mod_log_config.c

Apache HTTP Server 是一个功能强大的灵活的与HTTP/1.1相兼容的web服务器.这里给出的是Apache HTTP服务器的源码。

{
    int i;
    multi_log_state *mls = ap_get_module_config(s->module_config,
                                             &log_config_module);
    config_log_state *clsarray;
    const char *dummy;
    const char *format;

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

            if (!open_config_log(s, p, cls, mls->default_format)) {
                /* Failure already logged by open_config_log */
                return DONE;
            }
        }
    }
    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 = apr_table_get(mls->formats, cls->format_string);
                if (format) {
                    cls->format = parse_log_string(p, format, &dummy);
                }
            }

            if (!open_config_log(s, p, cls, mls->default_format)) {
                /* Failure already logged by open_config_log */
                return DONE;
            }
        }
    }

    return OK;
}


static apr_status_t flush_all_logs(void *data)
{
    server_rec *s = data;
    multi_log_state *mls;
    apr_array_header_t *log_list;
    config_log_state *clsarray;
    buffered_log *buf;
    int i;

    if (!buffered_logs)
        return APR_SUCCESS;
    
    for (; s; s = s->next) {
        mls = ap_get_module_config(s->module_config, &log_config_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) {
                buf = clsarray[i].log_writer;
                flush_log(buf);
            }
        }
    }
    return APR_SUCCESS;
}


static int init_config_log(apr_pool_t *pc, apr_pool_t *p, apr_pool_t *pt, server_rec *s)
{
    int res;

    /* First init the buffered logs array, which is needed when opening the logs. */
    if (buffered_logs) {
        all_buffered_logs = apr_array_make(p, 5, sizeof(buffered_log *));
    }

    /* Next, do "physical" server, which gets default log fd and format
     * for the virtual servers, if they don't override...
     */
    res = open_multi_logs(s, p);

    /* Then, virtual servers */

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

    return res;
}

static void init_child(apr_pool_t *p, server_rec *s)
{
    int mpm_threads;

    ap_mpm_query(AP_MPMQ_MAX_THREADS, &mpm_threads);

    /* Now register the last buffer flush with the cleanup engine */
    if (buffered_logs) {
        int i;
        buffered_log **array = (buffered_log **)all_buffered_logs->elts;
        
        apr_pool_cleanup_register(p, s, flush_all_logs, flush_all_logs);

        for (i = 0; i < all_buffered_logs->nelts; i++) {
            buffered_log *this = array[i];
            
#if APR_HAS_THREADS
            if (mpm_threads > 1) {
                apr_status_t rv;

                this->mutex.type = apr_anylock_threadmutex;
                rv = apr_thread_mutex_create(&this->mutex.lock.tm,
                                             APR_THREAD_MUTEX_DEFAULT,
                                             p);
                if (rv != APR_SUCCESS) {
                    ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s,
                                 "could not initialize buffered log mutex, "
                                 "transfer log may become corrupted");
                    this->mutex.type = apr_anylock_none;
                }
            }
            else
#endif
            {
                this->mutex.type = apr_anylock_none;
            }
        }
    }
}

static void ap_register_log_handler(apr_pool_t *p, char *tag, 
                                    ap_log_handler_fn_t *handler, int def)
{
    ap_log_handler *log_struct = apr_palloc(p, sizeof(*log_struct));
    log_struct->func = handler;
    log_struct->want_orig_default = def;

    apr_hash_set(log_hash, tag, 1, (const void *)log_struct);
}
static void ap_log_set_writer_init(ap_log_writer_init *handle)
{
    log_writer_init = handle;

}
static void ap_log_set_writer(ap_log_writer *handle)
{
    log_writer = handle;
}

static apr_status_t ap_default_log_writer( request_rec *r,
                           void *handle, 
                           const char **strs,
                           int *strl,
                           int nelts,
                           apr_size_t len)

{
    char *str;
    char *s;
    int i;
    apr_status_t rv;

    str = apr_palloc(r->pool, len + 1);

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

    rv = apr_file_write((apr_file_t*)handle, str, &len);

    return rv;
}
static void *ap_default_log_writer_init(apr_pool_t *p, server_rec *s, 
                                        const char* name)
{
    if (*name == '|') {
        piped_log *pl;

        pl = ap_open_piped_log(p, name + 1);
        if (pl == NULL) {
           return NULL;;
        }
        return ap_piped_log_write_fd(pl);
    }
    else {
        const char *fname = ap_server_root_relative(p, name);
        apr_file_t *fd;
        apr_status_t rv;

        if (!fname) {
            ap_log_error(APLOG_MARK, APLOG_ERR, APR_EBADPATH, s,
                            "invalid transfer log path %s.", name);
            return NULL;
        }
        rv = apr_file_open(&fd, fname, xfer_flags, xfer_perms, p);
        if (rv != APR_SUCCESS) {
            ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
                            "could not open transfer log file %s.", fname);
            return NULL;
        }
        return fd;
    }
}
static void *ap_buffered_log_writer_init(apr_pool_t *p, server_rec *s, 
                                        const char* name)
{
    buffered_log *b;
    b = apr_pcalloc(p, sizeof(buffered_log));
    b->handle = ap_default_log_writer_init(p, s, name);
    
    if (b->handle) {
        *(buffered_log **)apr_array_push(all_buffered_logs) = b;
        return b;
    }
    else
        return NULL;
}
static apr_status_t ap_buffered_log_writer(request_rec *r,
                                           void *handle, 
                                           const char **strs,
                                           int *strl,
                                           int nelts,
                                           apr_size_t len)

