# Copyright 2023 The EASYDEL Author @erfanzar (Erfan Zare Chavoshi).
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import functools
import itertools
import typing as tp
import chex
import flax.struct
import jax
import jax.numpy as jnp
from einops import repeat
from flax import nnx as nn
from jax import lax
from easydel.infra.base_module import EasyDeLBaseModule
from easydel.infra.factory import register_module
from easydel.infra.modeling_outputs import FlaxBaseModelOutput
from easydel.infra.utils import (
ACT2FN,
auto_remat,
get_dot_general_by_bits,
)
from easydel.layers.caching import MambaCache
from easydel.layers.caching.mamba_cache import MambaCacheMetaData, MambaCacheView
from easydel.layers.norms import RMSNorm as MambaRMSNorm
from easydel.modules.mamba.mamba_configuration import MambaConfig as MambaConfig
[docs]def init_to_value(x, dtype):
return lambda _, shape, dtype: jnp.broadcast_to(jnp.asarray(x, dtype=dtype), shape)
[docs]@flax.struct.dataclass
class MambaOutput(FlaxBaseModelOutput):
last_hidden_state: chex.Array = None
cache: tp.Optional[MambaCache] = None
hidden_states: tp.Optional[tp.Tuple[chex.Array]] = None
[docs]@flax.struct.dataclass
class MambaCausalLMOutput(FlaxBaseModelOutput):
logits: chex.Array = None
cache: tp.Optional[MambaCache] = None
hidden_states: tp.Optional[tp.Tuple[chex.Array]] = None
_T = tp.TypeVar("_T")
[docs]def create_tuple_parser(
n: int,
) -> tp.Callable[[tp.Union[_T, tp.Sequence[_T]]], tuple[_T, ...]]:
def parse(x: tp.Union[_T, tp.Sequence[_T]]) -> tuple[_T, ...]:
if isinstance(x, tp.Sequence):
if len(x) == n:
return tuple(x)
else:
raise ValueError(f"x!=n ({x}!=({n}))")
else:
return tuple(itertools.repeat(x, n))
return parse
[docs]class Lambda(nn.Module):
fn: tp.Callable
def __call__(self, x, **kwargs):
return self.fn(x, **kwargs)
[docs]class MambaConv1D(nn.Module):
def __init__(
self,
features: int,
kernel_size: int = 1,
stride: int = 1,
padding: int = 0,
dilation: int = 1,
groups: int = 1,
use_bias: bool = True,
num_spatial_dims: int = 1,
dtype: jnp.dtype = jnp.float32,
param_dtype: jnp.dtype = jnp.float32,
precision: tp.Optional[tp.Union[str, lax.Precision]] = None,
*,
rngs: nn.Rngs,
):
kernel_shape = (kernel_size, 1, features)
self.kernel = nn.Param(
nn.initializers.lecun_normal(dtype=param_dtype)(
rngs.params(),
kernel_shape,
param_dtype,
),
)
if use_bias:
self.bias = nn.Param(
nn.initializers.zeros(
rngs.params(),
shape=(features,),
dtype=param_dtype,
)
)
self.features = features
self.kernel_size = kernel_size
self.stride = stride
self.padding = padding
self.dilation = dilation
self.groups = groups
self.use_bias = use_bias
self.num_spatial_dims = num_spatial_dims
self.dtype = dtype
self.param_dtype = param_dtype
self.precision = precision
def __call__(self, x):
unbatched_rank = self.num_spatial_dims + 2
if x.ndim != unbatched_rank:
raise ValueError(
f"Input to `Conv` needs to have rank {unbatched_rank},"
f" but input has shape {x.shape}.",
)
x = lax.conv_general_dilated(
lhs=x,
rhs=jnp.asarray(jnp.swapaxes(self.kernel.value, 0, 2), dtype=self.dtype),
window_strides=(self.stride,),
padding=((self.padding, self.padding),),
rhs_dilation=(self.dilation,),
feature_group_count=self.groups,
)
if self.use_bias:
x = x + jnp.asarray(self.bias.value.reshape(1, -1, 1), dtype=self.dtype)
return x
[docs]class MambaMixer(nn.Module):
def __init__(
self,
config: MambaConfig,
layer_idx: int,
dtype: jnp.dtype = jnp.float32,
param_dtype: jnp.dtype = jnp.float32,
precision: tp.Optional[tp.Union[str, lax.Precision]] = None,
*,
rngs: nn.Rngs,
) -> None:
self.config = config
self.layer_idx = layer_idx
self.dtype = dtype
self.param_dtype = param_dtype
self.precision = precision
hidden_size = config.hidden_size
ssm_state_size = config.state_size
intermediate_size = config.intermediate_size
time_step_rank = config.time_step_rank
conv_kernel_size = config.conv_kernel
self.conv1d = MambaConv1D(
features=intermediate_size,
use_bias=config.use_conv_bias,
kernel_size=config.conv_kernel,
groups=intermediate_size,
