mindnet/app/core/chunking/chunking_strategies.py

143 lines
6.9 KiB
Python

"""
FILE: app/core/chunking/chunking_strategies.py
DESCRIPTION: Strategien für atomares Sektions-Chunking v3.8.5.
Implementiert das 'Pack-and-Carry-Over' Verfahren:
1. Packt ganze Abschnitte basierend auf Schätzung.
2. Kein physischer Overflow-Check während des Packens.
3. Smart-Zerlegung von Übergrößen mit Carry-Over in die Queue.
"""
from typing import List, Dict, Any, Optional
from .chunking_models import RawBlock, Chunk
from .chunking_utils import estimate_tokens
from .chunking_parser import split_sentences
def _create_win(doc_title: str, sec_title: Optional[str], text: str) -> str:
parts = [doc_title] if doc_title else []
if sec_title and sec_title != doc_title: parts.append(sec_title)
prefix = " > ".join(parts)
return f"{prefix}\n{text}".strip() if prefix else text
def strategy_by_heading(blocks: List[RawBlock], config: Dict[str, Any], note_id: str, doc_title: str = "") -> List[Chunk]:
"""
Universelle Heading-Strategie mit Fallunterscheidung für Smart-Edge-Allocation.
"""
smart_edge = config.get("enable_smart_edge_allocation", True)
target = config.get("target", 400)
max_tokens = config.get("max", 600)
split_level = config.get("split_level", 2)
overlap_cfg = config.get("overlap", (50, 80))
overlap = sum(overlap_cfg) // 2 if isinstance(overlap_cfg, (list, tuple)) else overlap_cfg
chunks: List[Chunk] = []
def _emit(txt, title, path):
idx = len(chunks)
win = _create_win(doc_title, title, txt)
chunks.append(Chunk(
id=f"{note_id}#c{idx:02d}", note_id=note_id, index=idx,
text=txt, window=win, token_count=estimate_tokens(txt),
section_title=title, section_path=path, neighbors_prev=None, neighbors_next=None
))
# --- FALL A: HARD SPLIT (enable_smart_edge_allocation: false) ---
if not smart_edge:
buf = []
for b in blocks:
# Trenne bei jeder Überschrift <= split_level
if b.kind == "heading" and b.level <= split_level:
# Nur flashen, wenn der Puffer nicht nur aus der aktuellen Überschrift besteht
if buf and not (len(buf) == 1 and buf[0].kind == "heading"):
_emit("\n\n".join([x.text for x in buf]), buf[0].section_title, buf[0].section_path)
buf = []
buf.append(b)
if buf: _emit("\n\n".join([x.text for x in buf]), buf[0].section_title, buf[0].section_path)
return chunks
# --- FALL B: SMART EDGE ALLOCATION (Pack-and-Carry-Over) ---
# 1. Gruppierung in atomare Sektions-Einheiten (Sektions-Isolation)
sections: List[List[RawBlock]] = []
curr = []
for b in blocks:
if b.kind == "heading" and b.level <= split_level:
if curr: sections.append(curr)
curr = [b]
else: curr.append(b)
if curr: sections.append(curr)
# 2. Queue-Management für Carry-Over
processing_queue = [{"blocks": s, "text": "\n\n".join([b.text for b in s])} for s in sections]
current_chunk_text = ""
current_meta = {"title": None, "path": "/"}
while processing_queue:
item = processing_queue.pop(0)
item_text = item["text"]
item_tokens = estimate_tokens(item_text)
# Metadaten-Initialisierung falls Chunk leer
if not current_chunk_text and "blocks" in item:
current_meta["title"] = item["blocks"][0].section_title
current_meta["path"] = item["blocks"][0].section_path
combined_est = estimate_tokens(current_chunk_text + "\n\n" + item_text) if current_chunk_text else item_tokens
# Regel 1: Passt die vollständige Sektion nach Schätzung rein? (Kein harter Overflow-Check)
if combined_est <= max_tokens:
current_chunk_text = (current_chunk_text + "\n\n" + item_text).strip()
else:
# Regel 2: Wenn Puffer voll -> Emittieren und Sektion zurücklegen
if current_chunk_text:
_emit(current_chunk_text, current_meta["title"], current_meta["path"])
current_chunk_text = ""
processing_queue.insert(0, item)
else:
# Regel 3: Einzelne Sektion zu groß -> Smart Zerlegung
sents = split_sentences(item_text)
header_text = ""
if "blocks" in item and item["blocks"][0].kind == "heading":
header_text = item["blocks"][0].text
take_sents = []; take_len = 0
while sents:
s = sents.pop(0)
slen = estimate_tokens(s)
if take_len + slen > target and take_sents:
sents.insert(0, s); break
take_sents.append(s); take_len += slen
_emit(" ".join(take_sents), current_meta["title"], current_meta["path"])
# Carry-Over: Der Rest wird an den Anfang der Queue geschoben
if sents:
remainder_text = " ".join(sents)
# Falls wir einen Header haben, fügen wir ihn dem Rest für den Kontext hinzu
if header_text and not remainder_text.startswith(header_text):
remainder_text = header_text + "\n\n" + remainder_text
processing_queue.insert(0, {"text": remainder_text, "is_split": True})
if current_chunk_text:
_emit(current_chunk_text, current_meta["title"], current_meta["path"])
return chunks
def strategy_sliding_window(blocks: List[RawBlock], config: Dict[str, Any], note_id: str, context_prefix: str = "") -> List[Chunk]:
"""Sliding Window Strategie: Erhalten für alternative Anwendungsfälle."""
target = config.get("target", 400); max_tokens = config.get("max", 600)
chunks: List[Chunk] = []; buf: List[RawBlock] = []
for b in blocks:
b_tokens = estimate_tokens(b.text)
current_tokens = sum(estimate_tokens(x.text) for x in buf) if buf else 0
if current_tokens + b_tokens > max_tokens and buf:
txt = "\n\n".join([x.text for x in buf]); idx = len(chunks)
win = f"{context_prefix}\n{txt}".strip() if context_prefix else txt
chunks.append(Chunk(id=f"{note_id}#c{idx:02d}", note_id=note_id, index=idx, text=txt, window=win, token_count=current_tokens, section_title=buf[0].section_title, section_path=buf[0].section_path, neighbors_prev=None, neighbors_next=None))
buf = []
buf.append(b)
if buf:
txt = "\n\n".join([x.text for x in buf]); idx = len(chunks)
win = f"{context_prefix}\n{txt}".strip() if context_prefix else txt
chunks.append(Chunk(id=f"{note_id}#c{idx:02d}", note_id=note_id, index=idx, text=txt, window=win, token_count=estimate_tokens(txt), section_title=buf[0].section_title, section_path=buf[0].section_path, neighbors_prev=None, neighbors_next=None))
return chunks