release initial code

Co-authored-by: Ying Sheng <sqy1415@gmail.com>
Co-authored-by: Liangsheng Yin <hnyls2002@gmail.com>
Co-authored-by: Zhiqiang Xie <xiezhq@stanford.edu>
Co-authored-by: parasol-aser <3848358+parasol-aser@users.noreply.github.com>
Co-authored-by: LiviaSun <33578456+ChuyueSun@users.noreply.github.com>
Co-authored-by: Cody Yu <hao.yu.cody@gmail.com>

python/sglang/srt/hf_transformers_utils.py

@@ -0,0 +1,164 @@
+"""Utilities for Huggingface Transformers."""
+
+import json
+import os
+import warnings
+from typing import List, Optional, Tuple, Union
+
+from huggingface_hub import snapshot_download
+from sglang.srt.utils import is_multimodal_model
+from transformers import (
+    AutoConfig,
+    AutoProcessor,
+    AutoTokenizer,
+    PreTrainedTokenizer,
+    PreTrainedTokenizerFast,
+)
+
+
+def download_from_hf(model_path: str):
+    if os.path.exists(model_path):
+        return model_path
+
+    return snapshot_download(model_path, allow_patterns=["*.json", "*.bin", "*.model"])
+
+
+def get_config_json(model_path: str):
+    with open(os.path.join(model_path, "config.json")) as f:
+        config = json.load(f)
+    return config
+
+
+def get_config(model: str, trust_remote_code: bool, revision: Optional[str] = None):
+    config = AutoConfig.from_pretrained(
+        model, trust_remote_code=trust_remote_code, revision=revision
+    )
+    return config
+
+
+# Models don't use the same configuration key for determining the maximum
+# context length.  Store them here so we can sanely check them.
+# NOTE: The ordering here is important. Some models have two of these and we
+# have a preference for which value gets used.
+CONTEXT_LENGTH_KEYS = [
+    "max_sequence_length",
+    "seq_length",
+    "max_position_embeddings",
+    "max_seq_len",
+    "model_max_length",
+]
+
+
+def get_context_length(config):
+    """Get the context length of a model from a huggingface model config."""
+    rope_scaling = getattr(config, "rope_scaling", None)
+    if rope_scaling:
+        rope_scaling_factor = config.rope_scaling["factor"]
+    else:
+        rope_scaling_factor = 1
+
+    for key in CONTEXT_LENGTH_KEYS:
+        val = getattr(config, key, None)
+        if val is not None:
+            return int(rope_scaling_factor * val)
+    return 2048
+
+
+# A fast LLaMA tokenizer with the pre-processed `tokenizer.json` file.
+_FAST_LLAMA_TOKENIZER = "hf-internal-testing/llama-tokenizer"
+
+
+def get_tokenizer(
+    tokenizer_name: str,
+    *args,
+    tokenizer_mode: str = "auto",
+    trust_remote_code: bool = False,
+    tokenizer_revision: Optional[str] = None,
+    **kwargs,
+) -> Union[PreTrainedTokenizer, PreTrainedTokenizerFast]:
+    """Gets a tokenizer for the given model name via Huggingface."""
+    if is_multimodal_model(tokenizer_name):
+        processor = get_processor(
+            tokenizer_name,
+            *args,
+            trust_remote_code=trust_remote_code,
+            tokenizer_revision=tokenizer_revision,
+            **kwargs,
+        )
+        tokenizer = processor.tokenizer
+        return tokenizer
+
+    if tokenizer_mode == "slow":
+        if kwargs.get("use_fast", False):
+            raise ValueError("Cannot use the fast tokenizer in slow tokenizer mode.")
+        kwargs["use_fast"] = False
+
+    if (
+        "llama" in tokenizer_name.lower()
+        and kwargs.get("use_fast", True)
+        and tokenizer_name != _FAST_LLAMA_TOKENIZER
+    ):
+        pass
+        # warnings.warn(
+        #    "For some LLaMA V1 models, initializing the fast tokenizer may "
+        #    "take a long time. To reduce the initialization time, consider "
+        #    f"using '{_FAST_LLAMA_TOKENIZER}' instead of the original "
+        #    "tokenizer."
+        # )
+    try:
+        tokenizer = AutoTokenizer.from_pretrained(
+            tokenizer_name,
+            *args,
+            trust_remote_code=trust_remote_code,
+            tokenizer_revision=tokenizer_revision,
+            **kwargs,
+        )
+    except TypeError as e:
+        # The LLaMA tokenizer causes a protobuf error in some environments.
+        err_msg = (
+            "Failed to load the tokenizer. If you are using a LLaMA V1 model "
+            f"consider using '{_FAST_LLAMA_TOKENIZER}' instead of the "
+            "original tokenizer."
+        )
+        raise RuntimeError(err_msg) from e
+    except ValueError as e:
+        # If the error pertains to the tokenizer class not existing or not
+        # currently being imported, suggest using the --trust-remote-code flag.
+        if not trust_remote_code and (
+            "does not exist or is not currently imported." in str(e)
+            or "requires you to execute the tokenizer file" in str(e)
+        ):
+            err_msg = (
+                "Failed to load the tokenizer. If the tokenizer is a custom "
+                "tokenizer not yet available in the HuggingFace transformers "
+                "library, consider setting `trust_remote_code=True` in LLM "
+                "or using the `--trust-remote-code` flag in the CLI."
+            )
+            raise RuntimeError(err_msg) from e
+        else:
+            raise e
+
+    if not isinstance(tokenizer, PreTrainedTokenizerFast):
+        warnings.warn(
+            "Using a slow tokenizer. This might cause a significant "
+            "slowdown. Consider using a fast tokenizer instead."
+        )
+    return tokenizer
+
+
+def get_processor(
+    tokenizer_name: str,
+    *args,
+    tokenizer_mode: str = "auto",
+    trust_remote_code: bool = False,
+    tokenizer_revision: Optional[str] = None,
+    **kwargs,
+):
+    processor = AutoProcessor.from_pretrained(
+        tokenizer_name,
+        *args,
+        trust_remote_code=trust_remote_code,
+        tokenizer_revision=tokenizer_revision,
+        **kwargs,
+    )
+    return processor