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llm-connect/llm_connect/problem_classes.py
tegwick c11c6afa3f
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Implement-LLM-WP-0005-cost-model-estimators
2026-05-19 05:02:20 +02:00

464 lines
16 KiB
Python

"""Problem-class token estimators for common LLM workflow shapes."""
from __future__ import annotations
from collections.abc import Mapping, Sequence
from dataclasses import dataclass
from typing import Any, Protocol
DEFAULT_WORDS_PER_TOKEN = 0.75
@dataclass(frozen=True)
class TokenEstimate:
"""Prompt/completion token estimate for a prospective LLM call."""
prompt_tokens: int
completion_tokens: int
confidence: float = 0.5
def __post_init__(self) -> None:
prompt_tokens = _non_negative_int("prompt_tokens", self.prompt_tokens)
completion_tokens = _non_negative_int("completion_tokens", self.completion_tokens)
confidence = _bounded_float("confidence", self.confidence)
object.__setattr__(self, "prompt_tokens", prompt_tokens)
object.__setattr__(self, "completion_tokens", completion_tokens)
object.__setattr__(self, "confidence", confidence)
@dataclass(frozen=True)
class Observation:
"""Actual token use paired with the problem dimensions that produced it."""
dimensions: dict[str, Any]
prompt_tokens: int
completion_tokens: int
def __post_init__(self) -> None:
object.__setattr__(self, "dimensions", dict(self.dimensions))
object.__setattr__(self, "prompt_tokens", _non_negative_int("prompt_tokens", self.prompt_tokens))
object.__setattr__(
self,
"completion_tokens",
_non_negative_int("completion_tokens", self.completion_tokens),
)
class ProblemClass(Protocol):
"""Estimator contract implemented by built-in and consumer classes."""
name: str
base_dimensions: tuple[str, ...]
tunable_params: tuple[str, ...]
params: dict[str, float]
def estimate(
self,
dimensions: dict[str, Any],
params: dict[str, Any] | None = None,
) -> TokenEstimate:
"""Estimate token use from dimensions and optional parameter overrides."""
...
def fit(
self,
observations: Sequence[Any],
*,
min_observations: int = 3,
) -> "ProblemClass":
"""Return an estimator with params adapted from observed token use."""
...
class ProblemClassRegistry:
"""Registry keyed by stable problem-class names."""
schema_version = 1
def __init__(self, classes: Sequence[ProblemClass] | None = None) -> None:
self._classes: dict[str, ProblemClass] = {}
for problem_class in classes or ():
self.register(problem_class)
def get(self, name: str) -> ProblemClass | None:
"""Return a registered class by name."""
return self._classes.get(str(name).strip())
def all(self) -> dict[str, ProblemClass]:
"""Return a copy of registered problem classes."""
return dict(self._classes)
def register(self, problem_class: ProblemClass, *, replace: bool = False) -> None:
"""Register *problem_class* under its name."""
name = str(problem_class.name).strip()
if not name:
raise ValueError("problem_class.name must be a non-empty string")
if name in self._classes and not replace:
raise ValueError(f"Problem class {name!r} is already registered")
self._classes[name] = problem_class
@classmethod
def default(cls) -> "ProblemClassRegistry":
"""Return the built-in problem-class registry."""
return cls(
[
ChunkSummarizationProblemClass(),
EntityExtractionProblemClass(),
RelationExtractionProblemClass(),
JudgeEvalProblemClass(),
ReportSynthesisProblemClass(),
]
)
class _BaseProblemClass:
name = ""
base_dimensions: tuple[str, ...] = ()
tunable_params: tuple[str, ...] = ()
seed_params: Mapping[str, float] = {}
def __init__(
self,
*,
params: Mapping[str, Any] | None = None,
confidence: float = 0.5,
) -> None:
merged = dict(self.seed_params)
for key, value in (params or {}).items():
if key not in self.tunable_params:
raise ValueError(f"Unknown parameter {key!r} for problem class {self.name!r}")
merged[key] = _non_negative_float(key, value)
self.params: dict[str, float] = merged
self.confidence = _bounded_float("confidence", confidence)
def estimate(
self,
dimensions: dict[str, Any],
params: dict[str, Any] | None = None,
) -> TokenEstimate:
dimensions = dict(dimensions)
self._validate_dimensions(dimensions)
merged_params = dict(self.params)
for key, value in (params or {}).items():
if key not in self.tunable_params:
raise ValueError(f"Unknown parameter {key!r} for problem class {self.name!r}")
merged_params[key] = _non_negative_float(key, value)
prompt_tokens, completion_tokens = self._estimate_tokens(dimensions, merged_params)
return TokenEstimate(
prompt_tokens=prompt_tokens,
completion_tokens=completion_tokens,
confidence=self.confidence,
)
def fit(
self,
observations: Sequence[Any],
*,
min_observations: int = 3,
) -> ProblemClass:
if min_observations <= 0:
raise ValueError("min_observations must be positive")
parsed = [
observation
for observation in (
_coerce_observation(raw, self.name, self.base_dimensions) for raw in observations
)
if observation is not None
]
if len(parsed) < min_observations:
return self
fitted: dict[str, float] = {}
for param in self.tunable_params:
values = [
value
for value in (
self._infer_param(param, observation) for observation in parsed
)
if value is not None
]
if values:
fitted[param] = sum(values) / len(values)
if not fitted:
return self
confidence = min(0.95, max(self.confidence, len(parsed) / (len(parsed) + 5)))
return type(self)(params={**self.params, **fitted}, confidence=confidence)
