import sys
import math
import functools
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
sys.path.append('utils')
from proj_adaptive_softmax import ProjectedAdaptiveLogSoftmax
from log_uniform_sampler import LogUniformSampler, sample_logits
class PositionalEmbedding(nn.Module):
def __init__(self, demb):
super(PositionalEmbedding, self).__init__()
self.demb = demb
inv_freq = 1 / (10000 ** (torch.arange(0.0, demb, 2.0) / demb))
self.register_buffer('inv_freq', inv_freq)
def forward(self, pos_seq, bsz=None):
sinusoid_inp = torch.ger(pos_seq, self.inv_freq)
pos_emb = torch.cat([sinusoid_inp.sin(), sinusoid_inp.cos()], dim=-1)
if bsz is not None:
return pos_emb[:,None,:].expand(-1, bsz, -1)
else:
return pos_emb[:,None,:]
class PositionwiseFF(nn.Module):
def __init__(self, d_model, d_inner, dropout, pre_lnorm=False):
super(PositionwiseFF, self).__init__()
self.d_model = d_model
self.d_inner = d_inner
self.dropout = dropout
self.CoreNet = nn.Sequential(
nn.Linear(d_model, d_inner), nn.ReLU(inplace=True),
nn.Dropout(dropout),
nn.Linear(d_inner, d_model),
nn.Dropout(dropout),
)
self.layer_norm = nn.LayerNorm(d_model)
self.pre_lnorm = pre_lnorm
def forward(self, inp):
if self.pre_lnorm:
##### layer normalization + positionwise feed-forward
core_out = self.CoreNet(self.layer_norm(inp))
##### residual connection
output = core_out + inp
else:
##### positionwise feed-forward
core_out = self.CoreNet(inp)
##### residual connection + layer normalization
output = self.layer_norm(inp + core_out)
return output
class MultiHeadAttn(nn.Module):
def __init__(self, n_head, d_model, d_head, dropout, dropatt=0,
pre_lnorm=False):
super(MultiHeadAttn, self).__init__()
self.n_head = n_head
self.d_model = d_model
self.d_head = d_head
self.dropout = dropout
self.q_net = nn.Linear(d_model, n_head * d_head, bias=False)
self.kv_net = nn.Linear(d_model, 2 * n_head * d_head, bias=False)
self.drop = nn.Dropout(dropout)
self.dropatt = nn.Dropout(dropatt)
self.o_net = nn.Linear(n_head * d_head, d_model, bias=False)
self.layer_norm = nn.LayerNorm(d_model)
self.scale = 1 / (d_head ** 0.5)
self.pre_lnorm = pre_lnorm
def forward(self, h, attn_mask=None, mems=None):
##### multihead attention
# [hlen x bsz x n_head x d_head]
if mems is not None:
c = torch.cat([mems, h], 0)
else:
c = h
if self.pre_lnorm:
##### layer normalization
c = self.layer_norm(c)
head_q = self.q_net(h)
head_k, head_v = torch.chunk(self.kv_net(c), 2, -1)
head_q = head_q.view(h.size(0), h.size(1), self.n_head, self.d_head)
head_k = head_k.view(c.size(0), c.size(1), self.n_head, self.d_head)
head_v = head_v.view(c.size(0), c.size(1), self.n_head, self.d_head)
# [qlen x klen x bsz x n_head]
attn_score = torch.einsum('ibnd,jbnd->ijbn', (head_q, head_k))
attn_score.mul_(self.scale)
if attn_mask is not None and attn_mask.any().item():
if attn_mask.dim() == 2:
attn_score.masked_fill_(attn_mask[None,:,:,None], -float('inf'))
elif attn_mask.dim() == 3:
attn_score.masked_fill_(attn_mask[:,:,:,None], -float('inf'))
# [qlen x klen x bsz x n_head]
attn_prob = F.softmax(attn_score, dim=1)
attn_prob = self.dropatt(attn_prob)
# [qlen x klen x bsz x n_head] + [klen x bsz x n_head x d_head] -> [qlen x bsz x n_head x d_head]
attn_vec = torch.einsum('ijbn,jbnd->ibnd', (attn_prob, head_v))
attn_vec = attn_vec.contiguous().view(
attn_vec.size(0), attn_vec.size(1), self.n_head * self.d_head)
