ulut/ul_cbuff.h

   1 /*******************************************************************
   2   uLan Utilities Library - C library of basic reusable constructions
   3
   4   ul_cbuff.h    - circular buffer
   5
   6   (C) Copyright 2006 by Pavel Pisa - Originator
   7
   8   The uLan utilities library can be used, copied and modified under
   9   next licenses
  10     - GPL - GNU General Public License
  11     - LGPL - GNU Lesser General Public License
  12     - MPL - Mozilla Public License
  13     - and other licenses added by project originators
  14   Code can be modified and re-distributed under any combination
  15   of the above listed licenses. If contributor does not agree with
  16   some of the licenses, he/she can delete appropriate line.
  17   Warning, if you delete all lines, you are not allowed to
  18   distribute source code and/or binaries utilizing code.
  19
  20   See files COPYING and README for details.
  21
  22  *******************************************************************/
  23
  24 #ifndef _UL_CBUFF_H
  25 #define _UL_CBUFF_H
  26
  27 #include "ul_utdefs.h"
  28
  29 #include <string.h>
  30
  31 #ifdef __cplusplus
  32 extern "C" {
  33 #endif
  34
  35 #define UL_CBUFF_NO_INLINE
  36
  37 #ifndef UL_CBUFF_NO_INLINE
  38 #define UL_CBUFF_INLINE
  39 #endif
  40
  41 #ifndef ul_cbuff_inline
  42 #ifdef UL_CBUFF_INLINE
  43 #define ul_cbuff_inline static inline
  44 #else
  45 #define ul_cbuff_inline
  46 #endif
  47 #endif
  48
  49 #define ul_cbuff_align(x) (((x)+3)&~3)
  50
  51 typedef unsigned int ul_cbuff_loc_t;
  52
  53 typedef struct ul_cbuff_msg_head_t {
  54   unsigned short flags;
  55   unsigned short length;
  56 } ul_cbuff_msg_head_t;
  57
  58 #define UL_CBUFF_MSG_READY    0x8000
  59 #define UL_CBUFF_MSG_OVERFLOW 0x4000
  60 #define UL_CBUFF_MSG_READERS  0x3fff
  61
  62 #define ul_cbuff_msg_head_size (ul_cbuff_align(sizeof(ul_cbuff_msg_head_t)))
  63
  64 typedef struct ul_cbuff_state_t {
  65   ul_cbuff_loc_t buff_size;
  66   ul_cbuff_loc_t head;
  67   ul_cbuff_loc_t lasttail;
  68   ul_cbuff_loc_t firsttail;
  69   unsigned int   cycles;
  70   unsigned int   readers;
  71   ul_cbuff_loc_t rear_size;
  72 } ul_cbuff_state_t;
  73
  74 typedef struct ul_cbuff_t {
  75   unsigned char    *buff_start;
  76   ul_cbuff_state_t *state;
  77 } ul_cbuff_t;
  78
  79 typedef struct ul_cbuff_data_info_t {
  80   unsigned char *ptr;
  81   unsigned char *wrap_ptr;
  82   unsigned int  cont_len;
  83   unsigned int  wrap_len;
  84 } ul_cbuff_data_info_t;
  85
  86 typedef struct ul_cbuff_put_info_t {
  87   ul_cbuff_data_info_t data;
  88   ul_cbuff_msg_head_t *msg_head;
  89 } ul_cbuff_put_info_t;
  90
  91 typedef struct ul_cbuff_tail_info_t {
  92   ul_cbuff_data_info_t data;
  93   ul_cbuff_msg_head_t *msg_head;
  94 } ul_cbuff_tail_info_t;
  95
  96 #if !defined(UL_CBUFF_INLINE)
  97
  98 void ul_cbuff_mark_ready(ul_cbuff_msg_head_t *msg);
  99 int ul_cbuff_is_ready(const ul_cbuff_msg_head_t *msg);
 100 int ul_cbuff_head_alloc(ul_cbuff_t *buff, ul_cbuff_put_info_t *put_info, unsigned int size, unsigned int flags);
 101 int ul_cbuff_head_put(ul_cbuff_t *buff, ul_cbuff_put_info_t *put_info);
 102 ul_cbuff_loc_t ul_cbuff_head_loc(const ul_cbuff_t *buff, const ul_cbuff_msg_head_t *msg_head);
