nmsg_json.h

#ifndef NMSG_JSON_H
#define NMSG_JSON_H
 
#include "strbuf.h"
#include "libmy/my_alloc.h"
 
static inline void
num_to_str(int num, int size, char * ptr) {
        int ndx = size - 1;
 
        while (size > 0) {
                int digit = num % 10;
                ptr[ndx] = '0' + digit;
                --ndx;
                --size;
                num /= 10;
        }
}
 
static inline size_t
vnum_to_str(uint64_t num, char *ptr) {
        uint64_t tmp = num;
        size_t ndx, left, ndigits = 0;
 
        do {
                ndigits++;
                tmp /= 10;
        } while (tmp != 0);
 
        left = ndigits;
        ndx = left - 1;
        while(left > 0) {
                int digit = num % 10;
                ptr[ndx] = '0' + digit;
                --ndx;
                --left;
                num = num/10;
        }
 
        ptr[ndigits] = '\0';
 
        return ndigits;
}
 
static inline void
declare_json_value(struct nmsg_strbuf *sb, const char *name, bool is_first) {
        if (!is_first) {
                nmsg_strbuf_append_str(sb, ",\"", 2);
        } else {
                nmsg_strbuf_append_str(sb, "\"", 1);
        }
 
        nmsg_strbuf_append_str(sb, name, strlen(name));
        nmsg_strbuf_append_str(sb, "\":", 2);
}
 
static inline void
append_json_value_string(struct nmsg_strbuf *sb, const char *val, size_t vlen) {
        nmsg_strbuf_append_str(sb, "\"", 1);
        nmsg_strbuf_append_str_json(sb, val, vlen);
        nmsg_strbuf_append_str(sb, "\"", 1);    // guaranteed success x 3
}
 
/* More performant variant for when we know data doesn't need to be escaped. */
static inline void
append_json_value_string_noescape(struct nmsg_strbuf *sb, const char *val, size_t vlen) {
        nmsg_strbuf_append_str(sb, "\"", 1);
        nmsg_strbuf_append_str(sb, val, vlen);
        nmsg_strbuf_append_str(sb, "\"", 1);    // guaranteed success x 3
}
 
static inline void
append_json_value_int(struct nmsg_strbuf *sb, uint64_t val) {
        char numbuf[32];
        size_t nlen;
 
        nlen = vnum_to_str(val, numbuf);
        nmsg_strbuf_append_str(sb, numbuf, nlen);       // guaranteed succes
}
 
static inline void
append_json_value_bool(struct nmsg_strbuf *sb, bool val) {
 
        if (val)
                nmsg_strbuf_append_str(sb, "true", 4);
        else
                nmsg_strbuf_append_str(sb, "false", 5); // guaranteed success
}
 
static inline void
append_json_value_double(struct nmsg_strbuf *sb, double val) {
        char dubbuf[64], *endp;
        size_t dlen;
 
        dlen = snprintf(dubbuf, sizeof(dubbuf), "%.18f", val);
        dubbuf[sizeof(dubbuf)-1] = 0;
 
        /* Trim possible trailing numerical zero padding */
        endp = dubbuf + dlen - 1;
        while (*endp != '\0' && endp > dubbuf) {
                if (*endp != '0' || *(endp-1) == '.')
                        break;
                *endp-- = '\0';
                dlen--;
        }
 
        nmsg_strbuf_append_str(sb, dubbuf, dlen);       // guaranteed success
}
 
static inline void
append_json_value_null(struct nmsg_strbuf *sb) {
        nmsg_strbuf_append_str(sb, "null", 4);  // guaranteed success
}
 
#endif /* NMSG_JSON_H */