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sglang/python/sglang/srt/managers/schedule_batch.py
2024-08-11 17:57:02 -07:00

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"""
Copyright 2023-2024 SGLang Team
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
http://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.
"""
"""Meta data for requests and batches"""
import logging
import warnings
from dataclasses import dataclass
from typing import List, Optional, Union
import torch
from flashinfer.sampling import top_k_top_p_sampling_from_probs
import sglang.srt.sampling.penaltylib as penaltylib
from sglang.global_config import global_config
from sglang.srt.constrained import RegexGuide
from sglang.srt.constrained.jump_forward import JumpForwardMap
from sglang.srt.mem_cache.base_prefix_cache import BasePrefixCache
from sglang.srt.mem_cache.chunk_cache import ChunkCache
from sglang.srt.mem_cache.memory_pool import BaseTokenToKVPool, ReqToTokenPool
INIT_INCREMENTAL_DETOKENIZATION_OFFSET = 5
# Put some global args for easy access
global_server_args_dict = {
"disable_flashinfer": False,
"disable_flashinfer_sampling": False,
"attention_reduce_in_fp32": False,
"enable_mla": False,
}
logger = logging.getLogger(__name__)
class BaseFinishReason:
def __init__(self, is_error: bool = False):
self.is_error = is_error
def __str__(self):
raise NotImplementedError("Subclasses must implement this method")
class FINISH_MATCHED_TOKEN(BaseFinishReason):
def __init__(self, matched: Union[int, List[int]]):
super().__init__()
self.matched = matched
def __str__(self) -> str:
return f"FINISH_MATCHED_TOKEN: {self.matched}"
class FINISH_LENGTH(BaseFinishReason):
def __init__(self, length: int):
super().__init__()
self.length = length
def __str__(self) -> str:
return f"FINISH_LENGTH: {self.length}"
class FINISH_MATCHED_STR(BaseFinishReason):
def __init__(self, matched: str):
super().__init__()
self.matched = matched
def __str__(self) -> str:
return f"FINISH_MATCHED_STR: {self.matched}"
class FINISH_ABORT(BaseFinishReason):
def __init__(self):
super().__init__(is_error=True)
def __str__(self) -> str:
return "FINISH_ABORT"
class Req:
"""Store all inforamtion of a request."""
def __init__(self, rid, origin_input_text, origin_input_ids):
# Input and output info
self.rid = rid
self.origin_input_text = origin_input_text
self.origin_input_ids_unpadded = origin_input_ids # Before image padding
self.origin_input_ids = origin_input_ids
self.output_ids = [] # Each decode stage's output ids
self.fill_ids = None # fill_ids = origin_input_ids + output_ids
# Memory info
self.req_pool_idx = None
# For incremental decoding
# ----- | --------- read_ids -------|
# ----- | surr_ids |
# xxxxx | xxxxxxxxxxx | xxxxxxxxxxx |
# ----- ^ ----------- ^ ----------- ^
# ----- 1 ----------- 2 ----------- 3
# 1: surr_offset
# 2: read_offset
# 3: last token
self.vid = 0 # version id to sync decode status with in detokenizer_manager
self.decoded_text = ""
