Tue, 07 Feb 2023 21:53:06 +0100
fix README showing how tests were run in the automake era
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 <stdio.h>
33 #include <string.h>
35 int cxBufferInit(
36 CxBuffer *buffer,
37 void *space,
38 size_t capacity,
39 CxAllocator const *allocator,
40 int flags
41 ) {
42 buffer->allocator = allocator;
43 buffer->flags = flags;
44 if (!space) {
45 buffer->bytes = cxMalloc(allocator, capacity);
46 if (buffer->bytes == NULL) {
47 return 1;
48 }
49 buffer->flags |= CX_BUFFER_FREE_CONTENTS;
50 } else {
51 buffer->bytes = space;
52 }
53 buffer->capacity = capacity;
54 buffer->size = 0;
55 buffer->pos = 0;
57 buffer->flush_func = NULL;
58 buffer->flush_target = NULL;
59 buffer->flush_blkmax = 0;
60 buffer->flush_blksize = 4096;
61 buffer->flush_threshold = SIZE_MAX;
63 return 0;
64 }
66 void cxBufferDestroy(CxBuffer *buffer) {
67 if ((buffer->flags & CX_BUFFER_FREE_CONTENTS) == CX_BUFFER_FREE_CONTENTS) {
68 cxFree(buffer->allocator, buffer->bytes);
69 }
70 }
72 int cxBufferSeek(
73 CxBuffer *buffer,
74 off_t offset,
75 int whence
76 ) {
77 size_t npos;
78 switch (whence) {
79 case SEEK_CUR:
80 npos = buffer->pos;
81 break;
82 case SEEK_END:
83 npos = buffer->size;
84 break;
85 case SEEK_SET:
86 npos = 0;
87 break;
88 default:
89 return -1;
90 }
92 size_t opos = npos;
93 npos += offset;
95 if ((offset > 0 && npos < opos) || (offset < 0 && npos > opos)) {
96 return -1;
97 }
99 if (npos >= buffer->size) {
100 return -1;
101 } else {
102 buffer->pos = npos;
103 return 0;
104 }
106 }
108 void cxBufferClear(CxBuffer *buffer) {
109 memset(buffer->bytes, 0, buffer->size);
110 buffer->size = 0;
111 buffer->pos = 0;
112 }
114 int cxBufferEof(CxBuffer const *buffer) {
115 return buffer->pos >= buffer->size;
116 }
118 int cxBufferMinimumCapacity(
119 CxBuffer *buffer,
120 size_t newcap
121 ) {
122 if (newcap <= buffer->capacity) {
123 return 0;
124 }
126 if (cxReallocate(buffer->allocator,
127 (void **) &buffer->bytes, newcap) == 0) {
128 buffer->capacity = newcap;
129 return 0;
130 } else {
131 return -1;
132 }
133 }
135 /**
136 * Helps flushing data to the flush target of a buffer.
137 *
138 * @param buffer the buffer containing the config
139 * @param space the data to flush
140 * @param size the element size
141 * @param nitems the number of items
142 * @return the number of items flushed
143 */
144 static size_t cx_buffer_write_flush_helper(
145 CxBuffer *buffer,
146 unsigned char const *space,
147 size_t size,
148 size_t nitems
149 ) {
150 size_t pos = 0;
151 size_t remaining = nitems;
152 size_t max_items = buffer->flush_blksize / size;
153 while (remaining > 0) {
154 size_t items = remaining > max_items ? max_items : remaining;
155 size_t flushed = buffer->flush_func(
156 space + pos,
157 size, items,
158 buffer->flush_target);
159 if (flushed > 0) {
160 pos += (flushed * size);
161 remaining -= flushed;
162 } else {
163 // if no bytes can be flushed out anymore, we give up
164 break;
165 }
166 }
167 return nitems - remaining;
168 }
170 size_t cxBufferWrite(
171 void const *ptr,
172 size_t size,
173 size_t nitems,
174 CxBuffer *buffer
175 ) {
176 // optimize for easy case
177 if (size == 1 && (buffer->capacity - buffer->pos) >= nitems) {
178 memcpy(buffer->bytes + buffer->pos, ptr, nitems);
179 buffer->pos += nitems;
180 if (buffer->pos > buffer->size) {
181 buffer->size = buffer->pos;
182 }
183 return nitems;
184 }
186 size_t len;
187 size_t nitems_out = nitems;
188 if (cx_szmul(size, nitems, &len)) {
189 return 0;
190 }
191 size_t required = buffer->pos + len;
192 if (buffer->pos > required) {
193 return 0;
194 }
196 bool perform_flush = false;
197 if (required > buffer->capacity) {
198 if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND && required) {
199 if (buffer->flush_blkmax > 0 && required > buffer->flush_threshold) {
200 perform_flush = true;
201 } else {
202 if (cxBufferMinimumCapacity(buffer, required)) {
203 return 0;
204 }
205 }
206 } else {
207 if (buffer->flush_blkmax > 0) {
208 perform_flush = true;
209 } else {
210 // truncate data to be written, if we can neither extend nor flush
211 len = buffer->capacity - buffer->pos;
212 if (size > 1) {
213 len -= len % size;
214 }
215 nitems_out = len / size;