##### linear projection
attn_out = self.o_net(attn_vec)
attn_out = self.drop(attn_out)
if self.pre_lnorm:
##### residual connection
output = h + attn_out
else:
##### residual connection + layer normalization
output = self.layer_norm(h + attn_out)
return output
class RelMultiHeadAttn(nn.Module):
def __init__(self, n_head, d_model, d_head, dropout, dropatt=0,
tgt_len=None, ext_len=None, mem_len=None, pre_lnorm=False):
super(RelMultiHeadAttn, self).__init__()
self.n_head = n_head
self.d_model = d_model
self.d_head = d_head
self.dropout = dropout
self.qkv_net = nn.Linear(d_model, 3 * n_head * d_head, bias=False)
self.drop = nn.Dropout(dropout)
self.dropatt = nn.Dropout(dropatt)
self.o_net = nn.Linear(n_head * d_head, d_model, bias=False)
self.layer_norm = nn.LayerNorm(d_model)
self.scale = 1 / (d_head ** 0.5)
self.pre_lnorm = pre_lnorm
def _parallelogram_mask(self, h, w, left=False):
mask = torch.ones((h, w)).byte()
m = min(h, w)
mask[:m,:m] = torch.triu(mask[:m,:m])
mask[-m:,-m:] = torch.tril(mask[-m:,-m:])
if left:
return mask
else:
return mask.flip(0)
def _shift(self, x, qlen, klen, mask, left=False):
if qlen > 1:
zero_pad = torch.zeros((x.size(0), qlen-1, x.size(2), x.size(3)),
device=x.device, dtype=x.dtype)
else:
zero_pad = torch.zeros(0, device=x.device, dtype=x.dtype)
if left:
mask = mask.flip(1)
x_padded = torch.cat([zero_pad, x], dim=1).expand(qlen, -1, -1, -1)
else:
x_padded = torch.cat([x, zero_pad], dim=1).expand(qlen, -1, -1, -1)
x = x_padded.masked_select(mask[:,:,None,None]) \
.view(qlen, klen, x.size(2), x.size(3))
return x
def _rel_shift(self, x, zero_triu=False):
zero_pad = torch.zeros((x.size(0), 1, *x.size()[2:]),
device=x.device, dtype=x.dtype)
x_padded = torch.cat([zero_pad, x], dim=1)
x_padded = x_padded.view(x.size(1) + 1, x.size(0), *x.size()[2:])
x = x_padded[1:].view_as(x)
if zero_triu:
ones = torch.ones((x.size(0), x.size(1)))
x = x * torch.tril(ones, x.size(1) - x.size(0))[:,:,None,None]
return x
def forward(self, w, r, attn_mask=None, mems=None):
raise NotImplementedError
class RelPartialLearnableMultiHeadAttn(RelMultiHeadAttn):
def __init__(self, *args, **kwargs):
super(RelPartialLearnableMultiHeadAttn, self).__init__(*args, **kwargs)
self.r_net = nn.Linear(self.d_model, self.n_head * self.d_head, bias=False)
def forward(self, w, r, r_w_bias, r_r_bias, attn_mask=None, mems=None):
qlen, rlen, bsz = w.size(0), r.size(0), w.size(1)
if mems is not None:
cat = torch.cat([mems, w], 0)
if self.pre_lnorm:
w_heads = self.qkv_net(self.layer_norm(cat))
else:
w_heads = self.qkv_net(cat)
r_head_k = self.r_net(r)
w_head_q, w_head_k, w_head_v = torch.chunk(w_heads, 3, dim=-1)
w_head_q = w_head_q[-qlen:]
else:
if self.pre_lnorm:
w_heads = self.qkv_net(self.layer_norm(w))
else:
w_heads = self.qkv_net(w)
r_head_k = self.r_net(r)
w_head_q, w_head_k, w_head_v = torch.chunk(w_heads, 3, dim=-1)
klen = w_head_k.size(0)
w_head_q = w_head_q.view(qlen, bsz, self.n_head, self.d_head) # qlen x bsz x n_head x d_head
w_head_k = w_head_k.view(klen, bsz, self.n_head, self.d_head) # qlen x bsz x n_head x d_head
w_head_v = w_head_v.view(klen, bsz, self.n_head, self.d_head) # qlen x bsz x n_head x d_head
r_head_k = r_head_k.view(rlen, self.n_head, self.d_head) # qlen x n_head x d_head
#### compute attention score
rw_head_q = w_head_q + r_w_bias # qlen x bsz x n_head x d_head
