Files
ragflow/rag/advanced_rag/knowlege_compile/raptor.py
2026-07-06 21:09:35 +08:00

983 lines
43 KiB
Python

#
# Copyright 2024 The InfiniFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import asyncio
from dataclasses import dataclass, field
import logging
import re
import numpy as np
from sklearn.cluster import AgglomerativeClustering
from sklearn.mixture import GaussianMixture
from api.db.services.task_service import has_canceled
from common.connection_utils import timeout
from common.exceptions import TaskCanceledException
from common.token_utils import truncate
from rag.graphrag.utils import (
chat_limiter,
get_embed_cache,
get_llm_cache,
set_embed_cache,
set_llm_cache,
)
from common.misc_utils import thread_pool_exec
from rag.utils.raptor_utils import (
AHC_CLUSTERING_METHOD,
GMM_CLUSTERING_METHOD,
PSI_TREE_BUILDER,
RAPTOR_TREE_BUILDER,
SUPPORTED_CLUSTERING_METHODS,
SUPPORTED_TREE_BUILDERS,
)
# Regularization added to GMM covariance diagonals; keeps components
# from collapsing on singleton/near-identical reduced points.
_GMM_REG_COVAR = 1e-4
@dataclass
class _PsiTreeNode:
"""Node used to represent the in-memory Psi merge tree."""
index: int
text: str = ""
embedding: np.ndarray | None = None
children: list["_PsiTreeNode"] = field(default_factory=list)
parent: "_PsiTreeNode | None" = None
# Original (leaf-level) chunk ids that contributed to this node. On
# a leaf this is a single-element list with the leaf's own id; on an
# internal node it's the order-preserving deduped union of its
# children's lists. Carried up through the merge tree so each
# produced summary knows which source chunks it covers.
source_chunk_ids: list[str] = field(default_factory=list)
class _PsiUnionFind:
"""Build parent links for the Psi merge tree from ranked leaf pairs."""
def __init__(self, n: int):
"""Initialize the union-find state for n leaf nodes."""
self._rank = [0 for _ in range(n)]
self._parent_chains = [[] for _ in range(n)]
self._node_ids = [[i] for i in range(n)]
self._tree = [-1 for _ in range(max(1, 2 * n - 1))]
self._next_id = n
@staticmethod
def _ordered_extend(target: list[int], values: list[int]):
"""Append unseen values while preserving their original order."""
for value in values:
if value not in target:
target.append(value)
def _find(self, i: int) -> list[int]:
"""Return the parent chain for a leaf, extending it lazily."""
chain = self._parent_chains[i]
if not chain or (len(chain) == 1 and chain[0] == i):
return [i]
if chain[0] == i:
self._ordered_extend(chain, self._find(chain[1]))
else:
self._ordered_extend(chain, self._find(chain[0]))
return chain
def _rank_bisect_right(self, chain: list[int], rank: int) -> int:
"""Return the first chain index whose rank is greater than rank."""
idx = 0
while idx < len(chain) and self._rank[chain[idx]] <= rank:
idx += 1
return idx
def _build(self, i: int, j: int, insert_point: int | None = None):
"""Record a merge edge in the compact parent array."""
if insert_point is not None:
parent_ids = self._node_ids[insert_point]
parent_rank_idx = self._rank[i] + 1
if parent_rank_idx >= len(parent_ids):
logging.warning(
"RAPTOR Psi union fallback: rank index %d is out of bounds for node %d with %d parent ids",
parent_rank_idx,
insert_point,
len(parent_ids),
)
parent_rank_idx = len(parent_ids) - 1
self._tree[self._node_ids[i][-1]] = parent_ids[parent_rank_idx]
return
self._tree[self._node_ids[i][-1]] = self._next_id
self._tree[self._node_ids[j][-1]] = self._next_id
self._node_ids[i].append(self._next_id)
self._next_id += 1
def union(self, i: int, j: int) -> bool:
"""Merge two ranked leaves and return whether a new edge was added."""
root_i = self._find(i)[-1]
root_j = self._find(j)[-1]
if root_i == root_j:
return False
if self._rank[root_i] < self._rank[root_j]:
if not self._parent_chains[root_j]:
self._parent_chains[root_j].append(root_j)
chain = self._parent_chains[j]
higher_rank_idx = self._rank_bisect_right(chain, self._rank[root_i])
if higher_rank_idx >= len(chain):
higher_rank_idx = len(chain) - 1
insert_point = chain[higher_rank_idx]
self._ordered_extend(self._parent_chains[root_i], chain[higher_rank_idx:])
self._build(root_i, root_j, insert_point=insert_point)
elif self._rank[root_i] > self._rank[root_j]:
if not self._parent_chains[root_i]:
self._parent_chains[root_i].append(root_i)
chain = self._parent_chains[i]
higher_rank_idx = self._rank_bisect_right(chain, self._rank[root_j])
if higher_rank_idx >= len(chain):
higher_rank_idx = len(chain) - 1
insert_point = chain[higher_rank_idx]
self._ordered_extend(self._parent_chains[root_j], chain[higher_rank_idx:])
self._build(root_j, root_i, insert_point=insert_point)
else:
if not self._parent_chains[root_i]:
self._parent_chains[root_i].append(root_i)
self._ordered_extend(self._parent_chains[root_j], self._parent_chains[i][-1:])
self._rank[root_i] += 1
self._build(root_i, root_j)
return True
@property
def tree(self) -> list[int]:
"""Return the compact child-to-parent array for constructed nodes."""
