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
 193   put_info->msg_head->length=length;
 194
 195   return 0;
 196 }
 197
 198 ul_cbuff_inline int
 199 ul_cbuff_head_put(ul_cbuff_t *buff, ul_cbuff_put_info_t *put_info)
 200 {
 201   ul_cbuff_mark_ready(put_info->msg_head);
 202   put_info->msg_head=NULL;
 203   return 0;
 204 }
 205
 206 ul_cbuff_inline ul_cbuff_loc_t
 207 ul_cbuff_head_loc(const ul_cbuff_t *buff, const ul_cbuff_msg_head_t *msg_head)
 208 {
 209   return (unsigned char*)msg_head-buff->buff_start;
 210 }
 211
 212 ul_cbuff_inline ul_cbuff_loc_t
 213 ul_cbuff_next_loc(const ul_cbuff_t *buff, const ul_cbuff_msg_head_t *msg_head)
 214 {
 215   ul_cbuff_loc_t loc;
 216   unsigned int size;
 217
 218   size=ul_cbuff_align(msg_head->length+buff->state->rear_size)+ul_cbuff_msg_head_size;
 219
 220   loc=(unsigned char*)msg_head-buff->buff_start;
 221   if(buff->state->buff_size-loc > size)
 222     loc+=size;
 223   else
 224     loc=size-(buff->state->buff_size-loc);
 225
 226   return loc;
 227 }
 228
 229 ul_cbuff_inline int
 230 ul_cbuff_msg_head2data(const ul_cbuff_t *buff, ul_cbuff_data_info_t *data, const ul_cbuff_msg_head_t *msg_head)
 231 {
 232   ul_cbuff_loc_t res_size;
 233   unsigned int length;
 234   ul_cbuff_loc_t msg_loc=(unsigned char *)msg_head-buff->buff_start;
 235
 236   res_size=buff->state->buff_size-msg_loc;
 237   length=msg_head->length;
 238
 239   if(res_size > ul_cbuff_msg_head_size){
 240     data->ptr=(unsigned char*)msg_head+ul_cbuff_msg_head_size;
 241     if(res_size-ul_cbuff_msg_head_size >= length){
 242       data->cont_len=length;
 243       data->wrap_ptr=NULL;
 244       data->wrap_len=0;
 245     }else{
 246       data->cont_len=res_size-ul_cbuff_msg_head_size;
 247       data->wrap_ptr=buff->buff_start;
 248       data->wrap_len=length-(res_size-ul_cbuff_msg_head_size);
 249     }
 250   } else {
 251     data->ptr=buff->buff_start;
 252     data->cont_len=length;
 253     data->wrap_ptr=NULL;
 254     data->wrap_len=0;
 255   }
 256   return msg_head->flags;
 257 }
 258
 259 ul_cbuff_inline int
 260 ul_cbuff_tail_attach(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info, int mode)
 261 {
 262   ul_cbuff_state_t *state=buff->state;
 263   ul_cbuff_msg_head_t *msg_head;
 264
 265   msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->head);
 266   if(state->readers>=0)
 267     state->readers++;
 268   tail_info->msg_head=msg_head;
 269   tail_info->data.ptr=NULL;
 270   return 0;
 271 }
 272
 273 ul_cbuff_inline int
 274 ul_cbuff_tail_incontact(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 275 {
 276   if(tail_info->msg_head==NULL){
 277     return 0;
 278   }
 279   return 1;
 280 }
 281
 282 ul_cbuff_inline int
 283 ul_cbuff_tail_test(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 284 {
 285   ul_cbuff_msg_head_t *msg_head=tail_info->msg_head;
 286
 287   if(!msg_head)
 288     return -1;
 289
 290   if(!ul_cbuff_is_ready(msg_head))
 291     return 0;
 292
 293   return ul_cbuff_msg_head2data(buff, &tail_info->data, msg_head);
 294 }
 295
 296 ul_cbuff_inline int
