+function pageToStartAndCount (page: number, itemsPerPage: number) {
+ const start = (page - 1) * itemsPerPage
+
+ return { start, count: itemsPerPage }
+}
+
+function buildPath (path: string) {
+ if (isAbsolute(path)) return path
+
+ return join(root(), path)
+}
+
+// Consistent with .length, lodash truncate function is not
+function peertubeTruncate (str: string, maxLength: number) {
+ const options = {
+ length: maxLength
+ }
+ const truncatedStr = truncate(str, options)
+
+ // The truncated string is okay, we can return it
+ if (truncatedStr.length <= maxLength) return truncatedStr
+
+ // Lodash takes into account all UTF characters, whereas String.prototype.length does not: some characters have a length of 2
+ // We always use the .length so we need to truncate more if needed
+ options.length -= truncatedStr.length - maxLength
+ return truncate(str, options)
+}
+
+function sha256 (str: string, encoding: HexBase64Latin1Encoding = 'hex') {
+ return createHash('sha256').update(str).digest(encoding)
+}
+
+function promisify0<A> (func: (cb: (err: any, result: A) => void) => void): () => Promise<A> {
+ return function promisified (): Promise<A> {
+ return new Promise<A>((resolve: (arg: A) => void, reject: (err: any) => void) => {
+ func.apply(null, [ (err: any, res: A) => err ? reject(err) : resolve(res) ])
+ })
+ }
+}
+
+// Thanks to https://gist.github.com/kumasento/617daa7e46f13ecdd9b2
+function promisify1<T, A> (func: (arg: T, cb: (err: any, result: A) => void) => void): (arg: T) => Promise<A> {
+ return function promisified (arg: T): Promise<A> {
+ return new Promise<A>((resolve: (arg: A) => void, reject: (err: any) => void) => {
+ func.apply(null, [ arg, (err: any, res: A) => err ? reject(err) : resolve(res) ])
+ })
+ }
+}
+
+function promisify1WithVoid<T> (func: (arg: T, cb: (err: any) => void) => void): (arg: T) => Promise<void> {
+ return function promisified (arg: T): Promise<void> {
+ return new Promise<void>((resolve: () => void, reject: (err: any) => void) => {
+ func.apply(null, [ arg, (err: any) => err ? reject(err) : resolve() ])
+ })
+ }
+}
+
+function promisify2<T, U, A> (func: (arg1: T, arg2: U, cb: (err: any, result: A) => void) => void): (arg1: T, arg2: U) => Promise<A> {
+ return function promisified (arg1: T, arg2: U): Promise<A> {
+ return new Promise<A>((resolve: (arg: A) => void, reject: (err: any) => void) => {
+ func.apply(null, [ arg1, arg2, (err: any, res: A) => err ? reject(err) : resolve(res) ])
+ })
+ }
+}
+
+function promisify2WithVoid<T, U> (func: (arg1: T, arg2: U, cb: (err: any) => void) => void): (arg1: T, arg2: U) => Promise<void> {
+ return function promisified (arg1: T, arg2: U): Promise<void> {
+ return new Promise<void>((resolve: () => void, reject: (err: any) => void) => {
+ func.apply(null, [ arg1, arg2, (err: any) => err ? reject(err) : resolve() ])
+ })
+ }
+}
+
+const pseudoRandomBytesPromise = promisify1<number, Buffer>(pseudoRandomBytes)
+const createPrivateKey = promisify1<number, { key: string }>(pem.createPrivateKey)
+const getPublicKey = promisify1<string, { publicKey: string }>(pem.getPublicKey)
+const bcryptComparePromise = promisify2<any, string, boolean>(bcrypt.compare)
+const bcryptGenSaltPromise = promisify1<number, string>(bcrypt.genSalt)
+const bcryptHashPromise = promisify2<any, string | number, string>(bcrypt.hash)
+const createTorrentPromise = promisify2<string, any, any>(createTorrent)
+const execPromise2 = promisify2<string, any, string>(exec)
+const execPromise = promisify1<string, string>(exec)
+