self.surr_offset = None # Surrounding offset to defeat the cleanup algorithm
self.read_offset = None
# The number of decoded tokens for token usage report. Note that
# this does not include the jump forward tokens.
self.completion_tokens_wo_jump_forward = 0
# For vision input
self.pixel_values = None
self.image_size = None
self.image_offset = None
self.pad_value = None
# Prefix info
self.extend_input_len = 0
self.prefix_indices = []
self.last_node = None
# Sampling parameters
self.sampling_params = None
self.stream = False
# Check finish
self.tokenizer = None
self.finished_reason = None
# Logprobs
self.return_logprob = False
self.embedding = None
self.logprob_start_len = 0
self.top_logprobs_num = 0
self.normalized_prompt_logprob = None
self.input_token_logprobs = None
self.input_top_logprobs = None
self.output_token_logprobs = []
self.output_top_logprobs = []
# The tokens is prefilled but need to be considered as decode tokens
# and should be updated for the decode logprobs
self.last_update_decode_tokens = 0
# Constrained decoding
self.regex_fsm: RegexGuide = None
self.regex_fsm_state: int = 0
self.jump_forward_map: JumpForwardMap = None
# whether request reached finished condition
def finished(self) -> bool:
return self.finished_reason is not None
def init_next_round_input(self, tree_cache: Optional[BasePrefixCache] = None):
self.fill_ids = self.origin_input_ids + self.output_ids
if tree_cache is not None:
self.prefix_indices, self.last_node = tree_cache.match_prefix(
rid=self.rid, key=self.adjust_max_prefix_ids()
)
self.extend_input_len = len(self.fill_ids) - len(self.prefix_indices)
def adjust_max_prefix_ids(self):
self.fill_ids = self.origin_input_ids + self.output_ids
input_len = len(self.fill_ids)
max_prefix_len = input_len
if self.sampling_params.max_new_tokens > 0:
# Need at least one token to compute logits
max_prefix_len = min(max_prefix_len, input_len - 1)
if self.return_logprob:
max_prefix_len = min(max_prefix_len, self.logprob_start_len)
if self.normalized_prompt_logprob is None:
# Need at least two tokens to compute normalized logprob
max_prefix_len = min(max_prefix_len, input_len - 2)
return self.fill_ids[:max_prefix_len]
# Based on https://github.com/vllm-project/vllm/blob/7a64d24aad69e4d2548aa0bf528d9fe63428ab01/vllm/transformers_utils/detokenizer.py#L194-L313
def init_incremental_detokenize(self):
first_iter = self.surr_offset is None or self.read_offset is None
if first_iter:
self.read_offset = len(self.origin_input_ids_unpadded)
self.surr_offset = max(
self.read_offset - INIT_INCREMENTAL_DETOKENIZATION_OFFSET, 0
)
all_ids = self.origin_input_ids_unpadded + self.output_ids
return all_ids[self.surr_offset :], self.read_offset - self.surr_offset
def get_next_inc_detokenization(self):
if self.tokenizer is None:
return False, ""
read_ids, read_offset = self.init_incremental_detokenize()
surr_ids = read_ids[:read_offset]
surr_text = self.tokenizer.decode(
surr_ids,
skip_special_tokens=self.sampling_params.skip_special_tokens,
spaces_between_special_tokens=self.sampling_params.spaces_between_special_tokens,
)
new_text = self.tokenizer.decode(
read_ids,
skip_special_tokens=self.sampling_params.skip_special_tokens,
spaces_between_special_tokens=self.sampling_params.spaces_between_special_tokens,
)
if len(new_text) > len(surr_text) and not new_text.endswith("<EFBFBD>"):
return True, new_text[len(surr_text) :]
return False, ""
def check_finished(self):
if self.finished():
return
if len(self.output_ids) >= self.sampling_params.max_new_tokens:
self.finished_reason = FINISH_LENGTH(
length=self.sampling_params.max_new_tokens
)
return
last_token_id = self.output_ids[-1]
if self.tokenizer is None:
matched_eos = last_token_id in self.sampling_params.stop_token_ids
else:
matched_eos = last_token_id == self.tokenizer.eos_token_id
if matched_eos and not self.sampling_params.ignore_eos:
self.finished_reason = FINISH_MATCHED_TOKEN(matched=last_token_id)
return
if len(self.sampling_params.stop_strs) > 0:
tail_str = self.tokenizer.decode(
self.output_ids[-(self.sampling_params.stop_str_max_len + 1) :]
)
for stop_str in self.sampling_params.stop_strs:
if stop_str in tail_str or stop_str in self.decoded_text:
self.finished_reason = FINISH_MATCHED_STR(matched=stop_str)
return
def jump_forward_and_retokenize(self, jump_forward_str, next_state):
if self.origin_input_text is None:
# Recovering text can only use unpadded ids
self.origin_input_text = self.tokenizer.decode(
self.origin_input_ids_unpadded
)
all_text = self.origin_input_text + self.decoded_text + jump_forward_str
all_ids = self.tokenizer.encode(all_text)
prompt_tokens = len(self.origin_input_ids_unpadded)
if all_ids[prompt_tokens - 1] != self.origin_input_ids_unpadded[-1]:
# TODO(lsyin): fix token fusion
warnings.warn(
"Token fusion between input and output, try to avoid this by removing the space at the end of the input."