AC = torch.einsum('ibnd,jbnd->ijbn', (rw_head_q, w_head_k)) # qlen x klen x bsz x n_head
rr_head_q = w_head_q + r_r_bias
BD = torch.einsum('ibnd,jnd->ijbn', (rr_head_q, r_head_k)) # qlen x klen x bsz x n_head
BD = self._rel_shift(BD)
# [qlen x klen x bsz x n_head]
attn_score = AC + BD
attn_score.mul_(self.scale)
#### compute attention probability
if attn_mask is not None and attn_mask.any().item():
if attn_mask.dim() == 2:
attn_score = attn_score.float().masked_fill(
attn_mask[None,:,:,None], -float('inf')).type_as(attn_score)
elif attn_mask.dim() == 3:
attn_score = attn_score.float().masked_fill(
attn_mask[:,:,:,None], -float('inf')).type_as(attn_score)
# [qlen x klen x bsz x n_head]
attn_prob = F.softmax(attn_score, dim=1)
attn_prob = self.dropatt(attn_prob)
#### compute attention vector
attn_vec = torch.einsum('ijbn,jbnd->ibnd', (attn_prob, w_head_v))
# [qlen x bsz x n_head x d_head]
attn_vec = attn_vec.contiguous().view(
attn_vec.size(0), attn_vec.size(1), self.n_head * self.d_head)
##### linear projection
attn_out = self.o_net(attn_vec)
attn_out = self.drop(attn_out)
if self.pre_lnorm:
##### residual connection
output = w + attn_out
else:
##### residual connection + layer normalization
output = self.layer_norm(w + attn_out)
return output
class RelLearnableMultiHeadAttn(RelMultiHeadAttn):
def __init__(self, *args, **kwargs):
super(RelLearnableMultiHeadAttn, self).__init__(*args, **kwargs)
def forward(self, w, r_emb, r_w_bias, r_bias, attn_mask=None, mems=None):
# r_emb: [klen, n_head, d_head], used for term B
# r_w_bias: [n_head, d_head], used for term C
# r_bias: [klen, n_head], used for term D
qlen, bsz = w.size(0), w.size(1)
if mems is not None:
cat = torch.cat([mems, w], 0)
if self.pre_lnorm:
w_heads = self.qkv_net(self.layer_norm(cat))
else:
w_heads = self.qkv_net(cat)
w_head_q, w_head_k, w_head_v = torch.chunk(w_heads, 3, dim=-1)
w_head_q = w_head_q[-qlen:]
else:
if self.pre_lnorm:
w_heads = self.qkv_net(self.layer_norm(w))
else:
w_heads = self.qkv_net(w)
w_head_q, w_head_k, w_head_v = torch.chunk(w_heads, 3, dim=-1)
klen = w_head_k.size(0)
w_head_q = w_head_q.view(qlen, bsz, self.n_head, self.d_head)
w_head_k = w_head_k.view(klen, bsz, self.n_head, self.d_head)
w_head_v = w_head_v.view(klen, bsz, self.n_head, self.d_head)
if klen > r_emb.size(0):
r_emb_pad = r_emb[0:1].expand(klen-r_emb.size(0), -1, -1)
r_emb = torch.cat([r_emb_pad, r_emb], 0)
r_bias_pad = r_bias[0:1].expand(klen-r_bias.size(0), -1)
r_bias = torch.cat([r_bias_pad, r_bias], 0)
else:
r_emb = r_emb[-klen:]
r_bias = r_bias[-klen:]
#### compute attention score
rw_head_q = w_head_q + r_w_bias[None] # qlen x bsz x n_head x d_head
AC = torch.einsum('ibnd,jbnd->ijbn', (rw_head_q, w_head_k)) # qlen x klen x bsz x n_head
B_ = torch.einsum('ibnd,jnd->ijbn', (w_head_q, r_emb)) # qlen x klen x bsz x n_head
D_ = r_bias[None, :, None] # 1 x klen x 1 x n_head
BD = self._rel_shift(B_ + D_)
# [qlen x klen x bsz x n_head]
attn_score = AC + BD
attn_score.mul_(self.scale)
#### compute attention probability
if attn_mask is not None and attn_mask.any().item():
if attn_mask.dim() == 2:
attn_score.masked_fill_(attn_mask[None,:,:,None], -float('inf'))
elif attn_mask.dim() == 3:
attn_score.masked_fill_(attn_mask[:,:,:,None], -float('inf'))
# [qlen x klen x bsz x n_head]
attn_prob = F.softmax(attn_score, dim=1)
attn_prob = self.dropatt(attn_prob)
