Incorporated a Doc.content_hash to ensure doc_id uniqueness, with tests

Author: jamesbraza

src/paperqa/clients/__init__.py

@@ -222,6 +222,8 @@ async def upgrade_doc_to_doc_details(self, doc: Doc, **kwargs) -> DocDetails:
                 doc_details.key = doc.docname
             if "citation" in doc.fields_to_overwrite_from_metadata:
                 doc_details.citation = doc.citation
+            if "content_hash" in doc.fields_to_overwrite_from_metadata:
+                doc_details.content_hash = doc.content_hash
             return provided_doc_details + doc_details
 
         # if we can't get metadata, just return the doc, but don't overwrite any fields

src/paperqa/docs.py

@@ -265,18 +265,20 @@ async def aadd(  # noqa: PLR0912
         """Add a document to the collection."""
         all_settings = get_settings(settings)
         parse_config = all_settings.parsing
+        content_hash = md5sum(path)
         dockey_is_content_hash = False
         if dockey is None:
-            # md5 sum of file contents (not path!)
-            dockey = md5sum(path)
+            dockey = content_hash
             dockey_is_content_hash = True
         if llm_model is None:
             llm_model = all_settings.get_llm()
         if citation is None:
             # Peek first chunk
             texts = await read_doc(
                 path,
-                Doc(docname="", citation="", dockey=dockey),  # Fake doc
+                Doc(  # Fake doc
+                    docname="", citation="", dockey=dockey, content_hash=content_hash
+                ),
                 chunk_chars=parse_config.chunk_size,
                 overlap=parse_config.overlap,
                 page_size_limit=parse_config.page_size_limit,
@@ -306,6 +308,7 @@ async def aadd(  # noqa: PLR0912
             ),
             citation=citation,
             dockey=dockey,
+            content_hash=content_hash,
         )
 
         # try to extract DOI / title from the citation

src/paperqa/llms.py

@@ -30,7 +30,7 @@
 )
 from typing_extensions import override
 
-from paperqa.types import Doc, Text
+from paperqa.types import AUTOPOPULATE_VALUE, Doc, Text
 
 if TYPE_CHECKING:
     from qdrant_client.http.models import Record
@@ -495,6 +495,7 @@ async def fetch_batch_with_semaphore(offset: int) -> None:
                         docname=doc_data.get("docname", ""),
                         citation=doc_data.get("citation", ""),
                         dockey=doc_data["dockey"],
+                        content_hash=doc_data.get("content_hash", AUTOPOPULATE_VALUE),
                     )
                     docs.docnames.add(doc_data.get("docname", ""))
 

src/paperqa/types.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import ast
+import contextlib
 import csv
 import logging
 import os
@@ -30,11 +31,13 @@
 )
 
 from paperqa.utils import (
+    compute_unique_doc_id,
     create_bibtex_key,
     encode_id,
     format_bibtex,
     get_citation_ids,
     maybe_get_date,
+    md5sum,
 )
 from paperqa.version import __version__ as pqa_version
 
@@ -53,7 +56,10 @@
     "docname",
     "dockey",
     "citation",
+    "content_hash",  # Metadata providers won't give this
 }
+# Sentinel to autopopulate a field within model_validator
+AUTOPOPULATE_VALUE = ""  # NOTE: this is falsy by design
 
 
 class Doc(Embeddable):
@@ -62,6 +68,13 @@ class Doc(Embeddable):
     docname: str
     dockey: DocKey
     citation: str
+    content_hash: str | None = Field(
+        default=AUTOPOPULATE_VALUE,
+        description=(
+            "Optional hash of the document's contents (to reiterate, not a file path to"
+            " the document, but the document's contents itself)."
+        ),
+    )
     # Sort the serialization to minimize the diff of serialized objects
     fields_to_overwrite_from_metadata: Annotated[set[str], PlainSerializer(sorted)] = (
         Field(
@@ -160,10 +173,6 @@ def __hash__(self) -> int:
         return hash((self.name, self.text))
 
 
-# Sentinel to autopopulate a field within model_validator
-AUTOPOPULATE_VALUE = ""  # NOTE: this is falsy by design
-
-
 class Context(BaseModel):
     """A class to hold the context of a question."""
 
@@ -570,8 +579,8 @@ class DocDetails(Doc):
     doc_id: str | None = Field(
         default=None,
         description=(
-            "Unique ID for this document. Simple ways to acquire one include"
-            " hashing the DOI or a stringifying a UUID."
+            "Unique ID for this document. A simple and robust way to acquire one is"
+            " hashing the paper content's hash concatenate with the lowercased DOI."
         ),
     )
     file_location: str | os.PathLike | None = Field(
@@ -630,9 +639,9 @@ def lowercase_doi_and_populate_doc_id(cls, data: dict[str, Any]) -> dict[str, An
                     doi = doi.replace(url_prefix_to_remove, "")
             data["doi"] = doi.lower()
             if not data.get("doc_id"):  # keep user defined doc_ids
-                data["doc_id"] = encode_id(doi.lower())
+                data["doc_id"] = compute_unique_doc_id(doi, data.get("content_hash"))
         elif not data.get("doc_id"):  # keep user defined doc_ids
-            data["doc_id"] = encode_id(uuid4())
+            data["doc_id"] = compute_unique_doc_id(doi, data.get("content_hash"))
 
         if "dockey" in data.get(
             "fields_to_overwrite_from_metadata",
@@ -838,6 +847,17 @@ def populate_bibtex_key_citation(cls, data: dict[str, Any]) -> dict[str, Any]:
             data["citation"] = data.get("title") or CITATION_FALLBACK_DATA["title"]
         return data
 
