haiku.rag/haiku_rag_slim/haiku/rag/client/search.py
Yiorgis Gozadinos 569947b28d
Separate fetching from ranking in search
`search` fetched, reranked and truncated in one pass, with the reranker's
over-fetch and the reranking itself interleaved in the same branch. Searching
several databases needs to fuse their candidates before anything is ranked, so
the phases have to be separable.

`_fetch` returns one database's candidates, over-fetching only when a reranker
will re-order them. `_rank` orders and cuts them, leaving an image query's vector
ranking alone since there is no text for a reranker to score against. The
over-fetch multiplier is named rather than a literal 10 at the point of use.

Both check the query type before reading `client.reranker`, which is a
cached_property that builds the reranker on first access and loads model weights
for a local one. An image query never used it and must not start.

No behaviour change: the same suite passes, and the search outputs digest
identically to before.
2026-08-24 10:03:45 +03:00

458 lines
17 KiB
Python

import base64
from collections.abc import Sequence
from typing import TYPE_CHECKING
from haiku.rag.store.models.chunk import Chunk, SearchResult, SearchType
from haiku.rag.store.models.document_item import PICTURE_REF_PREFIX
if TYPE_CHECKING:
from PIL import Image as PILImage
from haiku.rag.client import HaikuRAG
async def search(
client: "HaikuRAG",
query: "str | bytes | PILImage.Image",
limit: int | None = None,
search_type: SearchType | None = None,
filter: str | None = None,
include_images: bool = True,
) -> list[SearchResult]:
"""Search for relevant chunks with optional reranking.
Args:
client: The HaikuRAG client (provides config + chunk repository).
query: Text (``str``) or image (``bytes`` / ``PIL.Image.Image``).
Image queries require a multimodal embedder and run vector-only.
limit: Maximum number of results to return. Defaults to config.search.limit.
search_type: "vector", "fts", or "hybrid".
Applicable only for text queries, where the default is "hybrid".
filter: Optional SQL WHERE clause to filter documents before searching chunks.
include_images: When True, populate ``SearchResult.image_data`` with
base64 picture bytes for picture-labeled chunks.
Returns:
List of SearchResult objects ordered by relevance.
"""
if limit is None:
limit = client._config.search.limit
candidates = await _fetch(client, query, limit, search_type, filter)
chunk_results = await _rank(client, query, candidates, limit)
results = [SearchResult.from_chunk(chunk, score) for chunk, score in chunk_results]
results = _dedup_picture_chunks(results)
if include_images:
await _populate_image_data(client, results)
return results
# Candidates per requested result when a reranker will re-order them.
_RERANK_OVERFETCH = 10
async def _fetch(
client: "HaikuRAG",
query: "str | bytes | PILImage.Image",
limit: int,
search_type: SearchType | None,
filter: str | None,
) -> list[tuple[Chunk, float]]:
"""Candidates from one database, ranked by that database.
Over-fetches when a reranker will re-order them. Separate from `_rank` so a
caller searching several databases can fuse their candidates before anything
is ranked or enriched.
"""
if isinstance(query, str):
if search_type is None:
search_type = "hybrid"
fetch_limit = limit * _RERANK_OVERFETCH if client.reranker else limit
return await client.chunk_repository.search(
query, fetch_limit, search_type, filter
)
embedder = client.embedder
if not embedder.supports_images:
raise ValueError(
"Image queries require a multimodal embedder. Set "
"embeddings.model.multimodal: true on a vllm, voyageai, or cohere "
"model."
)
query_vector = await embedder.embed_image(query)
return await client.chunk_repository.search(
query="",
limit=limit,
filter=filter,
query_vector=query_vector,
)
async def _rank(
client: "HaikuRAG",
query: "str | bytes | PILImage.Image",
candidates: list[tuple[Chunk, float]],
limit: int,
) -> list[tuple[Chunk, float]]:
"""Order candidates and cut them to `limit`.
