ReMe/reme2/component/file_parser/linked_file_parser.py
jinli.yl cca6cce0e0 up
2026-05-14 12:17:51 +08:00

584 lines
19 KiB
Python

"""Markdown file parser — frontmatter + wikilink graph + AST tree chunks.
Each chunk carries the **complete heading skeleton** of the document
with its content inlined under the section that owns it; other sections
appear as bare headings so the reader always sees a full document map.
Pipeline: build mistletoe AST → ``MdNode`` tree (sections nest by
heading level) → recursive chunk (try whole subtree; on overflow walk
children — body siblings pack as a run, subsections recurse). Leaf
blocks (table / code / list / paragraph) split on internal boundaries
and each piece is annotated ``[Part X/N]``.
"""
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any
import frontmatter
from .base_file_parser import BaseFileParser
from ..component_registry import R
from ..file_graph import BaseFileGraph
from ...enumeration import ComponentEnum
from ...schema import (
FileChunk,
FileLink,
FileFrontMatter,
FileNode,
)
from ...utils import hash_text
from ...utils.wikilink_resolver import text_to_links
# -- AST node + helpers ---------------------------------------------------
@dataclass
class MdNode:
"""``root`` (top-level container) / ``section`` (heading + children
until next equal-or-shallower heading) / ``body`` (one mistletoe
block, ``block`` keeps the original).
``text`` is the rendered subtree (own heading excluded for sections;
set by build for bodies, by ``_finalize`` for sections/root).
``desc_toc`` caches the section-only DFS outline of descendants
(own heading excluded), used as the TOC suffix when emitting chunks
inside a section. Line ranges span the full subtree.
"""
kind: str # "root" | "section" | "body"
heading: str | None = None
level: int = 0
children: list["MdNode"] = field(default_factory=list)
block: Any = None
text: str = ""
start_line: int = 0
end_line: int = 0
desc_toc: str = ""
def _heading_text(node: Any, renderer) -> str:
"""Heading text without `#` markers (for outline)."""
rendered = renderer.render(node).rstrip("\n")
if rendered.startswith("#"):
return rendered.lstrip("#").strip()
return rendered.split("\n", 1)[0].strip()
def _dedup_links(links: list[FileLink]) -> list[FileLink]:
"""Drop links with identical (path, predicate, anchor); preserve order."""
seen: set[tuple] = set()
out: list[FileLink] = []
for link in links:
key = (link.path, link.predicate, link.anchor)
if key not in seen:
seen.add(key)
out.append(link)
return out
def _finalize(n: MdNode) -> None:
"""Bottom-up post-build pass: propagate line ranges up from children,
populate ``n.text`` (rendered subtree, own heading excluded for
sections; bodies already set by build), and ``n.desc_toc`` (DFS
section outline of descendants — own heading excluded; used as the
TOC suffix when emitting body chunks inside this section).
"""
parts: list[str] = []
desc_lines: list[str] = []
for c in n.children:
_finalize(c)
if c.kind == "section":
heading = f"{'#' * c.level} {c.heading or ''}"
parts.append(f"{heading}\n\n{c.text}" if c.text else heading)
desc_lines.append(f"{heading}\n\n{c.desc_toc}" if c.desc_toc else heading)
elif c.text:
parts.append(c.text)
if n.children:
first = n.children[0].start_line
n.start_line = min(n.start_line, first) if n.start_line else first
n.end_line = max(c.end_line for c in n.children)
elif n.end_line < n.start_line:
n.end_line = n.start_line
if n.kind != "body":
n.text = "\n\n".join(parts)
n.desc_toc = "\n\n".join(desc_lines)
def _toc_join(*parts: str) -> str:
"""Concatenate TOC fragments with ``\\n\\n``, skipping empty ones."""
return "\n\n".join(p for p in parts if p)
def _subtree_toc(n: MdNode) -> str:
"""Section's heading + descendants TOC — its contribution to a parent's
``desc_toc``. For root (no own heading) this is just ``desc_toc``."""
