main.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <time.h>
#include <strings.h>
#include "msgpack.h"

#define MSGMAX 256
#define STRING_AND_SIZE(s) (s), (sizeof((s)) - 1)

char vestige_buf[MSGMAX];
char *vestige_cur = vestige_buf;
char *vestige_lim = vestige_buf + sizeof(vestige_buf);

void flush_buffer() {
  printf("flushing %ld bytes\n", vestige_cur - vestige_buf);
  bzero(vestige_buf, sizeof(vestige_buf));
  vestige_cur = vestige_buf;
}

void append_with_fallback(char* (*writer_func)(char*, char*)) {
  char *orig_cur = vestige_cur;

  vestige_cur = (*writer_func)(vestige_cur, vestige_lim);
  if(vestige_cur == 0) {
    // need to flush and write again
    vestige_cur = orig_cur;
    flush_buffer();
    vestige_cur = (*writer_func)(vestige_cur, vestige_lim);
    printf("successfully written %zu after flush flush\n", vestige_cur - vestige_buf);
  } else {
    printf("successfully written %zu\n", vestige_cur - orig_cur);
  }
}

char *
msgpack_start_span(char *dst, char *lim) {
  dst = msgpack_map(dst, lim, 1);
  if(dst == 0) return 0;
  dst = msgpack_string(dst, lim, STRING_AND_SIZE("type"));
  if(dst == 0) return 0;
  dst = msgpack_string(dst, lim, STRING_AND_SIZE("start"));
  return dst;
}

char *
msgpack_end_span(char *dst, char *lim) {
  dst = msgpack_map(dst, lim, 1);
  if(dst == 0) return 0;
  dst = msgpack_string(dst, lim, STRING_AND_SIZE("type"));
  if(dst == 0) return 0;
  dst = msgpack_string(dst, lim, STRING_AND_SIZE("end"));
  return dst;
}

void start_span() {
  append_with_fallback(msgpack_start_span);
}

void end_span() {
  append_with_fallback(msgpack_end_span);
}

int main() {
  /* Intializes random number generator */
  time_t t;
  srand((unsigned) time(&t));

  int z = 20;
  while (z > 0) {
    start_span();
    end_span();
    z--;
  }
  return 0;
}