mdw@git.distorted.org.uk Git - mLib/blob - struct/buf.c

   1 /* -*-c-*-
   2  *
   3  * Buffer handling
   4  *
   5  * (c) 2001 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include <string.h>
  31
  32 #include "buf.h"
  33 #include "growbuf.h"
  34 #include "macros.h"
  35
  36 /*----- Main code ---------------------------------------------------------*/
  37
  38 /* --- @buf_init@ --- *
  39  *
  40  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
  41  *              @void *p@ = pointer to a buffer
  42  *              @size_t sz@ = size of the buffer
  43  *
  44  * Returns:     ---
  45  *
  46  * Use:         Initializes the buffer block appropriately.
  47  */
  48
  49 void buf_init(buf *b, void *p, size_t sz)
  50 {
  51   b->base = b->p = p;
  52   b->limit = b->p + sz;
  53   b->f = 0;
  54 }
  55
  56 /* --- @dbuf_create@ --- *
  57  *
  58  * Arguments:   @dbuf *db@ = pointer to a dynamic buffer block
  59  *
  60  * Returns:     ---
  61  *
  62  * Use:         Initializes a dynamic buffer.  The buffer is initially empty,
  63  *              and ready for writing.
  64  */
  65
  66 void dbuf_create(dbuf *db) { DBCREATE(db); }
  67
  68 /* --- @dbuf_reset@ --- *
  69  *
  70  * Arguments:   @dbuf *db@ = pointer to a buffer block
  71  *
  72  * Returns:     ---
  73  *
  74  * Use:         Resets a buffer so that it can be written again.
  75  */
  76
  77 void dbuf_reset(dbuf *db) { DBRESET(db); }
  78
  79 /* --- @dbuf_destroy@ --- *
  80  *
  81  * Arguments:   @dbuf *db@ = pointer to a buffer block
  82  *
  83  * Returns:     ---
  84  *
  85  * Use:         Release all of the resources held by a dynamic buffer.
  86  */
  87
  88 void dbuf_destroy(dbuf *db) { DBDESTROY(db); }
  89
  90 /* --- @{,d}buf_break@ --- *
  91  *
  92  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
  93  *
  94  * Returns:     Some negative value.
  95  *
  96  * Use:         Marks a buffer as broken.
  97  */
  98
  99 int buf_break(buf *b) { BBREAK(b); return (-1); }
 100 int (dbuf_break)(dbuf *db) { DBBREAK(db); return (-1); }
 101
 102 /* --- @{,d}buf_flip@ --- *
 103  *
 104  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 105  *
 106  * Returns:     ---
 107  *
 108  * Use:         Flips a buffer so that if you've just been writing to it,
 109  *              you can now read from the bit you've written.
 110  */
 111
 112 void buf_flip(buf *b) { BFLIP(b); }
 113 void (dbuf_flip)(dbuf *db) { DBFLIP(db); }
 114
 115 /* --- @{,d}buf_ensure@ --- *
 116  *
 117  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 118  *              @size_t sz@ = size of data wanted
 119  *
 120  * Returns:     Zero if it worked, nonzero if there wasn't enough space.
 121  *
 122  * Use:         Ensures that there are @sz@ bytes still in the buffer.
 123  */
 124
 125 int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); }
 126 int (dbuf_ensure)(dbuf *db, size_t sz) { return (dbuf_ensure(db, sz)); }
 127
 128 /* --- @{,d}buf_tryextend@ --- *
 129  *
 130  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 131  *              @size_t sz@ = size of data wanted
 132  *
 133  * Returns:     Zero if it worked, nonzero if the buffer won't grow.
 134  *
 135  * Use:         Extend the buffer so that at least @sz@ bytes are available.
 136  *              This only works if the buffer is allocated.
 137  */
 138
 139 int buf_tryextend(buf *b, size_t sz)
 140 {
 141   dbuf *db;
 142   size_t want, len;
 143
 144   if (sz <= BLEFT(b)) return (0);
 145   if (~b->f&(BF_ALLOC | BF_WRITE)) { b->f |= BF_BROKEN; return (-1); }
 146
 147   db = (dbuf *)b; len = DBLEN(db); want = sz + len;
 148   if (db->sz < want) {
 149     GROWBUF_EXTEND(db->a, db->_b.base, db->sz, want, 64, 1);
 150     db->_b.p = db->_b.base + len;
 151   }
 152   db->_b.limit = db->_b.base + db->sz;
 153   return (0);
 154 }
 155 int (dbuf_tryextend)(dbuf *db, size_t sz)
 156   { return (dbuf_tryextend(db, sz)); }
 157
 158 /* --- @{,d}buf_get@ --- *
 159  *
 160  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 161  *              @size_t sz@ = size of the buffer
 162  *
 163  * Returns:     Pointer to the place in the buffer.