return self._tree[: self._next_id]
class RecursiveAbstractiveProcessing4TreeOrganizedRetrieval:
"""Build RAPTOR summary layers with the classic or Psi tree strategy."""
def __init__(
self,
max_cluster,
llm_model,
embd_model,
prompt,
max_token=512,
threshold=0.1,
small_layer_collapse=8,
max_errors=3,
tree_builder=RAPTOR_TREE_BUILDER,
clustering_method=GMM_CLUSTERING_METHOD,
psi_exact_max_leaves=4096,
psi_bucket_size=1024,
):
"""Configure RAPTOR summarization, clustering, and Psi limits."""
self._max_cluster = max_cluster
self._small_layer_collapse = small_layer_collapse
self._llm_model = llm_model
self._embd_model = embd_model
self._threshold = threshold
self._prompt = prompt
self._max_token = max_token
self._max_errors = max(1, max_errors)
self._error_count = 0
self._tree_builder = tree_builder or RAPTOR_TREE_BUILDER
if self._tree_builder not in SUPPORTED_TREE_BUILDERS:
raise ValueError(f"Unsupported RAPTOR tree builder: {self._tree_builder}")
self._clustering_method = clustering_method or GMM_CLUSTERING_METHOD
if self._clustering_method not in SUPPORTED_CLUSTERING_METHODS:
raise ValueError(f"Unsupported RAPTOR clustering method: {self._clustering_method}")
self._psi_exact_max_leaves = max(2, int(psi_exact_max_leaves or 4096))
self._psi_bucket_size = min(max(2, int(psi_bucket_size or 1024)), self._psi_exact_max_leaves)
def _check_task_canceled(self, task_id: str, message: str = ""):
"""Raise if the current document task was canceled."""
if task_id and has_canceled(task_id):
log_msg = f"Task {task_id} cancelled during RAPTOR {message}."
logging.info(log_msg)
raise TaskCanceledException(f"Task {task_id} was cancelled")
@timeout(60 * 20)
async def _chat(self, system, history, gen_conf):
"""Call the configured LLM with caching and short retries."""
cached = await thread_pool_exec(get_llm_cache, self._llm_model.llm_name, system, history, gen_conf)
if cached:
return cached
last_exc = None
for attempt in range(3):
try:
response = await self._llm_model.async_chat(system, history, gen_conf)
response = re.sub(r"^.*</think>", "", response, flags=re.DOTALL)
if response.find("**ERROR**") >= 0:
raise Exception(response)
await thread_pool_exec(set_llm_cache, self._llm_model.llm_name, system, response, history, gen_conf)
return response
except Exception as exc:
last_exc = exc
logging.warning("RAPTOR LLM call failed on attempt %d/3: %s", attempt + 1, exc)
if attempt < 2:
await asyncio.sleep(1 + attempt)
raise last_exc if last_exc else Exception("LLM chat failed without exception")
@timeout(20)
async def _embedding_encode(self, txt):
"""Encode text with the configured embedding model and cache result."""
response = await thread_pool_exec(get_embed_cache, self._embd_model.llm_name, txt)
if response is not None:
return response
embds, _ = await thread_pool_exec(self._embd_model.encode, [txt])
if len(embds) < 1 or len(embds[0]) < 1:
raise Exception("Embedding error: empty embeddings returned")
embds = embds[0]
await thread_pool_exec(set_embed_cache, self._embd_model.llm_name, txt, embds)
return embds
def _get_optimal_clusters(self, embeddings: np.ndarray, random_state: int, task_id: str = ""):
"""Choose the GMM cluster count with the lowest BIC score."""
