json_parse.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "yajl/yajl_tree.h"

#define CAPI_TRACE_ERR(x...) printf(x)
#define CAPI_TRACE_DBG(x...) printf(x)
#define CSCO_HAI_STATUS_INIT_ERR -1
#define CSCO_HAI_STATUS_SUCCESS 0

//#define CAPI_IS_INTEGER(v) YAJL_IS_INTEGER(v)
//#define CAPI_GET_INTEGER(v) YAJL_GET_INTEGER(v)

#define CAPI_IS_INTEGER(v) YAJL_IS_DOUBLE(v)
#define CAPI_GET_INTEGER(v) YAJL_GET_DOUBLE(v)

#define MAX_NUM_INSTANCES 4

static char errbuf[1024];

int
csco_hai_parse_cfg (const char *cfg)
{
    int             i;
    yajl_val        ynode, inst_nodes, id_node, api_port_node, api_addr_node;
    const char      *inst_path[] = { "instances", (const char *) 0 };
    const char      *id_path[] = { "id", (const char *) 0 };
    const char      *api_port_path[] = { "communications", "ports",
                                         "api", (const char *) 0 };
    const char      *api_addr_path[] = { "communications", "addr",
                                         (const char *) 0 };

    ynode = yajl_tree_parse((const char *)cfg, errbuf, sizeof(errbuf));
    if (ynode == NULL) {
        CAPI_TRACE_ERR("Config parse error, err : %s\n", errbuf);
        return CSCO_HAI_STATUS_INIT_ERR;
    }

    inst_nodes = yajl_tree_get(ynode, inst_path, yajl_t_array);
    if (inst_nodes && YAJL_IS_ARRAY(inst_nodes)) {
          CAPI_TRACE_DBG("num instances in cfg = %d\n", (int )inst_nodes->u.array.len);
        if (inst_nodes->u.array.len > MAX_NUM_INSTANCES) {
            CAPI_TRACE_ERR("Cfg parse error, Max NUM instances exceeded num instances in cfg = %d max num instances = %d\n", (
int )inst_nodes->u.array.len, MAX_NUM_INSTANCES);
            goto cleanup;
        }
          // process each instance
          for (i = 0; i < inst_nodes->u.array.len; i++) {
              // get the instance id
              id_node = yajl_tree_get(inst_nodes->u.array.values[i],
                                      id_path, yajl_t_number);
              if (id_node && CAPI_IS_INTEGER(id_node)) {
                  CAPI_TRACE_DBG("Found instance %d\n",
                               CAPI_GET_INTEGER(id_node));
              } else {
                  CAPI_TRACE_ERR("Cfg parse error, instance id not found\n");
                  goto cleanup;
              }
  
              // set the api host
            api_addr_node = yajl_tree_get(inst_nodes->u.array.values[i],
                                          api_addr_path, yajl_t_number);
            if (api_addr_node && YAJL_IS_STRING(api_addr_node)) {
                CAPI_TRACE_DBG("api addr  = %s\n",
                               YAJL_GET_STRING(api_addr_node));
            }
  
            // get the api port
            api_port_node = yajl_tree_get(inst_nodes->u.array.values[i],
                                          api_port_path, yajl_t_number);
            if (api_port_node && CAPI_IS_INTEGER(api_port_node)) {
                CAPI_TRACE_DBG("api port  = %d\n",
                      CAPI_GET_INTEGER(api_port_node));
            } else {
                CAPI_TRACE_ERR("Config parse error, api port not found\n");
                goto cleanup;

            }
        }
    }

    return CSCO_HAI_STATUS_SUCCESS;

cleanup:

    CAPI_TRACE_DBG("Config parsing failed\n");
    return CSCO_HAI_STATUS_INIT_ERR;
}


int main () {
        const char *str = " \
{ \
    \"heart-beat-timeout\"    : 90, \
    \"debug\" : \
    { \
        \"logs\" : \
        { \
            \"destination\"        : \"/logs/\" \
        } \
    }, \
    \"instances\" : \
    [ \
        { \
            \"id\"    : 0, \
            \"communications\" : \
            { \
                \"ports\" : \
                { \
                    \"api\"                : 60000 \
                } \
            } \
        }, \
        { \
            \"id\"    : 1, \
            \"communications\" : \
            { \
                \"ports\" : \
                { \
                    \"api\"                : 61000 \
                } \
            } \
        } \
    ] \
}";
        printf("Str: %s", str);
        csco_hai_parse_cfg(str);
}