#### compute attention vector
attn_vec = torch.einsum('ijbn,jbnd->ibnd', (attn_prob, w_head_v))
# [qlen x bsz x n_head x d_head]
attn_vec = attn_vec.contiguous().view(
attn_vec.size(0), attn_vec.size(1), self.n_head * self.d_head)
##### linear projection
attn_out = self.o_net(attn_vec)
attn_out = self.drop(attn_out)
if self.pre_lnorm:
##### residual connection
output = w + attn_out
else:
##### residual connection + layer normalization
output = self.layer_norm(w + attn_out)
return output
class DecoderLayer(nn.Module):
def __init__(self, n_head, d_model, d_head, d_inner, dropout, **kwargs):
super(DecoderLayer, self).__init__()
self.dec_attn = MultiHeadAttn(n_head, d_model, d_head, dropout, **kwargs)
self.pos_ff = PositionwiseFF(d_model, d_inner, dropout,
pre_lnorm=kwargs.get('pre_lnorm'))
def forward(self, dec_inp, dec_attn_mask=None, mems=None):
output = self.dec_attn(dec_inp, attn_mask=dec_attn_mask,
mems=mems)
output = self.pos_ff(output)
return output
class RelLearnableDecoderLayer(nn.Module):
def __init__(self, n_head, d_model, d_head, d_inner, dropout,
**kwargs):
super(RelLearnableDecoderLayer, self).__init__()
self.dec_attn = RelLearnableMultiHeadAttn(n_head, d_model, d_head, dropout,
**kwargs)
self.pos_ff = PositionwiseFF(d_model, d_inner, dropout,
pre_lnorm=kwargs.get('pre_lnorm'))
def forward(self, dec_inp, r_emb, r_w_bias, r_bias, dec_attn_mask=None, mems=None):
output = self.dec_attn(dec_inp, r_emb, r_w_bias, r_bias,
attn_mask=dec_attn_mask,
mems=mems)
output = self.pos_ff(output)
return output
class RelPartialLearnableDecoderLayer(nn.Module):
def __init__(self, n_head, d_model, d_head, d_inner, dropout,
**kwargs):
super(RelPartialLearnableDecoderLayer, self).__init__()
self.dec_attn = RelPartialLearnableMultiHeadAttn(n_head, d_model,
d_head, dropout, **kwargs)
self.pos_ff = PositionwiseFF(d_model, d_inner, dropout,
pre_lnorm=kwargs.get('pre_lnorm'))
def forward(self, dec_inp, r, r_w_bias, r_r_bias, dec_attn_mask=None, mems=None):
output = self.dec_attn(dec_inp, r, r_w_bias, r_r_bias,
attn_mask=dec_attn_mask,
mems=mems)
output = self.pos_ff(output)
return output
class AdaptiveEmbedding(nn.Module):
def __init__(self, n_token, d_embed, d_proj, cutoffs, div_val=1,
sample_softmax=False):
super(AdaptiveEmbedding, self).__init__()
self.n_token = n_token
self.d_embed = d_embed
self.cutoffs = cutoffs + [n_token]
print('cutoffs', cutoffs)
self.div_val = div_val
self.d_proj = d_proj
self.emb_scale = d_proj ** 0.5
self.cutoff_ends = [0] + self.cutoffs
self.emb_layers = nn.ModuleList()
self.emb_projs = nn.ParameterList()
if div_val == 1:
self.emb_layers.append(
nn.Embedding(n_token, d_embed, sparse=sample_softmax>0)
)
if d_proj != d_embed:
self.emb_projs.append(nn.Parameter(torch.Tensor(d_proj, d_embed)))
else:
for i in range(len(self.cutoffs)):
l_idx, r_idx = self.cutoff_ends[i], self.cutoff_ends[i+1]
d_emb_i = d_embed // (div_val ** i)
print(r_idx, l_idx, d_emb_i)
self.emb_layers.append(nn.Embedding(r_idx-l_idx, d_emb_i))
self.emb_projs.append(nn.Parameter(torch.Tensor(d_proj, d_emb_i)))
def forward(self, inp):
if self.div_val == 1:
embed = self.emb_layers[0](inp)
if self.d_proj != self.d_embed:
embed = F.linear(embed, self.emb_projs[0])
else:
param = next(self.parameters())
inp_flat = inp.view(-1)
emb_flat = torch.zeros([inp_flat.size(0), self.d_proj],
dtype=param.dtype, device=param.device)
for i in range(len(self.cutoffs)):