max_clusters = min(self._max_cluster, len(embeddings))
if max_clusters <= 1:
logging.info(
"RAPTOR GMM: _get_optimal_clusters returning 1 (max_clusters=%s, embeddings=%d)",
max_clusters,
len(embeddings),
)
return 1
n_clusters = np.arange(1, max_clusters + 1)
bics = []
for n in n_clusters:
self._check_task_canceled(task_id, "get optimal clusters")
gm = GaussianMixture(n_components=n, random_state=random_state, covariance_type="diag", reg_covar=_GMM_REG_COVAR)
gm.fit(embeddings)
bics.append(gm.bic(embeddings))
optimal_clusters = n_clusters[np.argmin(bics)]
return int(optimal_clusters)
def _get_clusters_ahc(self, embeddings: np.ndarray, task_id: str = "") -> np.ndarray:
"""Cluster embeddings with Ward-linkage AHC and a dendrogram gap heuristic."""
n = len(embeddings)
if n <= 1:
return np.zeros(n, dtype=int)
if n == 2:
return np.arange(n)
self._check_task_canceled(task_id, "_get_clusters_ahc dendrogram")
full_clust = AgglomerativeClustering(
n_clusters=None,
distance_threshold=0,
compute_distances=True,
linkage="ward",
)
full_clust.fit(embeddings)
distances = full_clust.distances_
if len(distances) > 1:
gaps = np.diff(distances)
max_gap_idx = int(np.argmax(gaps))
n_clusters = max(1, min(n - max_gap_idx - 1, self._max_cluster))
else:
n_clusters = max(1, min(n, self._max_cluster))
if n_clusters <= 1:
logging.info("RAPTOR AHC: _get_clusters_ahc selected one cluster for %d embeddings", n)
return np.zeros(n, dtype=int)
logging.info("RAPTOR AHC: _get_clusters_ahc selected n_clusters=%d for %d embeddings", n_clusters, n)
self._check_task_canceled(task_id, "_get_clusters_ahc fit")
clustering = AgglomerativeClustering(n_clusters=n_clusters, linkage="ward")
return clustering.fit_predict(embeddings)
def _adjust_tree_nodes(self, embeddings: np.ndarray, labels: np.ndarray, max_iter: int = 5) -> np.ndarray:
"""Refine AHC assignments by reassigning nodes to nearest centroids."""
labels = labels.copy()
for _ in range(max_iter):
unique_labels = np.unique(labels)
if len(unique_labels) <= 1:
return labels
centroids = np.stack([embeddings[labels == lbl].mean(axis=0) for lbl in unique_labels])
diffs = embeddings[:, np.newaxis, :] - centroids[np.newaxis, :, :]
sq_dists = (diffs**2).sum(axis=2)
new_label_indices = np.argmin(sq_dists, axis=1)
new_labels = unique_labels[new_label_indices]
if np.array_equal(new_labels, labels):
break
unique_new = np.unique(new_labels)
remap = {old: new for new, old in enumerate(unique_new)}
labels = np.array([remap[int(lbl)] for lbl in new_labels])
return labels
def clustering(self, embeddings, random_state: int, task_id: str = "") -> tuple[int, list[int]]:
"""Cluster one RAPTOR layer and return contiguous labels."""
reduced_embeddings = np.asarray(embeddings, dtype=np.float64)
if len(reduced_embeddings) == 0:
return 0, []
# Degrade too much ??
n_neighbors = min(int((len(embeddings) - 1) ** 0.8), 100)
import umap
reduced_embeddings = umap.UMAP(
n_neighbors=max(2, n_neighbors),
n_components=min(12, len(embeddings) - 2),
metric="cosine",
).fit_transform(embeddings)
if self._clustering_method == AHC_CLUSTERING_METHOD:
logging.info("RAPTOR: using clustering_method=%s before _get_clusters_ahc", self._clustering_method)
raw_labels = self._get_clusters_ahc(reduced_embeddings, task_id=task_id)
raw_cluster_count = np.unique(raw_labels).size
logging.info("RAPTOR AHC: _get_clusters_ahc produced n_clusters=%d", raw_cluster_count)
if raw_cluster_count > 1:
labels = self._adjust_tree_nodes(reduced_embeddings, raw_labels)
adjusted_cluster_count = np.unique(labels).size
logging.info("RAPTOR AHC: _adjust_tree_nodes adjusted n_clusters=%d", adjusted_cluster_count)
else:
labels = raw_labels
logging.warning("RAPTOR AHC: _adjust_tree_nodes skipped because _get_clusters_ahc returned one cluster")
else:
n_clusters = int(self._get_optimal_clusters(reduced_embeddings, random_state, task_id=task_id))
if n_clusters <= 1:
labels = [0 for _ in range(len(reduced_embeddings))]
else:
gm = GaussianMixture(n_components=n_clusters, random_state=random_state, covariance_type="diag", reg_covar=_GMM_REG_COVAR)
gm.fit(reduced_embeddings)
probs = gm.predict_proba(reduced_embeddings)
labels = []
for prob in probs:
candidates = np.where(prob > self._threshold)[0]
labels.append(int(candidates[0]) if len(candidates) else int(np.argmax(prob)))
normalized_labels: list[int] = []
for label in labels:
if isinstance(label, np.ndarray):
normalized_labels.append(int(label[0]) if len(label) else 0)
else:
normalized_labels.append(int(label))
if len(normalized_labels) <= 0:
return 0, []
unique_labels = np.unique(normalized_labels)
if len(unique_labels) <= 1:
return 1, [0 for _ in normalized_labels]
label_map = {int(old): idx for idx, old in enumerate(unique_labels)}
return len(unique_labels), [label_map[label] for label in normalized_labels]
@timeout(60 * 20)
async def _summarize_texts(self, texts: list[str], callback=None, task_id: str = ""):
"""Summarize a cluster and return text plus embedding when successful."""
