@azure/cosmos
Version:
Microsoft Azure Cosmos DB Service Node.js SDK for SQL API
68 lines • 3.06 kB
JavaScript
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.
import JSBI from "jsbi";
import { BytePrefix } from "./prefix";
export function writeNumberForBinaryEncodingJSBI(hash) {
let payload = encodeNumberAsUInt64JSBI(hash);
let outputStream = Buffer.from(BytePrefix.Number, "hex");
const firstChunk = JSBI.asUintN(64, JSBI.signedRightShift(payload, JSBI.BigInt(56)));
outputStream = Buffer.concat([outputStream, Buffer.from(firstChunk.toString(16), "hex")]);
payload = JSBI.asUintN(64, JSBI.leftShift(JSBI.BigInt(payload), JSBI.BigInt(0x8)));
let byteToWrite = JSBI.BigInt(0);
let firstIteration = false;
let shifted;
let padded;
do {
if (!firstIteration) {
// we pad because after shifting because we will produce characters like "f" or similar,
// which cannot be encoded as hex in a buffer because they are invalid hex
// https://github.com/nodejs/node/issues/24491
padded = byteToWrite.toString(16).padStart(2, "0");
if (padded !== "00") {
outputStream = Buffer.concat([outputStream, Buffer.from(padded, "hex")]);
}
}
else {
firstIteration = false;
}
shifted = JSBI.asUintN(64, JSBI.signedRightShift(payload, JSBI.BigInt(56)));
byteToWrite = JSBI.asUintN(64, JSBI.bitwiseOr(shifted, JSBI.BigInt(0x01)));
payload = JSBI.asUintN(64, JSBI.leftShift(payload, JSBI.BigInt(7)));
} while (JSBI.notEqual(payload, JSBI.BigInt(0)));
const lastChunk = JSBI.asUintN(64, JSBI.bitwiseAnd(byteToWrite, JSBI.BigInt(0xfe)));
// we pad because after shifting because we will produce characters like "f" or similar,
// which cannot be encoded as hex in a buffer because they are invalid hex
// https://github.com/nodejs/node/issues/24491
padded = lastChunk.toString(16).padStart(2, "0");
if (padded !== "00") {
outputStream = Buffer.concat([outputStream, Buffer.from(padded, "hex")]);
}
return outputStream;
}
function encodeNumberAsUInt64JSBI(value) {
const rawValueBits = getRawBitsJSBI(value);
const mask = JSBI.BigInt(0x8000000000000000);
const returned = rawValueBits < mask
? JSBI.bitwiseXor(rawValueBits, mask)
: JSBI.add(JSBI.bitwiseNot(rawValueBits), JSBI.BigInt(1));
return returned;
}
export function doubleToByteArrayJSBI(double) {
const output = Buffer.alloc(8);
const lng = getRawBitsJSBI(double);
for (let i = 0; i < 8; i++) {
output[i] = JSBI.toNumber(JSBI.bitwiseAnd(JSBI.signedRightShift(lng, JSBI.multiply(JSBI.BigInt(i), JSBI.BigInt(8))), JSBI.BigInt(0xff)));
}
return output;
}
function getRawBitsJSBI(value) {
const view = new DataView(new ArrayBuffer(8));
view.setFloat64(0, value);
return JSBI.BigInt(`0x${buf2hex(view.buffer)}`);
}
function buf2hex(buffer) {
return Array.prototype.map
.call(new Uint8Array(buffer), (x) => ("00" + x.toString(16)).slice(-2))
.join("");
}
//# sourceMappingURL=number.js.map