mindnet/app/core/chunking/chunking_strategies.py

151 lines
7.2 KiB
Python

"""
FILE: app/core/chunking/chunking_strategies.py
DESCRIPTION: Strategie für atomares Sektions-Chunking v3.9.5.
Implementiert das 'Pack-and-Carry-Over' Verfahren nach Nutzerwunsch.
"""
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 Sektions-Strategie:
- Smart-Edge=True: Packt Sektionen basierend auf Schätzung (Regel 1-3).
- Smart-Edge=False: Hard Split an Überschriften (außer leere Header).
- Strict=True erzwingt Hard Split Verhalten innerhalb der Smart-Logik.
"""
smart_edge = config.get("enable_smart_edge_allocation", True)
strict = config.get("strict_heading_split", False)
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
))
# --- SCHRITT 1: Gruppierung in atomare Sektions-Einheiten ---
sections: List[Dict[str, Any]] = []
curr_blocks = []
for b in blocks:
if b.kind == "heading" and b.level <= split_level:
if curr_blocks:
sections.append({"text": "\n\n".join([x.text for x in curr_blocks]),
"meta": curr_blocks[0], "is_empty": len(curr_blocks) == 1})
curr_blocks = [b]
else: curr_blocks.append(b)
if curr_blocks:
sections.append({"text": "\n\n".join([x.text for x in curr_blocks]),
"meta": curr_blocks[0], "is_empty": len(curr_blocks) == 1})
# --- SCHRITT 2: Verarbeitung der Queue ---
queue = list(sections)
current_chunk_text = ""
current_meta = {"title": None, "path": "/"}
# Hard-Split-Bedingung: Entweder Smart-Edge aus ODER Profil ist Strict
is_hard_split_mode = (not smart_edge) or (strict)
while queue:
item = queue.pop(0)
item_text = item["text"]
# Initialisierung für neuen Chunk
if not current_chunk_text:
current_meta["title"] = item["meta"].section_title
current_meta["path"] = item["meta"].section_path
# FALL A: Hard Split Modus (Regel: Trenne bei jeder Sektion <= Level)
if is_hard_split_mode:
# Regel: Leere Überschriften verbleiben am nächsten Chunk
if item.get("is_empty", False) and queue:
current_chunk_text = (current_chunk_text + "\n\n" + item_text).strip()
continue # Nimm das nächste Item dazu
combined = (current_chunk_text + "\n\n" + item_text).strip()
if estimate_tokens(combined) > max_tokens and current_chunk_text:
# Falls es trotz Hard-Split zu groß wird, flashen wir erst den alten Teil
_emit(current_chunk_text, current_meta["title"], current_meta["path"])
current_chunk_text = item_text
else:
current_chunk_text = combined
# Im Hard Split flashen wir nach jeder Sektion, die nicht leer ist
_emit(current_chunk_text, current_meta["title"], current_meta["path"])
current_chunk_text = ""
continue
# FALL B: Smart Mode (Regel 1-3)
combined_text = (current_chunk_text + "\n\n" + item_text).strip() if current_chunk_text else item_text
combined_est = estimate_tokens(combined_text)
if combined_est <= max_tokens:
# Regel 1 & 2: Passt nach Schätzung -> Aufnehmen
current_chunk_text = combined_text
else:
# Regel 3: Passt nicht -> Entweder Puffer flashen oder Item zerlegen
if current_chunk_text:
_emit(current_chunk_text, current_meta["title"], current_meta["path"])
current_chunk_text = ""
queue.insert(0, item) # Item für neuen Chunk zurücklegen
else:
# Einzelne Sektion zu groß -> Smart Zerlegung
sents = split_sentences(item_text)
header_prefix = item["meta"].text if item["meta"].kind == "heading" else ""
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: Rest wird vorne in die Queue geschoben
if sents:
remainder = " ".join(sents)
if header_prefix and not remainder.startswith(header_prefix):
remainder = header_prefix + "\n\n" + remainder
queue.insert(0, {"text": remainder, "meta": item["meta"], "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, doc_title: str = "") -> List[Chunk]:
"""Standard Sliding Window Strategie."""
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)
curr_tokens = sum(estimate_tokens(x.text) for x in buf) if buf else 0
if curr_tokens + b_tokens > max_tokens and buf:
txt = "\n\n".join([x.text for x in buf]); idx = len(chunks)
win = _create_win(doc_title, buf[0].section_title, txt)
chunks.append(Chunk(id=f"{note_id}#c{idx:02d}", note_id=note_id, index=idx, text=txt, window=win, token_count=curr_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 = _create_win(doc_title, buf[0].section_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=buf[0].section_title, section_path=buf[0].section_path, neighbors_prev=None, neighbors_next=None))
return chunks