README
mmap-mio
A cross-platform memory-mapped library for nodejs(& TypeScript).
powered by mio (C++11 cross-platform memory mapping library)
and node-addon-api
- TypeScript support.
- only support node 8.0+.
- gc friendly.
Usage
const { mmap ,mmap_ro } = require('mmap-mio')
const m = mmap('./file.hex')
const ro = mmap_ro('./file.hex') // for read-only mode
const buffer = m.buffer() // get file Buffer
// buffer.toString()
// buffer[0] = 65
// const byte = buffer[123]
m.sync() // force flush changes to disk.
m.unmap() // unmap the file. Note: do not access the buffer after unmapped;
api
/**
* Creates an instance of MappedFile.
*
* @export
* @param {(string | number)} path_or_fd
* @param {number} [offset]
* @param {number} [size_to_map]
* @returns {MappedFile}
*/
function mmap(path_or_fd: string | number, offset?: number, size_to_map ?: number): MappedFile
/**
* Creates an instance of ReadOnlyMappedFile.
*
* @export
* @param {(string | number)} path_or_fd
* @param {number} [offset]
* @param {number} [size_to_map]
* @returns {ReadOnlyMappedFile}
*/
function mmap_ro(path_or_fd: string | number, offset ?: number, size_to_map ?: number): ReadOnlyMappedFile
// same as ReadOnlyMappedFile
class MappedFile {
constructor(path_or_fd: string | number, offset ?: number, size_to_map ?: number);
readonly writable: boolean
readonly length: number // mapped length
readonly offset: number
buffer(offset?:number,length?:number): Buffer // get the buffer of mapped data
size(): number // mapped length same with .length
isMapped(): boolean
unmap(): void // unmap the file
sync(): void // flush changes to disk
}