self._check_task_canceled(task_id, "summarization")
len_per_chunk = int((self._llm_model.max_length - self._max_token) / len(texts))
cluster_content = "\n".join([truncate(t, max(1, len_per_chunk)) for t in texts])
try:
async with chat_limiter:
self._check_task_canceled(task_id, "before LLM call")
cnt = await self._chat(
"You're a helpful assistant.\n\nHelp me with the following task.\n\n%s" % self._prompt.format(cluster_content=cluster_content),
[
{
"role": "user",
"content": "Beside the summarization, give a title at the first line of your summarization. Must be in the same language as the paragraphs.",
}
],
{"max_tokens": max(self._max_token, 512)}, # fix issue: #10235
)
cnt = re.sub(
"(······\n由于长度的原因,回答被截断了,要继续吗?|For the content length reason, it stopped, continue?)",
"",
cnt,
)
logging.debug(f"SUM: {cnt}")
self._check_task_canceled(task_id, "before embedding")
embds = await self._embedding_encode(cnt)
return cnt.split("\n")[0], cnt, embds
except TaskCanceledException:
raise
except Exception as exc:
self._error_count += 1
warn_msg = f"[RAPTOR] Skip cluster ({len(texts)} chunks) due to error: {exc}"
logging.warning(warn_msg)
if callback:
callback(msg=warn_msg)
if self._error_count >= self._max_errors:
raise RuntimeError(f"RAPTOR aborted after {self._error_count} errors. Last error: {exc}") from exc
return None
@staticmethod
def _root(node: _PsiTreeNode) -> _PsiTreeNode:
"""Return the current root for a Psi tree node."""
while node.parent is not None:
node = node.parent
return node
def _rank_leaf_pairs(self, leaves: list[_PsiTreeNode]) -> np.ndarray:
"""Rank all leaf pairs by original embedding-space cosine similarity."""
node_embeddings = np.asarray([leaf.embedding for leaf in leaves], dtype=np.float64)
node_embeddings = self._normalize_embeddings(node_embeddings)
similarities = node_embeddings @ node_embeddings.T
lower = np.tril_indices(len(leaves), -1)
ordered = np.argsort(similarities[lower], axis=0)[::-1]
return np.stack([lower[0][ordered], lower[1][ordered]], axis=-1)
@staticmethod
def _normalize_embeddings(node_embeddings: np.ndarray) -> np.ndarray:
"""Normalize embeddings for cosine operations while tolerating zero vectors."""
node_embeddings = np.asarray(node_embeddings, dtype=np.float64)
norms = np.linalg.norm(node_embeddings, axis=1, keepdims=True)
return node_embeddings / np.maximum(norms, 1e-12)
def _split_psi_buckets(self, nodes: list[_PsiTreeNode]) -> list[list[_PsiTreeNode]]:
"""Split large Psi inputs so exact pair ranking is bounded per bucket."""
if len(nodes) <= self._psi_bucket_size:
return [nodes]
node_embeddings = self._normalize_embeddings(np.asarray([node.embedding for node in nodes], dtype=np.float64))
groups = [np.arange(len(nodes), dtype=int)]
buckets = []
while groups:
group = np.asarray(groups.pop(), dtype=int)
if len(group) <= self._psi_bucket_size:
buckets.append(group.tolist())
continue
fanout = min(max(2, int(np.ceil(len(group) / self._psi_bucket_size))), len(group), 32)
group_embeddings = node_embeddings[group]
center_idx = np.linspace(0, len(group_embeddings) - 1, num=fanout, dtype=int)
centers = group_embeddings[center_idx].copy()
for _ in range(5):
labels = np.argmax(group_embeddings @ centers.T, axis=1)
for center_id in range(fanout):
mask = labels == center_id
if not np.any(mask):
continue
center = group_embeddings[mask].mean(axis=0)
norm = np.linalg.norm(center)
centers[center_id] = center / norm if norm > 0 else center
labels = np.argmax(group_embeddings @ centers.T, axis=1)
split_groups = [group[labels == center_id].tolist() for center_id in range(fanout)]
split_groups = [bucket for bucket in split_groups if bucket]
if len(split_groups) <= 1:
split_groups = [group[start : start + self._psi_bucket_size].tolist() for start in range(0, len(group), self._psi_bucket_size)]
groups.extend(split_groups)
buckets = [bucket for bucket in buckets if bucket]
buckets.sort(key=lambda bucket: (len(bucket), bucket[0]))
return [[nodes[idx] for idx in bucket] for bucket in buckets]
def _assign_prototype_embeddings(self, node: _PsiTreeNode) -> np.ndarray:
"""Assign mean child embeddings to internal Psi nodes for bucket-level ranking."""