 103 ul_cbuff_loc_t ul_cbuff_next_loc(const ul_cbuff_t *buff, const ul_cbuff_msg_head_t *msg_head);
 104 int ul_cbuff_msg_head2data(const ul_cbuff_t *buff, ul_cbuff_data_info_t *data, const ul_cbuff_msg_head_t *msg_head);
 105 int ul_cbuff_tail_attach(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info, int mode);
 106 int ul_cbuff_tail_incontact(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info);
 107 int ul_cbuff_tail_test(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info);
 108 int ul_cbuff_tail_release(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info);
 109 int ul_cbuff_tail_next(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info);
 110 int ul_cbuff_tail_state_update(ul_cbuff_t *buff, int release_result, ul_cbuff_loc_t loc, ul_cbuff_loc_t loc_next);
 111 int ul_cbuff_tail_detach_onestep(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info);
 112 void ul_cbuff_data_do_wrap(ul_cbuff_data_info_t *data_info);
 113 int ul_cbuff_data_at_once(ul_cbuff_data_info_t *data_info, void **pptr, int size);
 114 int ul_cbuff_put_data(ul_cbuff_data_info_t *data_info, const void *data, int size);
 115 int ul_cbuff_get_data(ul_cbuff_data_info_t *data_info, void *data, int size);
 116 void *ul_cbuff_get_rear_ptr(ul_cbuff_t *buff, ul_cbuff_msg_head_t *msg_head);
 117 void *ul_cbuff_prev_rear_ptr(ul_cbuff_t *buff, ul_cbuff_loc_t loc);
 118
 119 #endif /* UL_CBUFF_INLINE */
 120
 121 #if defined(UL_CBUFF_INLINE) || defined(UL_CBUFF_INCLUDE_INTERNAL)
 122
 123 ul_cbuff_inline void
 124 ul_cbuff_mark_ready(ul_cbuff_msg_head_t *msg)
 125 {
 126   msg->flags|=UL_CBUFF_MSG_READY;
 127 }
 128
 129 ul_cbuff_inline int
 130 ul_cbuff_is_ready(const ul_cbuff_msg_head_t *msg)
 131 {
 132   return msg->flags&UL_CBUFF_MSG_READY;
 133 }
 134
 135 ul_cbuff_inline int
 136 ul_cbuff_head_alloc(ul_cbuff_t *buff, ul_cbuff_put_info_t *put_info, unsigned int size, unsigned int flags)
 137 {
 138   ul_cbuff_state_t *state=buff->state;
 139   unsigned int length=size;
 140
 141   size=ul_cbuff_align(size+state->rear_size)+ul_cbuff_msg_head_size;
 142
 143   if((state->lasttail > state->head) &&
 144      (state->lasttail-state->head <= size))
 145       return -1;
 146
 147   if((state->lasttail > state->head) ||
 148      (state->buff_size-state->head > size)){
 149     put_info->msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->head);
 150
 151     put_info->data.ptr=(buff->buff_start+state->head+ul_cbuff_msg_head_size);
 152     put_info->data.cont_len=length;
 153     put_info->data.wrap_ptr=NULL;
 154     put_info->data.wrap_len=0;
 155
 156     state->head+=size;
 157   }else{
 158     ul_cbuff_loc_t res_size=state->buff_size-state->head;
 159     if(size-res_size >= state->lasttail)
 160       return -1;
 161
 162     put_info->msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->head);
 163
 164     if(res_size != ul_cbuff_msg_head_size){
 165       put_info->data.ptr=(buff->buff_start+state->head+ul_cbuff_msg_head_size);
 166       put_info->data.cont_len=res_size-ul_cbuff_msg_head_size;
 167       if(put_info->data.cont_len<length){
 168         put_info->data.wrap_ptr=buff->buff_start;
 169         put_info->data.wrap_len=length-put_info->data.cont_len;
 170       }else{
 171         put_info->data.wrap_ptr=NULL;
 172         put_info->data.wrap_len=0;
 173       }
 174     }else{