if n.kind != "section" or n.heading is None:
return n.desc_toc
heading = f"{'#' * n.level} {n.heading}"
return f"{heading}\n\n{n.desc_toc}" if n.desc_toc else heading
# -- Parser ---------------------------------------------------------------
@R.register("md")
class LinkedFileParser(BaseFileParser):
"""Markdown parser: frontmatter + wikilink edges + full-skeleton chunks."""
def __init__(
self,
encoding: str = "utf-8",
chunk_chars: int = 2000,
embed_toc: bool = True,
file_graph: str = "default",
**kwargs,
):
super().__init__(**kwargs)
self.encoding = encoding
self.chunk_chars = max(100, chunk_chars)
self.embed_toc = embed_toc
self._file_graph_name: str = file_graph
def _resolve_file_graph(self) -> BaseFileGraph | None:
"""Lazily fetch the configured file_graph from app_context.
Lazy (rather than ``_start``) so the parser doesn't impose a
component start-order constraint, and so tests can construct
the parser without a graph wired up.
"""
if self.app_context is None:
return None
graphs = self.app_context.components.get(ComponentEnum.FILE_GRAPH, {})
graph = graphs.get(self._file_graph_name)
if graph is None:
return None
if not isinstance(graph, BaseFileGraph):
raise TypeError(
f"Expected BaseFileGraph, got {type(graph).__name__}",
)
return graph
async def parse(self, path: str | Path) -> tuple[FileNode, list[FileChunk]]:
from mistletoe.markdown_renderer import MarkdownRenderer
from mistletoe.block_token import Document
file_path = Path(path)
post = frontmatter.loads(file_path.read_text(encoding=self.encoding))
chunks: list[FileChunk] = []
if post.content and post.content.strip():
with MarkdownRenderer() as renderer:
tree = self._build_tree(Document(post.content), renderer)
chunks = self._chunk_node(tree, "", "", str(file_path), renderer)
links: list[FileLink] = []
graph = self._resolve_file_graph()
if graph is not None:
links = _dedup_links(await text_to_links(graph, post.content))
node = FileNode(
path=str(file_path),
st_mtime=file_path.stat().st_mtime,
chunk_ids=[chunk.id for chunk in chunks],
links=links,
front_matter=FileFrontMatter(**dict(post.metadata)),
)
return node, chunks
def _build_tree(self, doc: Any, renderer) -> MdNode:
"""Heading-level stack folds mistletoe's flat children into nested
sections; non-headings attach as ``body`` to the current section
(or root before the first heading)."""
from mistletoe.markdown_renderer import BlankLine
from mistletoe.block_token import (
Heading,
SetextHeading,
)
root = MdNode(kind="root", start_line=1, end_line=1)
stack: list[MdNode] = [root]
for child in doc.children or []:
if isinstance(child, BlankLine):
continue
line = getattr(child, "line_number", None) or stack[-1].start_line
if isinstance(child, (Heading, SetextHeading)):
level = max(1, getattr(child, "level", 1))
while len(stack) > 1 and stack[-1].level >= level:
stack.pop()
sec = MdNode(
kind="section",
heading=_heading_text(child, renderer),
level=level,
start_line=line,
)
stack[-1].children.append(sec)
stack.append(sec)
continue
rendered = renderer.render(child).rstrip("\n")
if not rendered:
continue
stack[-1].children.append(
MdNode(
kind="body",
block=child,
text=rendered,
start_line=line,
end_line=line + rendered.count("\n"),
),
)
_finalize(root)
return root
# -- Recursive chunker ------------------------------------------------
def _chunk_node(
self,
node: MdNode,
before: str,
after: str,
path: str,
renderer,
) -> list[FileChunk]:
"""Try the whole subtree; on overflow split (leaf) or descend.
``before``/``after`` are TOC fragments that bracket each emitted
chunk's content (chunk text = ``before + content + after``).
As we descend, the prefix grows with section headings already
passed and the suffix shrinks correspondingly.
