init
This commit is contained in:
318
vllm/core/block/naive_block.py
Normal file
318
vllm/core/block/naive_block.py
Normal file
@@ -0,0 +1,318 @@
|
||||
from typing import Dict, FrozenSet, Iterable, List, Optional, Set
|
||||
|
||||
from vllm.core.block.common import (CopyOnWriteTracker, RefCounter,
|
||||
get_all_blocks_recursively)
|
||||
from vllm.core.block.interfaces import Block, BlockAllocator, BlockId, Device
|
||||
|
||||
Refcount = int
|
||||
|
||||
|
||||
class NaiveBlockAllocator(BlockAllocator):
|
||||
"""A simple block allocator that manages blocks of memory without prefix
|
||||
caching.
|
||||
|
||||
Args:
|
||||
create_block (Block.Factory): A factory function for creating new
|
||||
blocks. This is used when a NaiveBlockAllocator is composed within
|
||||
a prefix caching allocator -- the naive block allocator must
|
||||
construct prefix caching blocks (but shouldn't know anything else
|
||||
about them).
|
||||
num_blocks (int): The total number of blocks to manage.
|
||||
block_size (int): The size of each block in tokens.
|
||||
block_ids (Optional[Iterable[int]], optional): An optional iterable of
|
||||
block IDs. If not provided, block IDs will be assigned sequentially
|
||||
from 0 to num_blocks - 1.
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
create_block: Block.Factory,
|
||||
num_blocks: int,
|
||||
block_size: int,
|
||||
block_ids: Optional[Iterable[int]] = None,
|
||||
):
|
||||
if block_ids is None:
|
||||
block_ids = range(num_blocks)
|
||||
|
||||
self._free_block_indices: Set[BlockId] = set(block_ids)
|
||||
self._all_block_indices = frozenset(block_ids)
|
||||
assert len(self._all_block_indices) == num_blocks
|
||||
|
||||
self._refcounter = RefCounter(
|
||||
all_block_indices=self._free_block_indices)
|
||||
self._create_block = create_block
|
||||
self._block_size = block_size
|
||||
|
||||
self._cow_tracker = CopyOnWriteTracker(
|
||||
refcounter=self._refcounter.as_readonly(),
|
||||
allocator=self,
|
||||
)
|
||||
|
||||
def allocate_immutable(self,
|
||||
prev_block: Optional[Block],
|
||||
token_ids: List[int],
|
||||
device: Optional[Device] = None) -> Block:
|
||||
"""Allocates a new immutable block with the given token IDs, linked to
|
||||
the previous block.
|
||||
|
||||
Args:
|
||||
prev_block (Optional[Block]): The previous block in the sequence. If
|
||||
None, then the block to be allocated is the first block in the
|
||||
sequence.
|
||||
token_ids (List[int]): The token IDs to be stored in the new block.
|
||||
|
||||
Returns:
|
||||
Block: The newly allocated immutable block.
|
||||
"""
|
||||
assert device is None
|
||||
block = self.allocate_mutable(prev_block=prev_block)
|
||||
block.append_token_ids(token_ids)
|
||||
return block
|
||||
|
||||
def allocate_mutable(self,
|
||||
prev_block: Optional[Block],
|
||||
device: Optional[Device] = None) -> Block:
|
||||
"""Allocates a new mutable block, linked to the previous block.
|
||||
|
||||
Args:
|
||||
prev_block (Optional[Block]): The previous block in the sequence. If
|
||||
None, then the block to be allocated is the first block in the
|
||||
sequence.
|
||||
|
||||
Returns:
|
||||
Block: The newly allocated mutable block.
|
||||
"""
|
||||
assert device is None
|
||||
block_id = self._allocate_new_block_id()
|
||||
return self._create_block(
|
||||
prev_block=prev_block,
|
||||
token_ids=[],
|
||||
block_id=block_id,
|
||||
block_size=self._block_size,
|
||||
allocator=self,
|
||||
)
|
||||
|
||||
def free(self, block: Block) -> None:
|
||||
assert block.block_id is not None
|
||||
self._free_block_id(block.block_id)
|
||||
|
||||
# Mark the block as having no allocation.
|
||||
block.block_id = None
|
||||
|
||||
def fork(self, last_block: Block) -> List[Block]:
|
||||
"""Creates a new sequence of blocks that shares the same underlying
|
||||
memory as the original sequence.