An image query carries no text for a reranker to score against, so its
candidates keep the vector ranking. Its type is checked before
`client.reranker`, which builds the reranker on first access and loads model
weights for a local one.
"""
if not isinstance(query, str):
return candidates[:limit]
reranker = client.reranker
if reranker is None:
return candidates[:limit]
chunks = [chunk for chunk, _ in candidates]
if client._config.reranking.multimodal:
await _attach_picture_data(client, chunks)
return await reranker.rerank(query, chunks, top_n=limit)
async def _attach_picture_data(client: "HaikuRAG", chunks: list[Chunk]) -> None:
"""Attach picture bytes to synthetic picture chunks in-place, so a
multimodal reranker can score the pixels instead of just the chunk's
description text.
One query however many documents the candidates span, which matters here
more than anywhere: reranking fetches `limit * 10` candidates.
"""
by_doc: dict[str, list[tuple[Chunk, str]]] = {}
for chunk in chunks:
if chunk.document_id is None:
continue
refs = chunk.get_chunk_metadata().doc_item_refs
if len(refs) == 1 and refs[0].startswith(PICTURE_REF_PREFIX):
by_doc.setdefault(chunk.document_id, []).append((chunk, refs[0]))
bytes_by_document, _ = await client.document_item_repository.get_pictures_grouped(
{doc_id: [ref for _, ref in pairs] for doc_id, pairs in by_doc.items()}
)
for doc_id, doc_chunks in by_doc.items():
bytes_by_ref = bytes_by_document.get(doc_id, {})
for chunk, ref in doc_chunks:
data = bytes_by_ref.get(ref)
if data:
chunk._picture_data = data
def _dedup_picture_chunks(results: list[SearchResult]) -> list[SearchResult]:
"""Collapse duplicate picture-only chunks to one result per ``self_ref``.
A single picture can produce two chunks for the same self_ref: one whose
vector is the text embedding of the picture's description, and one whose
vector is the image embedding of the picture's bytes. Both can rank for
the same query. When two results share a single picture self_ref as
their only ref, keep the higher-scoring one. Wider chunks that span the
picture plus surrounding items pass through untouched.
"""
seen: dict[tuple[str | None, str], int] = {}
keep: list[bool] = [True] * len(results)
for i, r in enumerate(results):
if len(r.doc_item_refs) == 1 and r.doc_item_refs[0].startswith(
PICTURE_REF_PREFIX
):
key = (r.document_id, r.doc_item_refs[0])
prior = seen.get(key)
if prior is None:
seen[key] = i
elif r.score > results[prior].score:
keep[prior] = False
seen[key] = i
else:
keep[i] = False
return [r for r, k in zip(results, keep) if k]
async def _populate_image_data(client: "HaikuRAG", results: list[SearchResult]) -> None:
"""Attach base64 picture bytes to ``SearchResult.image_data`` in-place.
A result carries a picture when its refs include the picture directly, or
when they include the picture's caption — the common case where a prose
chunk carrying a figure's caption ranks while the picture is its own chunk.
Costs a fixed number of reads however many documents the result set spans.
"""
repo = client.document_item_repository
by_doc: dict[str, list[SearchResult]] = {}
for r in results:
if r.document_id and r.doc_item_refs:
by_doc.setdefault(r.document_id, []).append(r)
if not by_doc:
return
refs_by_document = {
doc_id: list({ref for r in doc_results for ref in r.doc_item_refs})
for doc_id, doc_results in by_doc.items()
}
captions_to_pictures = await repo.get_caption_picture_refs_grouped(refs_by_document)
