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# Copyright(c)2020-2025 Shanghai Biren Technology Co., Ltd. All rights reserved.
# 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.
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################################################################################

import torch

import vllm
from vllm.model_executor.layers.utils import get_token_bin_counts_and_mask


def apply_penalties_fit(logits: torch.Tensor,
                        prompt_tokens_tensor: torch.Tensor,
                        output_tokens_tensor: torch.Tensor,
                        presence_penalties: torch.Tensor,
                        frequency_penalties: torch.Tensor,
                        repetition_penalties: torch.Tensor) -> torch.Tensor:
    """
    Applies penalties in place to the logits tensor
    logits : The input logits tensor of shape [num_seqs, vocab_size]
    prompt_tokens_tensor: A tensor containing the prompt tokens. The prompts 
        are padded to the maximum prompt length within the batch using 
        `vocab_size` as the padding value. The value `vocab_size` is used 
        for padding because it does not correspond to any valid token ID 
        in the vocabulary.
    output_tokens_tensor: The output tokens tensor.
    presence_penalties: The presence penalties of shape (num_seqs, )
    frequency_penalties: The frequency penalties of shape (num_seqs, )
    repetition_penalties: The repetition penalties of shape (num_seqs, )
    """
    num_seqs, vocab_size = logits.shape
    _, prompt_mask = get_token_bin_counts_and_mask(prompt_tokens_tensor,
                                                   vocab_size, num_seqs)
    output_bin_counts, output_mask = get_token_bin_counts_and_mask(
        output_tokens_tensor, vocab_size, num_seqs)
    repetition_penalties = repetition_penalties.unsqueeze(dim=1).repeat(
        1, vocab_size)

    # If token appears in prompt or output, apply, otherwise use 1.0 for no-op.
    penalties = torch.where(prompt_mask | output_mask, repetition_penalties,
                            1.0)

    # If logits are positive, divide by penalty, otherwise multiply by penalty.
    scaling = torch.where(logits > 0, 1.0 / penalties, penalties)
    logits *= scaling

    # We follow the definition in OpenAI API.
    # Refer to https://platform.openai.com/docs/api-reference/parameter-details
    logits -= frequency_penalties.unsqueeze(dim=1) * output_bin_counts
    logits -= presence_penalties.unsqueeze(dim=1) * output_mask
    return logits


vllm.model_executor.layers.utils.apply_penalties = apply_penalties_fit