open5gs/lib/base/context.c

#define TRACE_MODULE _context

#include "core_file.h"

#include "context.h"

#define DEFAULT_CONFIG_FILE_PATH SYSCONFDIR PACKAGE ".conf"

static context_t self;

static int context_initialized = 0;

status_t context_init()
{
    d_assert(context_initialized == 0, return CORE_ERROR,
            "Context already has been context_initialized");

    memset(&self, 0, sizeof(context_t));

    context_initialized = 1;

    return CORE_OK;
}

status_t context_parse_config()
{
    config_t *config = &self.config;

    char *json = config->json;
    jsmntok_t *token = config->token;

    typedef enum { START, ROOT, SKIP, STOP } parse_state;
    parse_state state = START;

    size_t root_tokens = 0;
    size_t skip_tokens = 0;
    size_t i = 0, j = 1;

    for (i = 0, j = 1; j > 0; i++, j--)
    {
        jsmntok_t *t = &token[i];

        j += t->size;

        switch (state)
        {
            case START:
            {
                state = ROOT;
                root_tokens = t->size;

                break;
            }
            case ROOT:
            {
                if (jsmntok_equal(json, t, "DB_URI") == 0)
                    self.db_uri = jsmntok_to_string(json, t+1);
                else if (jsmntok_equal(json, t, "LOG_PATH") == 0)
                    self.log_path = jsmntok_to_string(json, t+1);

                state = SKIP;
                skip_tokens = t->size;

                root_tokens--;
                if (root_tokens == 0) state = STOP;

                break;
            }
            case SKIP:
            {
                skip_tokens += t->size;

                skip_tokens--;
                if (skip_tokens == 0) state = ROOT;

                break;
            }
            case STOP:
            {
                break;
            }
            default:
            {
                d_error("Failed to parse configuration in the state(%u)", 
                        state);
                break;
            }

        }
    }

    return CORE_OK;
}

status_t context_final()
{
    d_assert(context_initialized == 1, return CORE_ERROR,
            "HyperCell context already has been finalized");

    context_initialized = 0;

    return CORE_OK;
}

context_t* context_self()
{
    return &self;
}

status_t context_read_file(char *file_path)
{
    char buf[MAX_ERROR_STRING_LEN];
    config_t *config = &self.config;
    status_t rv;
    file_t *file;

    jsmn_parser parser;
    size_t json_len;
    int result;

    config->path = file_path;
    if (config->path == NULL) config->path = DEFAULT_CONFIG_FILE_PATH;

    rv = file_open(&file, config->path, FILE_READ, FILE_OS_DEFAULT);
    if (rv != CORE_OK) 
    {
        d_fatal("Can't open configuration file '%s' (errno = %d, %s)", 
            config->path, rv, core_strerror(rv, buf, MAX_ERROR_STRING_LEN));
        return rv;
    }

    json_len = MAX_CONFIG_FILE_SIZE;
    rv = file_read(file, config->json, &json_len);
    if (rv != CORE_OK) 
    {
        d_fatal("Can't read configuration file '%s' (errno = %d, %s)", 
            config->path, rv, core_strerror(rv, buf, MAX_ERROR_STRING_LEN));
        return rv;
    }
    file_close(file);

    jsmn_init(&parser);
    result = jsmn_parse(&parser, config->json, strlen(config->json), 
        config->token, sizeof(config->token)/sizeof(config->token[0]));
    if (result < 0) 
    {
        d_fatal("Failed to parse configuration file '%s' (jsmnerr = %d)", 
                config->path, result);
        return CORE_ERROR;
    }

    if (result < 1 || config->token[0].type != JSMN_OBJECT) 
    {
        d_fatal("Failed to parse configuration file '%s' (OBJECT expected)",
                config->path);
        return CORE_ERROR;
    }

    d_print("  Config '%s'\n", config->path);

    return CORE_OK;
}