writers.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2026, Sangoma Technologies Corporation
 *
 * George Joseph <gjoseph@sangoma.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*!
 * \file
 * \author George Joseph <gjoseph@sangoma.com>
 *
 * \brief Backend output functions.
 *
 * The writers all take a vector of cdrel_value objects and write them to the output
 * file or database.
 *
 */
 
#include "cdrel.h"
 
/*
 * We can save some time and ast_str memory allocation work by allocating a single
 * thread-local buffer and re-using it.
 */
AST_THREADSTORAGE(custom_buf);
 
/*!
 * \internal
 * \brief Write a record to a text file
 *
 * Besides being used here, this function is also used by the legacy loggers
 * that shortcut the advanced stuff.
 *
 * \param config The configuration object.
 * \param record The data to write.
 * \retval 0 on success
 * \retval -1 on failure
 */
int write_record_to_file(struct cdrel_config *config, struct ast_str *record)
{
    FILE *out;
    int res = 0;
 
    ast_mutex_lock(&config->lock);
    if ((out = fopen(config->output_filename, "a"))) {
        res = fputs(ast_str_buffer(record), out);
        fputs("\n", out);
        fclose(out);
    }
    ast_mutex_unlock(&config->lock);
 
    if (!out || res < 0) {
        ast_log(LOG_ERROR, "Unable to write %s to file %s : %s\n",
            RECORD_TYPE_STR(config->record_type), config->output_filename, strerror(errno));
        return -1;
    }
    return 0;
}
 
/*!
 * \internal
 * \brief Concatenate and append a list of values to an ast_str
 *
 * \param config Config object
 * \param values A vector of values
 * \param str The ast_str to append to
 * \retval 0 on success
 * \retval -1 on failure
 */
static int dsv_appender(struct cdrel_config *config, struct cdrel_values *values, struct ast_str **str)
{
    int ix = 0;
    int res = 0;
 
    for (ix = 0; ix < AST_VECTOR_SIZE(values); ix++) {
        struct cdrel_value *value = AST_VECTOR_GET(values, ix);
        ast_assert(value->data_type == cdrel_type_string);
 
        res = ast_str_append(str, -1, "%s%s", ix == 0 ? "" : config->separator, value->values.string);
        if (res < 0) {
            return -1;
        }
    }
 
    return res;
}
 
/*!
 * \internal
 * \brief Write a DSV list of values to a text file
 *
 * \param config Config object
 * \param values A vector of values
 * \retval 0 on success
 * \retval -1 on failure
 */
static int dsv_writer(struct cdrel_config *config, struct cdrel_values *values)
{
    int res = 0;
    struct ast_str *str = ast_str_thread_get(&custom_buf, 1024);
 
    ast_str_reset(str);
 
    res = dsv_appender(config, values, &str);
    if (res < 0) {
        return -1;
    }
 
    return write_record_to_file(config, str);
}
 
/*!
 * \internal
 * \brief Write a list of values as a JSON object to a text file
 *
 * \param config Config object
 * \param values A vector of values
 * \retval 0 on success
 * \retval -1 on failure
 *
 * \note We are intentionally NOT using the ast_json APIs here because
 * they're expensive and these are simple objects.
 */
static int json_writer(struct cdrel_config *config, struct cdrel_values *values)
{
    int ix = 0;
    int res = 0;
    /*
     * Since JSON records include the field names, the actual record size can be quite
     * lengthy and since the thread-local backed ast_str used by the DSV writer can't be
     * extended, we need to use a regular, extendable ast_str.
     */
    RAII_VAR(struct ast_str *, str, ast_str_create(1024), ast_free);
 
    if (!str) {
        return -1;
    }
 
    ast_str_set(&str, -1, "%s", "{");
 
    for (ix = 0; ix < AST_VECTOR_SIZE(values); ix++) {
        struct cdrel_value *value = AST_VECTOR_GET(values, ix);
        ast_assert(value->data_type == cdrel_type_string);
 
        res = ast_str_append(&str, -1, "%s\"%s\":%s", ix == 0 ? "" : config->separator, value->field_name, value->values.string);
        if (res < 0) {
            return -1;
        }
    }
    ast_str_append(&str, -1, "%s", "}");
 
    return write_record_to_file(config, str);
}
 
/*!
 * \internal
 * \brief Write a record to a database
 *
 * Besides being used here, this function is also used by the legacy loggers
 * that shortcut the advanced stuff.
 *
 * \param config The configuration object.
 * \param record The data to write.
 * \retval 0 on success
 * \retval -1 on failure
 */
int write_record_to_database(struct cdrel_config *config, struct cdrel_values *values)
{
    int res = 0;
    int ix;
 
    ast_mutex_lock(&config->lock);
    for (ix = 0; ix < AST_VECTOR_SIZE(values); ix++) {
        struct cdrel_value *value = AST_VECTOR_GET(values, ix);
        ast_assert(value->data_type == cdrel_type_string);
        ast_debug(6, "%s '%s'\n", value->field_name, value->values.string);
        res = sqlite3_bind_text(config->insert, ix + 1, value->values.string, -1, SQLITE_STATIC);
        if (res != SQLITE_OK) {
            ast_log(LOG_ERROR, "Unable to write %s to database %s.  SQL bind for field %s:'%s'. Error: %s\n",
                RECORD_TYPE_STR(config->record_type), config->output_filename,
                value->field_name, value->values.string,
                sqlite3_errmsg(config->db));
            sqlite3_reset(config->insert);
            ast_mutex_unlock(&config->lock);
            return -1;
        }
    }
 
    res = sqlite3_step(config->insert);
    if (res != SQLITE_DONE) {
        ast_log(LOG_ERROR, "Unable to write %s to database %s. Error: %s\n",
            RECORD_TYPE_STR(config->record_type), config->output_filename,
            sqlite3_errmsg(config->db));
        sqlite3_reset(config->insert);
        ast_mutex_unlock(&config->lock);
        return -1;
    }
 
    sqlite3_reset(config->insert);
    ast_mutex_unlock(&config->lock);
 
    return res;
}
 
/*!
 * \internal
 * \brief Write a list of values to a database
 *
 * \param config Config object
 * \param values A vector of values
 * \retval 0 on success
 * \retval -1 on failure
 */
static int database_writer(struct cdrel_config *config, struct cdrel_values *values)
{
    return write_record_to_database(config, values);
}
 
int load_writers(void)
{
    ast_debug(1, "Loading Writers\n");
    cdrel_backend_writers[cdrel_format_dsv] = dsv_writer;
    cdrel_backend_writers[cdrel_format_json] = json_writer;
    cdrel_backend_writers[cdrel_format_sql] = database_writer;
 
    return 0;
}