216 }
217 }
218 }
220 if (len == 0) {
221 return len;
222 }
224 if (perform_flush) {
225 size_t flush_max;
226 if (cx_szmul(buffer->flush_blkmax, buffer->flush_blksize, &flush_max)) {
227 return 0;
228 }
229 size_t flush_pos = buffer->flush_func == NULL || buffer->flush_target == NULL
230 ? buffer->pos
231 : cx_buffer_write_flush_helper(buffer, buffer->bytes, 1, buffer->pos);
232 if (flush_pos == buffer->pos) {
233 // entire buffer has been flushed, we can reset
234 buffer->size = buffer->pos = 0;
236 size_t items_flush; // how many items can also be directly flushed
237 size_t items_keep; // how many items have to be written to the buffer
239 items_flush = flush_max >= required ? nitems : (flush_max - flush_pos) / size;
240 if (items_flush > 0) {
241 items_flush = cx_buffer_write_flush_helper(buffer, ptr, size, items_flush / size);
242 // in case we could not flush everything, keep the rest
243 }
244 items_keep = nitems - items_flush;
245 if (items_keep > 0) {
246 // try again with the remaining stuff
247 unsigned char const *new_ptr = ptr;
248 new_ptr += items_flush * size;
249 // report the directly flushed items as written plus the remaining stuff
250 return items_flush + cxBufferWrite(new_ptr, size, items_keep, buffer);
251 } else {
252 // all items have been flushed - report them as written
253 return nitems;
254 }
255 } else if (flush_pos == 0) {
256 // nothing could be flushed at all, we immediately give up without writing any data
257 return 0;
258 } else {
259 // we were partially successful, we shift left and try again
260 cxBufferShiftLeft(buffer, flush_pos);
261 return cxBufferWrite(ptr, size, nitems, buffer);
262 }
263 } else {
264 memcpy(buffer->bytes + buffer->pos, ptr, len);
265 buffer->pos += len;
266 if (buffer->pos > buffer->size) {
267 buffer->size = buffer->pos;
268 }
269 return nitems_out;
270 }
272 }
274 int cxBufferPut(
275 CxBuffer *buffer,
276 int c
277 ) {
278 c &= 0xFF;
279 unsigned char const ch = c;
280 if (cxBufferWrite(&ch, 1, 1, buffer) == 1) {
281 return c;
282 } else {
283 return EOF;
284 }
285 }
287 size_t cxBufferPutString(
288 CxBuffer *buffer,
289 const char *str
290 ) {
291 return cxBufferWrite(str, 1, strlen(str), buffer);
292 }
294 size_t cxBufferRead(
295 void *ptr,
296 size_t size,
297 size_t nitems,
298 CxBuffer *buffer
299 ) {
300 size_t len;
301 if (cx_szmul(size, nitems, &len)) {
302 return 0;
303 }
304 if (buffer->pos + len > buffer->size) {
305 len = buffer->size - buffer->pos;
306 if (size > 1) len -= len % size;
307 }
309 if (len <= 0) {
310 return len;
311 }
313 memcpy(ptr, buffer->bytes + buffer->pos, len);
314 buffer->pos += len;
316 return len / size;
317 }
319 int cxBufferGet(CxBuffer *buffer) {
320 if (cxBufferEof(buffer)) {
321 return EOF;
322 } else {
323 int c = buffer->bytes[buffer->pos];
324 buffer->pos++;
325 return c;
326 }
327 }
329 int cxBufferShiftLeft(
330 CxBuffer *buffer,
331 size_t shift
332 ) {
333 if (shift >= buffer->size) {
334 buffer->pos = buffer->size = 0;
335 } else {
336 memmove(buffer->bytes, buffer->bytes + shift, buffer->size - shift);
337 buffer->size -= shift;
339 if (buffer->pos >= shift) {
340 buffer->pos -= shift;
341 } else {
342 buffer->pos = 0;
343 }
344 }
345 return 0;
346 }
348 int cxBufferShiftRight(
349 CxBuffer *buffer,
350 size_t shift
351 ) {
352 size_t req_capacity = buffer->size + shift;
353 size_t movebytes;
355 // auto extend buffer, if required and enabled
356 if (buffer->capacity < req_capacity) {
357 if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
358 if (cxBufferMinimumCapacity(buffer, req_capacity)) {
359 return 1;
360 }
361 movebytes = buffer->size;
362 } else {
363 movebytes = buffer->capacity - shift;
364 }
365 } else {
366 movebytes = buffer->size;
367 }
369 memmove(buffer->bytes + shift, buffer->bytes, movebytes);
370 buffer->size = shift + movebytes;
372 buffer->pos += shift;
373 if (buffer->pos > buffer->size) {
374 buffer->pos = buffer->size;
375 }
377 return 0;
378 }
380 int cxBufferShift(
381 CxBuffer *buffer,
382 off_t shift
383 ) {
384 if (shift < 0) {
385 return cxBufferShiftLeft(buffer, (size_t) (-shift));
386 } else if (shift > 0) {
387 return cxBufferShiftRight(buffer, (size_t) shift);
388 } else {
389 return 0;
390 }
391 }