pluotsorbet/util.js

136 строки
3.2 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
'use strict';
var util = (function () {
var Utf8TextDecoder;
function decodeUtf8(arrayBuffer) {
if (!Utf8TextDecoder) {
Utf8TextDecoder = new TextDecoder("utf-8");
}
return Utf8TextDecoder.decode(new Uint8Array(arrayBuffer));
}
function defaultValue(type) {
if (type === 'J')
return Long.ZERO;
if (type[0] === '[' || type[0] === 'L')
return null;
return 0;
}
var INT_MAX = Math.pow(2, 31) - 1;
var INT_MIN = -INT_MAX - 1;
function double2int(d) {
if (d > INT_MAX)
return INT_MAX;
if (d < INT_MIN)
return INT_MIN;
return d|0;
}
function double2long(d) {
if (d === Number.POSITIVE_INFINITY)
return Long.MAX_VALUE;
if (d === Number.NEGATIVE_INFINITY)
return Long.MIN_VALUE;
return Long.fromNumber(d);
}
var jStringEncoder = new TextEncoder('utf-16');
var jStringDecoder = new TextDecoder('utf-16');
function fromJavaChars(chars, offset, count) {
if (!chars) {
return null;
}
if (typeof count !== 'number')
count = chars.length;
if (typeof offset !== 'number')
offset = 0;
return jStringDecoder.decode(chars.subarray(offset, offset + count));
}
function fromJavaString(jStr) {
if (!jStr)
return null;
return jStr.str;
}
/**
* Returns an ArrayBufferView of the underlying code points
* represented by the given Java string.
*
* NOTE: Do not modify the ArrayBuffer; it may be shared between
* multiple string instances.
*/
function stringToCharArray(str) {
return new Uint16Array(jStringEncoder.encode(str).buffer);
}
var id = (function() {
var gen = 0;
return function() {
return ++gen;
}
})();
function tag(obj) {
if (!obj.tag)
obj.tag = id();
return obj.tag;
}
/**
* Compare two typed arrays, returning *true* if they have the same length
* and values, *false* otherwise. Note that we compare by value, not by byte,
* so:
* compareTypedArrays(new Uint8Array([0x00, 0xFF]), new Uint8Array[0x00, 0xFF])
* returns *true*;
*
* and:
* compareTypedArrays(new Uint8Array([0x00, 0xFF]), new Uint32Array[0x00000000, 0x000000FF])
* also returns *true*;
*
* but:
* compareTypedArrays(new Uint8Array([0x00, 0xFF]), new Uint16Array([0x00FF]))
* returns *false*.
*/
function compareTypedArrays(ary1, ary2) {
if (ary1.length != ary2.length) {
return false;
}
for (var i = 0; i < ary1.length; i++) {
if (ary1[i] !== ary2[i]) {
return false;
}
}
return true;
}
function pad(num, len) {
return "0".repeat(len - num.toString().length) + num;
}
return {
INT_MAX: INT_MAX,
INT_MIN: INT_MIN,
decodeUtf8: decodeUtf8,
defaultValue: defaultValue,
double2int: double2int,
double2long: double2long,
fromJavaChars: fromJavaChars,
fromJavaString: fromJavaString,
stringToCharArray: stringToCharArray,
id: id,
tag: tag,
compareTypedArrays: compareTypedArrays,
pad: pad,
};
})();