 175       put_info->data.ptr=buff->buff_start;
 176       put_info->data.cont_len=length;
 177       put_info->data.wrap_ptr=NULL;
 178       put_info->data.wrap_len=0;
 179     }
 180
 181     state->cycles++;
 182     state->head=size-res_size;
 183   }
 184
 185   ((ul_cbuff_msg_head_t *)(buff->buff_start+state->head))->flags=0;
 186
 187   flags&=~(UL_CBUFF_MSG_READY|UL_CBUFF_MSG_READERS);
 188
 189   put_info->msg_head->flags|=flags;
 190   if(buff->state->readers>0)
 191     put_info->msg_head->flags+=buff->state->readers;
 192   else if (buff->state->readers==0)
 193     put_info->msg_head->flags+=1;
 194
 195   put_info->msg_head->length=length;
 196
 197   return 0;
 198 }
 199
 200 ul_cbuff_inline int
 201 ul_cbuff_head_put(ul_cbuff_t *buff, ul_cbuff_put_info_t *put_info)
 202 {
 203   ul_cbuff_mark_ready(put_info->msg_head);
 204   put_info->msg_head=NULL;
 205   return 0;
 206 }
 207
 208 ul_cbuff_inline ul_cbuff_loc_t
 209 ul_cbuff_head_loc(const ul_cbuff_t *buff, const ul_cbuff_msg_head_t *msg_head)
 210 {
 211   return (unsigned char*)msg_head-buff->buff_start;
 212 }
 213
 214 ul_cbuff_inline ul_cbuff_loc_t
 215 ul_cbuff_next_loc(const ul_cbuff_t *buff, const ul_cbuff_msg_head_t *msg_head)
 216 {
 217   ul_cbuff_loc_t loc;
 218   unsigned int size;
 219
 220   size=ul_cbuff_align(msg_head->length+buff->state->rear_size)+ul_cbuff_msg_head_size;
 221
 222   loc=(unsigned char*)msg_head-buff->buff_start;
 223   if(buff->state->buff_size-loc > size)
 224     loc+=size;
 225   else
 226     loc=size-(buff->state->buff_size-loc);
 227
 228   return loc;
 229 }
 230
 231 ul_cbuff_inline int
 232 ul_cbuff_msg_head2data(const ul_cbuff_t *buff, ul_cbuff_data_info_t *data, const ul_cbuff_msg_head_t *msg_head)
 233 {
 234   ul_cbuff_loc_t res_size;
 235   unsigned int length;
 236   ul_cbuff_loc_t msg_loc=(unsigned char *)msg_head-buff->buff_start;
 237
 238   res_size=buff->state->buff_size-msg_loc;
 239   length=msg_head->length;
 240
 241   if(res_size > ul_cbuff_msg_head_size){
 242     data->ptr=(unsigned char*)msg_head+ul_cbuff_msg_head_size;
 243     if(res_size-ul_cbuff_msg_head_size >= length){
 244       data->cont_len=length;
 245       data->wrap_ptr=NULL;
 246       data->wrap_len=0;
 247     }else{
 248       data->cont_len=res_size-ul_cbuff_msg_head_size;
 249       data->wrap_ptr=buff->buff_start;
 250       data->wrap_len=length-(res_size-ul_cbuff_msg_head_size);
 251     }
 252   } else {
 253     data->ptr=buff->buff_start;
 254     data->cont_len=length;
 255     data->wrap_ptr=NULL;
 256     data->wrap_len=0;
 257   }
 258   return msg_head->flags;
 259 }
 260
 261 ul_cbuff_inline int
 262 ul_cbuff_tail_attach(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info, int mode)
 263 {
 264   ul_cbuff_state_t *state=buff->state;
 265   ul_cbuff_msg_head_t *msg_head;
 266
 267   if(state->readers>0)
 268     msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->head);
 269   else if(state->readers==0)
 270     msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->lasttail);
 271   if(state->readers>=0)
 272     state->readers++;
 273   tail_info->msg_head=msg_head;
 274   tail_info->data.ptr=NULL;
 275   return 0;
 276 }
 277
 278 ul_cbuff_inline int
 279 ul_cbuff_tail_incontact(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 280 {
