mod_log_config.c

apache简化版

    orig = r;
    while (orig->prev) {
        orig = orig->prev;
    }
    while (r->next) {
        r = r->next;
    }

    for (i = 0; i < format->nelts; ++i) {
        strs[i] = process_item(r, orig, &items[i]);
    }

    for (i = 0; i < format->nelts; ++i) {
        len += strl[i] = strlen(strs[i]);
    }

#ifdef BUFFERED_LOGS
    if (len + cls->outcnt > LOG_BUFSIZE) {
        flush_log(cls);
    }
    if (len >= LOG_BUFSIZE) {
        str = ap_palloc(r->pool, len + 1);
        for (i = 0, s = str; i < format->nelts; ++i) {
            memcpy(s, strs[i], strl[i]);
            s += strl[i];
        }
        write(cls->log_fd, str, len);
    }
    else {
        for (i = 0, s = &cls->outbuf[cls->outcnt]; i < format->nelts; ++i) {
            memcpy(s, strs[i], strl[i]);
            s += strl[i];
        }
        cls->outcnt += len;
    }
#else
    str = ap_palloc(r->pool, len + 1);

    for (i = 0, s = str; i < format->nelts; ++i) {
        memcpy(s, strs[i], strl[i]);
        s += strl[i];
    }

    write(cls->log_fd, str, len);
#endif

    return OK;
}

static int multi_log_transaction(request_rec *r)
{
    multi_log_state *mls = ap_get_module_config(r->server->module_config,
                                             &config_log_module);
    config_log_state *clsarray;
    int i;

    if (mls->config_logs->nelts) {
        clsarray = (config_log_state *) mls->config_logs->elts;
        for (i = 0; i < mls->config_logs->nelts; ++i) {
            config_log_state *cls = &clsarray[i];

            config_log_transaction(r, cls, mls->default_format);
        }
    }
    else if (mls->server_config_logs) {
        clsarray = (config_log_state *) mls->server_config_logs->elts;
        for (i = 0; i < mls->server_config_logs->nelts; ++i) {
            config_log_state *cls = &clsarray[i];

            config_log_transaction(r, cls, mls->default_format);
        }
    }

    return OK;
}

/*****************************************************************
 *
 * Module glue...
 */

static void *make_config_log_state(pool *p, server_rec *s)
{
    multi_log_state *mls = (multi_log_state *) ap_palloc(p, sizeof(multi_log_state));

    mls->config_logs = ap_make_array(p, 1, sizeof(config_log_state));
    mls->default_format_string = NULL;
    mls->default_format = NULL;
    mls->server_config_logs = NULL;
    mls->formats = ap_make_table(p, 4);
    ap_table_setn(mls->formats, "CLF", DEFAULT_LOG_FORMAT);

    return mls;
}

/*
 * Use the merger to simply add a pointer from the vhost log state
 * to the log of logs specified for the non-vhost configuration.  Make sure
 * vhosts inherit any globally-defined format names.
 */

static void *merge_config_log_state(pool *p, void *basev, void *addv)
{
    multi_log_state *base = (multi_log_state *) basev;
    multi_log_state *add = (multi_log_state *) addv;

    add->server_config_logs = base->config_logs;
    if (!add->default_format) {
        add->default_format_string = base->default_format_string;
        add->default_format = base->default_format;
    }
    add->formats = ap_overlay_tables(p, base->formats, add->formats);

    return add;
}

/*
 * Set the default logfile format, or define a nickname for a format string.
 */
static const char *log_format(cmd_parms *cmd, void *dummy, char *fmt,
                              char *name)
{
    const char *err_string = NULL;
    multi_log_state *mls = ap_get_module_config(cmd->server->module_config,
                                             &config_log_module);

    /*
     * If we were given two arguments, the second is a name to be given to the
     * format.  This syntax just defines the nickname - it doesn't actually
     * make the format the default.
     */
    if (name != NULL) {
        parse_log_string(cmd->pool, fmt, &err_string);
        if (err_string == NULL) {
            ap_table_setn(mls->formats, name, fmt);
        }
    }
    else {
        mls->default_format_string = fmt;
        mls->default_format = parse_log_string(cmd->pool, fmt, &err_string);
    }
    return err_string;
}

static const char *add_custom_log(cmd_parms *cmd, void *dummy, char *fn,
                                  char *fmt)
{
    const char *err_string = NULL;
    multi_log_state *mls = ap_get_module_config(cmd->server->module_config,
                                             &config_log_module);
    config_log_state *cls;

    cls = (config_log_state *) ap_push_array(mls->config_logs);
    cls->fname = fn;
    cls->format_string = fmt;
    if (!fmt) {
        cls->format = NULL;
    }
    else {
        cls->format = parse_log_string(cmd->pool, fmt, &err_string);
    }
    cls->log_fd = -1;

    return err_string;
}

static const char *set_transfer_log(cmd_parms *cmd, void *dummy, char *fn)
{
    return add_custom_log(cmd, dummy, fn, NULL);
}

static const char *set_cookie_log(cmd_parms *cmd, void *dummy, char *fn)
{
    return add_custom_log(cmd, dummy, fn, "%{Cookie}n \"%r\" %t");
}