padding=config.conv_kernel - 1,
rngs=rngs,
)
self.activation = config.hidden_act
self.act = ACT2FN[config.hidden_act]
dt_init_std = time_step_rank**-0.5 * config.time_step_scale
if config.time_step_init_scheme == "constant":
init_kernel_dt = nn.initializers.constant(dt_init_std, dtype=param_dtype)
elif config.time_step_init_scheme == "random":
def init_kernel_dt(key, _shape, _dtype):
return (
jax.nn.initializers.uniform(scale=dt_init_std * 2, dtype=param_dtype)(
key, _shape, _dtype
)
- dt_init_std
)
else:
init_kernel_dt = nn.initializers.normal(config.initializer_range, param_dtype)
dt = jax.lax.clamp(
config.time_step_floor,
jnp.exp(
jax.random.normal(
key=rngs.params(),
shape=(intermediate_size,),
dtype=jnp.float32,
)
* (jnp.log(config.time_step_max) - jnp.log(config.time_step_min))
+ jnp.log(config.time_step_min)
),
config.time_step_max,
)
inv_dt = dt + jnp.log(-jnp.expm1(-dt))
linear_class = functools.partial(
nn.Linear,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
**get_dot_general_by_bits(config.bits, config.easy_method),
)
self.in_proj = linear_class(
hidden_size,
intermediate_size * 2,
use_bias=config.use_bias,
rngs=rngs,
)
self.x_proj = linear_class(
intermediate_size,
time_step_rank + ssm_state_size * 2,
use_bias=False,
rngs=rngs,
)
self.dt_proj = linear_class(
time_step_rank,
intermediate_size,
use_bias=True,
kernel_init=init_kernel_dt,
bias_init=lambda _, shape, dtype: inv_dt,
rngs=rngs,
)
self.out_proj = linear_class(
intermediate_size,
hidden_size,
use_bias=config.use_bias,
rngs=rngs,
)
A = repeat(jnp.arange(1, ssm_state_size + 1), "n -> d n", d=intermediate_size)
self.A_log = nn.Param(jnp.log(A))
self.D = nn.Param(jnp.ones(intermediate_size))
self.ssm_state_size = ssm_state_size
self.intermediate_size = intermediate_size
self.conv_kernel_size = conv_kernel_size
self.time_step_rank = time_step_rank
def __call__(
self,
input_states: chex.Array,
cache: tp.Optional[MambaCacheView] = None,
position_ids: tp.Optional[chex.Array] = None,
attention_mask: tp.Optional[chex.Array] = None,
):
batch_size, seq_len, _ = input_states.shape
dtype = input_states.dtype
# 1. Gated MLP's linear projection
projected_states = self.in_proj(input_states)
projected_states = jnp.swapaxes(projected_states, 2, 1)
# [batch, 2 * intermediate_size, seq_len]
hidden_states, gate = jnp.split(projected_states, 2, axis=1)
if attention_mask is not None:
hidden_states = hidden_states * jnp.expand_dims(attention_mask, 1)
# 2. Convolution sequence transformation
if cache is not None:
ssm_state = jnp.array(cache.ssm_states)
if position_ids.shape[0] == self.conv_kernel_size:
conv_state = jnp.pad(
hidden_states,
(
(0, 0),
(0, 0),
(self.conv_kernel_size - hidden_states.shape[-1], 0),
),
)
cache.update_conv_state(conv_state, position_ids)
hidden_states = self.act(
self.conv1d(hidden_states)[..., :seq_len]
) # [batch, intermediate_size, seq_len]
else:
conv_state = cache.update_conv_state(hidden_states, position_ids)
hidden_states = jnp.sum(conv_state * self.conv1d.weight[:, 0, :], axis=-1)
if self.use_conv_bias:
hidden_states = hidden_states + self.conv1d.bias
hidden_states = jnp.expand_dims(
self.act(hidden_states).astype(dtype), -1
) # [batch, intermediate_size, 1]
else:
ssm_state = jnp.zeros(
(batch_size, self.intermediate_size, self.ssm_state_size), dtype=dtype
)
hidden_states = self.act(self.conv1d(hidden_states)[..., :seq_len])
# [batch, intermediate_size, seq_len]
if attention_mask is not None:
hidden_states = hidden_states * jnp.expand_dims(attention_mask, 1)
# 3. State Space Model sequence transformation
# 3.a. Selection
ssm_parameters = self.x_proj(jnp.swapaxes(hidden_states, 2, 1))
time_step, B, C = jnp.split(
ssm_parameters,
[
self.time_step_rank,
self.ssm_state_size + self.time_step_rank,
],
axis=-1,
)
discrete_time_step = self.dt_proj(time_step)
# [batch, seq_len, intermediate_size]
discrete_time_step = jnp.swapaxes(jax.nn.softplus(discrete_time_step), 2, 1)
# [batch, intermediate_size, seq_len]
# 3.b. Discretization
A = -jnp.exp(self.A_log.value.astype(jnp.float32))
