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LLaMA-Factory/src/llamafactory/v1/plugins/trainer_plugins/batching.py

209 lines
7.4 KiB
Python

# Copyright 2025 the LlamaFactory team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from collections.abc import Callable
from math import ceil
from typing import Any
import torch
from torch.utils.data import default_collate
from ...utils.constants import IGNORE_INDEX
from ...utils.helper import pad_and_truncate
from ...utils.objects import StatefulBuffer
from ...utils.plugin import BasePlugin
from ...utils.types import BatchInfo, BatchInput, DataLoader, ModelInput
class BatchingPlugin(BasePlugin):
def get_data_provider_batch_size(self, batch_info: BatchInfo) -> int:
"""Return the raw data provider batch size for this batching strategy."""
return self["get_data_provider_batch_size"](batch_info)
def compute_length(self, data_provider: DataLoader, batch_info: BatchInfo) -> int:
"""Compute the length of the batch generator.
The approximate length is used to calculate the lr schedule.
"""
return self["compute_length"](data_provider, batch_info)
def fill_buffer(
self,
buffer: StatefulBuffer,
batch_info: BatchInfo,
next_samples: Callable[[bool], list[ModelInput] | None],
) -> None:
"""Fill the buffer with data."""
return self["fill_buffer"](buffer, batch_info, next_samples)
def generate_batch(self, buffer: StatefulBuffer, batch_info: BatchInfo) -> list[BatchInput] | None:
"""Generate a batch from the buffer."""
return self["generate_batch"](buffer, batch_info)
def _get_dynamic_micro_batch_sizes(samples: list[ModelInput], batch_info: BatchInfo) -> list[int]:
"""Return sample counts for micro batches formed by one padded-token budget."""
budget = batch_info["cutoff_len"] * batch_info["micro_batch_size"]
cutoff_len = batch_info["cutoff_len"]
sizes = []
index = 0
while index < len(samples) and len(sizes) < batch_info["num_micro_batch"]:
max_sample_len = 0
used = 0
is_complete = False
while index + used < len(samples):
sample_len = min(len(samples[index + used]["input_ids"]), cutoff_len)
padded_tokens = max(max_sample_len, sample_len) * (used + 1)
if used > 0 and padded_tokens > budget:
is_complete = True
break
max_sample_len = max(max_sample_len, sample_len)
used += 1
if max_sample_len * used >= budget:
is_complete = True
break
if used == 0 or not is_complete:
break
sizes.append(used)
index += used
return sizes
def _pack_padding_free_samples(samples: list[ModelInput], cutoff_len: int) -> BatchInput | None:
"""Pack fixed samples into one padding-free sequence without a token budget."""
packed: dict[str, list[Any]] = {}
position_ids: list[int] = []
for sample_index, sample in enumerate(samples):
# Padding-free still truncates each sample by cutoff_len before packing
# all samples into one contiguous sequence.
sample_len = min(len(sample["input_ids"]), cutoff_len)
if sample_len <= 0:
continue
for key, value in sample.items():
if key in ("attention_mask", "position_ids") or isinstance(value, str):
continue
if key not in packed:
packed[key] = []
sliced_value = list(value[:sample_len])
if sample_index > 0 and sliced_value:
if key == "labels":
sliced_value[0] = IGNORE_INDEX
elif key == "loss_weights":
sliced_value[0] = 0.0
packed[key].extend(sliced_value)
position_ids.extend(range(sample_len))
if not position_ids:
return None
packed["position_ids"] = position_ids
packed["attention_mask"] = [1] * len(position_ids)
return {key: torch.tensor(value).unsqueeze(0) for key, value in packed.items()}
@BatchingPlugin("padding_free").register("get_data_provider_batch_size")
def get_padding_free_data_provider_batch_size(batch_info: BatchInfo) -> int:
return batch_info["micro_batch_size"] * batch_info["num_micro_batch"]
@BatchingPlugin("padding_free").register("compute_length")
def compute_padding_free_length(data_provider: DataLoader, batch_info: BatchInfo) -> int:
return len(data_provider)
@BatchingPlugin("padding_free").register("fill_buffer")
def fill_padding_free_buffer(
buffer: StatefulBuffer,
batch_info: BatchInfo,
next_samples: Callable[[bool], list[ModelInput] | None],
) -> None:
while len(buffer) < batch_info["micro_batch_size"] * batch_info["num_micro_batch"]:
samples = next_samples(False)
if samples is None:
break
buffer.put(samples)
@BatchingPlugin("padding_free").register("generate_batch")
def generate_padding_free_batch(buffer: StatefulBuffer, batch_info: BatchInfo) -> list[BatchInput] | None:
micro_batch_size = batch_info["micro_batch_size"]
num_micro_batch = batch_info["num_micro_batch"]
cutoff_len = batch_info["cutoff_len"]
batch_size = micro_batch_size * num_micro_batch
if len(buffer) < batch_size:
return None
samples = buffer.get(batch_size)
batch = []
for i in range(num_micro_batch):
micro_batch = samples[i * micro_batch_size : (i + 1) * micro_batch_size]
packed_micro_batch = _pack_padding_free_samples(micro_batch, cutoff_len)
if packed_micro_batch is None:
return None
batch.append(packed_micro_batch)
return batch
@BatchingPlugin("dynamic_batching").register("get_data_provider_batch_size")
def get_dynamic_batching_data_provider_batch_size(batch_info: BatchInfo) -> int:
return 1
@BatchingPlugin("dynamic_batching").register("compute_length")
def compute_dynamic_batching_length(data_provider: DataLoader, batch_info: BatchInfo) -> int:
batch_size = batch_info["micro_batch_size"] * batch_info["num_micro_batch"]
return ceil(len(data_provider) / batch_size)
@BatchingPlugin("dynamic_batching").register("fill_buffer")
def fill_dynamic_batching_buffer(
buffer: StatefulBuffer,
batch_info: BatchInfo,
next_samples: Callable[[bool], list[ModelInput] | None],
) -> None:
while len(_get_dynamic_micro_batch_sizes(buffer.samples, batch_info)) < batch_info["num_micro_batch"]:
samples = next_samples(True)
if samples is None:
break
buffer.put(samples)
@BatchingPlugin("dynamic_batching").register("generate_batch")
def generate_dynamic_batching_batch(buffer: StatefulBuffer, batch_info: BatchInfo) -> list[BatchInput] | None:
micro_batch_sample_counts = _get_dynamic_micro_batch_sizes(buffer.samples, batch_info)
if len(micro_batch_sample_counts) < batch_info["num_micro_batch"]:
return None
batch = []
cutoff_len = batch_info["cutoff_len"]
for num_samples in micro_batch_sample_counts:
samples = buffer.get(num_samples)
batch.append(default_collate(pad_and_truncate(samples, cutoff_len)))
return batch