def _validate_dimensions(self, dimensions: Mapping[str, Any]) -> None:
missing = [name for name in self.base_dimensions if name not in dimensions]
if missing:
raise ValueError(f"Missing dimensions for {self.name!r}: {', '.join(missing)}")
for name in self.base_dimensions:
_non_negative_float(name, dimensions[name])
def _estimate_tokens(
self,
dimensions: Mapping[str, Any],
params: Mapping[str, float],
) -> tuple[int, int]:
raise NotImplementedError
def _infer_param(self, param: str, observation: Observation) -> float | None:
raise NotImplementedError
class ChunkSummarizationProblemClass(_BaseProblemClass):
name = "chunk-summarization"
base_dimensions: tuple[str, ...] = ("chunk_words", "template_words")
tunable_params: tuple[str, ...] = ("completion_ratio",)
seed_params: Mapping[str, float] = {"completion_ratio": 0.25}
def _estimate_tokens(
self,
dimensions: Mapping[str, Any],
params: Mapping[str, float],
) -> tuple[int, int]:
prompt_tokens = _words_to_tokens(
_dimension(dimensions, "chunk_words") + _dimension(dimensions, "template_words")
)
completion_tokens = _round_tokens(prompt_tokens * params["completion_ratio"])
return prompt_tokens, completion_tokens
def _infer_param(self, param: str, observation: Observation) -> float | None:
if param != "completion_ratio" or observation.prompt_tokens == 0:
return None
return observation.completion_tokens / observation.prompt_tokens
class EntityExtractionProblemClass(_BaseProblemClass):
name = "entity-extraction"
base_dimensions: tuple[str, ...] = ("chunk_words", "template_words", "expected_entities")
tunable_params: tuple[str, ...] = ("tokens_per_entity",)
seed_params: Mapping[str, float] = {"tokens_per_entity": 70.0}
def _estimate_tokens(
self,
dimensions: Mapping[str, Any],
params: Mapping[str, float],
) -> tuple[int, int]:
prompt_tokens = _words_to_tokens(
_dimension(dimensions, "chunk_words") + _dimension(dimensions, "template_words")
)
completion_tokens = _round_tokens(
_dimension(dimensions, "expected_entities") * params["tokens_per_entity"]
)
return prompt_tokens, completion_tokens
def _infer_param(self, param: str, observation: Observation) -> float | None:
expected_entities = _dimension(observation.dimensions, "expected_entities")
if param != "tokens_per_entity" or expected_entities <= 0:
return None
return observation.completion_tokens / expected_entities
class RelationExtractionProblemClass(_BaseProblemClass):
name = "relation-extraction"
base_dimensions: tuple[str, ...] = ("chunk_words", "template_words", "expected_relations")
tunable_params: tuple[str, ...] = ("tokens_per_relation",)
seed_params: Mapping[str, float] = {"tokens_per_relation": 80.0}
def _estimate_tokens(
self,
dimensions: Mapping[str, Any],
params: Mapping[str, float],
) -> tuple[int, int]:
prompt_tokens = _words_to_tokens(
_dimension(dimensions, "chunk_words") + _dimension(dimensions, "template_words")
)
completion_tokens = _round_tokens(
_dimension(dimensions, "expected_relations") * params["tokens_per_relation"]
)
return prompt_tokens, completion_tokens
def _infer_param(self, param: str, observation: Observation) -> float | None:
expected_relations = _dimension(observation.dimensions, "expected_relations")
if param != "tokens_per_relation" or expected_relations <= 0:
return None
return observation.completion_tokens / expected_relations
class JudgeEvalProblemClass(_BaseProblemClass):
name = "judge-eval"
base_dimensions: tuple[str, ...] = ("artifact_words", "template_words", "n_criteria")
tunable_params: tuple[str, ...] = ("tokens_per_criterion",)
seed_params: Mapping[str, float] = {"tokens_per_criterion": 35.0}
def _estimate_tokens(
self,
dimensions: Mapping[str, Any],
params: Mapping[str, float],
) -> tuple[int, int]:
prompt_tokens = _words_to_tokens(
_dimension(dimensions, "artifact_words") + _dimension(dimensions, "template_words")
)
completion_tokens = _round_tokens(
_dimension(dimensions, "n_criteria") * params["tokens_per_criterion"]
)
return prompt_tokens, completion_tokens
def _infer_param(self, param: str, observation: Observation) -> float | None:
n_criteria = _dimension(observation.dimensions, "n_criteria")
if param != "tokens_per_criterion" or n_criteria <= 0:
return None
return observation.completion_tokens / n_criteria
class ReportSynthesisProblemClass(_BaseProblemClass):
name = "report-synthesis"
base_dimensions: tuple[str, ...] = ("n_chunks", "n_entities", "n_relations", "template_words")
tunable_params: tuple[str, ...] = ("base_completion_tokens",)
seed_params: Mapping[str, float] = {"base_completion_tokens": 400.0}
def _estimate_tokens(
self,
dimensions: Mapping[str, Any],
params: Mapping[str, float],
) -> tuple[int, int]:
prompt_tokens = _words_to_tokens(_dimension(dimensions, "template_words"))
prompt_tokens += _round_tokens(_dimension(dimensions, "n_chunks") * 40)
prompt_tokens += _round_tokens(_dimension(dimensions, "n_entities") * 25)
prompt_tokens += _round_tokens(_dimension(dimensions, "n_relations") * 35)
return prompt_tokens, _round_tokens(params["base_completion_tokens"])
def _infer_param(self, param: str, observation: Observation) -> float | None:
if param != "base_completion_tokens":
return None
return float(observation.completion_tokens)
def default_problem_class_registry() -> ProblemClassRegistry:
"""Return the built-in problem-class registry."""