# [intermediate_size, ssm_state_size]
modified_a = jnp.expand_dims(jnp.expand_dims(A, axis=0), axis=2)
modified_time_step = jnp.expand_dims(discrete_time_step, axis=-1)
discrete_A = jnp.exp(modified_a * modified_time_step)
discrete_B = modified_time_step * B[:, jnp.newaxis, :, :].astype(jnp.float32)
# [batch, intermediate_size, seq_len, ssm_state_size]
deltaB_u = discrete_B * hidden_states[:, :, :, jnp.newaxis].astype(jnp.float32)
scan_outputs = []
for i in range(seq_len):
ssm_state = discrete_A[:, :, i, :] * ssm_state + deltaB_u[:, :, i, :]
# [batch, intermediate_size, 1, ssm_state]
scan_output = jax.lax.batch_matmul(
ssm_state.astype(dtype),
jnp.expand_dims(C[:, i, :], -1),
)
# [batch, intermediate_size, 1]
scan_outputs.append(scan_output[:, :, 0])
scan_output = jnp.stack(scan_outputs, axis=-1)
scan_output = scan_output + (hidden_states * self.D[None, :, None])
scan_output = scan_output * self.act(gate)
if cache is not None:
cache.ssm_states = ssm_state
# 4. Final linear projection
contextualized_states = self.out_proj(jnp.swapaxes(scan_output, 2, 1))
return contextualized_states
[docs]class MambaBlock(nn.Module):
def __init__(
self,
config: MambaConfig,
layer_idx: int,
dtype: jnp.dtype = jnp.float32,
param_dtype: jnp.dtype = jnp.float32,
precision: tp.Optional[tp.Union[str, lax.Precision]] = None,
*,
rngs: nn.Rngs,
):
self.config = config
self.layer_idx = layer_idx
self.dtype = dtype
self.param_dtype = param_dtype
self.precision = precision
self.residual_in_fp32 = config.residual_in_fp32
self.norm = MambaRMSNorm(
config.hidden_size,
eps=config.layer_norm_epsilon,
dtype=dtype,
param_dtype=param_dtype,
)
block = MambaMixer
(block,) = auto_remat(
block,
policy=config.gradient_checkpointing,
)
self.mixer = block(
config=config,
layer_idx=layer_idx,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
rngs=rngs,
)
def __call__(
self,
hidden_states: chex.Array,
cache: tp.Optional[MambaCacheView] = None,
position_ids: tp.Optional[chex.Array] = None,
attention_mask: tp.Optional[chex.Array] = None,
) -> chex.Array:
residual = hidden_states
hidden_states = self.norm(hidden_states)
if self.residual_in_fp32:
residual = residual.astype(jnp.float32)
hidden_states = self.mixer(
hidden_states,
cache,
position_ids,
attention_mask,
)
hidden_states = residual + hidden_states
return hidden_states
[docs]@register_module(
"base-module",
config=MambaConfig,
model_type="mamba",
embedding_layer_names=["embeddings"],
)
class MambaModel(EasyDeLBaseModule):
def __init__(
self,
config: MambaConfig,
dtype: jnp.dtype = jnp.float32,
param_dtype: jnp.dtype = jnp.float32,
precision: tp.Optional[tp.Union[str, lax.Precision]] = None,
*,
rngs: nn.Rngs,
) -> None:
super().__init__(
config=config,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
rngs=rngs,
)
self.embeddings = nn.Embed(
num_embeddings=config.vocab_size,
features=config.hidden_size,
dtype=dtype,
param_dtype=param_dtype,
rngs=rngs,
)
self.layers = [
MambaBlock(
config=config,
layer_idx=layer_idx,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
rngs=rngs,
)
for layer_idx in range(config.num_hidden_layers)
]
self.norm_f = MambaRMSNorm(
config.hidden_size,
eps=config.layer_norm_epsilon,
dtype=dtype,
param_dtype=param_dtype,
)
def __call__(
self,
input_ids: tp.Optional[chex.Array] = None,
inputs_embeds: tp.Optional[chex.Array] = None,
cache: tp.Optional[MambaCache] = None,
position_ids: tp.Optional[chex.Array] = None,
attention_mask: tp.Optional[chex.Array] = None,
output_hidden_states: tp.Optional[bool] = None,
return_dict: tp.Optional[bool] = None,
**kwargs,
) -> tp.Union[tp.Tuple, MambaOutput]:
output_hidden_states = (
output_hidden_states
if output_hidden_states is not None
else self.config.output_hidden_states
)
return_dict = (
return_dict if return_dict is not None else self.config.use_return_dict
)
if (input_ids is None) ^ (inputs_embeds is not None):
raise ValueError(
"You cannot specify both input_ids and inputs_embeds at the same time, and must specify either one"