 164  *
 165  * Use:         Reserves a space in the buffer of the requested size, and
 166  *              returns its start address.
 167  */
 168
 169 void *buf_get(buf *b, size_t sz)
 170 {
 171   void *p;
 172   if (BENSURE(b, sz))
 173     return (0);
 174   p = BCUR(b);
 175   BSTEP(b, sz);
 176   return (p);
 177 }
 178 void *(dbuf_get)(dbuf *db, size_t sz)
 179   { return (dbuf_get(db, sz)); }
 180
 181 /* --- @{,d}buf_put@ --- *
 182  *
 183  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 184  *              @const void *p@ = pointer to a buffer
 185  *              @size_t sz@ = size of the buffer
 186  *
 187  * Returns:     Zero if it worked, nonzero if there wasn't enough space.
 188  *
 189  * Use:         Fetches data from some place and puts it in the buffer
 190  */
 191
 192 int buf_put(buf *b, const void *p, size_t sz)
 193 {
 194   if (BENSURE(b, sz))
 195     return (-1);
 196   memcpy(BCUR(b), p, sz);
 197   BSTEP(b, sz);
 198   return (0);
 199 }
 200 int (dbuf_put)(dbuf *db, const void *p, size_t sz)
 201   { return (dbuf_put(db, p, sz)); }
 202
 203 /* --- @{,d}buf_getbyte@ --- *
 204  *
 205  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 206  *
 207  * Returns:     A byte, or less than zero if there wasn't a byte there.
 208  *
 209  * Use:         Gets a single byte from a buffer.
 210  */
 211
 212 int buf_getbyte(buf *b)
 213 {
 214   if (BENSURE(b, 1))
 215     return (-1);
 216   return (*b->p++);
 217 }
 218 int (dbuf_getbyte)(dbuf *db)
 219   { return (dbuf_getbyte(db)); }
 220
 221 /* --- @{,d}buf_putbyte@ --- *
 222  *
 223  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 224  *              @int ch@ = byte to write
 225  *
 226  * Returns:     Zero if OK, nonzero if there wasn't enough space.
 227  *
 228  * Use:         Puts a single byte in a buffer.
 229  */
 230
 231 int buf_putbyte(buf *b, int ch)
 232 {
 233   if (BENSURE(b, 1))
 234     return (-1);
 235   *b->p++ = ch;
 236   return (0);
 237 }
 238 int (dbuf_putbyte)(dbuf *db, int ch)
 239   { return (dbuf_putbyte(db, ch)); }
 240
 241 /* --- @{,d}buf_getu{8,{16,24,32,64}{,l,b}}@ --- *
 242  *
 243  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 244  *              @uintSZ *w@ = where to put the word
 245  *
 246  * Returns:     Zero if OK, or nonzero if there wasn't a word there.
 247  *
 248  * Use:         Gets a word of appropriate size and order from a buffer.
 249  */
 250
 251 #define BUF_GETU_(n, W, w)                                              \
 252   int buf_getu##w(buf *b, uint##n *ww)                                  \
 253   {                                                                     \
 254     if (BENSURE(b, SZ_##W)) return (-1);                                \
 255     *ww = LOAD##W(b->p);                                                \
 256     BSTEP(b, SZ_##W);                                                   \
 257     return (0);                                                         \
 258   }                                                                     \
 259   int (dbuf_getu##w)(dbuf *db, uint##n *ww)                             \
 260     { return (dbuf_getu##w(db, ww)); }
 261 DOUINTCONV(BUF_GETU_)
 262
 263 /* --- @{,d}buf_getk64{,l,b}@ --- *
 264  *
 265  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 266  *              @kludge64 *w@ = where to put the word
 267  *
 268  * Returns:     Zero if OK, or nonzero if there wasn't a word there.
 269  *
 270  * Use:         Gets a word of appropriate size and order from a buffer.