# Which pictures each result wants, and which to fetch per document.
result_pictures: list[tuple[SearchResult, list[str]]] = []
wanted: dict[str, list[str]] = {}
for doc_id, doc_results in by_doc.items():
caption_to_picture = captions_to_pictures.get(doc_id, {})
seen: set[str] = set()
for r in doc_results:
pictures: list[str] = []
for ref in r.doc_item_refs:
picture = (
ref
if ref.startswith(PICTURE_REF_PREFIX)
else caption_to_picture.get(ref)
)
if picture and picture not in pictures:
pictures.append(picture)
if pictures:
result_pictures.append((r, pictures))
for picture in pictures:
if picture not in seen:
wanted.setdefault(doc_id, []).append(picture)
seen.add(picture)
if not wanted:
return
bytes_by_document, captions_by_document = await repo.get_pictures_grouped(
wanted, with_text=True
)
if not bytes_by_document:
return
for r, pictures in result_pictures:
bytes_by_ref = bytes_by_document.get(r.document_id or "", {})
captions_by_ref = captions_by_document.get(r.document_id or "", {})
attached: dict[str, str] = {}
captions: dict[str, str] = {}
for ref in pictures:
blob = bytes_by_ref.get(ref)
if blob:
attached[ref] = base64.b64encode(blob).decode("ascii")
caption = captions_by_ref.get(ref)
if caption:
captions[ref] = caption
if attached:
r.image_data = attached
if captions:
r.picture_captions = captions
async def expand_context(
client: "HaikuRAG",
search_results: list[SearchResult],
) -> list[SearchResult]:
"""Expand search results with surrounding content from the document.
Uses the document_items table for section-bounded expansion.
See haiku.rag.context for the algorithm description.
Results without doc_item_refs pass through unexpanded. This happens when
chunks were created without docling metadata (e.g., custom chunks passed
to import_document).
"""
from haiku.rag.context import expand_with_items, window_for
max_chars = client._config.search.max_context_chars
# Group by document_id for efficient processing
document_groups: dict[str | None, list[SearchResult]] = {}
for result in search_results:
doc_id = result.document_id
if doc_id not in document_groups:
document_groups[doc_id] = []
document_groups[doc_id].append(result)
expanded_results = []
expandable = {
doc_id: doc_results
for doc_id, doc_results in document_groups.items()
if doc_id is not None and any(r.doc_item_refs for r in doc_results)
}
repo = client.document_item_repository
positions_by_document = await repo.resolve_refs_grouped(
{
doc_id: [ref for r in doc_results for ref in r.doc_item_refs]
for doc_id, doc_results in expandable.items()
}
)
windows = {
doc_id: window_for(positions)
for doc_id, positions in positions_by_document.items()
if positions
}
items_by_document = await repo.get_items_in_ranges(windows)
# In document_groups order: the score sort below is stable, so assembling
# expandable and passthrough documents in separate passes would reorder
# equal-scored results.
for doc_id, doc_results in document_groups.items():
if doc_id not in expandable:
expanded_results.extend(doc_results)
continue
expanded_results.extend(
expand_with_items(
doc_results,
max_chars,
positions_by_document.get(doc_id, {}),
items_by_document.get(doc_id, []),
)
)
expanded_results.sort(key=lambda r: r.score, reverse=True)
# image_data and picture_captions are preserved through expansion by
# expand_with_items — we deliberately do not re-attach bytes for refs
# introduced by section expansion, so the multimodal payload stays
# bounded by what was originally retrieved.
return expanded_results
async def visualize_chunk(
client: "HaikuRAG",
chunk: "Chunk | Sequence[Chunk]",
refs: list[str] | None = None,
expand: bool = True,
) -> list:
"""Render page images with bounding box highlights for one or more chunks.
When ``refs`` is given (the ``doc_item_refs`` of the citation, i.e. the
exact items the model saw), bounding boxes are resolved from them directly
so the visualization matches the cited context precisely. Otherwise, with
``expand=True`` (default) the chunks' context is re-expanded to recover the
surrounding section; with ``expand=False`` only the chunks' own items are
drawn, so the visualization shows just the retrieved chunk with no context.
The chunks' own items draw in a strong highlight; the remaining items draw
fainter, so the matched content stands out from its surrounding context.
Chunks from a different document than the first are ignored.
