smart-energy-monitor/software/flow/node_modules/npm/lib/utils/log-file.js

234 lines
6.9 KiB
JavaScript

const os = require('os')
const { join, dirname, basename } = require('path')
const { format, promisify } = require('util')
const glob = promisify(require('glob'))
const MiniPass = require('minipass')
const fsMiniPass = require('fs-minipass')
const fs = require('fs/promises')
const log = require('./log-shim')
const padZero = (n, length) => n.toString().padStart(length.toString().length, '0')
const globify = pattern => pattern.split('\\').join('/')
class LogFiles {
// Default to a plain minipass stream so we can buffer
// initial writes before we know the cache location
#logStream = null
// We cap log files at a certain number of log events per file.
// Note that each log event can write more than one line to the
// file. Then we rotate log files once this number of events is reached
#MAX_LOGS_PER_FILE = null
// Now that we write logs continuously we need to have a backstop
// here for infinite loops that still log. This is also partially handled
// by the config.get('max-files') option, but this is a failsafe to
// prevent runaway log file creation
#MAX_FILES_PER_PROCESS = null
#fileLogCount = 0
#totalLogCount = 0
#path = null
#logsMax = null
#files = []
constructor ({
maxLogsPerFile = 50_000,
maxFilesPerProcess = 5,
} = {}) {
this.#MAX_LOGS_PER_FILE = maxLogsPerFile
this.#MAX_FILES_PER_PROCESS = maxFilesPerProcess
this.on()
}
static format (count, level, title, ...args) {
let prefix = `${count} ${level}`
if (title) {
prefix += ` ${title}`
}
return format(...args)
.split(/\r?\n/)
.reduce((lines, line) =>
lines += prefix + (line ? ' ' : '') + line + os.EOL,
''
)
}
on () {
this.#logStream = new MiniPass()
process.on('log', this.#logHandler)
}
off () {
process.off('log', this.#logHandler)
this.#endStream()
}
load ({ path, logsMax = Infinity } = {}) {
// dir is user configurable and is required to exist so
// this can error if the dir is missing or not configured correctly
this.#path = path
this.#logsMax = logsMax
// Log stream has already ended
if (!this.#logStream) {
return
}
log.verbose('logfile', `logs-max:${logsMax} dir:${this.#path}`)
// Pipe our initial stream to our new file stream and
// set that as the new log logstream for future writes
// if logs max is 0 then the user does not want a log file
if (this.#logsMax > 0) {
const initialFile = this.#openLogFile()
if (initialFile) {
this.#logStream = this.#logStream.pipe(initialFile)
}
}
// Kickoff cleaning process, even if we aren't writing a logfile.
// This is async but it will always ignore the current logfile
// Return the result so it can be awaited in tests
return this.#cleanLogs()
}
log (...args) {
this.#logHandler(...args)
}
get files () {
return this.#files
}
get #isBuffered () {
return this.#logStream instanceof MiniPass
}
#endStream (output) {
if (this.#logStream) {
this.#logStream.end(output)
this.#logStream = null
}
}
#logHandler = (level, ...args) => {
// Ignore pause and resume events since we
// write everything to the log file
if (level === 'pause' || level === 'resume') {
return
}
// If the stream is ended then do nothing
if (!this.#logStream) {
return
}
const logOutput = this.#formatLogItem(level, ...args)
if (this.#isBuffered) {
// Cant do anything but buffer the output if we dont
// have a file stream yet
this.#logStream.write(logOutput)
return
}
// Open a new log file if we've written too many logs to this one
if (this.#fileLogCount >= this.#MAX_LOGS_PER_FILE) {
// Write last chunk to the file and close it
this.#endStream(logOutput)
if (this.#files.length >= this.#MAX_FILES_PER_PROCESS) {
// but if its way too many then we just stop listening
this.off()
} else {
// otherwise we are ready for a new file for the next event
this.#logStream = this.#openLogFile()
}
} else {
this.#logStream.write(logOutput)
}
}
#formatLogItem (...args) {
this.#fileLogCount += 1
return LogFiles.format(this.#totalLogCount++, ...args)
}
#getLogFilePath (count = '') {
return `${this.#path}debug-${count}.log`
}
#openLogFile () {
// Count in filename will be 0 indexed
const count = this.#files.length
try {
// Pad with zeros so that our log files are always sorted properly
// We never want to write files ending in `-9.log` and `-10.log` because
// log file cleaning is done by deleting the oldest so in this example
// `-10.log` would be deleted next
const f = this.#getLogFilePath(padZero(count, this.#MAX_FILES_PER_PROCESS))
// Some effort was made to make the async, but we need to write logs
// during process.on('exit') which has to be synchronous. So in order
// to never drop log messages, it is easiest to make it sync all the time
// and this was measured to be about 1.5% slower for 40k lines of output
const logStream = new fsMiniPass.WriteStreamSync(f, { flags: 'a' })
if (count > 0) {
// Reset file log count if we are opening
// after our first file
this.#fileLogCount = 0
}
this.#files.push(logStream.path)
return logStream
} catch (e) {
// If the user has a readonly logdir then we don't want to
// warn this on every command so it should be verbose
log.verbose('logfile', `could not be created: ${e}`)
}
}
async #cleanLogs () {
// module to clean out the old log files
// this is a best-effort attempt. if a rm fails, we just
// log a message about it and move on. We do return a
// Promise that succeeds when we've tried to delete everything,
// just for the benefit of testing this function properly.
try {
const logPath = this.#getLogFilePath()
const logGlob = join(dirname(logPath), basename(logPath)
// tell glob to only match digits
.replace(/\d/g, '[0123456789]')
// Handle the old (prior to 8.2.0) log file names which did not have a
// counter suffix
.replace(/-\.log$/, '*.log')
)
// Always ignore the currently written files
const files = await glob(globify(logGlob), { ignore: this.#files.map(globify), silent: true })
const toDelete = files.length - this.#logsMax
if (toDelete <= 0) {
return
}
log.silly('logfile', `start cleaning logs, removing ${toDelete} files`)
for (const file of files.slice(0, toDelete)) {
try {
await fs.rm(file, { force: true })
} catch (e) {
log.silly('logfile', 'error removing log file', file, e)
}
}
} catch (e) {
log.warn('logfile', 'error cleaning log files', e)
} finally {
log.silly('logfile', 'done cleaning log files')
}
}
}
module.exports = LogFiles