 271  */
 272
 273 int buf_getk64(buf *b, kludge64 *w)
 274 {
 275   if (BENSURE(b, 8)) return (-1);
 276   LOAD64_(*w, b->p); BSTEP(b, 8); return (0);
 277 }
 278
 279 int buf_getk64l(buf *b, kludge64 *w)
 280 {
 281   if (BENSURE(b, 8)) return (-1);
 282   LOAD64_L_(*w, b->p); BSTEP(b, 8); return (0);
 283 }
 284
 285 int buf_getk64b(buf *b, kludge64 *w)
 286 {
 287   if (BENSURE(b, 8)) return (-1);
 288   LOAD64_B_(*w, b->p); BSTEP(b, 8); return (0);
 289 }
 290
 291 int (dbuf_getk64)(dbuf *db, kludge64 *w) { return (dbuf_getk64(db, w)); }
 292 int (dbuf_getk64l)(dbuf *db, kludge64 *w) { return (dbuf_getk64l(db, w)); }
 293 int (dbuf_getk64b)(dbuf *db, kludge64 *w) { return (dbuf_getk64b(db, w)); }
 294
 295 /* --- @{,d}buf_putu{8,{16,24,32,64}{,l,b}}@ --- *
 296  *
 297  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 298  *              @uintSZ w@ = word to write
 299  *
 300  * Returns:     Zero if OK, or nonzero if there wasn't enough space
 301  *
 302  * Use:         Puts a word into a buffer with appropriate size and order.
 303  */
 304
 305 #define BUF_PUTU_(n, W, w)                                              \
 306   int buf_putu##w(buf *b, uint##n ww)                                   \
 307   {                                                                     \
 308     if (BENSURE(b, SZ_##W)) return (-1);                                \
 309     STORE##W(b->p, ww);                                                 \
 310     BSTEP(b, SZ_##W);                                                   \
 311     return (0);                                                         \
 312   }                                                                     \
 313   int (dbuf_putu##w)(dbuf *db, uint##n ww)                              \
 314     { return (dbuf_putu##w(db, ww)); }
 315 DOUINTCONV(BUF_PUTU_)
 316
 317 /* --- @{,d}buf_putk64{,l,b}@ --- *
 318  *
 319  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 320  *              @kludge64 w@ = word to write
 321  *
 322  * Returns:     Zero if OK, or nonzero if there wasn't enough space
 323  *
 324  * Use:         Gets a word of appropriate size and order from a buffer.
 325  */
 326
 327 int buf_putk64(buf *b, kludge64 w)
 328 {
 329   if (BENSURE(b, 8)) return (-1);
 330   STORE64_(b->p, w); BSTEP(b, 8); return (0);
 331 }
 332
 333 int buf_putk64l(buf *b, kludge64 w)
 334 {
 335   if (BENSURE(b, 8)) return (-1);
 336   STORE64_L_(b->p, w); BSTEP(b, 8); return (0);
 337 }
 338
 339 int buf_putk64b(buf *b, kludge64 w)
 340 {
 341   if (BENSURE(b, 8)) return (-1);
 342   STORE64_B_(b->p, w); BSTEP(b, 8); return (0);
 343 }
 344
 345 int (dbuf_putk64)(dbuf *db, kludge64 w) { return (dbuf_putk64(db, w)); }
 346 int (dbuf_putk64l)(dbuf *db, kludge64 w) { return (dbuf_putk64l(db, w)); }
 347 int (dbuf_putk64b)(dbuf *db, kludge64 w) { return (dbuf_putk64b(db, w)); }
 348
 349 /* --- @findz@ --- *
 350  *
 351  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 352  *              @size_t *nn@ = where to put the length
 353  *
 354  * Returns:     Zero if OK, nonzero if there wasn't a null byte to be found.
 355  *
 356  * Use:         Finds a terminating null byte.  The length includes this
 357  *              terminator.
 358  */
 359
 360 static int findz(buf *b, size_t *nn)
 361 {
 362   octet *p;
 363
 364   if ((p = memchr(BCUR(b), 0, BLEFT(b))) == 0) { BBREAK(b); return (-1); }
 365   *nn = p - BCUR(b) + 1;
 366   return (0);
 367 }
 368
 369 /* --- @{,d}buf_getmem{8,{16,24,32,64}{,l,b},z} --- *
 370  *
 371  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 372  *              @size_t *nn@ = where to put the length
 373  *
 374  * Returns:     Pointer to the buffer data, or null.
 375  *
 376  * Use:         Gets a chunk of memory from a buffer.  The suffix is the
 377  *              width and byte order of the length; @z@ means null-
 378  *              terminated.
