PTFIO provides functions to read and write entire files in a synchronized way. Many readers can concurrently read a file until a write is requested. The write will block until all existing readers exit and all new readers block until the file write can be completed.

npm i ptfio

    import ptfio from 'ptfio';

    const queue = [];

    queue.push(ptfio.readProtectedFile(Path));
    queue.push(ptfio.writeProtectFile(Path, newContent));
    queue.push(ptfio.readProtectedFile(Path));
    const results = Promise.all(queue);

result[0] will have the content before the write. result[1] will have the new content.

Reads the entire file as soon as no writes are occurring.

readProtectedFile(path: string)
readProtectedFile(path: string, encoding: string)

path (string) (required)
    The path (relative or absolute) to the file

encoding (any)
    The expected encoding. 

Promise<string | buffer>

Replaces file when exclusive access can be obtained.

writeProtectedFile(path: string, content:  any)
writeProtectedFile(path: string, content:  any, encoding: string)

path (string) (required)
    The path (relative or absolute) to the file

content (any) (required)
    The data to be written

encoding (any)
    The encoding of content. 

Promise<string | buffer>

npm tests

MIT

This npm is a thin application of reader/writter locks (written by Micah Gorrell) on whole files.