remove einops exts for better pytorch 2.0 compile compatibility

dalle2_pytorch/dalle2_pytorch.py

@@ -12,10 +12,8 @@ from torch.utils.checkpoint import checkpoint
 from torch import nn, einsum
 import torchvision.transforms as T
 
-from einops import rearrange, repeat, reduce
+from einops import rearrange, repeat, reduce, pack, unpack
 from einops.layers.torch import Rearrange
-from einops_exts import rearrange_many, repeat_many, check_shape
-from einops_exts.torch import EinopsToAndFrom
 
 from kornia.filters import gaussian_blur2d
 import kornia.augmentation as K
@@ -669,6 +667,23 @@ class NoiseScheduler(nn.Module):
             return loss
         return loss * extract(self.p2_loss_weight, times, loss.shape)
 
+# rearrange image to sequence
+
+class RearrangeToSequence(nn.Module):
+    def __init__(self, fn):
+        super().__init__()
+        self.fn = fn
+
+    def forward(self, x):
+        x = rearrange(x, 'b c ... -> b ... c')
+        x, ps = pack([x], 'b * c')
+
+        x = self.fn(x)
+
+        x, = unpack(x, ps, 'b * c')
+        x = rearrange(x, 'b ... c -> b c ...')
+        return x
+
 # diffusion prior
 
 class LayerNorm(nn.Module):
@@ -867,7 +882,7 @@ class Attention(nn.Module):
 
         # add null key / value for classifier free guidance in prior net
 
-        nk, nv = repeat_many(self.null_kv.unbind(dim = -2), 'd -> b 1 d', b = b)
+        nk, nv = map(lambda t: repeat(t, 'd -> b 1 d', b = b), self.null_kv.unbind(dim = -2))
         k = torch.cat((nk, k), dim = -2)
         v = torch.cat((nv, v), dim = -2)
 
@@ -1629,14 +1644,10 @@ class ResnetBlock(nn.Module):
         self.cross_attn = None
 
         if exists(cond_dim):
-            self.cross_attn = EinopsToAndFrom(
-                'b c h w',
-                'b (h w) c',
-                CrossAttention(
-                    dim = dim_out,
-                    context_dim = cond_dim,
-                    cosine_sim = cosine_sim_cross_attn
-                )
+            self.cross_attn = CrossAttention(
+                dim = dim_out,
+                context_dim = cond_dim,
+                cosine_sim = cosine_sim_cross_attn
             )
 
         self.block1 = Block(dim, dim_out, groups = groups, weight_standardization = weight_standardization)
@@ -1655,8 +1666,15 @@ class ResnetBlock(nn.Module):
 
         if exists(self.cross_attn):
             assert exists(cond)
+
+            h = rearrange(h, 'b c ... -> b ... c')
+            h, ps = pack([h], 'b * c')
+
             h = self.cross_attn(h, context = cond) + h
 
+            h, = unpack(h, ps, 'b * c')
+            h = rearrange(h, 'b ... c -> b c ...')
+
         h = self.block2(h)
         return h + self.res_conv(x)
 
@@ -1702,11 +1720,11 @@ class CrossAttention(nn.Module):
 
         q, k, v = (self.to_q(x), *self.to_kv(context).chunk(2, dim = -1))
 
-        q, k, v = rearrange_many((q, k, v), 'b n (h d) -> b h n d', h = self.heads)
+        q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> b h n d', h = self.heads), (q, k, v))
 
         # add null key / value for classifier free guidance in prior net
 
-        nk, nv = repeat_many(self.null_kv.unbind(dim = -2), 'd -> b h 1 d', h = self.heads,  b = b)
+        nk, nv = map(lambda t: repeat(t, 'd -> b h 1 d', h = self.heads,  b = b), self.null_kv.unbind(dim = -2))
 
         k = torch.cat((nk, k), dim = -2)
         v = torch.cat((nv, v), dim = -2)
@@ -1759,7 +1777,7 @@ class LinearAttention(nn.Module):
 
         fmap = self.norm(fmap)
         q, k, v = self.to_qkv(fmap).chunk(3, dim = 1)
-        q, k, v = rearrange_many((q, k, v), 'b (h c) x y -> (b h) (x y) c', h = h)
+        q, k, v = map(lambda t: rearrange(t, 'b (h c) x y -> (b h) (x y) c', h = h), (q, k, v))
 
         q = q.softmax(dim = -1)
         k = k.softmax(dim = -2)
@@ -1993,7 +2011,7 @@ class Unet(nn.Module):
 
         self_attn = cast_tuple(self_attn, num_stages)
 
-        create_self_attn = lambda dim: EinopsToAndFrom('b c h w', 'b (h w) c', Residual(Attention(dim, **attn_kwargs)))
+        create_self_attn = lambda dim: RearrangeToSequence(Residual(Attention(dim, **attn_kwargs)))
 
         # resnet block klass
 
@@ -3230,7 +3248,7 @@ class Decoder(nn.Module):
         learned_variance    = self.learned_variance[unet_index]
         b, c, h, w, device, = *image.shape, image.device
 
-        check_shape(image, 'b c h w', c = self.channels)
+        assert image.shape[1] == self.channels
         assert h >= target_image_size and w >= target_image_size
 
         times = torch.randint(0, noise_scheduler.num_timesteps, (b,), device = device, dtype = torch.long)