 297 ul_cbuff_tail_release(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 298 {
 299   ul_cbuff_msg_head_t *msg_head=tail_info->msg_head;
 300   unsigned msg_readers;
 301
 302   if(!ul_cbuff_is_ready(msg_head))
 303     return -1;
 304
 305   if(buff->state->readers<=0)
 306     return 1;
 307
 308   msg_readers=msg_head->flags&UL_CBUFF_MSG_READERS;
 309   if(msg_readers)
 310     msg_head->flags--;
 311
 312   return msg_readers<=1?1:0;
 313 }
 314
 315 ul_cbuff_inline int
 316 ul_cbuff_tail_next(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 317 {
 318   ul_cbuff_msg_head_t *msg_head=tail_info->msg_head;
 319
 320   if(!ul_cbuff_is_ready(msg_head))
 321     return -1;
 322
 323   tail_info->msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+
 324                         ul_cbuff_next_loc(buff, msg_head));
 325   return 0;
 326 }
 327
 328 ul_cbuff_inline int
 329 ul_cbuff_tail_state_update(ul_cbuff_t *buff, int release_result, ul_cbuff_loc_t loc, ul_cbuff_loc_t loc_next)
 330 {
 331   if(loc==buff->state->firsttail)
 332     buff->state->firsttail=loc_next;
 333
 334   if(release_result<=0)
 335     return 0;
 336
 337   if(loc==buff->state->lasttail){
 338     buff->state->lasttail=loc_next;
 339     return 1;
 340   }else{
 341     return -1;
 342   }
 343 }
 344
 345 ul_cbuff_inline int
 346 ul_cbuff_tail_detach_onestep(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info)
 347 {
 348   ul_cbuff_state_t *state=buff->state;
 349   ul_cbuff_loc_t loc;
 350   ul_cbuff_loc_t loc_next;
 351   unsigned msg_readers;
 352
 353   if(tail_info->msg_head==NULL)
 354     return 0;
 355
 356   loc = ul_cbuff_head_loc(buff, tail_info->msg_head);
 357
 358   if(loc!=state->head) {
 359     if(!ul_cbuff_is_ready(tail_info->msg_head))
 360       return 2;
 361     msg_readers=tail_info->msg_head->flags&UL_CBUFF_MSG_READERS;
 362     loc_next=ul_cbuff_next_loc(buff, tail_info->msg_head);
 363     if(msg_readers)
 364       tail_info->msg_head->flags--;
 365     tail_info->msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+loc_next);
 366     ul_cbuff_tail_state_update(buff, msg_readers<=1? 1: 0, loc, loc_next);
 367     return 1;
 368   }
 369
 370   if(state->readers>0)
 371     state->readers--;
 372   tail_info->msg_head=NULL;
 373   tail_info->data.ptr=NULL;
 374   return 0;
 375 }
 376
 377
 378 ul_cbuff_inline void
 379 ul_cbuff_data_do_wrap(ul_cbuff_data_info_t *data_info)
 380 {
 381   data_info->ptr=data_info->wrap_ptr;
 382   data_info->cont_len=data_info->wrap_len;
 383   data_info->wrap_ptr=NULL;
 384   data_info->wrap_len=0;
 385 }
 386
 387 ul_cbuff_inline int
 388 ul_cbuff_data_at_once(ul_cbuff_data_info_t *data_info, void **pptr, int size)
 389 {
 390   int cont_len;
 391
 392   *pptr=data_info->ptr;
 393   if(!data_info->ptr)
 394     return 0;
 395   cont_len=data_info->cont_len;
 396   if(cont_len>size){
 397     cont_len=size;
 398     data_info->ptr+=size;
 399     data_info->cont_len-=cont_len;
 400   }else{
 401     ul_cbuff_data_do_wrap(data_info);
 402   }
 403   return cont_len;
 404 }
 405
