test_engine_args.py

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project

from argparse import ArgumentError

import pytest

from vllm.config import VllmConfig
from vllm.engine.arg_utils import EngineArgs
from vllm.usage.usage_lib import UsageContext
from vllm.utils.argparse_utils import FlexibleArgumentParser


def test_prefix_caching_from_cli():
    parser = EngineArgs.add_cli_args(FlexibleArgumentParser())
    args = parser.parse_args([])
    vllm_config = EngineArgs.from_cli_args(args=args).create_engine_config()
    assert vllm_config.cache_config.enable_prefix_caching, (
        "V1 turns on prefix caching by default."
    )

    # Turn it off possible with flag.
    args = parser.parse_args(["--no-enable-prefix-caching"])
    vllm_config = EngineArgs.from_cli_args(args=args).create_engine_config()
    assert not vllm_config.cache_config.enable_prefix_caching

    # Turn it on with flag.
    args = parser.parse_args(["--enable-prefix-caching"])
    vllm_config = EngineArgs.from_cli_args(args=args).create_engine_config()
    assert vllm_config.cache_config.enable_prefix_caching

    # default hash algorithm is "builtin"
    assert vllm_config.cache_config.prefix_caching_hash_algo == "sha256"

    # set hash algorithm to sha256_cbor
    args = parser.parse_args(["--prefix-caching-hash-algo", "sha256_cbor"])
    vllm_config = EngineArgs.from_cli_args(args=args).create_engine_config()
    assert vllm_config.cache_config.prefix_caching_hash_algo == "sha256_cbor"

    # set hash algorithm to sha256
    args = parser.parse_args(["--prefix-caching-hash-algo", "sha256"])
    vllm_config = EngineArgs.from_cli_args(args=args).create_engine_config()
    assert vllm_config.cache_config.prefix_caching_hash_algo == "sha256"

    # an invalid hash algorithm raises an error
    parser.exit_on_error = False
    with pytest.raises(ArgumentError):
        args = parser.parse_args(["--prefix-caching-hash-algo", "invalid"])


def test_defaults_with_usage_context():
    engine_args = EngineArgs(model="facebook/opt-125m")
    vllm_config: VllmConfig = engine_args.create_engine_config(UsageContext.LLM_CLASS)

    from vllm.platforms import current_platform

    device_name = current_platform.get_device_name().lower()
    if "h100" in device_name or "h200" in device_name:
        # For H100 and H200, we use larger default values.
        default_llm_tokens = 16384
        default_server_tokens = 8192
        default_max_num_seqs = 1024
    else:
        default_llm_tokens = 8192
        default_server_tokens = 2048
        default_max_num_seqs = 256

    assert vllm_config.scheduler_config.max_num_seqs == default_max_num_seqs
    assert vllm_config.scheduler_config.max_num_batched_tokens == default_llm_tokens  # noqa: E501

    engine_args = EngineArgs(model="facebook/opt-125m")
    vllm_config = engine_args.create_engine_config(UsageContext.OPENAI_API_SERVER)
    assert vllm_config.scheduler_config.max_num_seqs == default_max_num_seqs
    assert vllm_config.scheduler_config.max_num_batched_tokens == default_server_tokens  # noqa: E501