if not node.children:
return np.asarray(node.embedding, dtype=np.float64)
embeddings = np.asarray([self._assign_prototype_embeddings(child) for child in node.children], dtype=np.float64)
node.embedding = embeddings.mean(axis=0)
return node.embedding
@staticmethod
def _iter_nodes(root: _PsiTreeNode):
"""Yield nodes in a Psi tree using a stack traversal."""
stack = [root]
while stack:
node = stack.pop()
yield node
stack.extend(node.children)
def _create_psi_parent(self, index: int, children: list[_PsiTreeNode]) -> _PsiTreeNode:
"""Create a parent node and attach the provided children to it."""
parent = _PsiTreeNode(index=index, children=children)
for child in children:
child.parent = parent
return parent
def _rebalance_psi_tree(self, root: _PsiTreeNode, next_index: int) -> tuple[_PsiTreeNode, int]:
"""Group oversized Psi tree nodes so fanout stays within max_cluster."""
max_children = max(2, int(self._max_cluster or 2))
def rebalance(node: _PsiTreeNode):
"""Recursively group children when a Psi node exceeds fanout."""
nonlocal next_index
for child in list(node.children):
rebalance(child)
while len(node.children) > max_children:
original_children = len(node.children)
grouped_children = []
for start in range(0, len(node.children), max_children):
batch = node.children[start : start + max_children]
if len(batch) == 1:
grouped_children.append(batch[0])
batch[0].parent = node
else:
grouped_children.append(self._create_psi_parent(next_index, batch))
grouped_children[-1].parent = node
next_index += 1
node.children = grouped_children
logging.info(
"RAPTOR Psi rebalance: node=%s children=%d grouped_to=%d max_cluster=%d",
node.index,
original_children,
len(grouped_children),
max_children,
)
rebalance(root)
return self._root(root), next_index
def _build_exact_psi_structure(
self,
nodes: list[_PsiTreeNode],
next_index: int,
task_id: str = "",
) -> tuple[_PsiTreeNode, int, int]:
"""Build an exact Psi subtree for a bounded node set."""
if len(nodes) == 1:
return nodes[0], next_index, 0
ranked_pairs = self._rank_leaf_pairs(nodes)
union_find = _PsiUnionFind(len(nodes))
merges = 0
for left_idx, right_idx in ranked_pairs:
self._check_task_canceled(task_id, "Psi tree construction")
if union_find.union(int(left_idx), int(right_idx)):
merges += 1
if merges == len(nodes) - 1:
break
local_nodes = {idx: node for idx, node in enumerate(nodes)}
tree = union_find.tree
children_by_parent = {}
for child_idx, parent_idx in enumerate(tree):
if child_idx not in local_nodes:
local_nodes[child_idx] = _PsiTreeNode(index=next_index)
next_index += 1
if parent_idx == -1:
continue
children_by_parent.setdefault(parent_idx, []).append(child_idx)
if parent_idx not in local_nodes:
local_nodes[parent_idx] = _PsiTreeNode(index=next_index)
next_index += 1
for parent_idx, child_indices in children_by_parent.items():
parent = local_nodes[parent_idx]
parent.children = [local_nodes[child_idx] for child_idx in child_indices]
for child in parent.children:
child.parent = parent
roots = [local_nodes[idx] for idx, parent_idx in enumerate(tree) if parent_idx == -1 and idx in local_nodes]
root = max(roots, key=lambda node: node.index)
return root, next_index, merges
def _build_bucketed_psi_structure(
self,
nodes: list[_PsiTreeNode],
next_index: int,
task_id: str = "",
) -> tuple[_PsiTreeNode, int, int]:
"""Build large Psi trees by exact-ranking bounded buckets, then bucket roots."""