l_idx, r_idx = self.cutoff_ends[i], self.cutoff_ends[i + 1]
mask_i = (inp_flat >= l_idx) & (inp_flat < r_idx)
indices_i = mask_i.nonzero().squeeze()
if indices_i.numel() == 0:
continue
inp_i = inp_flat.index_select(0, indices_i) - l_idx
emb_i = self.emb_layers[i](inp_i)
emb_i = F.linear(emb_i, self.emb_projs[i])
emb_flat.index_copy_(0, indices_i, emb_i)
embed = emb_flat.view(*inp.size(), self.d_proj)
embed.mul_(self.emb_scale)
return embed
class MemTransformerLM(nn.Module):
def __init__(self, n_token, n_layer, n_head, d_model, d_head, d_inner,
dropout, dropatt, tie_weight=True, d_embed=None,
div_val=1, tie_projs=[False], pre_lnorm=False,
tgt_len=None, ext_len=None, mem_len=None,
cutoffs=[], adapt_inp=False,
same_length=False, attn_type=0, clamp_len=-1,
sample_softmax=-1):
super(MemTransformerLM, self).__init__()
self.n_token = n_token
d_embed = d_model if d_embed is None else d_embed
self.d_embed = d_embed
self.d_model = d_model
self.n_head = n_head
self.d_head = d_head
self.word_emb = AdaptiveEmbedding(n_token, d_embed, d_model, cutoffs,
div_val=div_val)
self.drop = nn.Dropout(dropout)
self.n_layer = n_layer
self.tgt_len = tgt_len
self.mem_len = mem_len
self.ext_len = ext_len
self.max_klen = tgt_len + ext_len + mem_len
self.attn_type = attn_type
self.layers = nn.ModuleList()
if attn_type == 0: # the default attention
for i in range(n_layer):
self.layers.append(
RelPartialLearnableDecoderLayer(
n_head, d_model, d_head, d_inner, dropout,
tgt_len=tgt_len, ext_len=ext_len, mem_len=mem_len,
dropatt=dropatt, pre_lnorm=pre_lnorm)
)
elif attn_type == 1: # learnable embeddings
for i in range(n_layer):
self.layers.append(
RelLearnableDecoderLayer(
n_head, d_model, d_head, d_inner, dropout,
tgt_len=tgt_len, ext_len=ext_len, mem_len=mem_len,
dropatt=dropatt, pre_lnorm=pre_lnorm)
)
elif attn_type in [2, 3]: # absolute embeddings
for i in range(n_layer):
self.layers.append(
DecoderLayer(
n_head, d_model, d_head, d_inner, dropout,
dropatt=dropatt, pre_lnorm=pre_lnorm)
)
self.sample_softmax = sample_softmax
# use sampled softmax
if sample_softmax > 0:
self.out_layer = nn.Linear(d_model, n_token)
if tie_weight:
self.out_layer.weight = self.word_emb.weight
self.tie_weight = tie_weight
self.sampler = LogUniformSampler(n_token, sample_softmax)
# use adaptive softmax (including standard softmax)
else:
self.crit = ProjectedAdaptiveLogSoftmax(n_token, d_embed, d_model,
cutoffs, div_val=div_val)
if tie_weight:
for i in range(len(self.crit.out_layers)):
self.crit.out_layers[i].weight = self.word_emb.emb_layers[i].weight
if tie_projs:
for i, tie_proj in enumerate(tie_projs):
if tie_proj and div_val == 1 and d_model != d_embed:
self.crit.out_projs[i] = self.word_emb.emb_projs[0]
elif tie_proj and div_val != 1:
self.crit.out_projs[i] = self.word_emb.emb_projs[i]
self.same_length = same_length
self.clamp_len = clamp_len
self._create_params()
def backward_compatible(self):
self.sample_softmax = -1
def _create_params(self):
if self.attn_type == 0: # default attention
self.pos_emb = PositionalEmbedding(self.d_model)
self.r_w_bias = nn.Parameter(torch.Tensor(self.n_head, self.d_head))
self.r_r_bias = nn.Parameter(torch.Tensor(self.n_head, self.d_head))
elif self.attn_type == 1: # learnable
self.r_emb = nn.Parameter(torch.Tensor(
self.n_layer, self.max_klen, self.n_head, self.d_head))
self.r_w_bias = nn.Parameter(torch.Tensor(