"""
if not node.text:
return []
if node.kind == "section":
heading_line = f"{'#' * node.level} {node.heading or ''}"
before_self = _toc_join(before, heading_line)
else:
before_self = before
if len(node.text) <= self.chunk_chars:
return [
self._make_chunk(
before_self,
node.text,
after,
node.start_line,
node.end_line,
path,
),
]
if node.kind == "body":
return self._split_leaf(node, before, after, path, renderer)
after_inside = _toc_join(node.desc_toc, after)
sub_tocs = [_subtree_toc(c) for c in node.children if c.kind == "section"]
chunks: list[FileChunk] = []
accumulated = before_self
sec_idx = 0
run: list[MdNode] = []
for c in node.children:
if c.kind == "section":
if run:
chunks.extend(
self._chunk_body_run(
run,
before_self,
after_inside,
path,
renderer,
),
)
run = []
remaining = "\n\n".join(sub_tocs[sec_idx + 1 :])
chunks.extend(
self._chunk_node(
c,
accumulated,
_toc_join(remaining, after),
path,
renderer,
),
)
accumulated = _toc_join(accumulated, sub_tocs[sec_idx])
sec_idx += 1
else:
run.append(c)
if run:
chunks.extend(
self._chunk_body_run(
run,
before_self,
after_inside,
path,
renderer,
),
)
return chunks
def _chunk_body_run(
self,
run: list[MdNode],
before: str,
after: str,
path: str,
renderer,
) -> list[FileChunk]:
"""Greedy-pack consecutive body siblings under the same TOC slot.
No ``[Part X/N]`` markers — distinct blocks, not a leaf split.
Oversized single body recurses to ``_split_leaf``."""
composite_size = sum(len(b.text) for b in run) + 2 * max(0, len(run) - 1)
if composite_size <= self.chunk_chars:
return [
self._make_chunk(
before,
"\n\n".join(b.text for b in run),
after,
run[0].start_line,
run[-1].end_line,
path,
),
]
chunks: list[FileChunk] = []
bucket: list[MdNode] = []
bucket_chars = 0
def flush() -> None:
nonlocal bucket, bucket_chars
if not bucket:
return
chunks.append(
self._make_chunk(
before,
"\n\n".join(b.text for b in bucket),
after,
bucket[0].start_line,
bucket[-1].end_line,
path,
),
)
bucket = []
bucket_chars = 0
for body in run:
if len(body.text) > self.chunk_chars:
flush()
chunks.extend(self._split_leaf(body, before, after, path, renderer))
continue
sep = 2 if bucket else 0
if bucket_chars + sep + len(body.text) > self.chunk_chars:
flush()
sep = 0
bucket.append(body)
bucket_chars += sep + len(body.text)
flush()
return chunks
# -- Leaf splitters: build (text, start, end) units, hand off to packer
def _split_leaf(
self,
body: MdNode,
before: str,
after: str,
path: str,
renderer,
) -> list[FileChunk]:
from mistletoe.block_token import (
CodeFence,
List,
Table,
)
block = body.block
if isinstance(block, Table):
return self._split_table(body, before, after, path)
if isinstance(block, CodeFence):
return self._split_code(body, before, after, path)
if isinstance(block, List):
return self._split_list(body, before, after, path, renderer)
return self._split_lines(body, before, after, path)
def _split_table(
self,
body: MdNode,
before: str,
after: str,
path: str,
) -> list[FileChunk]:
"""Repeat header + separator on every chunk."""
from mistletoe.block_token import TableRow
lines = body.text.split("\n")
header, data = "\n".join(lines[:2]), lines[2:]
rows = [r for r in (body.block.children or []) if isinstance(r, TableRow)]
base = body.start_line + 2
def line_of(i: int) -> int:
return rows[i].line_number if i < len(rows) and rows[i].line_number else base + i
units = [(text, line_of(i), line_of(i)) for i, text in enumerate(data)]
return self._emit_packed(
units,
before,
after,
path,
joiner="\n",
wrap=f"{header}\n{{inner}}",
)
def _split_code(
self,
body: MdNode,
before: str,
after: str,
path: str,
) -> list[FileChunk]:
"""Repeat fence opener + closer on every chunk."""
