tokenizer_util.py

import os
import pathlib
from rwkv_cpp import rwkv_world_tokenizer
from typing import List, Tuple, Callable
from app_util import prxxx


def add_tokenizer_argument(parser) -> None:
    parser.add_argument(
        "tokenizer",
        help="Tokenizer to use; supported tokenizers: auto (guess from n_vocab), 20B, world",
        nargs="?",
        type=str,
        default="auto",
    )


def get_tokenizer(
    tokenizer_name: str, n_vocab: int
) -> Tuple[Callable[[List[int]], str], Callable[[str], List[int]]]:
    if tokenizer_name == "auto":
        if n_vocab == 50277:
            tokenizer_name = "20B"
        elif n_vocab == 65536:
            tokenizer_name = "world"
        else:
            assert False, f"Can not guess the tokenizer from n_vocab value of {n_vocab}"

    parent: pathlib.Path = pathlib.Path(os.path.abspath(__file__)).parent

    if tokenizer_name == "world":
        prxxx("Loading World v20230424 tokenizer")
        return rwkv_world_tokenizer.get_world_tokenizer_v20230424()
    elif tokenizer_name == "20B":
        prxxx("Loading 20B tokenizer")
        import tokenizers

        tokenizer: tokenizers.Tokenizer = tokenizers.Tokenizer.from_file(
            str(parent / "rwkv_cpp/20B_tokenizer.json")
        )
        return tokenizer.decode, lambda x: tokenizer.encode(x).ids
    else:
        assert False, f"Unknown tokenizer {tokenizer_name}"