self.n_layer, self.n_head, self.d_head))
self.r_bias = nn.Parameter(torch.Tensor(
self.n_layer, self.max_klen, self.n_head))
elif self.attn_type == 2: # absolute standard
self.pos_emb = PositionalEmbedding(self.d_model)
elif self.attn_type == 3: # absolute deeper SA
self.r_emb = nn.Parameter(torch.Tensor(
self.n_layer, self.max_klen, self.n_head, self.d_head))
def reset_length(self, tgt_len, ext_len, mem_len):
self.tgt_len = tgt_len
self.mem_len = mem_len
self.ext_len = ext_len
def init_mems(self):
if self.mem_len > 0:
mems = []
param = next(self.parameters())
for i in range(self.n_layer+1):
empty = torch.empty(0, dtype=param.dtype, device=param.device)
mems.append(empty)
return mems
else:
return None
def _update_mems(self, hids, mems, qlen, mlen):
# does not deal with None
if mems is None: return None
# mems is not None
assert len(hids) == len(mems), 'len(hids) != len(mems)'
# There are `mlen + qlen` steps that can be cached into mems
# For the next step, the last `ext_len` of the `qlen` tokens
# will be used as the extended context. Hence, we only cache
# the tokens from `mlen + qlen - self.ext_len - self.mem_len`
# to `mlen + qlen - self.ext_len`.
with torch.no_grad():
new_mems = []
end_idx = mlen + max(0, qlen - 0 - self.ext_len)
beg_idx = max(0, end_idx - self.mem_len)
for i in range(len(hids)):
cat = torch.cat([mems[i], hids[i]], dim=0)
new_mems.append(cat[beg_idx:end_idx].detach())
return new_mems
def _forward(self, dec_inp, mems=None):
qlen, bsz = dec_inp.size()
word_emb = self.word_emb(dec_inp)
mlen = mems[0].size(0) if mems is not None else 0
klen = mlen + qlen
if self.same_length:
all_ones = word_emb.new_ones(qlen, klen)
mask_len = klen - self.mem_len
if mask_len > 0:
mask_shift_len = qlen - mask_len
else:
mask_shift_len = qlen
dec_attn_mask = (torch.triu(all_ones, 1+mlen)
+ torch.tril(all_ones, -mask_shift_len)).byte()[:, :, None] # -1
else:
dec_attn_mask = torch.triu(
word_emb.new_ones(qlen, klen), diagonal=1+mlen).byte()[:,:,None]
hids = []
if self.attn_type == 0: # default
pos_seq = torch.arange(klen-1, -1, -1.0, device=word_emb.device,
dtype=word_emb.dtype)
if self.clamp_len > 0:
pos_seq.clamp_(max=self.clamp_len)
pos_emb = self.pos_emb(pos_seq)
core_out = self.drop(word_emb)
pos_emb = self.drop(pos_emb)
hids.append(core_out)
for i, layer in enumerate(self.layers):
mems_i = None if mems is None else mems[i]
core_out = layer(core_out, pos_emb, self.r_w_bias,
self.r_r_bias, dec_attn_mask=dec_attn_mask, mems=mems_i)
hids.append(core_out)
elif self.attn_type == 1: # learnable
core_out = self.drop(word_emb)
hids.append(core_out)
for i, layer in enumerate(self.layers):
if self.clamp_len > 0:
r_emb = self.r_emb[i][-self.clamp_len :]
r_bias = self.r_bias[i][-self.clamp_len :]
else:
r_emb, r_bias = self.r_emb[i], self.r_bias[i]
mems_i = None if mems is None else mems[i]
core_out = layer(core_out, r_emb, self.r_w_bias[i],
r_bias, dec_attn_mask=dec_attn_mask, mems=mems_i)
hids.append(core_out)
elif self.attn_type == 2: # absolute
pos_seq = torch.arange(klen - 1, -1, -1.0, device=word_emb.device,
dtype=word_emb.dtype)
if self.clamp_len > 0:
pos_seq.clamp_(max=self.clamp_len)
pos_emb = self.pos_emb(pos_seq)
core_out = self.drop(word_emb + pos_emb[-qlen:])
hids.append(core_out)
for i, layer in enumerate(self.layers):
mems_i = None if mems is None else mems[i]
if mems_i is not None and i == 0:
mems_i += pos_emb[:mlen]
