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'use strict'
const util = require('util')
const fs = require('fs')
const fsm = require('fs-minipass')
const ssri = require('ssri')
const contentPath = require('./path')
const Pipeline = require('minipass-pipeline')
const lstat = util.promisify(fs.lstat)
const readFile = util.promisify(fs.readFile)
module.exports = read
const MAX_SINGLE_READ_SIZE = 64 * 1024 * 1024
function read (cache, integrity, opts = {}) {
const { size } = opts
return withContentSri(cache, integrity, (cpath, sri) => {
// get size
return lstat(cpath).then(stat => ({ stat, cpath, sri }))
}).then(({ stat, cpath, sri }) => {
if (typeof size === 'number' && stat.size !== size)
throw sizeError(size, stat.size)
if (stat.size > MAX_SINGLE_READ_SIZE)
return readPipeline(cpath, stat.size, sri, new Pipeline()).concat()
return readFile(cpath, null).then((data) => {
if (!ssri.checkData(data, sri))
throw integrityError(sri, cpath)
return data
})
})
}
const readPipeline = (cpath, size, sri, stream) => {
stream.push(
new fsm.ReadStream(cpath, {
size,
readSize: MAX_SINGLE_READ_SIZE,
}),
ssri.integrityStream({
integrity: sri,
size,
})
)
return stream
}
module.exports.sync = readSync
function readSync (cache, integrity, opts = {}) {
const { size } = opts
return withContentSriSync(cache, integrity, (cpath, sri) => {
const data = fs.readFileSync(cpath)
if (typeof size === 'number' && size !== data.length)
throw sizeError(size, data.length)
if (ssri.checkData(data, sri))
return data
throw integrityError(sri, cpath)
})
}
module.exports.stream = readStream
module.exports.readStream = readStream
function readStream (cache, integrity, opts = {}) {
const { size } = opts
const stream = new Pipeline()
withContentSri(cache, integrity, (cpath, sri) => {
// just lstat to ensure it exists
return lstat(cpath).then((stat) => ({ stat, cpath, sri }))
}).then(({ stat, cpath, sri }) => {
if (typeof size === 'number' && size !== stat.size)
return stream.emit('error', sizeError(size, stat.size))
readPipeline(cpath, stat.size, sri, stream)
}, er => stream.emit('error', er))
return stream
}
let copyFile
if (fs.copyFile) {
module.exports.copy = copy
module.exports.copy.sync = copySync
copyFile = util.promisify(fs.copyFile)
}
function copy (cache, integrity, dest) {
return withContentSri(cache, integrity, (cpath, sri) => {
return copyFile(cpath, dest)
})
}
function copySync (cache, integrity, dest) {
return withContentSriSync(cache, integrity, (cpath, sri) => {
return fs.copyFileSync(cpath, dest)
})
}
module.exports.hasContent = hasContent
function hasContent (cache, integrity) {
if (!integrity)
return Promise.resolve(false)
return withContentSri(cache, integrity, (cpath, sri) => {
return lstat(cpath).then((stat) => ({ size: stat.size, sri, stat }))
}).catch((err) => {
if (err.code === 'ENOENT')
return false
if (err.code === 'EPERM') {
/* istanbul ignore else */
if (process.platform !== 'win32')
throw err
else
return false
}
})
}
module.exports.hasContent.sync = hasContentSync
function hasContentSync (cache, integrity) {
if (!integrity)
return false
return withContentSriSync(cache, integrity, (cpath, sri) => {
try {
const stat = fs.lstatSync(cpath)
return { size: stat.size, sri, stat }
} catch (err) {
if (err.code === 'ENOENT')
return false
if (err.code === 'EPERM') {
/* istanbul ignore else */
if (process.platform !== 'win32')
throw err
else
return false
}
}
})
}
function withContentSri (cache, integrity, fn) {
const tryFn = () => {
const sri = ssri.parse(integrity)
// If `integrity` has multiple entries, pick the first digest
// with available local data.
const algo = sri.pickAlgorithm()
const digests = sri[algo]
if (digests.length <= 1) {
const cpath = contentPath(cache, digests[0])
return fn(cpath, digests[0])
} else {
// Can't use race here because a generic error can happen before
// a ENOENT error, and can happen before a valid result
return Promise
.all(digests.map((meta) => {
return withContentSri(cache, meta, fn)
.catch((err) => {
if (err.code === 'ENOENT') {
return Object.assign(
new Error('No matching content found for ' + sri.toString()),
{ code: 'ENOENT' }
)
}
return err
})
}))
.then((results) => {
// Return the first non error if it is found
const result = results.find((r) => !(r instanceof Error))
if (result)
return result
// Throw the No matching content found error
const enoentError = results.find((r) => r.code === 'ENOENT')
if (enoentError)
throw enoentError
// Throw generic error
throw results.find((r) => r instanceof Error)
})
}
}
return new Promise((resolve, reject) => {
try {
tryFn()
.then(resolve)
.catch(reject)
} catch (err) {
reject(err)
}
})
}
function withContentSriSync (cache, integrity, fn) {
const sri = ssri.parse(integrity)
// If `integrity` has multiple entries, pick the first digest
// with available local data.
const algo = sri.pickAlgorithm()
const digests = sri[algo]
if (digests.length <= 1) {
const cpath = contentPath(cache, digests[0])
return fn(cpath, digests[0])
} else {
let lastErr = null
for (const meta of digests) {
try {
return withContentSriSync(cache, meta, fn)
} catch (err) {
lastErr = err
}
}
throw lastErr
}
}
function sizeError (expected, found) {
const err = new Error(`Bad data size: expected inserted data to be ${expected} bytes, but got ${found} instead`)
err.expected = expected
err.found = found
err.code = 'EBADSIZE'
return err
}
function integrityError (sri, path) {
const err = new Error(`Integrity verification failed for ${sri} (${path})`)
err.code = 'EINTEGRITY'
err.sri = sri
err.path = path
return err
}