@deepkit/bson/src/continuation.ts

Deepkit BSON parser

/*
 * Deepkit Framework
 * Copyright (C) 2021 Deepkit UG, Marc J. Schmidt
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the MIT License.
 *
 * You should have received a copy of the MIT License along with this program.
 */

import { BaseParser } from './bson-parser';
import {
    BSON_BINARY_SUBTYPE_BYTE_ARRAY,
    BSON_DATA_ARRAY,
    BSON_DATA_BINARY,
    BSON_DATA_BOOLEAN,
    BSON_DATA_CODE,
    BSON_DATA_CODE_W_SCOPE,
    BSON_DATA_DATE,
    BSON_DATA_DBPOINTER,
    BSON_DATA_DECIMAL128,
    BSON_DATA_INT,
    BSON_DATA_LONG,
    BSON_DATA_MAX_KEY,
    BSON_DATA_MIN_KEY,
    BSON_DATA_NULL,
    BSON_DATA_NUMBER,
    BSON_DATA_OBJECT,
    BSON_DATA_OID,
    BSON_DATA_REGEXP,
    BSON_DATA_STRING,
    BSON_DATA_SYMBOL,
    BSON_DATA_TIMESTAMP,
    BSON_DATA_UNDEFINED, BSONType
} from './utils';

export function seekElementSize(elementType: number, parser: BaseParser): any {
    switch (elementType) {
        case BSON_DATA_STRING: {
            return parser.seek(parser.eatUInt32());
        }
        case BSON_DATA_OID: {
            return parser.seek(12);
        }
        case BSON_DATA_INT: {
            return parser.seek(4);
        }
        case BSON_DATA_NUMBER: {
            return parser.seek(8);
        }
        case BSON_DATA_DATE: {
            return parser.seek(8);
        }
        case BSON_DATA_BOOLEAN: {
            return parser.seek(1);
        }
        case BSON_DATA_OBJECT: {
            return parser.seek(parser.peekUInt32());
        }
        case BSON_DATA_ARRAY: {
            return parser.seek(parser.peekUInt32());
        }
        case BSON_DATA_NULL: {
            return;
        }
        case BSON_DATA_LONG:
        case BSON_DATA_TIMESTAMP: {
            return parser.seek(8);
        }
        case BSON_DATA_UNDEFINED:
            return;
        case BSON_DATA_BINARY:
            let size = parser.eatUInt32();
            const subType = parser.eatByte();

            if (subType === BSON_BINARY_SUBTYPE_BYTE_ARRAY) {
                size = parser.eatUInt32();
            }

            return parser.seek(size);
        case BSON_DATA_DECIMAL128:
        case BSON_DATA_REGEXP:
        case BSON_DATA_SYMBOL:
        case BSON_DATA_MIN_KEY:
        case BSON_DATA_MAX_KEY:
        case BSON_DATA_CODE:
        case BSON_DATA_CODE_W_SCOPE:
        case BSON_DATA_DBPOINTER:
            throw new Error('Unsupported BSON type ' + elementType);
        default:
            throw new Error('Unknown BSON type ' + elementType);
    }
}

export function findValueInObject(parser: BaseParser, checker: (elementType: BSONType, name: string) => boolean): any {
    const offset = parser.offset;
    const end = parser.eatUInt32() + parser.offset;

    while (parser.offset < end) {
        const elementType = parser.eatByte();
        if (elementType === 0) break;

        const name = parser.eatObjectPropertyName();
        if (checker(elementType, name)) {
            const v = parser.parse(elementType);
            parser.offset = offset;
            return v;
        } else {
            seekElementSize(elementType, parser);
        }
    }

    parser.offset = offset;
    return undefined;
}