Class SplitDataReader

index-native.cjs:2993–3050

}

class SplitDataReader extends Reader {

	constructor(readers) {
		super();
		this.readers = readers;
	}

	async init() {
		const reader = this;
		const { readers } = reader;
		reader.lastDiskNumber = 0;
		reader.lastDiskOffset = 0;
		await Promise.all(readers.map(async (diskReader, indexDiskReader) => {
			await diskReader.init();
			if (indexDiskReader != readers.length - 1) {
				reader.lastDiskOffset += diskReader.size;
			}
			reader.size += diskReader.size;
		}));
		super.init();
	}

	async readUint8Array(offset, length, diskNumber = 0) {
		const reader = this;
		const { readers } = this;
		let result;
		let currentDiskNumber = diskNumber;
		if (currentDiskNumber == -1) {
			currentDiskNumber = readers.length - 1;
		}
		let currentReaderOffset = offset;
		while (readers[currentDiskNumber] && currentReaderOffset >= readers[currentDiskNumber].size) {
			currentReaderOffset -= readers[currentDiskNumber].size;
			currentDiskNumber++;
		}
		const currentReader = readers[currentDiskNumber];
		if (currentReader) {
			const currentReaderSize = currentReader.size;
			if (currentReaderOffset + length <= currentReaderSize) {
				result = await readUint8Array(currentReader, currentReaderOffset, length);
			} else {
				const chunkLength = currentReaderSize - currentReaderOffset;
				result = new Uint8Array(length);
				const firstPart = await readUint8Array(currentReader, currentReaderOffset, chunkLength);
				result.set(firstPart, 0);
				const secondPart = await reader.readUint8Array(offset + chunkLength, length - chunkLength, diskNumber);
				result.set(secondPart, chunkLength);
				if (firstPart.length + secondPart.length < length) {
					result = result.subarray(0, firstPart.length + secondPart.length);
				}
			}
		} else {
			result = new Uint8Array();
		}
		reader.lastDiskNumber = Math.max(currentDiskNumber, reader.lastDiskNumber);
		return result;
	}
}