 281   if(tail_info->msg_head==NULL){
 282     return 0;
 283   }
 284   return 1;
 285 }
 286
 287 ul_cbuff_inline int
 288 ul_cbuff_tail_test(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 289 {
 290   ul_cbuff_msg_head_t *msg_head=tail_info->msg_head;
 291
 292   if(!msg_head)
 293     return -1;
 294
 295   if(!ul_cbuff_is_ready(msg_head))
 296     return 0;
 297
 298   return ul_cbuff_msg_head2data(buff, &tail_info->data, msg_head);
 299 }
 300
 301 ul_cbuff_inline int
 302 ul_cbuff_tail_release(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 303 {
 304   ul_cbuff_msg_head_t *msg_head=tail_info->msg_head;
 305   unsigned msg_readers;
 306
 307   if(!ul_cbuff_is_ready(msg_head))
 308     return -1;
 309
 310   if(buff->state->readers<=0)
 311     return 1;
 312
 313   msg_readers=msg_head->flags&UL_CBUFF_MSG_READERS;
 314   if(msg_readers)
 315     msg_head->flags--;
 316
 317   return msg_readers<=1?1:0;
 318 }
 319
 320 ul_cbuff_inline int
 321 ul_cbuff_tail_next(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 322 {
 323   ul_cbuff_msg_head_t *msg_head=tail_info->msg_head;
 324
 325   if(!ul_cbuff_is_ready(msg_head))
 326     return -1;
 327
 328   tail_info->msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+
 329                         ul_cbuff_next_loc(buff, msg_head));
 330   return 0;
 331 }
 332
 333 ul_cbuff_inline int
 334 ul_cbuff_tail_state_update(ul_cbuff_t *buff, int release_result, ul_cbuff_loc_t loc, ul_cbuff_loc_t loc_next)
 335 {
 336   if(loc==buff->state->firsttail)
 337     buff->state->firsttail=loc_next;
 338
 339   if(release_result<=0)
 340     return 0;
 341
 342   if(loc==buff->state->lasttail){
 343     buff->state->lasttail=loc_next;
 344     return 1;
 345   }else{
 346     return -1;
 347   }
 348 }
 349
 350 ul_cbuff_inline int
 351 ul_cbuff_tail_detach_onestep(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 352 {
 353   ul_cbuff_state_t *state=buff->state;
 354   ul_cbuff_loc_t loc;
 355   ul_cbuff_loc_t loc_next;
 356   unsigned msg_readers;
 357
 358   if(tail_info->msg_head==NULL)
 359     return 0;
 360
 361   loc = ul_cbuff_head_loc(buff, tail_info->msg_head);
 362
 363   if(loc!=state->head) {
 364     if(!ul_cbuff_is_ready(tail_info->msg_head))
 365       return 2;
 366     msg_readers=tail_info->msg_head->flags&UL_CBUFF_MSG_READERS;
 367     loc_next=ul_cbuff_next_loc(buff, tail_info->msg_head);
 368     if(msg_readers)
 369       tail_info->msg_head->flags--;
 370     tail_info->msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+loc_next);
 371     ul_cbuff_tail_state_update(buff, msg_readers<=1? 1: 0, loc, loc_next);
 372     return 1;
 373   }
 374
 375   if(state->readers>0)
 376     state->readers--;
 377   tail_info->msg_head=NULL;
 378   tail_info->data.ptr=NULL;
 379   return 0;
 380 }
 381
 382
 383 ul_cbuff_inline void
 384 ul_cbuff_data_do_wrap(ul_cbuff_data_info_t *data_info)
 385 {
 386   data_info->ptr=data_info->wrap_ptr;
 387   data_info->cont_len=data_info->wrap_len;
 388   data_info->wrap_ptr=NULL;
 389   data_info->wrap_len=0;
 390 }
 391
 392 ul_cbuff_inline int
 393 ul_cbuff_data_at_once(ul_cbuff_data_info_t *data_info, void **pptr, int size)
 394 {
 395   int cont_len;
 396
 397   *pptr=data_info->ptr;
 398   if(!data_info->ptr)
 399     return 0;
 400   cont_len=data_info->cont_len;