buckets = self._split_psi_buckets(nodes)
logging.info(
"RAPTOR Psi bucketed build: nodes=%d buckets=%d bucket_size=%d exact_max_leaves=%d",
len(nodes),
len(buckets),
self._psi_bucket_size,
self._psi_exact_max_leaves,
)
bucket_roots = []
merges = 0
for bucket in buckets:
bucket_root, next_index, bucket_merges = self._build_psi_structure_from_nodes(bucket, next_index, task_id)
self._assign_prototype_embeddings(bucket_root)
bucket_roots.append(bucket_root)
merges += bucket_merges
if len(bucket_roots) == 1:
return bucket_roots[0], next_index, merges
root, next_index, root_merges = self._build_psi_structure_from_nodes(bucket_roots, next_index, task_id)
return root, next_index, merges + root_merges
def _build_psi_structure_from_nodes(
self,
nodes: list[_PsiTreeNode],
next_index: int,
task_id: str = "",
) -> tuple[_PsiTreeNode, int, int]:
"""Build Psi structure exactly for small sets and bucket large sets."""
if len(nodes) <= self._psi_exact_max_leaves:
return self._build_exact_psi_structure(nodes, next_index, task_id)
return self._build_bucketed_psi_structure(nodes, next_index, task_id)
def _build_psi_structure(self, chunks, task_id: str = "") -> tuple[_PsiTreeNode, list[_PsiTreeNode]]:
"""Build the Psi merge tree from original chunk embeddings.
``chunks`` is expected in the normalized 3-tuple shape
``(text, vec, source_chunk_ids)`` — leaves are seeded with
their own source ids, internal nodes get their ids set during
layer materialization in ``_build_psi_layers``.
"""
leaves = [
_PsiTreeNode(
index=i,
text=item[0],
embedding=np.asarray(item[1]),
source_chunk_ids=list(item[2] if len(item) > 2 else []),
)
for i, item in enumerate(chunks)
]
if len(leaves) == 1:
return leaves[0], leaves
root, next_index, merges = self._build_psi_structure_from_nodes(leaves, len(leaves), task_id)
root, _ = self._rebalance_psi_tree(root, next_index)
logging.info(
"RAPTOR Psi tree built: leaves=%d merges=%d root_fanout=%d",
len(leaves),
merges,
len(root.children),
)
return root, leaves
@staticmethod
def _psi_layers(root: _PsiTreeNode) -> dict[int, list[_PsiTreeNode]]:
"""Collect non-leaf Psi nodes by height for bottom-up summarization."""
layers = {}
def height(node: _PsiTreeNode) -> int:
"""Return node height while collecting internal nodes by layer."""
if not node.children:
return 0
node_height = max(height(child) for child in node.children) + 1
layers.setdefault(node_height, []).append(node)
return node_height
height(root)
return layers
async def _build_psi_layers(self, chunks, callback=None, task_id: str = ""):
"""Materialize Psi tree layers as summary chunks."""
layers = [(0, len(chunks))]
root, _ = self._build_psi_structure(chunks, task_id=task_id)
for layer_idx, (_, nodes) in enumerate(sorted(self._psi_layers(root).items()), start=1):
layer_start = len(chunks)
async def summarize_node(node: _PsiTreeNode):
"""Summarize one Psi internal node if its children have text.
Also propagates leaf provenance: the node's
``source_chunk_ids`` becomes the order-preserving deduped
union of every child's ``source_chunk_ids``. Because
children at this layer have already been processed (leaves
first, then bottom-up), each child carries the full set
of leaf ids underneath it — so the union here is the
complete leaf set this summary covers.
"""
texts = [child.text for child in node.children if child.text]
if not texts:
logging.warning("RAPTOR Psi node %s skipped because it has no child text to summarize", node.index)
return None
result = await self._summarize_texts(texts, callback, task_id)
if result is None:
logging.warning("RAPTOR Psi node %s skipped because summarization failed", node.index)
return None
_, node.text, node.embedding = result
merged_ids: list[str] = []
seen: set[str] = set()
for child in node.children:
for src in child.source_chunk_ids:
if src and src not in seen:
seen.add(src)
merged_ids.append(src)
node.source_chunk_ids = merged_ids
return node
tasks = [asyncio.create_task(summarize_node(node)) for node in nodes]
try:
summarized_nodes = await asyncio.gather(*tasks, return_exceptions=False)
except Exception as e:
logging.error(f"Error in RAPTOR Psi tree processing: {e}")
for task in tasks:
task.cancel()
await asyncio.gather(*tasks, return_exceptions=True)
raise
summarized_nodes = [node for node in summarized_nodes if node is not None]
for node in summarized_nodes:
chunks.append((node.text, node.embedding, list(node.source_chunk_ids)))
if len(chunks) > layer_start:
layers.append((layer_start, len(chunks)))
logging.info(
"RAPTOR Psi layer materialized: layer=%d nodes=%d summaries=%d",
layer_idx,
len(nodes),
len(chunks) - layer_start,
)
if callback:
callback(msg="Build one Psi-RAG layer: {} -> {}".format(len(nodes), len(chunks) - layer_start))
else:
logging.warning("RAPTOR Psi layer %d produced no summaries; stopping materialization", layer_idx)
break
return chunks, layers
async def __call__(
self,
chunks,
random_state,
callback=None,
task_id: str = "",
is_tree: bool = False,
):
"""Build summary chunks and layer boundaries for RAPTOR retrieval.