code = body.block
indent = " " * (code.indentation or 0)
fence = f"{indent}{code.delimiter}"
opener = f"{fence}{code.info_string or ''}"
raw = (code.children[0].content if code.children else "").rstrip("\n")
if not raw:
return []
start = body.start_line + 1
units = [(indent + ln, start + i, start + i) for i, ln in enumerate(raw.split("\n"))]
return self._emit_packed(
units,
before,
after,
path,
joiner="\n",
wrap=f"{opener}\n{{inner}}\n{fence}",
allow_empty=True,
)
def _split_list(
self,
body: MdNode,
before: str,
after: str,
path: str,
renderer,
) -> list[FileChunk]:
"""Pack list items; oversized items emit alone (overflow accepted)."""
from mistletoe.block_token import ListItem
items = [c for c in (body.block.children or []) if isinstance(c, ListItem)]
if not items:
return self._split_lines(body, before, after, path)
units: list[tuple[str, int, int]] = []
for it in items:
text = renderer.render(it).rstrip("\n")
if not text:
continue
line = it.line_number or body.start_line
units.append((text, line, line + text.count("\n")))
return self._emit_packed(
units,
before,
after,
path,
joiner="\n",
wrap="{inner}",
)
def _split_lines(
self,
body: MdNode,
before: str,
after: str,
path: str,
) -> list[FileChunk]:
"""Last-resort line-greedy split for paragraphs / quotes / html."""
start = body.start_line
units = [(line, start + i, start + i) for i, line in enumerate(body.text.split("\n"))]
return self._emit_packed(
units,
before,
after,
path,
joiner="\n",
wrap="{inner}",
)
def _emit_packed(
self,
units: list[tuple[str, int, int]],
before: str,
after: str,
path: str,
joiner: str,
wrap: str,
allow_empty: bool = False,
) -> list[FileChunk]:
"""Greedy-pack units into ``wrap`` envelopes; emit each piece.
Envelope (table header, code fence) counts against ``chunk_chars``;
TOC (when on) is additive prefix/suffix downstream. Oversized
units overflow rather than truncate. Multi-piece outputs get
``[Part X/N]`` markers; single pieces don't.
"""
envelope = len(wrap.replace("{inner}", ""))
budget = max(64, self.chunk_chars - envelope)
sep_len = len(joiner)
parts: list[tuple[str, int, int]] = []
bucket: list[tuple[str, int, int]] = []
bucket_chars = 0
def flush() -> None:
nonlocal bucket, bucket_chars
if not bucket:
return
inner = joiner.join(t for t, _, _ in bucket)
parts.append((inner, bucket[0][1], bucket[-1][2]))
bucket = []
bucket_chars = 0
for text, s, e in units:
if not text and not allow_empty:
continue
sep = sep_len if bucket else 0
if bucket_chars + sep + len(text) > budget:
flush()
sep = 0
bucket.append((text, s, e))
bucket_chars += sep + len(text)
flush()
total = len(parts)
return [
self._make_chunk(
before,
(
f"[Part {idx}/{total}]\n\n{wrap.replace('{inner}', inner)}"
if total > 1
else wrap.replace("{inner}", inner)
),
after,
s,
e,
path,
)
for idx, (inner, s, e) in enumerate(parts, 1)
]
# -- Emit -------------------------------------------------------------
def _make_chunk(
self,
before: str,
content: str,
after: str,
start_line: int,
end_line: int,
path: str,
) -> FileChunk:
"""Build one ``FileChunk`` — text is ``before + content + after``
when ``embed_toc``, otherwise just ``content``."""
text = _toc_join(before, content, after) if self.embed_toc else content
return FileChunk(
path=path,
start_line=start_line,
end_line=end_line,
text=text,
).set_hash_id()