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mr_v100-vllm/vllm/v1/engine/mm_input_cache.py
2025-09-15 14:58:11 +08:00

56 lines
1.9 KiB
Python

# SPDX-License-Identifier: Apache-2.0
from vllm.envs import VLLM_MM_INPUT_CACHE_GIB
from vllm.multimodal import MultiModalKwargs
from vllm.multimodal.processing import ProcessingCache
# The idea of multimodal preprocessing caching is based on having a client and
# a server, where the client executes in the frontend process (=P0) and the
# server in the core process (=P1).
#
# -- Client:
# - BaseMultiModalProcessor to process MultiModalData into MultiModalKwargs
# with built-in caching functionality, with mm_hash as its identifier.
#
# -- Server:
# - MMInputCacheServer to perform caching of the received MultiModalKwargs.
#
# The caching for both client and server is mirrored, and this allows us
# to avoid the serialization of "mm_inputs" (like pixel values) between
# client (=P0) and server (=P1) processes if the mm_hash is found in the client
# cache.
# Both Client and Server must use the same cache size
# (to perform mirrored caching). This cache size is set by the environment
# variable VLLM_MM_INPUT_CACHE_GIB.
class MMInputCacheServer:
def __init__(self, model_config):
self.use_cache = not model_config.disable_mm_preprocessor_cache
self.mm_cache = ProcessingCache.get_lru_cache(VLLM_MM_INPUT_CACHE_GIB,
MultiModalKwargs)
def get_and_update(
self,
mm_inputs: list[MultiModalKwargs],
mm_hashes: list[str],
) -> list[MultiModalKwargs]:
assert len(mm_inputs) == len(mm_hashes)
if not self.use_cache:
return mm_inputs
full_mm_inputs = []
for mm_input, mm_hash in zip(mm_inputs, mm_hashes):
assert mm_hash is not None
if mm_input is None:
mm_input = self.mm_cache[mm_hash]
else:
self.mm_cache[mm_hash] = mm_input
full_mm_inputs.append(mm_input)
return full_mm_inputs