{
    char *str;
    char *s;
    int i;
    apr_status_t rv;
    buffered_log *buf = (buffered_log*)handle;

    if ((rv = APR_ANYLOCK_LOCK(&buf->mutex)) != APR_SUCCESS) {
        return rv;
    }

    if (len + buf->outcnt > LOG_BUFSIZE) {
        flush_log(buf);
    }
    if (len >= LOG_BUFSIZE) {
        apr_size_t w;

        str = apr_palloc(r->pool, len + 1);
        for (i = 0, s = str; i < nelts; ++i) {
            memcpy(s, strs[i], strl[i]);
            s += strl[i];
        }
        w = len;
        rv = apr_file_write(buf->handle, str, &w);
        
    }
    else {
        for (i = 0, s = &buf->outbuf[buf->outcnt]; i < nelts; ++i) {
            memcpy(s, strs[i], strl[i]);
            s += strl[i];
        }
        buf->outcnt += len;
        rv = APR_SUCCESS;
    }

    APR_ANYLOCK_UNLOCK(&buf->mutex);
    return rv;
}

static int log_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp)
{
    static APR_OPTIONAL_FN_TYPE(ap_register_log_handler) *log_pfn_register;
    
    log_pfn_register = APR_RETRIEVE_OPTIONAL_FN(ap_register_log_handler);

    if (log_pfn_register) {
        log_pfn_register(p, "h", log_remote_host, 0);
        log_pfn_register(p, "a", log_remote_address, 0 );
        log_pfn_register(p, "A", log_local_address, 0 );
        log_pfn_register(p, "l", log_remote_logname, 0);
        log_pfn_register(p, "u", log_remote_user, 0);
        log_pfn_register(p, "t", log_request_time, 0);
        log_pfn_register(p, "f", log_request_file, 0);
        log_pfn_register(p, "b", clf_log_bytes_sent, 0);
        log_pfn_register(p, "B", log_bytes_sent, 0);
        log_pfn_register(p, "i", log_header_in, 0);
        log_pfn_register(p, "o", log_header_out, 0);
        log_pfn_register(p, "n", log_note, 0);
        log_pfn_register(p, "e", log_env_var, 0);
        log_pfn_register(p, "V", log_server_name, 0);
        log_pfn_register(p, "v", log_virtual_host, 0);
        log_pfn_register(p, "p", log_server_port, 0);
        log_pfn_register(p, "P", log_pid_tid, 0);
        log_pfn_register(p, "H", log_request_protocol, 0);
        log_pfn_register(p, "m", log_request_method, 0);
        log_pfn_register(p, "q", log_request_query, 0);
        log_pfn_register(p, "X", log_connection_status, 0);
        log_pfn_register(p, "C", log_cookie, 0);
        log_pfn_register(p, "r", log_request_line, 1);
        log_pfn_register(p, "D", log_request_duration_microseconds, 1);
        log_pfn_register(p, "T", log_request_duration, 1);
        log_pfn_register(p, "U", log_request_uri, 1);
        log_pfn_register(p, "s", log_status, 1);
    }

    return OK;
}

static void register_hooks(apr_pool_t *p)
{
    ap_hook_pre_config(log_pre_config,NULL,NULL,APR_HOOK_REALLY_FIRST);
    ap_hook_child_init(init_child,NULL,NULL,APR_HOOK_MIDDLE);
    ap_hook_open_logs(init_config_log,NULL,NULL,APR_HOOK_MIDDLE);
    ap_hook_log_transaction(multi_log_transaction,NULL,NULL,APR_HOOK_MIDDLE);

    /* Init log_hash before we register the optional function. It is 
     * possible for the optional function, ap_register_log_handler,
     * to be called before any other mod_log_config hooks are called.
     * As a policy, we should init everything required by an optional function
     * before calling APR_REGISTER_OPTIONAL_FN.
     */ 
    log_hash = apr_hash_make(p);
    APR_REGISTER_OPTIONAL_FN(ap_register_log_handler);
    APR_REGISTER_OPTIONAL_FN(ap_log_set_writer_init);
    APR_REGISTER_OPTIONAL_FN(ap_log_set_writer);
}

module AP_MODULE_DECLARE_DATA log_config_module =
{
    STANDARD20_MODULE_STUFF,
    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 apr_table_t */
    register_hooks              /* register hooks */
};