apache-arrow/src/util/bigint.ts

Apache Arrow columnar in-memory format

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

/**
 * Converts an integer as a number or bigint to a number, throwing an error if the input cannot safely be represented as a number.
 */
export function bigIntToNumber(number: bigint | number): number {
    if (typeof number === 'bigint' && (number < Number.MIN_SAFE_INTEGER || number > Number.MAX_SAFE_INTEGER)) {
        throw new TypeError(`${number} is not safe to convert to a number.`);
    }
    return Number(number);
}

/**
 * Duivides the bigint number by the divisor and returns the result as a number.
 * Dividing bigints always results in bigints so we don't get the remainder.
 * This function gives us the remainder but assumes that the result fits into a number.
 *
 * @param number The number to divide.
 * @param divisor The divisor.
 * @returns The result of the division as a number.
 */
export function divideBigInts(number: bigint, divisor: bigint): number {
    return bigIntToNumber(number / divisor) + bigIntToNumber(number % divisor) / bigIntToNumber(divisor);
}