windows/cthelper/buffer.h

   1 #ifndef BUFFER_H
   2 #define BUFFER_H
   3
   4 #include <sys/types.h>
   5 #include <alloca.h>
   6
   7 typedef struct buffer_tag *Buffer;
   8 struct buffer_tag {
   9   size_t avail, len;
  10   unsigned char data[1];
  11 };
  12
  13 /* Initialize a Buffer */
  14 Buffer buffer_init(size_t size);
  15
  16 /* Free a buffer; sets *pb to NULL */
  17 void buffer_free(Buffer *pb);
  18
  19 /* Initialize a Buffer with alloca() */
  20 #define BUFFER_ALLOCA(b,s) do{\
  21     b = alloca(sizeof(b)+(s)); b->avail = s; b->len = 0;\
  22   }while(0)
  23
  24 /* Returns true if buffer is full */
  25 #define buffer_isfull(b) ((b)->avail == 0)
  26
  27 /* Returns true if buffer is empty */
  28 #define buffer_isempty(b) ((b)->len == 0)
  29
  30 /* Reads up to buffer_avail(b) bytes from descriptor `des' */
  31 ssize_t buffer_read(Buffer b, int des);
  32
  33 /* Writes as many bytes in the buffer as possible to descriptor `des' */
  34 ssize_t buffer_write(Buffer b, int des);
  35
  36 /* Appends data from data to end of buffer returning number of bytes
  37  * appended (which may be less than `len') */
  38 size_t buffer_append(Buffer b, const char *data, size_t len);
  39
  40 /* Clears len bytes from start of buffer, returning number of bytes removed */
  41 size_t buffer_consumed(Buffer b, size_t len);
  42
  43 #endif /* BUFFER_H */