feat(data_process): 模型缓存统一仓库根 .cache 并修复 PDF 页眉页脚清理

- 新增 app/core/cache_paths.py:HF_HOME / tiktoken 缓存统一指向 <repo>/.cache,
  本地与 Docker 路径一致,离线部署打包 .cache 即可
- Dockerfile.backend 的 tiktoken 词表改用官方 SHA 文件名,避免运行时回退重建
- 修复 layout_hybrid 路径不运行 detect_pdf_document_noise 的缺陷:
  needs_pdf_noise 不再与 needs_layout_raw 互斥,PDF 智能预处理在版面切分下也生效
- 新增 layout_noise.py:识别跨页重复的页眉表格标签组并按行剔除,
  解决 docling layout 模型把中文企业 PDF 页眉识别成普通 Table 导致清不掉的问题
- 回收 HybridChunker 丢弃的末尾孤立标题,找回章节标题内容
This commit is contained in:
caoxiaozhu
2026-08-21 10:15:08 +08:00
parent 3b9361c237
commit 03254f8196
14 changed files with 479 additions and 32 deletions

View File

@@ -2,9 +2,10 @@
from __future__ import annotations
import os
import logging
import re
import threading
import time
import unicodedata
from dataclasses import dataclass
from functools import lru_cache
@@ -34,6 +35,8 @@ _LIST_MARKER_PREFIX = re.compile(
_COMPACT_CHARACTER = re.compile(r"[\w\u3400-\u4dbf\u4e00-\u9fff]", re.UNICODE)
_CONVERTER_LOCK = threading.Lock()
logger = logging.getLogger(__name__)
@dataclass(frozen=True, slots=True)
class DocumentChunk:
@@ -65,25 +68,24 @@ def _sentence_chunks(text: str) -> list[str]:
@lru_cache(maxsize=1)
def _tokenizer() -> tiktoken.Encoding:
"""加载 cl100k_base 编码器,优先在线下载,失败时使用本地缓存以支持离线环境。"""
import os
import base64
# 先设置缓存目录环境变量
offline_cache = os.path.expanduser("~/.cache/tiktoken")
os.environ.setdefault("TIKTOKEN_CACHE_DIR", offline_cache)
from app.core.cache_paths import tiktoken_cache_dir
# 缓存目录已在 app.core.cache_paths.setup_local_caches 中统一指向 <repo>/.cache/tiktoken
# 此处直接读取TIKTOKEN_CACHE_DIR 已在启动阶段写入。
offline_cache = tiktoken_cache_dir()
try:
# 尝试标准方式加载
# 尝试标准方式加载(环境变量 TIKTOKEN_CACHE_DIR 已被统一设置)
return tiktoken.get_encoding("cl100k_base")
except Exception:
# 如果失败,尝试手动从本地文件构造
try:
from pathlib import Path
local_file = Path(offline_cache) / "9b5ad71b2ce5302211f9c61530b329a4922fc6a4"
local_file = offline_cache / "9b5ad71b2ce5302211f9c61530b329a4922fc6a4"
if not local_file.exists():
# 尝试另一个可能的文件名
local_file = Path(offline_cache) / "cl100k_base.tiktoken"
local_file = offline_cache / "cl100k_base.tiktoken"
if local_file.exists():
# 读取 BPE 文件内容
@@ -106,7 +108,7 @@ def _tokenizer() -> tiktoken.Encoding:
pat_str=r"""'(?i:[sdmt]|ll|ve|re)|[^\r\n\p{L}\p{N}]?+\p{L}+|\p{N}{1,3}| ?[^\s\p{L}\p{N}]++[\r\n]*|\s*[\r\n]|\s+(?!\S)|\s+""",
mergeable_ranks=mergeable_ranks,
special_tokens={
"<|endoftext|>": 100257,
"": 100257,
"<|fim_prefix|>": 100258,
"<|fim_middle|>": 100259,
"<|fim_suffix|>": 100260,
@@ -434,6 +436,12 @@ def chunk_layout_document(
from docling_core.transforms.chunker.tokenizer.openai import OpenAITokenizer
from docling_core.types.doc import DocItemLabel
from app.modules.data_process.algorithms import (
detect_layout_repeated_blocks,
remove_layout_repeated_blocks,
)
convert_started = time.perf_counter()
try:
with _CONVERTER_LOCK:
conversion = _document_converter().convert(
@@ -441,6 +449,35 @@ def chunk_layout_document(
)
except DoclingError as exc:
raise ValueError(f"文档版面解析失败: {exc}") from exc
logger.info(
"layout chunking convert done file=%s elapsed=%.2fs",
filename,
time.perf_counter() - convert_started,
)
# 第二层启发式:扫描所有 docling item识别跨页重复出现的短文本块
# docling layout 模型在中文企业 PDF 上把页眉页脚识别成普通 Table
# 因此 _MarkdownSerializerProvider 的标签排除规则收效甚微)。
page_count = len(getattr(conversion.document, "pages", {}) or {})
layout_items: list[tuple[str, object, str]] = []
