBufferEof(CxBuffer const *buffer) {
111 return buffer->pos >= buffer->size;
112 }
114 int cxBufferMinimumCapacity(
115 CxBuffer *buffer,
116 size_t newcap
117 ) {
118 if (newcap <= buffer->capacity) {
119 return 0;
120 }
122 if (cxReallocate(buffer->allocator,
123 (void **) &buffer->bytes, newcap) == 0) {
124 buffer->capacity = newcap;
125 return 0;
126 } else {
127 return -1;
128 }
129 }
131 size_t cxBufferWrite(
132 void const *ptr,
133 size_t size,
134 size_t nitems,
135 CxBuffer *buffer
136 ) {
137 size_t len;
138 if (cx_szmul(size, nitems, &len)) {
139 return 0;
140 }
141 size_t required = buffer->pos + len;
142 if (buffer->pos > required) {
143 return 0;
144 }
146 if (required > buffer->capacity) {
147 if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
148 if (cxBufferMinimumCapacity(buffer, required)) {
149 return 0;
150 }
151 } else {
152 len = buffer->capacity - buffer->pos;
153 if (size > 1) {
154 len -= len % size;
155 }
156 }
157 }
159 if (len == 0) {
160 return len;
161 }
163 memcpy(buffer->bytes + buffer->pos, ptr, len);
164 buffer->pos += len;
165 if (buffer->pos > buffer->size) {
166 buffer->size = buffer->pos;
167 }
169 return len / size;
170 }
172 size_t cxBufferRead(
173 void *ptr,
174 size_t size,
175 size_t nitems,
176 CxBuffer *buffer
177 ) {
178 size_t len;
179 if (cx_szmul(size, nitems, &len)) {
180 return 0;
181 }
182 if (buffer->pos + len > buffer->size) {
183 len = buffer->size - buffer->pos;
184 if (size > 1) len -= len % size;
185 }
187 if (len <= 0) {
188 return len;
189 }
191 memcpy(ptr, buffer->bytes + buffer->pos, len);
192 buffer->pos += len;
194 return len / size;
195 }
197 int cxBufferPut(
198 CxBuffer *buffer,
199 int c
200 ) {
201 if (buffer->pos >= buffer->capacity) {
202 if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
203 if (cxBufferMinimumCapacity(buffer, buffer->capacity + 1)) {
204 return EOF;
205 }
206 } else {
207 return EOF;
208 }
209 }
211 c &= 0xFF;
212 buffer->bytes[buffer->pos] = (unsigned char) c;
213 buffer->pos++;
214 if (buffer->pos > buffer->size) {
215 buffer->size = buffer->pos;
216 }
217 return c;
218 }
220 int cxBufferGet(CxBuffer *buffer) {
221 if (cxBufferEof(buffer)) {
222 return EOF;
223 } else {
224 int c = buffer->bytes[buffer->pos];
225 buffer->pos++;
226 return c;
227 }
228 }
230 size_t cxBufferPutString(
231 CxBuffer *buffer,
232 const char *str
233 ) {
234 return cxBufferWrite(str, 1, strlen(str), buffer);
235 }
237 int cxBufferShiftLeft(
238 CxBuffer *buffer,
239 size_t shift
240 ) {
241 if (shift >= buffer->size) {
242 buffer->pos = buffer->size = 0;
243 } else {
244 memmove(buffer->bytes, buffer->bytes + shift, buffer->size - shift);
245 buffer->size -= shift;
247 if (buffer->pos >= shift) {
248 buffer->pos -= shift;
249 } else {
250 buffer->pos = 0;
251 }
252 }
253 return 0;
254 }
256 int cxBufferShiftRight(
257 CxBuffer *buffer,
258 size_t shift
259 ) {
260 size_t req_capacity = buffer->size + shift;
261 size_t movebytes;
263 // auto extend buffer, if required and enabled
264 if (buffer->capacity < req_capacity) {
265 if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
266 if (cxBufferMinimumCapacity(buffer, req_capacity)) {
267 return 1;
268 }
269 movebytes = buffer->size;
270 } else {
271 movebytes = buffer->capacity - shift;
272 }
273 } else {
274 movebytes = buffer->size;
275 }
277 memmove(buffer->bytes + shift, buffer->bytes, movebytes);
278 buffer->size = shift + movebytes;
280 buffer->pos += shift;
281 if (buffer->pos > buffer->size) {
282 buffer->pos = buffer->size;
283 }
285 return 0;
286 }
288 int cxBufferShift(
289 CxBuffer *buffer,
290 off_t shift
291 ) {
292 if (shift < 0) {
293 return cxBufferShiftLeft(buffer, (size_t) (-shift));
294 } else if (shift > 0) {
295 return cxBufferShiftRight(buffer, (size_t) shift);
296 } else {
297 return 0;
298 }
299 }