)
return False
old_output_ids = self.output_ids
self.output_ids = all_ids[prompt_tokens:]
self.decoded_text = self.decoded_text + jump_forward_str
self.surr_offset = prompt_tokens
self.read_offset = len(all_ids)
# NOTE: A trick to reduce the surrouding tokens decoding overhead
for i in range(0, INIT_INCREMENTAL_DETOKENIZATION_OFFSET):
surr_text_ = self.tokenizer.decode(
all_ids[self.read_offset - i : self.read_offset]
)
if not surr_text_.endswith("<EFBFBD>"):
self.surr_offset = self.read_offset - i
break
self.regex_fsm_state = next_state
if self.return_logprob:
# For fast-forward part's logprobs
k = 0
for i, old_id in enumerate(old_output_ids):
if old_id == self.output_ids[i]:
k = k + 1
else:
break
self.output_token_logprobs = self.output_token_logprobs[:k]
self.output_top_logprobs = self.output_top_logprobs[:k]
self.logprob_start_len = prompt_tokens + k
self.last_update_decode_tokens = len(self.output_ids) - k
return True
def __repr__(self):
return f"rid(n={self.rid}, " f"input_ids={self.origin_input_ids}, "
@dataclass
class ScheduleBatch:
"""Store all inforamtion of a batch."""
# Request, memory pool, and cache
reqs: List[Req]
req_to_token_pool: ReqToTokenPool
token_to_kv_pool: BaseTokenToKVPool
tree_cache: BasePrefixCache
# Batched arguments to model runner
input_ids: torch.Tensor = None
req_pool_indices: torch.Tensor = None
seq_lens: torch.Tensor = None
position_ids_offsets: torch.Tensor = None
out_cache_loc: torch.Tensor = None
extend_num_tokens: int = None
# For processing logprobs
return_logprob: bool = False
top_logprobs_nums: List[int] = None
# Batched sampling params
temperatures: torch.Tensor = None
top_ps: torch.Tensor = None
top_ks: torch.Tensor = None
penalizer_orchestrator: penaltylib.BatchedPenalizerOrchestrator = None
logit_bias: torch.Tensor = None
@classmethod
def init_new(cls, reqs, req_to_token_pool, token_to_kv_pool, tree_cache):
return_logprob = any(req.return_logprob for req in reqs)
return cls(
reqs=reqs,
req_to_token_pool=req_to_token_pool,
token_to_kv_pool=token_to_kv_pool,
tree_cache=tree_cache,
return_logprob=return_logprob,
)
def batch_size(self):
return len(self.reqs) if self.reqs is not None else 0
def is_empty(self):
return len(self.reqs) == 0
def has_stream(self) -> bool:
# Return whether batch has at least 1 streaming request
return any(r.stream for r in self.reqs)
def alloc_req_slots(self, num_reqs):
req_pool_indices = self.req_to_token_pool.alloc(num_reqs)
if req_pool_indices is None:
raise RuntimeError(
"Out of memory. "
"Please set a smaller number for `--max-running-requests`."
