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/embeddings.py | 109 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 models/clip/embeddings.py

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

diff --git a/models/clip/embeddings.py b/models/clip/embeddings.py
new file mode 100644
index 0000000..7d63ffb
--- /dev/null
+++ b/models/clip/embeddings.py
@@ -0,0 +1,109 @@
+from typing import Union, Optional
+from pathlib import Path
+
+import torch
+import torch.nn as nn
+
+from safetensors import safe_open
+from safetensors.torch import save_file
+
+from transformers import CLIPTextModel
+from transformers.models.clip import CLIPTextConfig
+from transformers.models.clip.modeling_clip import CLIPTextEmbeddings
+
+
+def expand_embedding(old_embedding: nn.Embedding, n: int) -> nn.Embedding:
+    old_num_embeddings, old_embedding_dim = old_embedding.weight.size()
+
+    new_embedding = nn.Embedding(old_num_embeddings + n, old_embedding_dim)
+    new_embedding.to(old_embedding.weight.device, dtype=old_embedding.weight.dtype)
+    new_embedding.weight.data.zero_()
+    new_embedding.weight.data[:old_num_embeddings] = old_embedding.weight.data
+
+    return new_embedding
+
+
+class ManagedCLIPTextEmbeddings(CLIPTextEmbeddings):
+    def __init__(self, config: CLIPTextConfig, embeddings: CLIPTextEmbeddings):
+        super().__init__(config)
+
+        self.token_embedding = embeddings.token_embedding
+        self.position_embedding = embeddings.position_embedding
+
+        self.temp_token_embedding = nn.Embedding(
+            self.token_embedding.num_embeddings, self.token_embedding.embedding_dim)
+        self.temp_token_embedding.weight.data.zero_()
+        self.temp_token_ids = torch.tensor([])
+
+    def add_embed(self, token_ids: Union[int, list[int]], initializer: Optional[Union[int, list[int], torch.FloatTensor]] = None):
+        if isinstance(token_ids, int):
+            token_ids = [token_ids]
+
+        if initializer is not None:
+            if isinstance(initializer, int):
+                initializer = [initializer]
+
+            if isinstance(initializer, list):
+                initializer = (initializer * len(token_ids))[:len(token_ids)]
+
+                with torch.no_grad():
+                    initializer = self.get_embed(initializer)
+
+        self.temp_token_embedding = expand_embedding(self.temp_token_embedding, len(token_ids))
+        self.token_embedding = expand_embedding(self.token_embedding, len(token_ids))
+
+        token_ids = torch.tensor(token_ids)
+
+        self.temp_token_ids = torch.cat([self.temp_token_ids, token_ids])
+
+        if initializer is not None:
+            self.temp_token_embedding.weight.data[token_ids] = initializer
+        else:
+            self.temp_token_embedding.weight.data[token_ids].zero_()
+
+    def load_embed(self, input_ids: list[int], filename: Path):
+        with safe_open(filename, framework="pt", device="cpu") as file:
+            self.add_embed(input_ids, file.get_tensor("embed"))
+
+    def save_embed(self, input_ids: list[int], filename: Path):
+        save_file({"embed": self.get_embed(input_ids)}, filename)
+
+    def make_permanent(self):
+        self.token_embedding.weight.data[self.temp_token_ids] = self.temp_token_embedding.weight.data[self.temp_token_ids]
+        self.temp_token_ids = torch.tensor([])
+
+    def get_embed(self, input_ids: Union[list[int], torch.LongTensor]):
+        if isinstance(input_ids, list):
+            input_ids = torch.tensor(input_ids)
+
+        mask = torch.isin(input_ids, torch.tensor(self.temp_token_ids, device=input_ids.device))
+
+        embeds = self.token_embedding(input_ids)
+        embeds[mask] = self.temp_token_embedding(input_ids)[mask]
+
+        return embeds
+
+    def forward(
+        self,
+        input_ids: Optional[torch.LongTensor] = None,
+        position_ids: Optional[torch.LongTensor] = None,
+        inputs_embeds: Optional[torch.FloatTensor] = None,
+    ) -> torch.Tensor:
+        seq_length = input_ids.shape[-1] if input_ids is not None else inputs_embeds.shape[-2]
+
+        if position_ids is None:
+            position_ids = self.position_ids[:, :seq_length]
+
+        if inputs_embeds is None:
+            inputs_embeds = self.get_embed(input_ids)
+
+        position_embeddings = self.position_embedding(position_ids)
+        embeddings = inputs_embeds + position_embeddings
+
+        return embeddings
+
+
+def patch_managed_embeddings(text_encoder: CLIPTextModel) -> ManagedCLIPTextEmbeddings:
+    text_embeddings = ManagedCLIPTextEmbeddings(text_encoder.config, text_encoder.text_model.embeddings)
+    text_encoder.text_model.embeddings = text_embeddings
+    return text_embeddings
-- 
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