 379  */
 380
 381 #define BUF_GETMEM_(n, W, w)                                            \
 382   void *buf_getmem##w(buf *b, size_t *nn)                               \
 383   {                                                                     \
 384     uint##n sz;                                                         \
 385     if (buf_getu##w(b, &sz)) return (0);                                \
 386     if (BENSURE(b, sz)) return (0);                                     \
 387     *nn = sz;                                                           \
 388     return (buf_get(b, sz));                                            \
 389   }                                                                     \
 390   void *(dbuf_getmem##w)(dbuf *db, size_t *nn)                          \
 391     { return (dbuf_getmem##w(db, nn)); }
 392 DOUINTCONV(BUF_GETMEM_)
 393
 394 void *buf_getmemz(buf *b, size_t *nn)
 395 {
 396   if (findz(b, nn)) return (0);
 397   return (buf_get(b, *nn));
 398 }
 399 void *(dbuf_getmemz)(dbuf *db, size_t *nn)
 400   { return (dbuf_getmemz(db, nn)); }
 401
 402 #ifndef HAVE_UINT64
 403
 404 static void *getmem_k64(buf *b, size_t *nn_out, kludge64 k)
 405 {
 406   kludge64 szmax;
 407   size_t n;
 408
 409   ASSIGN64(szmax, (size_t)-1);
 410   if (CMP64(k, >, szmax)) { BBREAK(b); return (-1); }
 411   n = GET64(size_t, k); *nn_out = n; return (buf_get(b, n));
 412 }
 413
 414 void *buf_getmem64(buf *b, size_t *nn)
 415 {
 416   kludge64 k;
 417
 418   if (buf_getk64(b, &k)) return (-1);
 419   return (getmem_k64(b, nn, k));
 420 }
 421
 422 void *buf_getmem64l(buf *b, size_t *nn)
 423 {
 424   kludge64 k;
 425
 426   if (buf_getk64l(b, &k)) return (-1);
 427   return (getmem_k64(b, nn, k));
 428 }
 429
 430 void *buf_getmem64b(buf *b, size_t *nn)
 431 {
 432   kludge64 k;
 433
 434   if (buf_getk64b(b, &k)) return (-1);
 435   return (getmem_k64(b, nn, k));
 436 }
 437
 438 void *(dbuf_getmem64)(dbuf *db, size_t *nn)
 439   { return (dbuf_getmem64(db, nn)); }
 440 void *(dbuf_getmem64l)(dbuf *db, size_t *nn)
 441   { return (dbuf_getmem64l(db, nn)); }
 442 void *(dbuf_getmem64b)(dbuf *db, size_t *nn)
 443   { return (dbuf_getmem64b(db, nn)); }
 444
 445 #endif
 446
 447 /* --- @{,d}buf_putmem{8,{16,24,32,64}{,l,b},z} --- *
 448  *
 449  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 450  *              @const void *p@ = pointer to data to write
 451  *              @size_t n@ = length to write
 452  *
 453  * Returns:     Zero if OK, nonzero if there wasn't enough space.
 454  *
 455  * Use:         Writes a chunk of data to a buffer.  The suffix is the
 456  *              width and byte order of the length; @z@ means null-
 457  *              terminated.