 401   if(cont_len>size){
 402     cont_len=size;
 403     data_info->ptr+=size;
 404     data_info->cont_len-=cont_len;
 405   }else{
 406     ul_cbuff_data_do_wrap(data_info);
 407   }
 408   return cont_len;
 409 }
 410
 411 ul_cbuff_inline int
 412 ul_cbuff_put_data(ul_cbuff_data_info_t *data_info, const void *data, int size)
 413 {
 414   void *ptr;
 415   int count;
 416   int cont_len;
 417
 418   ptr=data_info->ptr;
 419   if(!ptr)
 420     return 0;
 421   cont_len=data_info->cont_len;
 422   if(cont_len>size){
 423     cont_len=size;
 424     data_info->ptr+=size;
 425     data_info->cont_len-=cont_len;
 426   }else{
 427     ul_cbuff_data_do_wrap(data_info);
 428   }
 429   if(cont_len<=0)
 430     return 0;
 431   memcpy(ptr,data,cont_len);
 432   count=cont_len;
 433   cont_len=size-cont_len;
 434   if(!cont_len)
 435     return count;
 436
 437   ptr=data_info->ptr;
 438   if(!ptr)
 439     return count;
 440   data=(char*)data+count;
 441   if(cont_len>data_info->cont_len)
 442     cont_len=data_info->cont_len;
 443   data_info->ptr+=cont_len;
 444   data_info->cont_len-=cont_len;
 445   memcpy(ptr,data,cont_len);
 446
 447   return cont_len+count;
 448 }
 449
 450 ul_cbuff_inline int
 451 ul_cbuff_get_data(ul_cbuff_data_info_t *data_info, void *data, int size)
 452 {
 453   void *ptr;
 454   int count;
 455   int cont_len;
 456
 457   ptr=data_info->ptr;
 458   if(!ptr)
 459     return 0;
 460   cont_len=data_info->cont_len;
 461   if(cont_len>size){
 462     cont_len=size;
 463     data_info->ptr+=size;
 464     data_info->cont_len-=cont_len;
 465   }else{
 466     ul_cbuff_data_do_wrap(data_info);
 467   }
 468   if(cont_len<=0)
 469     return 0;
 470   memcpy(data,ptr,cont_len);
 471   count=cont_len;
 472   cont_len=size-cont_len;
 473   if(!cont_len)
 474     return count;
 475
 476   ptr=data_info->ptr;
 477   if(!ptr)
 478     return count;
 479   data=(char*)data+count;
 480   if(cont_len>data_info->cont_len)
 481     cont_len=data_info->cont_len;
 482   data_info->ptr+=cont_len;
 483   data_info->cont_len-=cont_len;
 484   memcpy(data,ptr,cont_len);
 485
 486   return cont_len+count;
 487 }
 488
 489
 490 ul_cbuff_inline void *
 491 ul_cbuff_get_rear_ptr(ul_cbuff_t *buff, ul_cbuff_msg_head_t *msg_head)
 492 {
 493   ul_cbuff_loc_t loc;
 494   unsigned int size;
 495   ul_cbuff_state_t *state=buff->state;
 496
 497   size=ul_cbuff_align(msg_head->length+state->rear_size)+ul_cbuff_msg_head_size;
 498   size-=state->rear_size;
 499
 500   loc=(unsigned char*)msg_head-buff->buff_start;
 501   if(state->buff_size-loc > size)
 502     loc+=size;
 503   else
 504     loc=size-(state->buff_size-loc);
 505
 506   return buff->buff_start+loc;
 507 }
 508
 509 ul_cbuff_inline void *
 510 ul_cbuff_prev_rear_ptr(ul_cbuff_t *buff, ul_cbuff_loc_t loc)
 511 {
 512   ul_cbuff_state_t *state=buff->state;
 513
 514   if(loc>state->rear_size)
 515     return buff->buff_start+loc-state->rear_size;
 516   else
 517     return buff->buff_start+loc+state->buff_size-state->rear_size;
 518 }
 519
 520 #endif /*UL_CBUFF_INLINE*/
 521
 522 int ul_cbuff_init(ul_cbuff_t *buff, ul_cbuff_state_t *state,
 523                   void *buff_start, ul_cbuff_loc_t size);
 524
 525
 526 #ifdef __cplusplus
 527 } /* extern "C"*/
 528 #endif
 529
 530 #endif /* _UL_CBUFF_H */