Zazama / node-id3

import * as fs from 'fs'

import { promisify } from 'util'

export const fsOpenPromise = promisify(fs.open)

export const fsReadPromise = promisify(fs.read)

export const fsClosePromise = promisify(fs.close)

export const fsWritePromise = promisify(fs.write)

export const fsUnlinkPromise = promisify(fs.unlink)

export const fsRenamePromise = promisify(fs.rename)

export function processFileSync<T>(

    filepath: string,

    flags: string,

    process: (fileDescriptor: number) => T

) {

    const fileDescriptor = fs.openSync(filepath, flags)

    try {

        return process(fileDescriptor)

    }

    finally {

        fs.closeSync(fileDescriptor)

    }

}

export async function processFileAsync<T>(

    filepath: string,

    flags: string,

    process: (fileDescriptor: number) => Promise<T>

): Promise<T> {

    const fileDescriptor = await fsOpenPromise(filepath, flags)

    try {

        return await process(fileDescriptor)

    }

    finally {

        await fsClosePromise(fileDescriptor)

    }

}

export function fillBufferSync(

    fileDescriptor: number,

    buffer: Buffer,

    offset = 0

): Buffer {

    const bytesRead = fs.readSync(

        fileDescriptor,

        buffer,

        offset,

        buffer.length - offset,

        null

    )

    return buffer.subarray(0, bytesRead + offset)

}

export async function fillBufferAsync(

    fileDescriptor: number,

    buffer: Buffer,

    offset = 0

): Promise<Buffer> {

    const bytesRead = (await fsReadPromise(

        fileDescriptor,

        buffer,

        offset,

        buffer.length - offset,

        null

    )).bytesRead

    return buffer.subarray(0, bytesRead + offset)

}