114 lines
3.5 KiB
Python
114 lines
3.5 KiB
Python
#####################################################
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# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.03 #
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#####################################################
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import math
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from typing import Optional, Text
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from xautodl import spaces
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from .super_module import SuperModule
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from .super_module import IntSpaceType
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from .super_module import BoolSpaceType
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from .super_linear import SuperLinear
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class SuperQKVAttentionV2(SuperModule):
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"""The super model for attention layer."""
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def __init__(
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self,
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qk_att_dim: int,
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in_v_dim: int,
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hidden_dim: int,
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num_heads: int,
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proj_dim: int,
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qkv_bias: bool = False,
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attn_drop: Optional[float] = None,
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proj_drop: Optional[float] = None,
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):
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super(SuperQKVAttentionV2, self).__init__()
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self._in_v_dim = in_v_dim
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self._qk_att_dim = qk_att_dim
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self._proj_dim = proj_dim
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self._hidden_dim = hidden_dim
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self._num_heads = num_heads
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self._qkv_bias = qkv_bias
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self.qk_fc = SuperLinear(qk_att_dim, num_heads, bias=qkv_bias)
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self.v_fc = SuperLinear(in_v_dim, hidden_dim * num_heads, bias=qkv_bias)
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self.attn_drop = nn.Dropout(attn_drop or 0.0)
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self.proj = SuperLinear(hidden_dim * num_heads, proj_dim)
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self.proj_drop = nn.Dropout(proj_drop or 0.0)
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self._infinity = 1e9
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@property
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def num_heads(self):
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return spaces.get_max(self._num_heads)
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@property
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def in_v_dim(self):
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return spaces.get_max(self._in_v_dim)
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@property
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def qk_att_dim(self):
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return spaces.get_max(self._qk_att_dim)
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@property
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def hidden_dim(self):
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return spaces.get_max(self._hidden_dim)
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@property
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def proj_dim(self):
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return spaces.get_max(self._proj_dim)
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@property
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def abstract_search_space(self):
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root_node = spaces.VirtualNode(id(self))
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raise NotImplementedError
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def apply_candidate(self, abstract_child: spaces.VirtualNode):
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super(SuperQKVAttentionV2, self).apply_candidate(abstract_child)
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raise NotImplementedError
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def forward_qkv(
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self, qk_att_tensor, v_tensor, num_head: int, mask=None
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) -> torch.Tensor:
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qk_att = self.qk_fc(qk_att_tensor)
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B, N, S, _ = qk_att.shape
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assert _ == num_head
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attn_v1 = qk_att.permute(0, 3, 1, 2)
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if mask is not None:
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mask = torch.unsqueeze(mask, dim=1)
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attn_v1 = attn_v1.masked_fill(mask, -self._infinity)
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attn_v1 = attn_v1.softmax(dim=-1) # B * #head * N * S
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attn_v1 = self.attn_drop(attn_v1)
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v = self.v_fc(v_tensor)
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B0, _, _ = v.shape
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v_v1 = v.reshape(B0, S, num_head, -1).permute(0, 2, 1, 3)
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feats_v1 = (attn_v1 @ v_v1).permute(0, 2, 1, 3).reshape(B, N, -1)
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return feats_v1
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def forward_candidate(self, qk_att_tensor, v_tensor, mask=None) -> torch.Tensor:
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return self.forward_raw(qk_att_tensor, v_tensor, mask)
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def forward_raw(self, qk_att_tensor, v_tensor, mask=None) -> torch.Tensor:
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feats = self.forward_qkv(qk_att_tensor, v_tensor, self.num_heads, mask)
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outs = self.proj(feats)
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outs = self.proj_drop(outs)
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return outs
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def extra_repr(self) -> str:
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return "input_dim={:}, hidden_dim={:}, proj_dim={:}, num_heads={:}, infinity={:}".format(
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(self.qk_att_dim, self.in_v_dim),
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self._hidden_dim,
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self._proj_dim,
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self._num_heads,
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self._infinity,
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)
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