for item, _level in conversion.document.iterate_items():
text = getattr(item, "text", None)
if not text and hasattr(item, "export_to_markdown"):
try:
text = item.export_to_markdown(doc=conversion.document) or ""
except TypeError:
# 旧版 docling_core 无 doc 参数
text = item.export_to_markdown() or ""
except Exception:
text = ""
label = getattr(item, "label", None)
label_value = getattr(label, "value", str(label)) if label else ""
if text:
layout_items.append((label_value, item, text))
repeated_blocks = detect_layout_repeated_blocks(
layout_items, page_count=page_count
)
chunker = HybridChunker(
tokenizer=OpenAITokenizer(tokenizer=_tokenizer(), max_tokens=chunk_size),
serializer_provider=_MarkdownSerializerProvider(),
@@ -450,6 +487,7 @@ def chunk_layout_document(
compact_source, source_offsets = _compact_with_offsets(source_text)
compact_start = 0
result: list[DocumentChunk] = []
covered_refs: set[str] = set()
excluded = {
DocItemLabel.DOCUMENT_INDEX,
DocItemLabel.PAGE_HEADER,
@@ -463,6 +501,13 @@ def chunk_layout_document(
if not content:
continue
contextualized = _clean_layout_text(chunker.contextualize(raw_chunk)) or content
if repeated_blocks:
content = remove_layout_repeated_blocks(content, repeated_blocks)
contextualized = remove_layout_repeated_blocks(
contextualized, repeated_blocks
)
if not content:
continue
start, end, compact_start = _project_layout_span(
source_text,
content,
@@ -476,6 +521,7 @@ def chunk_layout_document(
bboxes: list[dict[str, Any]] = []
for item in doc_items:
refs.append(str(item.self_ref))
covered_refs.add(str(item.self_ref))
for provenance in item.prov or ():
pages.add(int(provenance.page_no))
bbox = provenance.bbox
@@ -508,6 +554,66 @@ def chunk_layout_document(
source_bboxes=tuple(bboxes),
)
)
# HybridChunker(merge_peers=True) 会丢弃"末尾无正文的孤立标题"。
# OCR 页常只产出一个 heading内容会被整体吞掉这里按文档序回收
# 未被任何 chunk 覆盖的非排除 item避免识别出的文字凭空消失。
# 注意 heading 会进入 meta.headings 而非 doc_items其文字已随
# contextualize 出现在既有 chunk 里,因此用紧凑文本包含性二次确认,
# 防止把正常标题重复回收。
chunk_haystack = _compact_with_offsets(
"\n".join(chunk.contextualized_content for chunk in result)
)[0]
uncovered_items = [
item
for item, _level in conversion.document.iterate_items()
if item.label not in excluded
and str(item.self_ref) not in covered_refs
and (getattr(item, "text", None) or "").strip()
and _compact_with_offsets(str(item.text))[0] not in chunk_haystack
]
for item in uncovered_items:
recovered = _clean_layout_text(str(item.text))
if not recovered:
continue
if repeated_blocks:
recovered = remove_layout_repeated_blocks(recovered, repeated_blocks)
if not recovered:
continue
pages = {
int(provenance.page_no) for provenance in item.prov or ()
}
bboxes = [
{
"page": int(provenance.page_no),
"left": float(provenance.bbox.l),
"top": float(provenance.bbox.t),
"right": float(provenance.bbox.r),
"bottom": float(provenance.bbox.b),
"origin": str(provenance.bbox.coord_origin.value),
}
for provenance in item.prov or ()
]
logger.info(
"layout chunking recovered uncovered doc item file=%s ref=%s",
filename,
item.self_ref,
)
result.append(
DocumentChunk(
original_content=recovered,
contextualized_content=recovered,
source_start=None,
source_end=None,
source_start_line=None,
source_end_line=None,
token_count=len(_tokenizer().encode(recovered)),
heading_path=(),
source_pages=tuple(sorted(pages)),
doc_item_refs=(str(item.self_ref),),
source_bboxes=tuple(bboxes),
)
)
return result