wiki-kb/wikikb/embed.py
kuhyx 71e4a6115e Consolidate CK3/KCD wiki knowledge bases into one generic wiki-kb
Merges ~/ck3-knowledge and ~/kcd-knowledge, which were 90% duplicate code and
neither of which had ever been committed anywhere.

Works on any wiki, not just MediaWiki:
- sources.py splits the engine-specific parts (enumerate, fetch) behind a Source
  protocol. MediaWikiSource is preferred whenever an api.php exists;
  SitemapHtmlSource handles custom engines with no API (verified on Fextralife).
  Everything downstream was already source-agnostic.
- scripts/detect_wiki.py probes /api.php, /w/api.php then /sitemap.xml and prints
  the config to use. The API path and article URL vary independently — Fandom
  serves /api.php but /wiki/{Title}.
- Profiles are plain env files, since config.py was already fully env-driven.

Per-wiki behaviour that must be measured rather than assumed:
- Subpage policy. On the CK3 wiki "A/B" is a mod; on the KCD wiki it is the
  sequel, and rejecting subpages deletes 441 pages of wanted content.
- Noise sections. "Other languages" tables were 7% of KCD chunks and matched
  English queries by repeating every title in eight languages.
- Variant tagging for wikis covering two editions, with scopes that exclude the
  other edition but keep both/unknown pages.

Build performance: length bucketing in embed_efficiently is 2.7x (fastembed pads
each batch to its longest member; 184-char median vs 2000-char max). With noise
sections that is 61 min -> 20 min on a 6,140-page wiki at half the workers.

Fandom portable-infoboxes are transformed to tables before markdownify —
otherwise stat values survive but detach from their labels.

100% branch coverage, ruff clean.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-26 18:12:56 +02:00

61 lines
2.1 KiB
Python

"""Local embeddings via fastembed (bge-small), L2-normalized for cosine = dot."""
from __future__ import annotations
from collections.abc import Iterable
from typing import Protocol
import numpy as np
from . import config
class EmbeddingModel(Protocol):
"""Minimal fastembed-compatible surface (also satisfied by test fakes)."""
def embed(self, texts: Iterable[str], **kwargs: object) -> Iterable[np.ndarray]: ...
def query_embed(self, texts: Iterable[str], **kwargs: object) -> Iterable[np.ndarray]: ...
_model: EmbeddingModel | None = None
def get_model() -> EmbeddingModel:
"""Lazily construct the (heavy) fastembed model once."""
global _model
if _model is None: # pragma: no cover - exercised only with the real model
from fastembed import TextEmbedding
# threads caps onnxruntime's intra-op parallelism (the main CPU driver);
# CPUExecutionProvider avoids grabbing any accelerator.
_model = TextEmbedding(
model_name=config.EMBED_MODEL,
threads=config.EMBED_THREADS,
providers=["CPUExecutionProvider"],
)
return _model
def _normalize(matrix: np.ndarray) -> np.ndarray:
if matrix.size == 0:
return matrix.reshape(0, config.EMBED_DIM).astype(np.float32)
norms = np.linalg.norm(matrix, axis=1, keepdims=True)
norms[norms == 0] = 1.0
return (matrix / norms).astype(np.float32)
def embed_passages(texts: list[str], *, model: EmbeddingModel | None = None) -> np.ndarray:
"""Embed corpus passages -> (N, dim) normalized float32."""
model = model or get_model()
vectors = list(
model.embed(texts, batch_size=config.EMBED_BATCH_SIZE, parallel=config.EMBED_PARALLEL)
)
return _normalize(np.array(vectors, dtype=np.float32))
def embed_query(text: str, *, model: EmbeddingModel | None = None) -> np.ndarray:
"""Embed a search query -> (dim,) normalized float32 (with bge query prefix)."""
model = model or get_model()
vector = np.array(next(iter(model.query_embed([text]))), dtype=np.float32)
return _normalize(vector.reshape(1, -1))[0]