|
||||
|
||||
Args:
|
||||
last_block (Block): The last block in the original sequence.
|
||||
|
||||
Returns:
|
||||
List[Block]: The new sequence of blocks that shares the same memory
|
||||
as the original sequence.
|
||||
"""
|
||||
source_blocks = get_all_blocks_recursively(last_block)
|
||||
|
||||
forked_blocks = []
|
||||
prev_block = None
|
||||
for block in source_blocks:
|
||||
|
||||
# Increment refcount for each block.
|
||||
assert block.block_id is not None
|
||||
refcount = self._refcounter.incr(block.block_id)
|
||||
assert refcount != 1, "can't fork free'd block"
|
||||
|
||||
forked_blocks.append(
|
||||
self._create_block(
|
||||
prev_block=prev_block,
|
||||
token_ids=block.token_ids,
|
||||
block_id=block.block_id,
|
||||
block_size=self._block_size,
|
||||
allocator=self,
|
||||
))
|
||||
prev_block = forked_blocks[-1]
|
||||
|
||||
return forked_blocks
|
||||
|
||||
def get_num_free_blocks(self) -> int:
|
||||
return len(self._free_block_indices)
|
||||
|
||||
def get_num_total_blocks(self) -> int:
|
||||
return len(self._all_block_indices)
|
||||
|
||||
def _allocate_new_block_id(self) -> BlockId:
|
||||
if not self._free_block_indices:
|
||||
raise BlockAllocator.NoFreeBlocksError()
|
||||
|
||||
block_id = next(iter(self._free_block_indices))
|
||||
self._refcounter.incr(block_id)
|
||||
self._free_block_indices.remove(block_id)
|
||||
return block_id
|
||||
|
||||
def _free_block_id(self, block_id: BlockId) -> None:
|
||||
refcount = self._refcounter.decr(block_id)
|
||||
if refcount == 0:
|
||||
self._free_block_indices.add(block_id)
|
||||
|
||||
@property
|
||||
def refcounter(self):
|
||||
return self._refcounter
|
||||
|
||||
@property
|
||||
def all_block_ids(self) -> FrozenSet[int]:
|
||||
return self._all_block_indices
|
||||
|
||||
def cow_block_if_not_appendable(self, block: Block) -> Optional[BlockId]:
|
||||
"""Performs a copy-on-write operation on the given block if it is not
|
||||
appendable.
|
||||
|
||||
Args:
|
||||
block (Block): The block to check for copy-on-write.
|
||||
|
||||
Returns:
|
||||
Optional[BlockId]: The block index of the new block if a copy-on
|
||||
-write operation was performed, or the original block index if
|
||||
no copy-on-write was necessary.
|
||||
"""
|
||||
return self._cow_tracker.cow_block_if_not_appendable(block)
|
||||
|
||||
def clear_copy_on_writes(self) -> Dict[BlockId, List[BlockId]]:
|
||||
"""Returns the copy-on-write source->destination mapping and clears it.
|
||||
|
||||
Returns:
|
||||
Dict[BlockId, List[BlockId]]: A dictionary mapping source
|
||||
block indices to lists of destination block indices.
|
||||
"""
|
||||
return self._cow_tracker.clear_cows()
|
||||
|
||||
def mark_blocks_as_accessed(self, block_ids: List[int],
|
||||
now: float) -> None:
|
||||
"""Mark blocks as accessed, used in prefix caching.
|
||||
|
||||
Since the naive allocator does not implement prefix caching, we do
|
||||
nothing.
|
||||
"""
|
||||
pass
|
||||
|
||||
def mark_blocks_as_computed(self, block_ids: List[int]) -> None:
|
||||
"""Mark blocks as computed, used in prefix caching.
|
||||
|
||||
Since the naive allocator does not implement prefix caching, we do
|
||||
nothing.
|
||||
"""
|
||||
pass
|
||||
|
||||
def get_common_computed_block_ids(
|
||||
self, seq_block_ids: List[List[int]]) -> List[int]:
|
||||
"""Determine blocks that can be skipped in prefill.
