autodl-projects/xautodl/xlayers/super_attention_v2.py

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2021-05-23 10:21:31 +02:00
#####################################################
# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.03 #
#####################################################
import math
from typing import Optional, Text
import torch
import torch.nn as nn
import torch.nn.functional as F
from xautodl import spaces
from .super_module import SuperModule
from .super_module import IntSpaceType
from .super_module import BoolSpaceType
from .super_linear import SuperLinear
class SuperQKVAttentionV2(SuperModule):
"""The super model for attention layer."""
def __init__(
self,
qk_att_dim: int,
in_v_dim: int,
hidden_dim: int,
num_heads: int,
proj_dim: int,
qkv_bias: bool = False,
attn_drop: Optional[float] = None,
proj_drop: Optional[float] = None,
):
super(SuperQKVAttentionV2, self).__init__()
self._in_v_dim = in_v_dim
self._qk_att_dim = qk_att_dim
self._proj_dim = proj_dim
self._hidden_dim = hidden_dim
self._num_heads = num_heads
self._qkv_bias = qkv_bias
self.qk_fc = SuperLinear(qk_att_dim, num_heads, bias=qkv_bias)
self.v_fc = SuperLinear(in_v_dim, hidden_dim * num_heads, bias=qkv_bias)
self.attn_drop = nn.Dropout(attn_drop or 0.0)
self.proj = SuperLinear(hidden_dim * num_heads, proj_dim)
self.proj_drop = nn.Dropout(proj_drop or 0.0)
self._infinity = 1e9
@property
def num_heads(self):
return spaces.get_max(self._num_heads)
@property
def in_v_dim(self):
return spaces.get_max(self._in_v_dim)
@property
def qk_att_dim(self):
return spaces.get_max(self._qk_att_dim)
@property
def hidden_dim(self):
return spaces.get_max(self._hidden_dim)
@property
def proj_dim(self):
return spaces.get_max(self._proj_dim)
@property
def abstract_search_space(self):
root_node = spaces.VirtualNode(id(self))
raise NotImplementedError
def apply_candidate(self, abstract_child: spaces.VirtualNode):
super(SuperQKVAttentionV2, self).apply_candidate(abstract_child)
raise NotImplementedError
def forward_qkv(
self, qk_att_tensor, v_tensor, num_head: int, mask=None
) -> torch.Tensor:
qk_att = self.qk_fc(qk_att_tensor)
B, N, S, _ = qk_att.shape
assert _ == num_head
attn_v1 = qk_att.permute(0, 3, 1, 2)
if mask is not None:
mask = torch.unsqueeze(mask, dim=1)
attn_v1 = attn_v1.masked_fill(mask, -self._infinity)
attn_v1 = attn_v1.softmax(dim=-1) # B * #head * N * S
attn_v1 = self.attn_drop(attn_v1)
v = self.v_fc(v_tensor)
B0, _, _ = v.shape
v_v1 = v.reshape(B0, S, num_head, -1).permute(0, 2, 1, 3)
feats_v1 = (attn_v1 @ v_v1).permute(0, 2, 1, 3).reshape(B, N, -1)
return feats_v1
def forward_candidate(self, qk_att_tensor, v_tensor, mask=None) -> torch.Tensor:
return self.forward_raw(qk_att_tensor, v_tensor, mask)
def forward_raw(self, qk_att_tensor, v_tensor, mask=None) -> torch.Tensor:
feats = self.forward_qkv(qk_att_tensor, v_tensor, self.num_heads, mask)
outs = self.proj(feats)
outs = self.proj_drop(outs)
return outs
def extra_repr(self) -> str:
return "input_dim={:}, hidden_dim={:}, proj_dim={:}, num_heads={:}, infinity={:}".format(
(self.qk_att_dim, self.in_v_dim),
self._hidden_dim,
self._proj_dim,
self._num_heads,
self._infinity,
)