)
return req_pool_indices
def alloc_token_slots(self, num_tokens: int):
out_cache_loc = self.token_to_kv_pool.alloc(num_tokens)
if out_cache_loc is None:
if self.tree_cache is not None:
self.tree_cache.evict(num_tokens, self.token_to_kv_pool.free)
out_cache_loc = self.token_to_kv_pool.alloc(num_tokens)
if out_cache_loc is None:
logger.error("Prefill out of memory. Try to lower your batch size.")
if self.tree_cache is not None:
self.tree_cache.pretty_print()
exit(1)
return out_cache_loc
def batch_sampling_params(self, vocab_size, int_token_logit_bias):
device = "cuda"
bs, reqs = self.batch_size(), self.reqs
self.temperatures = torch.tensor(
[r.sampling_params.temperature for r in reqs],
dtype=torch.float,
device=device,
).view(-1, 1)
self.top_ps = torch.tensor(
[r.sampling_params.top_p for r in reqs], dtype=torch.float, device=device
)
self.top_ks = torch.tensor(
[r.sampling_params.top_k for r in reqs], dtype=torch.int, device=device
)
# Each penalizers will do nothing if they evaluate themselves as not required by looking at
# the sampling_params of the requests (See {_is_required()} of each penalizers). So this
# should not add hefty computation overhead other than simple checks.
#
# While we choose not to even create the class instances if they are not required, this
# could add additional complexity to the {ScheduleBatch} class, especially we need to
# handle {filter_batch()} and {merge()} cases as well.
self.penalizer_orchestrator = penaltylib.BatchedPenalizerOrchestrator(
vocab_size=vocab_size,
batch=self,
device=device,
Penalizers={
penaltylib.BatchedFrequencyPenalizer,
penaltylib.BatchedMinNewTokensPenalizer,
penaltylib.BatchedPresencePenalizer,
penaltylib.BatchedRepetitionPenalizer,
},
)
# Handle logit bias but only allocate when needed
self.logit_bias = None
for i in range(bs):
if reqs[i].sampling_params.dtype == "int":
if self.logit_bias is None:
self.logit_bias = torch.zeros(
(bs, vocab_size), dtype=torch.float32, device=device
)
self.logit_bias[i][: len(int_token_logit_bias)] = int_token_logit_bias
def prepare_for_extend(self, vocab_size: int, int_token_logit_bias: torch.Tensor):
bs = self.batch_size()
reqs = self.reqs
input_ids = [r.fill_ids[len(r.prefix_indices) :] for r in reqs]
extend_num_tokens = sum(len(ids) for ids in input_ids)
seq_lens = []
# Allocate memory
req_pool_indices_cpu = self.alloc_req_slots(bs)
out_cache_loc = self.alloc_token_slots(extend_num_tokens)
pt = 0
for i, req in enumerate(reqs):
req.req_pool_idx = req_pool_indices_cpu[i]
pre_len, seq_len = len(req.prefix_indices), len(req.fill_ids)
ext_len = seq_len - pre_len
seq_lens.append(seq_len)
if pre_len > 0:
self.req_to_token_pool.req_to_token[req.req_pool_idx][
:pre_len
] = req.prefix_indices
self.req_to_token_pool.req_to_token[req.req_pool_idx][pre_len:seq_len] = (
out_cache_loc[pt : pt + ext_len]
)
pt += ext_len
# Set fields
with torch.device("cuda"):
self.input_ids = torch.tensor(sum(input_ids, []), dtype=torch.int32)
self.req_pool_indices = torch.tensor(req_pool_indices_cpu)
self.seq_lens = torch.tensor(seq_lens, dtype=torch.int32)
