Upload tokenization_phi3_small.py

tokenization_phi3_small.py

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+# Adapted from https://huggingface.co/Qwen/Qwen-7B-Chat/blob/main/tokenization_qwen.py
+import os
+from typing import Collection, List, Optional, Dict, Set, Tuple, Union
+
+from functools import cached_property
+
+import base64
+
+from transformers import PreTrainedTokenizer, AddedToken, AutoConfig
+from transformers.models.auto.tokenization_auto import get_tokenizer_config
+import tiktoken
+
+
+"""
+    This tokenizer is almost identical to tiktoken.get_encoding("cl100k_base")
+    with a few additional special tokens to support the ChatML format.
+
+    TODO(bapatra): Right now, I do not save the special tokens to the vocab file.
+    Maybe in the future, that would be useful? Can add that support later.
+
+"""
+
+def _load_tiktoken_bpe(tiktoken_bpe_file: str) -> Dict[bytes, int]:
+    with open(tiktoken_bpe_file, "rb") as f:
+        contents = f.read()
+    return {
+        base64.b64decode(token): int(rank)
+        for token, rank in (line.split() for line in contents.splitlines() if line)
+    }
+
+# On the megatron codebase, we pad vocabularies to ensure matrix multiplication is fast.
+# this in turn causes some indices to be empty. We account for these empty indices by adding
+# dummy tokens to the tokenizer.
+
+EFFECTIVE_PADDED_VOCAB_SIZE = 100352
+ACTUAL_VOCAB_SIZE = 100276
+
+
+DUMMY_TOKENS = {
+    f"<|dummy_id_{11 + offset}|>": 100276 + offset
+    for offset in range(1, EFFECTIVE_PADDED_VOCAB_SIZE - ACTUAL_VOCAB_SIZE)
+}
+
+SPECIAL_TOKENS = {
+    # tiktoken.get_encoding("cl100k_base")._special_tokens
+    '<|endoftext|>': 100257,
+    '<|fim_prefix|>': 100258,
+    '<|fim_middle|>': 100259,
+    '<|fim_suffix|>': 100260,
+    # Special tokens for post-training
+    "<|system|>": 100261, 
+    "<|user|>": 100262,
+    "<|assistant|>": 100263,
+    # Dummy unused tokens
+    "<|dummy_id_0|>": 100264,
+    "<|dummy_id_1|>": 100265,
+    # Special tokens for post-training continued
+    "<|end|>": 100266,
+    # Some dummy tokens, so that tokenization is contiguous and does not cause issues
+    # Note that the 100256th token of tiktoken.get_encoding("cl100k_base") does not
+    # actually map to anything. So we use a dummy token here.
+    "<|dummy_id_2|>": 100256,
+    # Likewise, tokens from 100267 to 100275 are also unused
+    "<|dummy_id_3|>": 100267,
+    "<|dummy_id_4|>": 100268,
+    "<|dummy_id_5|>": 100269,
+    "<|dummy_id_6|>": 100270,
+    "<|dummy_id_7|>": 100271,
+    "<|dummy_id_8|>": 100272,
+    "<|dummy_id_9|>": 100273,
+    "<|dummy_id_10|>": 100274,
+    "<|dummy_id_11|>": 100275,
+    # The final end of prompt token
+    # (unused, but present as a part of tiktoken.get_encoding("cl100k_base")._special_tokens)
+    '<|endofprompt|>': 100276,
+    # Dummy tokens to account for padding of the tokenizer
+    # We pad to ensure tensor cores are used for vocab multiplication
+    **DUMMY_TOKENS
+}
+
+class Phi3SmallTokenizer(PreTrainedTokenizer):
+    vocab_files_names = {
+        "vocab_file": "cl100k_base.tiktoken"
+    }
+
+    model_input_names: List[str] = ["input_ids", "attention_mask"]
+    padding_side = "left"
+
+    def __init__(
+        self,
+        vocab_file: Optional[str] = None,
+        errors: str = "replace",
+        **kwargs
+    ) -> None:
+        # PreTrainedTokenizer's init calls _add_tokens, which in turn checks
+        # if the token is present in `self.special_tokens``. Hence instantiating it here.
