@eyhn/msgpack-stream/src/decode.ts

MessagePack for ECMA-262/JavaScript/TypeScript

import { Decoder } from "./Decoder";
import type { ExtensionCodecType } from "./ExtensionCodec";
import type { ContextOf, SplitUndefined } from "./context";
import { StreamDecoder } from "./StreamDecoder";

export type DecodeOptions<ContextType = undefined> = Readonly<
  Partial<{
    extensionCodec: ExtensionCodecType<ContextType>;

    /**
     * The size of the stream buffer.
     *
     * Defaults to 2048.
     */
    streamBufferSize: number;

    /**
     * Maximum string length.
     *
     * Defaults to 4_294_967_295 (UINT32_MAX).
     */
    maxStrLength: number;
    /**
     * Maximum binary length.
     *
     * Defaults to 4_294_967_295 (UINT32_MAX).
     */
    maxBinLength: number;
    /**
     * Maximum array length.
     *
     * Defaults to 4_294_967_295 (UINT32_MAX).
     */
    maxArrayLength: number;
    /**
     * Maximum map length.
     *
     * Defaults to 4_294_967_295 (UINT32_MAX).
     */
    maxMapLength: number;
    /**
     * Maximum extension length.
     *
     * Defaults to 4_294_967_295 (UINT32_MAX).
     */
    maxExtLength: number;
  }>
> &
  ContextOf<ContextType>;

export const defaultDecodeOptions: DecodeOptions = {};

/**
 * It decodes a single MessagePack object in a buffer.
 *
 * This is a synchronous decoding function.
 * See other variants for asynchronous decoding: {@link decodeAsync()}, {@link decodeStream()}, or {@link decodeArrayStream()}.
 *
 * @throws {@link RangeError} if the buffer is incomplete, including the case where the buffer is empty.
 * @throws {@link DecodeError} if the buffer contains invalid data.
 */
export function decode<ContextType = undefined>(
  buffer: ArrayLike<number> | BufferSource,
  options: DecodeOptions<SplitUndefined<ContextType>> = defaultDecodeOptions as any,
): unknown {
  const decoder = new Decoder(
    options.extensionCodec,
    (options as typeof options & { context: any }).context,
    options.maxStrLength,
    options.maxBinLength,
    options.maxArrayLength,
    options.maxMapLength,
    options.maxExtLength,
  );
  return decoder.decode(buffer);
}

/**
 * It decodes multiple MessagePack objects in a buffer.
 * This is corresponding to {@link decodeMultiStream()}.
 *
 * @throws {@link RangeError} if the buffer is incomplete, including the case where the buffer is empty.
 * @throws {@link DecodeError} if the buffer contains invalid data.
 */
export function decodeMulti<ContextType = undefined>(
  buffer: ArrayLike<number> | BufferSource,
  options: DecodeOptions<SplitUndefined<ContextType>> = defaultDecodeOptions as any,
): Generator<unknown, void, unknown> {
  const decoder = new Decoder(
    options.extensionCodec,
    (options as typeof options & { context: any }).context,
    options.maxStrLength,
    options.maxBinLength,
    options.maxArrayLength,
    options.maxMapLength,
    options.maxExtLength,
  );
  return decoder.decodeMulti(buffer);
}

export function decodeStream<ContextType = undefined>(
  read: AsyncIterable<Uint8Array>,
  options: DecodeOptions<SplitUndefined<ContextType>> = defaultDecodeOptions as any,
): Promise<unknown> {
  const decoder = new StreamDecoder(
    read,
    options.extensionCodec,
    (options as typeof options & { context: any }).context,
    options.maxStrLength,
    options.maxBinLength,
    options.maxArrayLength,
    options.maxMapLength,
    options.maxExtLength,
  );
  return decoder.decode();
}