self.position_ids_offsets = torch.zeros((bs,), dtype=torch.int64)
self.extend_num_tokens = extend_num_tokens
self.out_cache_loc = out_cache_loc
self.top_logprobs_nums = [r.top_logprobs_num for r in reqs]
self.batch_sampling_params(vocab_size, int_token_logit_bias)
def check_decode_mem(self):
bs = self.batch_size()
if self.token_to_kv_pool.available_size() >= bs:
return True
self.tree_cache.evict(bs, self.token_to_kv_pool.free)
if self.token_to_kv_pool.available_size() >= bs:
return True
return False
def retract_decode(self):
sorted_indices = [i for i in range(len(self.reqs))]
# TODO(lsyin): improve retraction policy for radix cache
sorted_indices.sort(
key=lambda i: (
len(self.reqs[i].output_ids),
-len(self.reqs[i].origin_input_ids),
),
reverse=True,
)
retracted_reqs = []
seq_lens_cpu = self.seq_lens.cpu().numpy()
while (
self.token_to_kv_pool.available_size()
< len(sorted_indices) * global_config.retract_decode_steps
):
if len(sorted_indices) == 1:
# Corner case: only one request left
assert (
self.token_to_kv_pool.available_size() > 0
), "No space left for only one request"
break
idx = sorted_indices.pop()
req = self.reqs[idx]
retracted_reqs.append(req)
if isinstance(self.tree_cache, ChunkCache):
# ChunkCache does not have eviction
token_indices = self.req_to_token_pool.req_to_token[req.req_pool_idx][
: seq_lens_cpu[idx]
]
self.token_to_kv_pool.free(token_indices)
self.req_to_token_pool.free(req.req_pool_idx)
del self.tree_cache.entries[req.rid]
else:
# TODO: apply more fine-grained retraction
last_uncached_pos = len(req.prefix_indices)
token_indices = self.req_to_token_pool.req_to_token[req.req_pool_idx][
last_uncached_pos : seq_lens_cpu[idx]
]
self.token_to_kv_pool.free(token_indices)
self.req_to_token_pool.free(req.req_pool_idx)
# release the last node
self.tree_cache.dec_lock_ref(req.last_node)
# NOTE(lsyin): we should use the newly evictable memory instantly.
residual_size = (
len(sorted_indices) * global_config.retract_decode_steps
- self.token_to_kv_pool.available_size()
)
residual_size = max(0, residual_size)
self.tree_cache.evict(residual_size, self.token_to_kv_pool.free)
req.prefix_indices = []
req.last_node = None
req.extend_input_len = 0
# For incremental logprobs
req.last_update_decode_tokens = 0
req.logprob_start_len = 10**9
self.filter_batch(sorted_indices)
# Reqs in batch are filtered
total_decoded_tokens = sum(len(r.output_ids) for r in self.reqs)
total_max_new_tokens = sum(r.sampling_params.max_new_tokens for r in self.reqs)
new_estimate_ratio = (
total_decoded_tokens + global_config.retract_decode_steps * len(self.reqs)
) / total_max_new_tokens
new_estimate_ratio = min(1.0, new_estimate_ratio)
return retracted_reqs, new_estimate_ratio
def check_for_jump_forward(self, model_runner):
jump_forward_reqs = []
filter_indices = [i for i in range(len(self.reqs))]
for i, req in enumerate(self.reqs):
if req.jump_forward_map is not None:
jump_forward_bytes = req.jump_forward_map.jump_forward_byte(
req.regex_fsm_state
)
if jump_forward_bytes is not None and len(jump_forward_bytes) > 1:
suffix_bytes = []
continuation_range = range(0x80, 0xC0)