Returns a list of PIL Image objects, one per page with bounding boxes.
Empty list if no bounding boxes or page images available.
"""
from copy import deepcopy
from PIL import ImageDraw
from haiku.rag.store.models.chunk import ChunkMetadata
chunks = [chunk] if isinstance(chunk, Chunk) else list(chunk)
if not chunks:
return []
document_id = chunks[0].document_id
if not document_id:
return []
chunks = [c for c in chunks if c.document_id == document_id]
doc = await client.document_repository.get_docling_data(document_id)
if not doc:
return []
docling_doc = doc.get_docling_document()
if not docling_doc:
return []
matched_refs = {r for c in chunks for r in c.get_chunk_metadata().doc_item_refs}
if refs is not None:
all_refs = list(refs)
elif not expand:
# Chunk-only: draw just the retrieved chunks' own items, no context.
all_refs = list(matched_refs)
else:
# No stored context: re-expand the chunks to recover their section.
search_results = [
SearchResult(
content=c.content,
score=1.0,
chunk_id=c.id,
document_id=c.document_id,
doc_item_refs=meta.doc_item_refs,
page_numbers=meta.page_numbers,
)
for c in chunks
if (meta := c.get_chunk_metadata()).doc_item_refs
]
if search_results:
expanded = await expand_context(client, search_results)
all_refs = []
for result in expanded:
all_refs.extend(r for r in result.doc_item_refs if r not in all_refs)
if not all_refs:
all_refs = [r for sr in search_results for r in sr.doc_item_refs]
else:
all_refs = list(chunks[0].get_chunk_metadata().doc_item_refs)
matched_draw = [r for r in all_refs if r in matched_refs]
swept_refs = [r for r in all_refs if r not in matched_refs]
matched_boxes = ChunkMetadata(doc_item_refs=matched_draw).resolve_bounding_boxes(
docling_doc
)
swept_boxes = ChunkMetadata(doc_item_refs=swept_refs).resolve_bounding_boxes(
docling_doc
)
if not matched_boxes and not swept_boxes:
return []
# Group bounding boxes by page; swept boxes first so matched draw on top
boxes_by_page: dict[int, list] = {}
for bbox, is_matched in [(b, False) for b in swept_boxes] + [
(b, True) for b in matched_boxes
]:
if bbox.page_no not in boxes_by_page:
boxes_by_page[bbox.page_no] = []
boxes_by_page[bbox.page_no].append((bbox, is_matched))
# Load only the needed page images
pages_doc = await client.document_repository.get_pages_data(document_id)
if not pages_doc:
return []
page_images = pages_doc.get_page_images(list(boxes_by_page.keys()))
images = []
for page_no in sorted(boxes_by_page.keys()):
if page_no not in page_images:
continue
page = page_images[page_no]
if page.image is None or page.image.pil_image is None:
continue
pil_image = page.image.pil_image
page_height = page.size.height
# Scale factor: image pixels vs document coordinates
scale_x = pil_image.width / page.size.width
scale_y = pil_image.height / page.size.height
image = deepcopy(pil_image)
draw = ImageDraw.Draw(image, "RGBA")
for bbox, is_matched in boxes_by_page[page_no]:
# Document coords are bottom-left origin; PIL uses top-left
x0 = bbox.left * scale_x
y0 = (page_height - bbox.top) * scale_y
x1 = bbox.right * scale_x
y1 = (page_height - bbox.bottom) * scale_y
if y0 > y1:
y0, y1 = y1, y0
if is_matched:
fill_color = (255, 150, 0, 55) # Orange, matched content
outline_color = (240, 130, 0, 150) # Orange outline
else:
fill_color = (255, 255, 0, 40) # Yellow, surrounding context
outline_color = (255, 165, 0, 100)
draw.rectangle([(x0, y0), (x1, y1)], fill=fill_color, outline=None)
draw.rectangle([(x0, y0), (x1, y1)], outline=outline_color, width=1)
images.append(image)
return images