elflib/dist/reader.js

ELF file reader and writer

import * as fs from 'fs';
function bufferRead(state, length, position) {
    let updatepos = false;
    const { array } = state;
    if (!array)
        return Promise.reject('state.array must be defined');
    if (!length)
        return Promise.reject('Length must be specified');
    if (!position) {
        position = state.position;
        updatepos = true;
    }
    if (position <= state.size) {
        if (position + length > state.size)
            length = state.size - position;
        if (length < 0)
            length = 0;
        if (updatepos)
            state.position += length;
        // return Promise.resolve(new Uint8Array(array, state.offset + position, length));
        return Promise.resolve(array instanceof ArrayBuffer ? new Uint8Array(array) : array);
    }
    else {
        return Promise.reject('read past end of file');
    }
}
function createView(from) {
    return new DataView(from.buffer, from.byteOffset, from.byteLength);
}
export function buffer(buffer) {
    const state = {
        array: buffer,
        offset: buffer instanceof Uint8Array ? buffer.byteOffset : 0,
        position: 0,
        size: buffer.byteLength
    };
    return {
        open: () => Promise.resolve(),
        size: () => state.size,
        close: () => Promise.resolve(),
        read: (length, position) => bufferRead(state, length, position),
        view: (length, position) => bufferRead(state, length, position).then(createView),
    };
}
export function array(array) {
    return buffer(Uint8Array.from(array));
}
export async function fileHandle(fh) {
    await fh.stat();
    return buffer(Uint8Array.from(await fh.readFile()));
}
export function fileDescriptor(handle) {
    fs.fstatSync(handle);
    return buffer(Uint8Array.from(fs.readFileSync(handle)));
}
export function filePath(path) {
    fs.accessSync(path, fs.constants.R_OK);
    return buffer(Uint8Array.from(fs.readFileSync(path)));
}
export function HelperDataView(view, bigEndian) {
    view.readUInt8 = view.getUint8.bind(view);
    view.readUInt16 = (ix) => view.getUint16(ix, !bigEndian);
    view.readUInt32 = (ix) => view.getUint32(ix, !bigEndian);
    view.readUInt64 = (ix) => view.getBigUint64(ix, !bigEndian);
    view.readSInt8 = (ix) => view.getInt8(ix);
    view.readSInt16 = (ix) => view.getInt16(ix, !bigEndian);
    view.readSInt32 = (ix) => view.getInt32(ix, !bigEndian);
    view.readSInt64 = (ix) => view.getBigInt64(ix, !bigEndian);
    return view;
}