cur_state = req.regex_fsm_state
while (
len(jump_forward_bytes)
and jump_forward_bytes[0][0] in continuation_range
):
# continuation bytes
byte_edge = jump_forward_bytes.pop(0)
suffix_bytes.append(byte_edge[0])
cur_state = byte_edge[1]
suffix_tokens = [f"<0x{hex(b)[2:].upper()}>" for b in suffix_bytes]
suffix_ids = req.tokenizer.convert_tokens_to_ids(suffix_tokens)
# Current ids, for cache and revert
cur_all_ids = tuple(req.origin_input_ids + req.output_ids)[:-1]
cur_output_ids = req.output_ids
req.output_ids.extend(suffix_ids)
decode_res, new_text = req.get_next_inc_detokenization()
if not decode_res:
req.output_ids = cur_output_ids
continue
(
jump_forward_str,
next_state,
) = req.jump_forward_map.jump_forward_symbol(cur_state)
# Make the incrementally decoded text part of jump_forward_str
# so that the UTF-8 will not corrupt
jump_forward_str = new_text + jump_forward_str
if not req.jump_forward_and_retokenize(
jump_forward_str, next_state
):
req.output_ids = cur_output_ids
continue
# The decode status has diverged from detokenizer_manager
req.vid += 1
# insert the old request into tree_cache
self.tree_cache.cache_finished_req(req, cur_all_ids)
# re-applying image padding
if req.pixel_values is not None:
(
req.origin_input_ids,
req.image_offset,
) = model_runner.model.pad_input_ids(
req.origin_input_ids_unpadded,
req.pad_value,
req.pixel_values.shape,
req.image_size,
)
jump_forward_reqs.append(req)
filter_indices.remove(i)
self.filter_batch(filter_indices)
return jump_forward_reqs
def prepare_for_decode(self, input_ids=None):
if input_ids is None:
input_ids = [
r.output_ids[-1] if r.output_ids else r.origin_input_ids[-1]
for r in self.reqs
]
else:
self.penalizer_orchestrator.cumulate_input_tokens(input_ids)
self.input_ids = torch.tensor(input_ids, dtype=torch.int32, device="cuda")
self.seq_lens.add_(1)
# Alloc mem
bs = self.batch_size()
self.out_cache_loc = self.alloc_token_slots(bs)
self.req_to_token_pool.req_to_token[
self.req_pool_indices, self.seq_lens - 1
] = self.out_cache_loc
def filter_batch(self, unfinished_indices: List[int]):
if unfinished_indices is None or len(unfinished_indices) == 0:
# Filter out all requests
self.reqs = []
return
if len(unfinished_indices) == len(self.reqs):
# No need to filter
return
self.reqs = [self.reqs[i] for i in unfinished_indices]
new_indices = torch.tensor(unfinished_indices, dtype=torch.int32, device="cuda")
self.seq_lens = self.seq_lens[new_indices]
self.input_ids = None
self.req_pool_indices = self.req_pool_indices[new_indices]
self.position_ids_offsets = self.position_ids_offsets[new_indices]
self.out_cache_loc = None
self.top_logprobs_nums = [self.top_logprobs_nums[i] for i in unfinished_indices]
self.return_logprob = any(req.return_logprob for req in self.reqs)
self.penalizer_orchestrator.filter(unfinished_indices, new_indices)
for item in [
"temperatures",
"top_ps",
"top_ks",
"logit_bias",
]:
self_val = getattr(self, item, None)
if self_val is not None: # logit_bias can be None
setattr(self, item, self_val[new_indices])
def merge(self, other: "ScheduleBatch"):