core_out = layer(core_out, dec_attn_mask=dec_attn_mask,
mems=mems_i)
hids.append(core_out)
elif self.attn_type == 3:
core_out = self.drop(word_emb)
hids.append(core_out)
for i, layer in enumerate(self.layers):
mems_i = None if mems is None else mems[i]
if mems_i is not None and mlen > 0:
cur_emb = self.r_emb[i][:-qlen]
cur_size = cur_emb.size(0)
if cur_size < mlen:
cur_emb_pad = cur_emb[0:1].expand(mlen-cur_size, -1, -1)
cur_emb = torch.cat([cur_emb_pad, cur_emb], 0)
else:
cur_emb = cur_emb[-mlen:]
mems_i += cur_emb.view(mlen, 1, -1)
core_out += self.r_emb[i][-qlen:].view(qlen, 1, -1)
core_out = layer(core_out, dec_attn_mask=dec_attn_mask,
mems=mems_i)
hids.append(core_out)
core_out = self.drop(core_out)
new_mems = self._update_mems(hids, mems, mlen, qlen)
return core_out, new_mems
def forward(self, data, target, *mems):
# nn.DataParallel does not allow size(0) tensors to be broadcasted.
# So, have to initialize size(0) mems inside the model forward.
# Moreover, have to return new_mems to allow nn.DataParallel to piece
# them together.
if not mems: mems = self.init_mems()
tgt_len = target.size(0)
hidden, new_mems = self._forward(data, mems=mems)
pred_hid = hidden[-tgt_len:]
if self.sample_softmax > 0 and self.training:
assert self.tie_weight
logit = sample_logits(self.word_emb,
self.out_layer.bias, target, pred_hid, self.sampler)
loss = -F.log_softmax(logit, -1)[:, :, 0]
else:
loss = self.crit(pred_hid.view(-1, pred_hid.size(-1)), target.view(-1))
loss = loss.view(tgt_len, -1)
if new_mems is None:
return [loss]
else:
return [loss] + new_mems
if __name__ == '__main__':
import argparse
parser = argparse.ArgumentParser(description='unit test')
parser.add_argument('--n_layer', type=int, default=4, help='')
parser.add_argument('--n_rel_layer', type=int, default=4, help='')
parser.add_argument('--n_head', type=int, default=2, help='')
parser.add_argument('--d_head', type=int, default=2, help='')
parser.add_argument('--d_model', type=int, default=200, help='')
parser.add_argument('--d_embed', type=int, default=200, help='')
parser.add_argument('--d_inner', type=int, default=200, help='')
parser.add_argument('--dropout', type=float, default=0.0, help='')
parser.add_argument('--cuda', action='store_true', help='')
parser.add_argument('--seed', type=int, default=1111, help='')
parser.add_argument('--multi_gpu', action='store_true', help='')
args = parser.parse_args()
device = torch.device("cuda" if args.cuda else "cpu")
B = 4
tgt_len, mem_len, ext_len = 36, 36, 0
data_len = tgt_len * 20
args.n_token = 10000
import data_utils
data = torch.LongTensor(data_len*B).random_(0, args.n_token).to(device)
diter = data_utils.LMOrderedIterator(data, B, tgt_len, device=device, ext_len=ext_len)
cutoffs = [args.n_token // 2]
tie_projs = [False] + [True] * len(cutoffs)
for div_val in [1, 2]:
for d_embed in [200, 100]:
model = MemTransformerLM(args.n_token, args.n_layer, args.n_head,
args.d_model, args.d_head, args.d_inner, args.dropout,
dropatt=args.dropout, tie_weight=True,
d_embed=d_embed, div_val=div_val,
tie_projs=tie_projs, pre_lnorm=True,
tgt_len=tgt_len, ext_len=ext_len, mem_len=mem_len,
cutoffs=cutoffs, attn_type=0).to(device)
print(sum(p.numel() for p in model.parameters()))
mems = tuple()
for idx, (inp, tgt, seqlen) in enumerate(diter):
print('batch {}'.format(idx))
out = model(inp, tgt, *mems)
mems = out[1:]