 458  */
 459
 460 #define BUF_PUTMEM_(n, W, w)                                            \
 461   int buf_putmem##w(buf *b, const void *p, size_t sz)                   \
 462   {                                                                     \
 463     MUFFLE_WARNINGS_STMT                                                \
 464       (CLANG_WARNING("-Wtautological-constant-out-of-range-compare"),   \
 465        { if (sz > MASK##W) { BBREAK(b); return (-1); } });              \
 466     if (buf_putu##w(b, sz) || buf_put(b, p, sz))                        \
 467       return (-1);                                                      \
 468     return (0);                                                         \
 469   }                                                                     \
 470   int (dbuf_putmem##w)(dbuf *db, const void *p, size_t sz)              \
 471     { return (dbuf_putmem##w(db, p, sz)); }
 472 DOUINTCONV(BUF_PUTMEM_)
 473
 474 #ifndef HAVE_UINT64
 475
 476 void *buf_putmem64(buf *b, const void *p, size_t n)
 477 {
 478   kludge64 k;
 479
 480   ASSIGN64(k, n); if (buf_putk64(b, k) || buf_put(b, p, n)) return (-1);
 481   return (0);
 482 }
 483
 484 void *buf_putmem64l(buf *b, const void *p, size_t n)
 485 {
 486   kludge64 k;
 487
 488   ASSIGN64(k, n); if (buf_putk64l(b, k) || buf_put(b, p, n)) return (-1);
 489   return (0);
 490 }
 491
 492 void *buf_putmem64b(buf *b, const void *p, size_t n)
 493 {
 494   kludge64 k;
 495
 496   ASSIGN64(k, n); if (buf_putk64b(b, k) || buf_put(b, p, n)) return (-1);
 497   return (0);
 498 }
 499
 500 int (dbuf_putmem64)(dbuf *db, const void *p, size_t n)
 501   { return (dbuf_putmem64(db, p, n)); }
 502 int (dbuf_putmem64l)(dbuf *db, const void *p, size_t n)
 503   { return (dbuf_putmem64l(db, p, n)); }
 504 int (dbuf_putmem64b)(dbuf *db, const void *p, size_t n)
 505   { return (dbuf_putmem64b(db, p, n)); }
 506
 507 #endif
 508
 509 int buf_putmemz(buf *b, const void *p, size_t n)
 510 {
 511   octet *q;
 512
 513   if (memchr(p, 0, n)) { BBREAK(b); return (-1); }
 514   if ((q = buf_get(b, n + 1)) == 0)
 515     return (-1);
 516   memcpy(q, p, n);
 517   q[n] = 0;
 518   return (0);
 519 }
 520 int (dbuf_putmemz)(dbuf *db, const void *p, size_t n)
 521   { return (dbuf_putmemz(db, p, n)); }
 522
 523 /* --- @{,d}buf_getbuf{8,{16,24,32,64}{,l,b},z} --- *
 524  *
 525  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 526  *              @buf *bb@ = where to put the result
 527  *
 528  * Returns:     Zero if it worked, nonzero if there wasn't enough space.
 529  *
 530  * Use:         Gets a block of data from a buffer, and writes its bounds to
 531  *              another buffer.
 532  */
 533
 534 #define BUF_GETBUF_(n, W, w)                                            \
 535   int buf_getbuf##w(buf *b, buf *bb)                                    \
 536   {                                                                     \
 537     void *p;                                                            \
 538     size_t sz;                                                          \
 539                                                                         \
 540     if ((p = buf_getmem##w(b, &sz)) == 0)                               \
 541       return (-1);                                                      \
 542     buf_init(bb, p, sz);                                                \
 543     return (0);                                                         \
 544   }                                                                     \
 545   int (dbuf_getbuf##w)(dbuf *db, buf *bb)                               \
 546     { return (dbuf_getbuf##w(db, bb)); }
 547 BUF_DOSUFFIXES(BUF_GETBUF_)
 548
 549 /* --- @{,d}buf_putbuf{8,{16,24,32,64}{,l,b},z} --- *
 550  *
 551  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 552  *              @buf *bb@ = buffer to write
 553  *
 554  * Returns:     Zero if it worked, nonzero if there wasn't enough space.
 555  *
 556  * Use:         Puts the contents of a buffer to a buffer.
 557  */
 558
 559 #define BUF_PUTBUF_(n, W, w)                                            \
 560   int buf_putbuf##w(buf *b, buf *bb)                                    \
 561     { return (buf_putmem##w(b, BBASE(bb), BLEN(bb))); }                 \
 562   int (dbuf_putbuf##w)(dbuf *db, buf *bb)                               \
 563     { return (dbuf_putbuf##w(db, bb)); }
 564 BUF_DOSUFFIXES(BUF_PUTBUF_)
 565
 566 /* --- @{,d}buf_putstr{8,{16,24,32,64}{,l,b},z} --- *
 567  *
 568  * Arguments:   @buf *b@ or @dbuf *db@ = pointer to a buffer block
 569  *              @const char *p@ = string to write
 570  *
 571  * Returns:     Zero if it worked, nonzero if there wasn't enough space.
 572  *
 573  * Use:         Puts a null-terminated string to a buffer.
 574  */
 575
 576 #define BUF_PUTSTR_(n, W, w)                                            \
 577   int buf_putstr##w(buf *b, const char *p)                              \
 578     { return (buf_putmem##w(b, p, strlen(p))); }                        \
 579   int (dbuf_putstr##w)(dbuf *db, const char *p)                         \
 580     { return (dbuf_putstr##w(db, p)); }
 581 BUF_DOSUFFIXES(BUF_PUTSTR_)
 582
 583 /*----- That's all, folks -------------------------------------------------*/