``chunks`` accepts either the legacy 2-tuple shape
``(text, vec)`` or the provenance-carrying 3-tuple shape
``(text, vec, source_chunk_ids)`` where ``source_chunk_ids`` is
the list of original chunk ids that produced this entry. Output
always uses the 3-tuple shape so every appended summary carries
its leaves' ids. ``[]`` is left in the slot for a leaf whose id
was missing — see the caller for the normalization rules.
Return shapes:
* ``is_tree=False`` (default) — original behavior: returns
``(chunks, layers)`` where ``chunks`` is the flat list
(originals + summaries) and ``layers`` is the per-level
index range ``[(start, end), ...]``.
* ``is_tree=True`` — returns a hierarchical tree dict via
``_materialize_tree``. Supported for the classic builder
only; raises ``NotImplementedError`` for PSI_TREE_BUILDER
(PSI's hyperedge-driven summarization doesn't form a strict
parent-of relation). Returns ``None`` when there's nothing
to materialize.
"""
if len(chunks) <= 1:
return None if is_tree else ([], [])
# Normalize input to the 3-tuple shape. Reject empties / bad
# vectors at the same time the legacy path used to.
def _normalize(item):
if len(item) >= 3:
text, vec, src = item[0], item[1], item[2]
else:
text, vec = item[0], item[1]
src = []
if not text or vec is None or len(vec) <= 0:
return None
# Defensive: a leaf should carry a list of strings. Drop
# falsy entries so we don't propagate empty ids upward.
if isinstance(src, (list, tuple)):
src = [s for s in src if s]
else:
src = [src] if src else []
return (text, vec, list(src), "")
normalized = [t for t in (_normalize(c) for c in chunks) if t is not None]
if len(normalized) <= 1:
return None if is_tree else (normalized, [(0, len(normalized))])
chunks = normalized
if self._tree_builder == PSI_TREE_BUILDER:
if is_tree:
raise NotImplementedError(
"is_tree=True is not supported for PSI_TREE_BUILDER",
)
logging.info("RAPTOR: using %s tree builder for %d chunks", self._tree_builder, len(chunks))
return await self._build_psi_layers(chunks, callback, task_id)
# ``parent_child_map`` records each summary's immediate
# children so ``_materialize_tree`` can walk back into a tree
# when ``is_tree`` is set. Always populated (cheap) so the
# tree path is just a return-shape choice at the end.
parent_child_map: dict[int, list[int]] = {}
n_originals = len(chunks)
layers = [(0, len(chunks))]
start, end = 0, len(chunks)
@timeout(60 * 20)
async def summarize(ck_idx: list[int]):
"""Summarize one classic RAPTOR cluster into the chunk list.
On success appends ``(summary_text, summary_vec, src_ids)``
where ``src_ids`` is the order-preserving deduped union of
the ``source_chunk_ids`` of every chunk indexed in
``ck_idx`` — i.e. the full leaf set that contributed to
the cluster, even through nested summaries.
"""
nonlocal chunks
texts = [chunks[i][0] for i in ck_idx]
result = await self._summarize_texts(texts, callback, task_id)
if result is not None:
# ``dict.fromkeys`` is the cheapest way to de-dup a
# list of strings while preserving first-seen order.
merged_ids: list[str] = []
seen: set[str] = set()
for i in ck_idx:
for src in chunks[i][2]:
if src and src not in seen:
seen.add(src)
merged_ids.append(src)
summary_ti, summary_text, summary_vec = result
chunks.append((summary_text, summary_vec, merged_ids, summary_ti))
# Index of the just-appended summary; map it to its
# immediate children for the tree materializer below.
parent_child_map[len(chunks) - 1] = list(ck_idx)
while end - start > 1:
self._check_task_canceled(task_id, "layer processing")
# ``chunks`` is a mix of 3-tuples (layer-0 originals from
# _normalize) and 4-tuples (summaries appended by
# summarize). Vector is always at index 1 in both shapes,
# so use positional access — the older ``_, embd, _, _``
# form crashed on layer-0 entries.
embeddings = [entry[1] for entry in chunks[start:end]]
if end - start <= self._small_layer_collapse:
# Too few nodes for meaningful sub-clustering. Skip the
# clustering pass entirely and summarize the whole layer
# into one parent, so the upper tree doesn't descend one
# node per layer (N -> N-1 -> N-2 -> ... each a full
# clustering + summarize pass).
await summarize(list(range(start, end)))
produced = len(chunks) - end
if produced == 0:
logging.warning("RAPTOR layer produced no summaries; stopping materialization")
break
logging.info(
"RAPTOR small-N collapse: layer of %d node(s) [%d:%d] collapsed into %d summary; stopping at tree top",
end - start, start, end, produced,
)
layers.append((end, len(chunks)))
if callback:
callback(msg="Cluster one layer: {} -> {} (small-N collapse)".format(end - start, produced))
break
n_clusters, lbls = self.clustering(
embeddings,
random_state=random_state,
task_id=task_id,
)
# Loop-termination guarantee. The outer ``while end - start > 1``
# relies on each layer strictly shrinking the input count. If
# the clusterer degenerates and returns one cluster per input,
# every "cluster" is a single chunk, ``summarize()`` produces
# one summary per input, and ``produced == end - start`` —
# the same count carries into the next iteration and the loop
# spins forever, logging "Cluster one layer: N -> N".
#
# Collapse everything at this level into a single cluster so
# the layer produces exactly one summary. The tree gets a
# taller-than-usual "single trunk" segment at this depth
# instead of an infinite loop; downstream consumers only care
# that ``layers`` is monotonically shrinking.
if n_clusters >= len(embeddings):
logging.warning(
"RAPTOR clustering did not reduce input count (%d inputs → %d clusters); collapsing this layer into a single summary to prevent a non-terminating loop",
len(embeddings),
n_clusters,
)
n_clusters = 1
lbls = [0] * len(embeddings)
tasks = []
for c in range(n_clusters):
ck_idx = [i + start for i in range(len(lbls)) if lbls[i] == c]
assert len(ck_idx) > 0
self._check_task_canceled(task_id, "before cluster processing")
tasks.append(asyncio.create_task(summarize(ck_idx)))
try:
await asyncio.gather(*tasks, return_exceptions=False)
except Exception as e:
logging.error(f"Error in RAPTOR cluster processing: {e}")
for t in tasks:
t.cancel()
await asyncio.gather(*tasks, return_exceptions=True)
raise
produced = len(chunks) - end
assert produced <= n_clusters, "{} vs. {}".format(produced, n_clusters)
if produced < n_clusters:
logging.warning(
"RAPTOR layer produced %d/%d cluster summaries; skipped %d cluster(s) due to errors",
produced,
n_clusters,
n_clusters - produced,
)
if produced == 0:
logging.warning("RAPTOR layer produced no summaries; stopping materialization")
break
layers.append((end, len(chunks)))
if callback:
callback(msg="Cluster one layer: {} -> {}".format(end - start, produced))
start = end
end = len(chunks)
if is_tree:
return self._materialize_tree(chunks, layers, parent_child_map, n_originals), []
return chunks, layers
@staticmethod
def _materialize_tree(chunks, layers, parent_child_map, n_originals):
"""Walk ``parent_child_map`` from the top layer down to layer-1
and emit the user-facing tree dict. See ``__call__``'s
``is_tree=True`` contract for the shape.
chunks: [(summary_text, summary_vec, merged_ids, summary_ti)]"""
if not layers or len(chunks) == 0:
return None
top_start, top_end = layers[-1]
if top_end <= top_start:
return None
def _title_at(idx: int) -> str:
# Summary tuples are (text, vec, merged_ids, summary_ti)
# — title is the 4th slot. Layer-0 originals are 3-tuples
# and don't appear as tree nodes themselves (they collapse
# into source_chunk_ids on their layer-1 parent).
return chunks[idx][3] if len(chunks[idx]) >= 4 else ""
def _desc_at(idx: int) -> str:
return chunks[idx][0] if chunks[idx] else ""
def _build_node(idx: int) -> dict:
children_idx = parent_child_map.get(idx, [])
# If every immediate child is a layer-0 original, this
# node is a "leaf" in the tree contract — collapse to
# source_chunk_ids.
if children_idx and all(c < n_originals for c in children_idx):
ids: list[str] = []
seen: set[str] = set()
for c in children_idx:
for s in chunks[c][2]:
if s and s not in seen:
seen.add(s)
ids.append(s)
return {"title": _title_at(idx), "source_chunk_ids": ids, "description": _desc_at(idx)}
return {"children": [_build_node(c) for c in children_idx], "title": _title_at(idx), "description": _desc_at(idx)}
top_nodes = [_build_node(i) for i in range(top_start, top_end)]
if len(top_nodes) == 1:
return top_nodes[0]
# Multiple top-layer summaries — clustering didn't collapse to
# a single root. Wrap in a synthetic root so the caller always
# sees one dict.
return {"title": "(root)", "children": top_nodes}