# Penalizer orchestrator must be merged before Batch.reqs is merged. This is because
# orchestrator.merge() depends on Batch.reqs during preparation of each penalizers, so it
# needs to be called with pre-merged Batch.reqs.
self.penalizer_orchestrator.merge(other.penalizer_orchestrator)
self.reqs.extend(other.reqs)
self.req_pool_indices = torch.concat(
[self.req_pool_indices, other.req_pool_indices]
)
self.seq_lens = torch.concat([self.seq_lens, other.seq_lens])
self.position_ids_offsets = torch.concat(
[self.position_ids_offsets, other.position_ids_offsets]
)
self.out_cache_loc = None
self.top_logprobs_nums.extend(other.top_logprobs_nums)
self.return_logprob = any(req.return_logprob for req in self.reqs)
for item in [
"temperatures",
"top_ps",
"top_ks",
]:
self_val = getattr(self, item, None)
other_val = getattr(other, item, None)
setattr(self, item, torch.concat([self_val, other_val]))
# logit_bias can be None
if self.logit_bias is not None or other.logit_bias is not None:
vocab_size = (
self.logit_bias.shape[1]
if self.logit_bias is not None
else other.logit_bias.shape[1]
)
if self.logit_bias is None:
self.logit_bias = torch.zeros(
(len(self.reqs), vocab_size), dtype=torch.float32, device="cuda"
)
if other.logit_bias is None:
other.logit_bias = torch.zeros(
(len(other.reqs), vocab_size), dtype=torch.float32, device="cuda"
)
self.logit_bias = torch.concat([self.logit_bias, other.logit_bias])
def sample(self, logits: torch.Tensor):
# TODO(lsyin): move this into a part of layer and run with CUDA Graph
# Post process logits
logits = logits.contiguous()
logits.div_(self.temperatures)
if self.logit_bias is not None:
logits.add_(self.logit_bias)
has_regex = any(req.regex_fsm is not None for req in self.reqs)
if has_regex:
allowed_mask = torch.empty_like(logits[0], dtype=torch.bool)
for i, req in enumerate(self.reqs):
if req.regex_fsm is not None:
allowed_mask.zero_()
allowed_mask[
req.regex_fsm.get_next_instruction(req.regex_fsm_state).tokens
] = 1
logits[i].masked_fill_(~allowed_mask, float("-inf"))
logits = self.penalizer_orchestrator.apply(logits)
probs = torch.softmax(logits, dim=-1)
if not global_server_args_dict["disable_flashinfer_sampling"]:
max_top_k_round, batch_size = 32, probs.shape[0]
uniform_samples = torch.rand(
(max_top_k_round, batch_size), device=probs.device
)
batch_next_token_ids, success = top_k_top_p_sampling_from_probs(
probs, uniform_samples, self.top_ks, self.top_ps
)
else:
# Here we provide a slower fallback implementation.
batch_next_token_ids, success = top_k_top_p_sampling_from_probs_torch(
probs, self.top_ks, self.top_ps
)
if not torch.all(success):
warnings.warn("Sampling failed, fallback to top_k=1 strategy")
probs = probs.masked_fill(torch.isnan(probs), 0.0)
argmax_ids = torch.argmax(probs, dim=-1)
batch_next_token_ids = torch.where(
success, batch_next_token_ids, argmax_ids
)
if has_regex:
batch_next_token_ids_cpu = batch_next_token_ids.cpu().numpy()
for i, req in enumerate(self.reqs):
if req.regex_fsm is not None:
req.regex_fsm_state = req.regex_fsm.get_next_state(
req.regex_fsm_state, batch_next_token_ids_cpu[i]
)
self.penalizer_orchestrator.cumulate_output_tokens(batch_next_token_ids)
return batch_next_token_ids
def top_k_top_p_sampling_from_probs_torch(
probs: torch.Tensor, top_ks: torch.Tensor, top_ps: torch.Tensor
):
"""A top-k and top-k sampling implementation with native pytorch operations."""
probs_sort, probs_idx = probs.sort(dim=-1, descending=True)
probs_sum = torch.cumsum(probs_sort, dim=-1)
probs_sort[(probs_sum - probs_sort) > top_ps.view(-1, 1)] = 0.0
probs_sort[
torch.arange(0, probs.shape[-1], device=probs.device).view(1, -1)
>= top_ks.view(-1, 1)
] = 0.0
probs_sort.div_(probs_sort.max(dim=-1, keepdim=True)[0])
try:
sampled_index = torch.multinomial(probs_sort, num_samples=1)
except RuntimeError:
batch_next_token_ids = torch.zeros(
(probs_sort.shape[0],), dtype=torch.int32, device=probs.device
)
success = torch.zeros(probs.shape[0], dtype=torch.bool, device=probs.device)
return batch_next_token_ids, success
batch_next_token_ids = torch.gather(probs_idx, dim=1, index=sampled_index).view(-1)
success = torch.ones(probs.shape[0], dtype=torch.bool, device=probs.device)
return batch_next_token_ids, success