return ProblemClassRegistry.default()
def _coerce_observation(
raw: Any,
class_name: str,
required_dimensions: tuple[str, ...],
) -> Observation | None:
try:
if isinstance(raw, Observation):
return raw
if isinstance(raw, Mapping):
return _coerce_mapping_observation(raw, class_name, required_dimensions)
return _coerce_object_observation(raw, class_name, required_dimensions)
except (KeyError, TypeError, ValueError):
return None
def _coerce_mapping_observation(
raw: Mapping[str, Any],
class_name: str,
required_dimensions: tuple[str, ...],
) -> Observation | None:
raw_tags = raw.get("tags")
tags: Mapping[str, Any] = raw_tags if isinstance(raw_tags, Mapping) else {}
problem_class = raw.get("problem_class") or tags.get("problem_class")
if problem_class is not None and str(problem_class) != class_name:
return None
dimensions = _dimensions_from_sources(required_dimensions, raw, tags)
prompt_tokens = _token_value(raw, "prompt_tokens", "tokens_in", "actual_prompt_tokens")
completion_tokens = _token_value(
raw,
"completion_tokens",
"tokens_out",
"actual_completion_tokens",
)
return Observation(dimensions, prompt_tokens, completion_tokens)
def _coerce_object_observation(
raw: Any,
class_name: str,
required_dimensions: tuple[str, ...],
) -> Observation | None:
raw_tags = getattr(raw, "tags", {}) or {}
tags: Mapping[str, Any] = raw_tags if isinstance(raw_tags, Mapping) else {}
problem_class = tags.get("problem_class")
if problem_class is not None and str(problem_class) != class_name:
return None
dimensions = _dimensions_from_sources(required_dimensions, tags)
return Observation(
dimensions=dimensions,
prompt_tokens=getattr(raw, "tokens_in"),
completion_tokens=getattr(raw, "tokens_out"),
)
def _dimensions_from_sources(
required_dimensions: tuple[str, ...],
*sources: Mapping[str, Any],
) -> dict[str, Any]:
for source in sources:
candidate = source.get("dimensions")
if isinstance(candidate, Mapping):
return dict(candidate)
dimensions: dict[str, Any] = {}
for name in required_dimensions:
for source in sources:
if name in source:
dimensions[name] = source[name]
break
if len(dimensions) != len(required_dimensions):
raise ValueError("observation is missing required dimensions")
return dimensions
def _token_value(raw: Mapping[str, Any], *names: str) -> int:
for name in names:
if name in raw:
return _non_negative_int(name, raw[name])
usage = raw.get("usage")
if isinstance(usage, Mapping):
for name in names:
if name in usage:
return _non_negative_int(name, usage[name])
raise KeyError(names[0])
def _dimension(dimensions: Mapping[str, Any], name: str) -> float:
return _non_negative_float(name, dimensions[name])
def _words_to_tokens(words: float) -> int:
if words == 0:
return 0
return max(1, _round_tokens(words / DEFAULT_WORDS_PER_TOKEN))
def _round_tokens(value: float) -> int:
return max(0, int(round(value)))
def _non_negative_int(name: str, value: Any) -> int:
if isinstance(value, bool):
raise ValueError(f"{name} must be a non-negative integer")
try:
integer = int(value)
except (TypeError, ValueError) as exc:
raise ValueError(f"{name} must be a non-negative integer") from exc
if integer < 0 or integer != float(value):
raise ValueError(f"{name} must be a non-negative integer")
return integer
def _non_negative_float(name: str, value: Any) -> float:
if isinstance(value, bool):
raise ValueError(f"{name} must be a non-negative number")
try:
number = float(value)
except (TypeError, ValueError) as exc:
raise ValueError(f"{name} must be a non-negative number") from exc
if number < 0:
raise ValueError(f"{name} must be a non-negative number")
return number
def _bounded_float(name: str, value: Any) -> float:
number = _non_negative_float(name, value)
if number > 1:
raise ValueError(f"{name} must be between 0 and 1")
return number