+        # The way Qwen gets around this is by checking against SPECIAL_TOKENS
+        # But I think it's better to check against the objects own `special_tokens`
+        # in case we eventually want to allow the tokenizer to have special tokens.
+        self.special_tokens = SPECIAL_TOKENS
+
+        super().__init__(**kwargs)
+        self.errors = errors
+
+        base = tiktoken.get_encoding("cl100k_base")
+        if vocab_file is None:
+            self.mergeable_ranks: Dict[bytes, int] = base._mergeable_ranks
+        else:
+            self.mergeable_ranks = _load_tiktoken_bpe(vocab_file)
+
+        self.pat_str = base._pat_str
+        
+        enc = tiktoken.Encoding(
+            name="phi3small",
+            pat_str=self.pat_str,
+            mergeable_ranks=self.mergeable_ranks,
+            special_tokens=self.special_tokens,
+        )
+        self.tokenizer = enc
+
+        self.decoder: Dict[int, bytes] = {
+            v: k for k, v in self.mergeable_ranks.items()
+        }
+        self.decoder.update({v: k for k, v in self.special_tokens.items()})
+        
+        self.eod_id = self.tokenizer.eot_token
+        self._eos_token = self._convert_id_to_token(self.eod_id)
+
+        # Setting the bos_token to be the same as the eos_token
+        # Note that this is **not** the correct thing to do, and is done
+        # just so that some of the downstream libraries do not break.
+        self._bos_token = self._eos_token
+
+        # Assign the special tokens to class variables
+        self.system_id = self.special_tokens["<|system|>"]
+        self.user_id = self.special_tokens["<|user|>"]
+        self.assistant_id = self.special_tokens["<|assistant|>"]
+        self.end_id = self.special_tokens["<|end|>"]
+    
+    @cached_property
+    def dummy_token_indices(self) -> List[int]:
+        # There are some additional special tokens in the cl100k_base tokenizer
+        # that we do not use. Hence, we also consider them to be dummy tokens.
+        additional_tokens = [
+            "<|fim_prefix|>",
+            "<|fim_middle|>",
+            "<|fim_suffix|>",
+            "<|endofprompt|>"
+        ]
+        dummy_token_indices = [index for token, index in self.special_tokens.items() if "dummy_id" in token]
+        dummy_token_indices.extend([self.special_tokens[token] for token in additional_tokens])
+        return sorted(dummy_token_indices)
+
+    def __getstate__(self):
+        state = self.__dict__.copy()
+        del state["tokenizer"]
+        return state
+    
+    def __setstate__(self, state):
+        self.__dict__ = state
+        enc = tiktoken.Encoding(
+            name="cl100k_im",
+            pat_str=self.pat_str,
+            mergeable_ranks=self.mergeable_ranks,
+            special_tokens=self.special_tokens,
+        )
+        self.tokenizer = enc
+    
+    def __len__(self):
+        return self.tokenizer.n_vocab
+    
+    @classmethod
+    def from_pretrained(
+        cls,
+        pretrained_model_name_or_path: Union[str, os.PathLike],
+        *init_inputs,
+        **kwargs,
+    ):
+        cls_kwargs = kwargs
+        # First try to load from the tokenization config if it exists
+        tokenization_config = get_tokenizer_config(pretrained_model_name_or_path, **kwargs)
+        if tokenization_config:
+            cls_kwargs.update(
+                dict(
+                    model_max_length=tokenization_config["model_max_length"],
+                    chat_template=tokenization_config.get("chat_template", None)
+                )
+            )
+        else:
+            config = AutoConfig.from_pretrained(pretrained_model_name_or_path, trust_remote_code=True)
+            cls_kwargs["model_max_length"] = config.max_position_embeddings
+        return cls(**cls_kwargs)
+
+    def get_vocab(self) -> Dict[Union[str, bytes], int]:
+        return {**self.mergeable_ranks, **self.special_tokens}
+    
+    def convert_tokens_to_ids(
+        self,
+        tokens: Union[bytes, str, List[Union[bytes, str]]]
+    ) -> Union[int, List[int]]:
+        ids = []
+        if isinstance(tokens, (str, bytes)):
+            if tokens in self.special_tokens:
+                return self.special_tokens[tokens]
+            else:
