signalk-server/dist/logging.js

An implementation of a [Signal K](http://signalk.org) server for boats.

"use strict";
const debugCore = require('debug');
const moment = require('moment');
const path = require('path');
const fs = require('fs');
module.exports = function (app) {
    const log = [];
    let debugEnabled = '';
    let rememberDebug = false;
    const size = 100;
    let debugPath;
    if (process.env.DEBUG) {
        debugEnabled = process.env.DEBUG;
    }
    debugPath = path.join(app.config.configPath, 'debug');
    if (fs.existsSync(debugPath)) {
        const enabled = fs.readFileSync(debugPath, 'utf8');
        if (enabled.length > 0) {
            debugCore.enable(enabled);
            debugEnabled = enabled;
            rememberDebug = true;
        }
    }
    function storeOutput(output, isError) {
        const data = {
            ts: moment().format('MMM DD HH:mm:ss'),
            row: output
        };
        if (isError) {
            data.isError = true;
        }
        log.push(data);
        if (log.length > size) {
            log.splice(0, log.length - size);
        }
        app.emit('serverlog', {
            type: 'LOG',
            data: data
        });
    }
    const outWrite = process.stdout.write;
    const errWrite = process.stderr.write;
    process.stdout.write = function (string) {
        outWrite.apply(process.stdout, arguments);
        storeOutput(string, false);
    };
    process.stderr.write = function (string) {
        errWrite.apply(process.stderr, arguments);
        storeOutput(string, true);
    };
    // send debug to stdout so it does not look like an error
    debugCore.log = console.info.bind(console);
    function enableDebug(enabled) {
        if (enabled.length > 0) {
            let all = enabled.split(',');
            if (all.indexOf('*') !== -1) {
                return false;
            }
            debugCore.enable(enabled);
        }
        else {
            debugCore.disable();
        }
        debugEnabled = enabled;
        if (rememberDebug && debugPath) {
            fs.writeFileSync(debugPath, debugEnabled);
        }
        app.emit('serverevent', {
            type: 'DEBUG_SETTINGS',
            data: {
                debugEnabled: enabled,
                rememberDebug
            }
        });
        return true;
    }
    return {
        getLog: () => {
            return log;
        },
        enableDebug: enableDebug,
        getDebugSettings: () => {
            return { debugEnabled, rememberDebug };
        },
        rememberDebug: (enabled) => {
            if (debugPath) {
                if (enabled) {
                    fs.writeFileSync(debugPath, debugEnabled);
                }
                else {
                    fs.unlinkSync(debugPath);
                }
            }
            rememberDebug = enabled;
            app.emit('serverevent', {
                type: 'DEBUG_SETTINGS',
                data: {
                    debugEnabled,
                    rememberDebug
                }
            });
        },
        addDebug: (name) => {
            if (debugEnabled.length > 0) {
                const all = debugEnabled.split(',');
                if (all.indexOf(name) === -1) {
                    enableDebug(debugEnabled + ',' + name);
                }
            }
            else {
                enableDebug(name);
            }
        },
        removeDebug: (name) => {
            if (debugEnabled.length > 0) {
                const all = debugEnabled.split(',');
                const idx = all.indexOf(name);
                if (idx !== -1) {
                    all.splice(idx, 1);
                    enableDebug(all.join(','));
                }
            }
        }
    };
};