docling-studio/document-parser/infra/local_chunker.py
Pier-Jean Malandrino c2550867b7 feat(neo4j): Day 3 — ChunkWriter, graph API, GraphView, README
ChunkWriter mirrors chunks into Neo4j after OpenSearch indexing, creating
HAS_CHUNK edges and DERIVED_FROM back-references to the source Elements
(via doc_items propagated from the local chunker).

Graph API: GET /api/documents/{id}/graph returns a cytoscape-shaped
payload with nodes + edges for Document / Element / Page / Chunk.
Hard cap at 200 pages returns HTTP 413 per design §8.4.

Frontend: new Graph tab in Studio results, rendered with Cytoscape.js +
dagre layout (lazy-loaded, ~175 KB gz). Legend, node styling per element
label, directional edges styled per edge type.

README gains a Neo4j section with the schema, three demo Cypher
queries, and env vars. Backend tests skip cleanly when the neo4j python
package is not installed locally.

Refs #186
2026-04-29 14:00:00 +02:00

106 lines
3.6 KiB
Python

"""Local Docling chunker — runs chunking in-process using docling-core.
This adapter implements the DocumentChunker port. It deserializes a
DoclingDocument from JSON, applies the requested chunker, and returns
domain ChunkResult objects.
"""
from __future__ import annotations
import asyncio
import json
import logging
from docling_core.transforms.chunker import HierarchicalChunker
from docling_core.transforms.chunker.hybrid_chunker import HybridChunker
from docling_core.types.doc.document import DoclingDocument
from domain.value_objects import ChunkBbox, ChunkDocItem, ChunkingOptions, ChunkResult
from infra.bbox import EMPTY_BBOX, to_topleft_list
logger = logging.getLogger(__name__)
def _chunk_sync(document_json: str, options: ChunkingOptions) -> list[ChunkResult]:
if not document_json or not document_json.strip():
raise ValueError("Empty document JSON — nothing to chunk")
try:
doc_data = json.loads(document_json)
except json.JSONDecodeError as e:
raise ValueError(f"Malformed document JSON: {e}") from e
doc = DoclingDocument.model_validate(doc_data)
chunker = _build_chunker(options)
results: list[ChunkResult] = []
for chunk in chunker.chunk(doc):
source_page = None
token_count = 0
bboxes: list[ChunkBbox] = []
doc_items: list[ChunkDocItem] = []
if hasattr(chunk, "meta") and chunk.meta and chunk.meta.doc_items:
for doc_item in chunk.meta.doc_items:
ref = getattr(doc_item, "self_ref", None)
if ref:
doc_items.append(
ChunkDocItem(
self_ref=ref,
label=str(getattr(doc_item, "label", "") or ""),
)
)
if not hasattr(doc_item, "prov") or not doc_item.prov:
continue
for prov in doc_item.prov:
page_no = prov.page_no
if source_page is None:
source_page = page_no
if prov.bbox:
page_obj = doc.pages.get(page_no)
if page_obj:
bbox = to_topleft_list(prov.bbox, page_obj.size.height)
if bbox != EMPTY_BBOX:
bboxes.append(ChunkBbox(page=page_no, bbox=bbox))
if hasattr(chunker, "tokenizer") and chunker.tokenizer:
token_count = chunker.tokenizer.count_tokens(chunk.text)
headings = list(chunk.meta.headings) if chunk.meta and chunk.meta.headings else []
results.append(
ChunkResult(
text=chunk.text,
headings=headings,
source_page=source_page,
token_count=token_count,
bboxes=bboxes,
doc_items=doc_items,
)
)
logger.info("Chunked document into %d chunks (chunker=%s)", len(results), options.chunker_type)
return results
def _build_chunker(options: ChunkingOptions) -> HierarchicalChunker | HybridChunker:
if options.chunker_type == "hierarchical":
return HierarchicalChunker()
return HybridChunker(
max_tokens=options.max_tokens,
merge_peers=options.merge_peers,
repeat_table_header=options.repeat_table_header,
)
class LocalChunker:
"""Adapter that runs docling-core chunking locally."""
async def chunk(
self,
document_json: str,
options: ChunkingOptions,
) -> list[ChunkResult]:
return await asyncio.to_thread(_chunk_sync, document_json, options)