+                return self.mergeable_ranks.get(tokens)
+        ids: List[int] = []
+        for token in tokens:
+            ids.append(self.convert_tokens_to_ids(token))
+        return ids
+
+    def _add_tokens(
+            self,
+            new_tokens: Union[List[str], List[AddedToken]],
+            special_tokens: bool = False,
+    ) -> int:
+        if not special_tokens and new_tokens:
+            raise ValueError("Only special tokens can be added to this tokenizer")
+        for token in new_tokens:
+            surface_form = token.content if isinstance(token, AddedToken) else token
+            if surface_form not in self.special_tokens:
+                raise ValueError(
+                    "For now, we do not support unknown special tokens\n"
+                    "In the future, if there is a need for this, we can add special tokens to the tokenizer\n"
+                    "starting from rank 100261 - 100263 and then 100266 - 100275.\n"
+                    "And finally, we can re-construct the enc object back\n"
+                )
+        return 0
+
+    def save_vocabulary(self, save_directory: str, **kwargs) -> Tuple[str]:
+        file_path = os.path.join(save_directory, "cl100k_base.tiktoken")
+        with open(file_path, "w") as f:
+            for token, rank in self.mergeable_ranks.items():
+                line = base64.b64encode(token).decode("utf-8") + " " + str(rank) + "\n"
+                f.write(line)
+        return (file_path,)
+
+    def tokenize(
+        self,
+        text: str,
+        allowed_special: Union[Set, str] = "all",
+        disallowed_special: Union[Collection, str] = (),
+        **kwargs
+    ) -> List[Union[bytes, str]]:
+        tokens: List[Union[bytes, str]] = []
+        for token_id in self.tokenizer.encode(
+            text, allowed_special=allowed_special, disallowed_special=disallowed_special
+        ):
+            tokens.append(self.decoder[token_id])
+        return tokens
+
+    def convert_tokens_to_string(self, tokens: List[Union[bytes, str]]) -> str:
+        """
+        Converts a sequence of tokens in a single string.
+        """
+        text = ""
+        temp = b""
+        for t in tokens:
+            if isinstance(t, str):
+                if temp:
+                    text += temp.decode("utf-8", errors=self.errors)
+                    temp = b""
+                text += t
+            elif isinstance(t, bytes):
+                temp += t
+            else:
+                raise TypeError("token should only be of type types or str")
+        if temp:
+            text += temp.decode("utf-8", errors=self.errors)
+        return text
+
+    @property
+    def vocab_size(self):
+        return self.tokenizer.n_vocab
+
+    @property
+    def eos_token_id(self) -> int:
+        return self.eod_id
+
+    def _convert_id_to_token(self, index: int) -> Union[bytes, str]:
+        """Converts an id to a token, special tokens included"""
+        if index in self.decoder:
+            return self.decoder[index]
+        raise ValueError("unknown ids")
+
+    def _convert_token_to_id(self, token: Union[bytes, str]) -> int:
+        """Converts a token to an id using the vocab, special tokens included"""
+        if token in self.special_tokens:
+            return self.special_tokens[token]
+        if token in self.mergeable_ranks:
+            return self.mergeable_ranks[token]
+        raise ValueError("unknown token")
+
+    def _tokenize(self, text: str, **kwargs):
+        """
+        Converts a string in a sequence of tokens (string), using the tokenizer. Split in words for word-based
+        vocabulary or sub-words for sub-word-based vocabularies (BPE/SentencePieces/WordPieces).
+        Do NOT take care of added tokens.
+        """
+        raise NotImplementedError
+
+    def _decode(
+        self,
+        token_ids: Union[int, List[int]],
+        skip_special_tokens: bool = False,
+        errors: str = None,
+        **kwargs,
+    ) -> str:
+        if isinstance(token_ids, int):
+            token_ids = [token_ids]
+        if skip_special_tokens:
+            token_ids = [i for i in token_ids if i < self.eod_id]
+        return self.tokenizer.decode(token_ids, errors=errors or self.errors)
+
+