Rename and add flash atten

1 files changed, 28 insertions, 0 deletions

diff --git a/text_recognizer/network/transformer/embedding/absolute.py b/text_recognizer/network/transformer/embedding/absolute.py
new file mode 100644
index 0000000..08b2c2a
--- /dev/null
+++ b/text_recognizer/network/transformer/embedding/absolute.py
@@ -0,0 +1,28 @@
+from typing import Optional
+
+import torch
+from torch import nn, Tensor
+from text_recognizer.network.transformer.embedding.l2_norm import l2_norm
+
+
+class AbsolutePositionalEmbedding(nn.Module):
+    def __init__(self, dim: int, max_length: int, use_l2: bool = False) -> None:
+        super().__init__()
+        self.scale = dim**-0.5 if not use_l2 else 1.0
+        self.max_length = max_length
+        self.use_l2 = use_l2
+        self.to_embedding = nn.Embedding(max_length, dim)
+        if self.use_l2:
+            nn.init.normal_(self.to_embedding.weight, std=1e-5)
+
+    def forward(self, x: Tensor, pos: Optional[Tensor] = None) -> Tensor:
+        n, device = x.shape[1], x.device
+        assert (
+            n <= self.max_length
+        ), f"Sequence length {n} is greater than the maximum positional embedding {self.max_length}"
+
+        if pos is None:
+            pos = torch.arange(n, device=device)
+
+        embedding = self.to_embedding(pos) * self.scale
+        return l2_norm(embedding) if self.use_l2 else embedding