From d06c34dea5dc3abed1bc2df96b9616ec50d1040d Mon Sep 17 00:00:00 2001
From: oobabooga <112222186+oobabooga@users.noreply.github.com>
Date: Mon, 31 Jul 2023 13:34:41 -0300
Subject: [PATCH] Add an extension that makes chat replies longer (#3363)

---
 extensions/long_replies/script.py | 143 ++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 extensions/long_replies/script.py

diff --git a/extensions/long_replies/script.py b/extensions/long_replies/script.py
new file mode 100644
index 00000000..035e8c9e
--- /dev/null
+++ b/extensions/long_replies/script.py
@@ -0,0 +1,143 @@
+import torch
+from modules import chat, shared
+from modules.text_generation import (
+    decode,
+    encode,
+    generate_reply,
+)
+from transformers import LogitsProcessor
+import gradio as gr
+
+params = {
+    "display_name": "Long replies",
+    "is_tab": False,
+    "min_length": 120,
+}
+
+initial_size = 0
+
+class MyLogits(LogitsProcessor):
+    """
+    Manipulates the probabilities for the next token before it gets sampled.
+    Used in the logits_processor_modifier function below.
+    """
+    def __init__(self):
+        self.newline_id = shared.tokenizer.encode('\n')[-1]
+        pass
+
+    def __call__(self, input_ids, scores):
+        if input_ids.shape[-1] - initial_size < params["min_length"]:
+            scores[...,self.newline_id] = -1000
+            # scores[...,shared.tokenizer.eos_token_id] = -1000
+
+        # probs = torch.softmax(scores, dim=-1, dtype=torch.float)
+        # probs[0] /= probs[0].sum()
+        # scores = torch.log(probs / (1 - probs))
+        return scores
+
+def history_modifier(history):
+    """
+    Modifies the chat history.
+    Only used in chat mode.
+    """
+    return history
+
+def state_modifier(state):
+    """
+    Modifies the state variable, which is a dictionary containing the input
+    values in the UI like sliders and checkboxes.
+    """
+    return state
+
+def chat_input_modifier(text, visible_text, state):
+    """
+    Modifies the user input string in chat mode (visible_text).
+    You can also modify the internal representation of the user
+    input (text) to change how it will appear in the prompt.
+    """
+    return text, visible_text
+
+def input_modifier(string, state):
+    """
+    In default/notebook modes, modifies the whole prompt.
+
+    In chat mode, it is the same as chat_input_modifier but only applied
+    to "text", here called "string", and not to "visible_text".
+    """
+    return string
+
+def bot_prefix_modifier(string, state):
+    """
+    Modifies the prefix for the next bot reply in chat mode.
+    By default, the prefix will be something like "Bot Name:".
+    """
+    return string
+
+def tokenizer_modifier(state, prompt, input_ids, input_embeds):
+    """
+    Modifies the input ids and embeds.
+    Used by the multimodal extension to put image embeddings in the prompt.
+    Only used by loaders that use the transformers library for sampling.
+    """
+
+    global initial_size
+    initial_size = input_ids.shape[-1]
+
+    return prompt, input_ids, input_embeds
+
+def logits_processor_modifier(processor_list, input_ids):
+    """
+    Adds logits processors to the list, allowing you to access and modify
+    the next token probabilities.
+    Only used by loaders that use the transformers library for sampling.
+    """
+    processor_list.append(MyLogits())
+    return processor_list
+
+def output_modifier(string, state):
+    """
+    Modifies the LLM output before it gets presented.
+
+    In chat mode, the modified version goes into history['visible'],
+    and the original version goes into history['internal'].
+    """
+    return string
+
+def custom_generate_chat_prompt(user_input, state, **kwargs):
+    """
+    Replaces the function that generates the prompt from the chat history.
+    Only used in chat mode.
+    """
+    result = chat.generate_chat_prompt(user_input, state, **kwargs)
+    return result
+
+def custom_css():
+    """
+    Returns a CSS string that gets appended to the CSS for the webui.
+    """
+    return ''
+
+def custom_js():
+    """
+    Returns a javascript string that gets appended to the javascript
+    for the webui.
+    """
+    return ''
+
+def setup():
+    """
+    Gets executed only once, when the extension is imported.
+    """
+    pass
+
+def ui():
+    """
+    Gets executed when the UI is drawn. Custom gradio elements and
+    their corresponding event handlers should be defined here.
+
+    To learn about gradio components, check out the docs:
+    https://gradio.app/docs/
+    """
+
+    min_length = gr.Slider(0, 800, step=10, value=params['min_length'], label='Minimum reply length')
+    min_length.change(lambda x: params.update({'min_length': x}), min_length, None)