program to demonstrate lite3 behavior

empty-key.c

/*
 * Compile with:
 *
 *   gcc -Wall -O -o empty-key empty-key.c `pkg-config --libs --cflags --static lite3`
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lite3_context_api.h"

void die (const char *msg, int lineNo)
{
    int errnum = errno;
    const char *err = strerror (errnum);

    if (err == NULL || errnum == 0) {
        err = "unspecified error";
    }

    fprintf (stderr, "line %d: %s (%d: %s)\n", lineNo, msg, errnum, err);
    exit (EXIT_FAILURE);
}

#define DIE(dieMessage) die(dieMessage, __LINE__)

#define CHECK(errIfNegative, dieMessage)        \
    do {                                        \
        if ((errIfNegative) < 0) {              \
            die(dieMessage, __LINE__);          \
        }                                       \
    } while (0)

static const char *type_str (int t)
{
    switch (t) {
    case LITE3_TYPE_NULL:    return "LITE3_TYPE_NULL";
    case LITE3_TYPE_BOOL:    return "LITE3_TYPE_BOOL";
    case LITE3_TYPE_I64:     return "LITE3_TYPE_I64";
    case LITE3_TYPE_F64:     return "LITE3_TYPE_F64";
    case LITE3_TYPE_BYTES:   return "LITE3_TYPE_BYTES";
    case LITE3_TYPE_STRING:  return "LITE3_TYPE_STRING";
    case LITE3_TYPE_OBJECT:  return "LITE3_TYPE_OBJECT";
    case LITE3_TYPE_ARRAY:   return "LITE3_TYPE_ARRAY";
    case LITE3_TYPE_INVALID: return "LITE3_TYPE_INVALID";
    default:                 return "unknown";
    }
}

int main (int argc, char **argv)
{
    lite3_ctx *ctx = lite3_ctx_create();
    if (ctx == NULL) {
        DIE("lite3_ctx_create");
    }

    /* Create an object containing one key/value pair, where
     * the key is the empty string, and the value is null. */

    int ret = lite3_ctx_init_obj (ctx);
    CHECK(ret, "lite3_ctx_init_obj");

    ret = lite3_ctx_set_null(ctx, 0, "");
    CHECK(ret, "lite3_ctx_set_null");

    printf ("Created message of length %u\n",
            (unsigned int) (ctx->buflen));

    /* Now try to iterate over the object we just created. */

    lite3_iter it;
    ret = lite3_ctx_iter_create(ctx, 0, &it);
    CHECK(ret, "lite3_ctx_iter_create");

    int i;
    for (i = 0; ; i++) {
        lite3_str key_str;
        size_t    val_ofs;

        printf ("fetching %dth key/value pair...\n", i);

        ret = lite3_ctx_iter_next(ctx, &it, &key_str, &val_ofs);
        if (ret == LITE3_ITER_DONE) {
            break;
        }
        CHECK(ret, "lite3_ctx_iter_next");

        const char *key = LITE3_STR(ctx->buf, key_str);
        if (key == NULL) {
            DIE("LITE3_STR");
        }
        printf ("    key = '%s'; value is at offset %u\n",
                key, (unsigned int) val_ofs);

        lite3_val *val = (lite3_val *) (ctx->buf + val_ofs);
        int        t   = lite3_val_type (val);

        printf ("        value is of type %d (%s)\n", t, type_str(t));
    }

    printf ("Done!\n");
    lite3_ctx_destroy (ctx);

    return EXIT_SUCCESS;
}