)
if inputs_embeds is None:
inputs_embeds = self.embeddings(input_ids)
batch_size, sequence_length = inputs_embeds.shape[:2]
if attention_mask is None:
attention_mask = jnp.ones((batch_size, sequence_length), "b1")
else:
if attention_mask.dtype != jnp.bool:
attention_mask = jnp.astype(attention_mask == 1, "b1")
if position_ids is None:
position_ids = jnp.broadcast_to(
jnp.clip(jnp.cumsum(attention_mask, axis=-1) - 1, a_min=0),
(batch_size, sequence_length),
).astype(jnp.int32)
if cache is None:
cache = MambaCache.init_empty(len(self.layers))
hidden_states = inputs_embeds
all_hidden_states = () if output_hidden_states else None
for idx, block in enumerate(self.layers):
hidden_states = block(
hidden_states=hidden_states,
cache=cache.views[idx],
attention_mask=attention_mask,
position_ids=position_ids,
)
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
hidden_states = self.norm_f(hidden_states)
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
if not return_dict:
return tuple(
v
for v in [
hidden_states,
all_hidden_states,
cache,
]
if v is not None
)
return MambaOutput(
last_hidden_state=hidden_states,
cache=cache,
hidden_states=all_hidden_states,
)
[docs] def init_cache(self, batch_size: int, max_length: int):
return MambaCache.init_layers_cache(
num_hidden_layers=self.config.num_hidden_layers,
dtype=self.dtype,
partition_specs=jax.sharding.PartitionSpec(
self.config.partition_axis.batch_axis,
self.config.partition_axis.key_sequence_axis,
self.config.partition_axis.head_axis,
self.config.partition_axis.attention_dim_axis,
),
metadata=MambaCacheMetaData.create(
batch_size=batch_size,
sequence_length=max_length,
num_heads=self.config.num_key_value_heads,
head_dim=self.config.head_dim,
),
)
[docs]@register_module(
"causal-language-model",
config=MambaConfig,
model_type="mamba",
embedding_layer_names=["embeddings"],
)
class MambaForCausalLM(EasyDeLBaseModule):
def __init__(
self,
config: MambaConfig,
dtype: jnp.dtype = jnp.float32,
param_dtype: jnp.dtype = jnp.float32,
precision: tp.Optional[tp.Union[str, lax.Precision]] = None,
*,
rngs: nn.Rngs,
):
super().__init__(
config=config,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
rngs=rngs,
)
self.backbone = MambaModel(
config=config,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
rngs=rngs,
)
self.lm_head = nn.Linear(
config.hidden_size,
config.vocab_size,
use_bias=False,
dtype=dtype,
param_dtype=param_dtype,
precision=precision,
rngs=rngs,
)
def __call__(
self,
input_ids: tp.Optional[chex.Array] = None,
inputs_embeds: tp.Optional[chex.Array] = None,
cache: tp.Optional[MambaCache] = None,
position_ids: tp.Optional[chex.Array] = None,
attention_mask: tp.Optional[chex.Array] = None,
output_hidden_states: tp.Optional[bool] = None,
return_dict: tp.Optional[bool] = None,
**kwargs,
) -> tp.Union[tp.Tuple, MambaCausalLMOutput]:
return_dict = (
return_dict if return_dict is not None else self.config.use_return_dict
)
mamba_outputs = self.backbone(
input_ids=input_ids,
inputs_embeds=inputs_embeds,
attention_mask=attention_mask,
position_ids=position_ids,
cache=cache,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states = mamba_outputs[0]
self.lm_head.kernel.value = self.backbone.embeddings.embedding.value.T
logits = self.lm_head(hidden_states).astype(jnp.float32)
if not return_dict:
return (logits,) + mamba_outputs[1:]
return MambaCausalLMOutput(
logits=logits,
cache=mamba_outputs.cache,
hidden_states=mamba_outputs.hidden_states,
)
[docs] def init_cache(self, batch_size: int, max_length: int):
return MambaCache.init_layers_cache(
num_hidden_layers=self.config.num_hidden_layers,
dtype=self.dtype,
partition_specs=jax.sharding.PartitionSpec(
self.config.partition_axis.batch_axis,
self.config.partition_axis.key_sequence_axis,
self.config.partition_axis.head_axis,
self.config.partition_axis.attention_dim_axis,
),
metadata=MambaCacheMetaData.create(
batch_size=batch_size,
sequence_length=max_length,
num_heads=self.config.num_key_value_heads,
head_dim=self.config.head_dim,
),
)