 406 ul_cbuff_inline int
 407 ul_cbuff_put_data(ul_cbuff_data_info_t *data_info, const void *data, int size)
 408 {
 409   void *ptr;
 410   int count;
 411   int cont_len;
 412
 413   ptr=data_info->ptr;
 414   if(!ptr)
 415     return 0;
 416   cont_len=data_info->cont_len;
 417   if(cont_len>size){
 418     cont_len=size;
 419     data_info->ptr+=size;
 420     data_info->cont_len-=cont_len;
 421   }else{
 422     ul_cbuff_data_do_wrap(data_info);
 423   }
 424   if(cont_len<=0)
 425     return 0;
 426   memcpy(ptr,data,cont_len);
 427   count=cont_len;
 428   cont_len=size-cont_len;
 429   if(!cont_len)
 430     return count;
 431
 432   ptr=data_info->ptr;
 433   if(!ptr)
 434     return count;
 435   data=(char*)data+count;
 436   if(cont_len>data_info->cont_len)
 437     cont_len=data_info->cont_len;
 438   data_info->ptr+=cont_len;
 439   data_info->cont_len-=cont_len;
 440   memcpy(ptr,data,cont_len);
 441
 442   return cont_len+count;
 443 }
 444
 445 ul_cbuff_inline int
 446 ul_cbuff_get_data(ul_cbuff_data_info_t *data_info, void *data, int size)
 447 {
 448   void *ptr;
 449   int count;
 450   int cont_len;
 451
 452   ptr=data_info->ptr;
 453   if(!ptr)
 454     return 0;
 455   cont_len=data_info->cont_len;
 456   if(cont_len>size){
 457     cont_len=size;
 458     data_info->ptr+=size;
 459     data_info->cont_len-=cont_len;
 460   }else{
 461     ul_cbuff_data_do_wrap(data_info);
 462   }
 463   if(cont_len<=0)
 464     return 0;
 465   memcpy(data,ptr,cont_len);
 466   count=cont_len;
 467   cont_len=size-cont_len;
 468   if(!cont_len)
 469     return count;
 470
 471   ptr=data_info->ptr;
 472   if(!ptr)
 473     return count;
 474   data=(char*)data+count;
 475   if(cont_len>data_info->cont_len)
 476     cont_len=data_info->cont_len;
 477   data_info->ptr+=cont_len;
 478   data_info->cont_len-=cont_len;
 479   memcpy(data,ptr,cont_len);
 480
 481   return cont_len+count;
 482 }
 483
 484
 485 ul_cbuff_inline void *
 486 ul_cbuff_get_rear_ptr(ul_cbuff_t *buff, ul_cbuff_msg_head_t *msg_head)
 487 {
 488   ul_cbuff_loc_t loc;
 489   unsigned int size;
 490   ul_cbuff_state_t *state=buff->state;
 491
 492   size=ul_cbuff_align(msg_head->length+state->rear_size)+ul_cbuff_msg_head_size;
 493   size-=state->rear_size;
 494
 495   loc=(unsigned char*)msg_head-buff->buff_start;
 496   if(state->buff_size-loc > size)
 497     loc+=size;
 498   else
 499     loc=size-(state->buff_size-loc);
 500
 501   return buff->buff_start+loc;
 502 }
 503
 504 ul_cbuff_inline void *
 505 ul_cbuff_prev_rear_ptr(ul_cbuff_t *buff, ul_cbuff_loc_t loc)
 506 {
 507   ul_cbuff_state_t *state=buff->state;
 508
 509   if(loc>state->rear_size)
 510     return buff->buff_start+loc-state->rear_size;
 511   else
 512     return buff->buff_start+loc+state->buff_size-state->rear_size;
 513 }
 514
 515 #endif /*UL_CBUFF_INLINE*/
 516
 517 int ul_cbuff_init(ul_cbuff_t *buff, ul_cbuff_state_t *state,
 518                   void *buff_start, ul_cbuff_loc_t size);
 519
 520
 521 #ifdef __cplusplus
 522 } /* extern "C"*/
 523 #endif
 524
 525 #endif /* _UL_CBUFF_H */