|
||||
|
||||
Since the naive allocator does not support prefix caching, always return
|
||||
an empty list.
|
||||
"""
|
||||
return []
|
||||
|
||||
def promote_to_immutable_block(self, block: Block) -> BlockId:
|
||||
raise NotImplementedError
|
||||
|
||||
|
||||
class NaiveBlock(Block):
|
||||
"""An implementation of the Block class that does not support prefix
|
||||
caching.
|
||||
|
||||
The NaiveBlock class represents a block of token IDs with a fixed size. It
|
||||
provides methods for appending token IDs to the block and manages copy-on
|
||||
-write operations when necessary.
|
||||
|
||||
Args:
|
||||
prev_block (Block): The previous block in the sequence.
|
||||
token_ids (List[int]): The initial token IDs to be stored in the block.
|
||||
block_size (int): The maximum number of token IDs that can be stored in
|
||||
the block.
|
||||
allocator (BlockAllocator): The block allocator associated with this
|
||||
block.
|
||||
block_id (Optional[int], optional): The physical block index
|
||||
of this block. Defaults to None, which means no allocation has been
|
||||
made.
|
||||
_cow_target (Optional[Block], optional): The copy-on-write target block.
|
||||
If not provided, it defaults to self.
|
||||
"""
|
||||
|
||||
def __init__(self,
|
||||
prev_block: Optional[Block],
|
||||
token_ids: List[int],
|
||||
block_size: int,
|
||||
allocator: BlockAllocator,
|
||||
block_id: Optional[int] = None,
|
||||
_cow_target: Optional[Block] = None):
|
||||
self._token_ids: List[int] = []
|
||||
self._block_size = block_size
|
||||
self._prev_block = prev_block
|
||||
self._block_id = block_id
|
||||
self._allocator = allocator
|
||||
self._cow_target = _cow_target if _cow_target is not None else self
|
||||
|
||||
self._append_token_ids_no_cow(token_ids)
|
||||
|
||||
def append_token_ids(self, token_ids: List[int]) -> None:
|
||||
"""Appends the given token IDs to the block, instructing the allocator
|
||||
to perform a copy-on-write if necessary.
|
||||
|
||||
Args:
|
||||
token_ids (List[int]): The token IDs to be appended to the block.
|
||||
"""
|
||||
self._append_token_ids_no_cow(token_ids)
|
||||
|
||||
if self._block_id is not None:
|
||||
self._block_id = (self._allocator.cow_block_if_not_appendable(
|
||||
self._cow_target))
|
||||
|
||||
def _append_token_ids_no_cow(self, token_ids: List[int]) -> None:
|
||||
assert self.num_empty_slots >= len(token_ids)
|
||||
self._token_ids.extend(token_ids)
|
||||
|
||||
@property
|
||||
def computed(self) -> bool:
|
||||
raise NotImplementedError
|
||||
|
||||
@computed.setter
|
||||
def computed(self, value) -> None:
|
||||
raise NotImplementedError
|
||||
|
||||
@property
|
||||
def last_accessed(self) -> float:
|
||||
raise NotImplementedError
|
||||
|
||||
@last_accessed.setter
|
||||
def last_accessed(self, last_accessed_ts: float):
|
||||
raise NotImplementedError
|
||||
|
||||
@property
|
||||
def block_id(self) -> Optional[int]:
|
||||
return self._block_id
|
||||
|
||||
@block_id.setter
|
||||
def block_id(self, value: Optional[int]) -> None:
|
||||
self._block_id = value
|
||||
|
||||
@property
|
||||
def is_full(self) -> bool:
|
||||
return self.num_empty_slots == 0
|
||||
|
||||
@property
|
||||
def num_empty_slots(self) -> int:
|
||||
return self._block_size - len(self._token_ids)
|
||||
|
||||
@property
|
||||
def token_ids(self) -> List[int]:
|
||||
return self._token_ids
|
||||
|
||||
@property
|
||||
def block_size(self) -> int:
|
||||
return self._block_size
|
||||
|
||||
@property
|
||||
def prev_block(self) -> Optional["Block"]:
|
||||
return self._prev_block
|
||||
|
||||
@property
|
||||
def content_hash(self) -> Optional[int]:
|
||||
return None
|
||||
Reference in New Issue
Block a user