From 6b58e9de249e872bd2d83e5916e6c633f52cfbb8 Mon Sep 17 00:00:00 2001
From: Volpeon <git@volpeon.ink>
Date: Sat, 31 Dec 2022 12:58:54 +0100
Subject: Added multi-vector embeddings

---
 models/clip/tokenizer.py | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 models/clip/tokenizer.py

(limited to 'models/clip/tokenizer.py')

diff --git a/models/clip/tokenizer.py b/models/clip/tokenizer.py
new file mode 100644
index 0000000..78871db
--- /dev/null
+++ b/models/clip/tokenizer.py
@@ -0,0 +1,64 @@
+import copy
+from typing import NamedTuple, Union
+
+import numpy as np
+
+from transformers import CLIPTokenizer
+
+
+class MultiCLIPTokenizerItem(NamedTuple):
+    token: str
+    placeholder_id: int
+    multi_ids: list[int]
+
+
+class MultiCLIPTokenizer(CLIPTokenizer):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.token_map: dict[int, list[int]] = {}
+
+    def add_multi_tokens(self, new_tokens: Union[str, list[str]], num_vectors: Union[int, list[int]] = 1) -> MultiCLIPTokenizerItem:
+        if isinstance(new_tokens, list):
+            if isinstance(num_vectors, int):
+                num_vectors = [num_vectors] * len(new_tokens)
+
+            if len(num_vectors) != len(new_tokens):
+                raise ValueError("Expected new_tokens and num_vectors to have the same len")
+
+            return [self.add_multi_tokens(new_token, vecs) for new_token, vecs in zip(new_tokens, num_vectors)]
+
+        if isinstance(num_vectors, list):
+            raise ValueError("Expected num_vectors to be int for single token")
+
+        super().add_tokens(new_tokens)
+
+        if num_vectors == 1:
+            multi_token = [new_tokens]
+        else:
+            multi_token = [f"{new_tokens}_{i}" for i in range(num_vectors)]
+            super().add_tokens(multi_token)
+
+        meta_id = super().convert_tokens_to_ids(new_tokens)
+        multi_ids = super().convert_tokens_to_ids(multi_token)
+
+        self.token_map[meta_id] = multi_ids
+
+        return MultiCLIPTokenizerItem(new_tokens, meta_id, multi_ids)
+
+    def encode(self, *args, vector_shuffle=True, **kwargs):
+        ids = super().encode(*args, **kwargs)
+        new_ids = []
+
+        for id in ids:
+            if id in self.token_map:
+                tokens = self.token_map[id]
+
+                if vector_shuffle:
+                    tokens = copy.copy(tokens)
+                    np.random.shuffle(tokens)
+
+                new_ids = new_ids + self.token_map[id]
+            else:
+                new_ids.append(id)
+
+        return new_ids
-- 
cgit v1.2.3-54-g00ecf