git.squeep.com Git - reservoir_sample/blob - buf.h

   1 #ifndef BUF_H_B87OZOFU
   2 #define BUF_H_B87OZOFU
   3
   4 #include <stdlib.h>
   5
   6 #ifndef NDEBUG
   7 #include "notify.h"
   8 #endif /* NDEBUG */
   9
  10 /*      A simple sliding-window byte buffer. */
  11
  12 typedef struct buf_ {
  13         size_t buf_sz;
  14         size_t buf_start;
  15         size_t buf_used;
  16         unsigned char buf[];
  17 } *buf_t;
  18 #define BUF_ROOM(__b__) ( (__b__)->buf_sz - ( (__b__)->buf_start + (__b__)->buf_used ) )
  19
  20 #ifndef NDEBUG
  21 /*      For debugging, dump a buffer. */
  22 #define D_BUF(__pre__,__b__,...) do {\
  23         if ( (__b__) == NULL )\
  24                 NOTIFY_DEBUG(__pre__ "buf:%p", ## __VA_ARGS__, (__b__));\
  25         else {\
  26                 NOTIFY_DEBUG(__pre__ "buf:%p sz:%zu start:%zu used:%zu free:%zu '%.*s'",\
  27                              ## __VA_ARGS__,\
  28                              (__b__),\
  29                              (__b__)->buf_sz,\
  30                              (__b__)->buf_start,\
  31                              (__b__)->buf_used,\
  32                              BUF_ROOM((__b__)),\
  33                              (int)(__b__)->buf_used, (__b__)->buf + (__b__)->buf_start);\
  34                 assert( (__b__)->buf_sz >= (__b__)->buf_start + (__b__)->buf_used );\
  35         }\
  36 } while (0)
  37 #else /* NDEBUG */
  38 #define D_BUF(...)
  39 #endif /* NDEBUG */
  40
  41 /*      buf_new
  42                 Allocate and return a new buf_t capable of holding #sz bytes.
  43 */
  44 buf_t buf_new(size_t sz);
  45
  46 /*      buf_del
  47                 Deallocate the buf_t pointed to by #pbuf.
  48 */
  49 void buf_del(buf_t *pbuf);
  50
  51 /*      buf_rebase
  52                 Reclaim any free space from the start of #buf, preserving active content.
  53 */
  54 void buf_rebase(buf_t buf);
  55
  56 /*      buf_makeroom
  57                 Assures that the buf pointed to by #pbuf has at space to hold #roomfor
  58         more bytes.
  59 */
  60 int buf_makeroom(buf_t *pbuf, size_t roomfor);
  61
  62 /*      buf_range_dup_or_append
  63                 Starting at the #src_offset byte of #src, appends the following #n
  64         bytes to the buffer pointed to by #dstp, which will be re/allocated if
  65         needed.
  66 */
  67 int buf_range_dup_or_append(buf_t src, size_t src_offset, size_t n, buf_t *pdst);
  68
  69 /*      buf_flense
  70                 Starting after #src_offset characters, scan through the buffer pointed
  71         to by #psrc, stopping at the first byte matching #delimiter, whereupon, if
  72         #pdst is not NULL, all the bytes previous to #delimiter are appended onto
  73         the buffer pointed to by *#pdst.  The buffer pointed to by #psrc is then
  74         trimmed to only contain the bytes following #delimiter.  The delimiter byte
  75         is discarded.
  76                 Returns the number of characters flensed from #src.
  77 */
  78 ssize_t buf_flense(buf_t *psrc, size_t src_offset, int delimiter, buf_t *pdst);
  79
  80 #endif /* BUF_H_B87OZOFU */