static const command_rec config_log_cmds[] =
{
    {"CustomLog", add_custom_log, NULL, RSRC_CONF, TAKE2,
     "a file name and a custom log format string or format name"},
    {"TransferLog", set_transfer_log, NULL, RSRC_CONF, TAKE1,
     "the filename of the access log"},
    {"LogFormat", log_format, NULL, RSRC_CONF, TAKE12,
     "a log format string (see docs) and an optional format name"},
    {"CookieLog", set_cookie_log, NULL, RSRC_CONF, TAKE1,
     "the filename of the cookie log"},
    {NULL}
};

static config_log_state *open_config_log(server_rec *s, pool *p,
                                         config_log_state *cls,
                                         array_header *default_format)
{
    if (cls->log_fd > 0) {
        return cls;             /* virtual config shared w/main server */
    }

    if (cls->fname == NULL) {
        return cls;             /* Leave it NULL to decline.  */
    }

    if (*cls->fname == '|') {
        piped_log *pl;

        pl = ap_open_piped_log(p, cls->fname + 1);
        if (pl == NULL) {
            exit(1);
        }
        cls->log_fd = ap_piped_log_write_fd(pl);
    }
    else {
        char *fname = ap_server_root_relative(p, cls->fname);
        if ((cls->log_fd = ap_popenf(p, fname, xfer_flags, xfer_mode)) < 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, s,
                         "httpd: could not open transfer log file %s.", fname);
            exit(1);
        }
    }
#ifdef BUFFERED_LOGS
    cls->outcnt = 0;
#endif

    return cls;
}

static config_log_state *open_multi_logs(server_rec *s, pool *p)
{
    int i;
    multi_log_state *mls = ap_get_module_config(s->module_config,
                                             &config_log_module);
    config_log_state *clsarray;
    const char *dummy;
    const char *format;

    if (mls->default_format_string) {
	format = ap_table_get(mls->formats, mls->default_format_string);
	if (format) {
	    mls->default_format = parse_log_string(p, format, &dummy);
	}
    }    

    if (!mls->default_format) {
        mls->default_format = parse_log_string(p, DEFAULT_LOG_FORMAT, &dummy);
    }

    if (mls->config_logs->nelts) {
        clsarray = (config_log_state *) mls->config_logs->elts;
        for (i = 0; i < mls->config_logs->nelts; ++i) {
            config_log_state *cls = &clsarray[i];

	    if (cls->format_string) {
		format = ap_table_get(mls->formats, cls->format_string);
		if (format) {
		    cls->format = parse_log_string(p, format, &dummy);
		}
	    }

            cls = open_config_log(s, p, cls, mls->default_format);
        }
    }
    else if (mls->server_config_logs) {
        clsarray = (config_log_state *) mls->server_config_logs->elts;
        for (i = 0; i < mls->server_config_logs->nelts; ++i) {
            config_log_state *cls = &clsarray[i];

	    if (cls->format_string) {
		format = ap_table_get(mls->formats, cls->format_string);
		if (format) {
		    cls->format = parse_log_string(p, format, &dummy);
		}
	    }

            cls = open_config_log(s, p, cls, mls->default_format);
        }
    }

    return NULL;
}

static void init_config_log(server_rec *s, pool *p)
{
    /* First, do "physical" server, which gets default log fd and format
     * for the virtual servers, if they don't override...
     */

    open_multi_logs(s, p);

    /* Then, virtual servers */

    for (s = s->next; s; s = s->next) {
        open_multi_logs(s, p);
    }
}

#ifdef BUFFERED_LOGS
static void flush_all_logs(server_rec *s, pool *p)
{
    multi_log_state *mls;
    array_header *log_list;
    config_log_state *clsarray;
    int i;

    for (; s; s = s->next) {
        mls = ap_get_module_config(s->module_config, &config_log_module);
        log_list = NULL;
        if (mls->config_logs->nelts) {
            log_list = mls->config_logs;
        }
        else if (mls->server_config_logs) {
            log_list = mls->server_config_logs;
        }
        if (log_list) {
            clsarray = (config_log_state *) log_list->elts;
            for (i = 0; i < log_list->nelts; ++i) {
                flush_log(&clsarray[i]);
            }
        }
    }
}
#endif

module MODULE_VAR_EXPORT config_log_module =
{
    STANDARD_MODULE_STUFF,
    init_config_log,            /* initializer */
    NULL,                       /* create per-dir config */
    NULL,                       /* merge per-dir config */
    make_config_log_state,      /* server config */
    merge_config_log_state,     /* merge server config */
    config_log_cmds,            /* command table */
    NULL,                       /* handlers */
    NULL,                       /* filename translation */
    NULL,                       /* check_user_id */
    NULL,                       /* check auth */
    NULL,                       /* check access */
    NULL,                       /* type_checker */
    NULL,                       /* fixups */
    multi_log_transaction,      /* logger */
    NULL,                       /* header parser */
    NULL,                       /* child_init */
#ifdef BUFFERED_LOGS
    flush_all_logs,             /* child_exit */
#else
    NULL,
#endif
    NULL                        /* post read-request */
};