+    @classmethod
+    def populate_content_hash(cls, data: dict[str, Any]) -> dict[str, Any]:
+        if (  # Check for missing or autopopulate value, but preserve `None`
+            data.get("content_hash", AUTOPOPULATE_VALUE) == AUTOPOPULATE_VALUE
+        ):
+            data["content_hash"] = None  # Assume we don't have it
+            if data.get("file_location"):  # Try to update it
+                with contextlib.suppress(FileNotFoundError):
+                    data["content_hash"] = md5sum(data["file_location"])
+        return data
+
     @model_validator(mode="before")
     @classmethod
     def validate_all_fields(cls, data: Mapping[str, Any]) -> dict[str, Any]:
@@ -857,6 +877,7 @@ def validate_all_fields(cls, data: Mapping[str, Any]) -> dict[str, Any]:
                 data[possibly_str_field], str
             ):
                 data[possibly_str_field] = ast.literal_eval(data[possibly_str_field])
+        data = cls.populate_content_hash(data)
         data = cls.lowercase_doi_and_populate_doc_id(data)
         data = cls.remove_invalid_authors(data)
         data = cls.misc_string_cleaning(data)
@@ -1017,6 +1038,14 @@ def __add__(self, other: DocDetails | int) -> DocDetails:  # noqa: PLR0912
                     )
                 else:
                     merged_data[field] = max(self_value, other_value)
+            elif field == "content_hash" and (  # noqa: PLR0916
+                # Hashes are both present but differ
+                (self_value and other_value and self_value != other_value)
+                # One hash is explicitly disabled (not autopopulated)
+                or (self_value is None or other_value is None)
+            ):
+                # We don't know which to pick, so just discard the value
+                merged_data[field] = None
 
             else:
                 # Prefer non-null values, default preference for 'other' object.
@@ -1031,10 +1060,13 @@ def __add__(self, other: DocDetails | int) -> DocDetails:  # noqa: PLR0912
                     else self_value
                 )
 
-        # Recalculate doc_id if doi has changed
-        if merged_data["doi"] != self.doi:
-            merged_data["doc_id"] = (
-                encode_id(merged_data["doi"].lower()) if merged_data["doi"] else None
+        if (
+            merged_data["doi"] != self.doi
+            or merged_data["content_hash"] != self.content_hash
+        ):
+            # Recalculate doc_id if doi or content hash has changed
+            merged_data["doc_id"] = compute_unique_doc_id(
+                merged_data["doi"], merged_data.get("content_hash")
             )
 
         # Create and return new DocDetails instance

src/paperqa/utils.py

@@ -16,7 +16,7 @@
 from http import HTTPStatus
 from pathlib import Path
 from typing import Any, BinaryIO, ClassVar, TypeVar
-from uuid import UUID
+from uuid import UUID, uuid4
 
 import aiohttp
 import httpx
@@ -97,7 +97,7 @@ def strings_similarity(s1: str, s2: str, case_insensitive: bool = True) -> float
 
 def hexdigest(data: str | bytes) -> str:
     if isinstance(data, str):
-        return hashlib.md5(data.encode("utf-8")).hexdigest()  # noqa: S324
+        data = data.encode("utf-8")
     return hashlib.md5(data).hexdigest()  # noqa: S324
 
 
@@ -210,6 +210,14 @@ def encode_id(value: str | bytes | UUID, maxsize: int | None = 16) -> str:
     return hashlib.md5(value).hexdigest()[:maxsize]  # noqa: S324
 
 
+def compute_unique_doc_id(doi: str | None, content_hash: str | None) -> str:
+    if doi:
+        value_to_encode: str = doi.lower() + (content_hash or "")
+    else:
+        value_to_encode = content_hash or str(uuid4())
+    return encode_id(value_to_encode)
+
+
 def get_year(ts: datetime | None = None) -> str:
     """Get the year from the input datetime, otherwise using the current datetime."""
     if ts is None:

tests/test_paperqa.py

@@ -13,6 +13,7 @@
 from typing import cast
 from uuid import UUID
 
+import anyio
 import httpx
 import numpy as np
 import pytest
@@ -633,9 +634,11 @@ async def test_get_reasoning(docs_fixture: Docs, llm: str, llm_settings: dict) -
 
 
 @pytest.mark.asyncio
-async def test_duplicate(stub_data_dir: Path) -> None:
+async def test_duplicate(stub_data_dir: Path, tmp_path) -> None:
     """Check Docs doesn't store duplicates, while checking nonduplicate docs are stored."""
     docs = Docs()
+
+    # First, check adding a straight-up duplicate doc
     assert await docs.aadd(
         stub_data_dir / "bates.txt",
         citation="WikiMedia Foundation, 2023, Accessed now",
@@ -648,16 +651,44 @@ async def test_duplicate(stub_data_dir: Path) -> None:
             dockey="test1",
         )
         is None
-    )
+    ), "Expected duplicate add to indicate no new doc was added"
     assert len(docs.docs) == 1, "Should have added only one document"
+
+    # Next, check adding a different doc works, and also check citation inference
+    common_doi = "10.1234/flag"
     assert await docs.aadd(
-        stub_data_dir / "flag_day.html",
-        citation="WikiMedia Foundation, 2023, Accessed now",
-        dockey="test2",
+        stub_data_dir / "flag_day.html", dockey="flag_day", doi=common_doi
     )
     assert (
-        len(set(docs.docs.values())) == 2
+        len(set(docs.docs.keys())) == 2
     ), "Unique documents should be hashed as unique"
+    flag_day = docs.docs["flag_day"]
+    assert isinstance(flag_day, DocDetails)
+    assert flag_day.doi == common_doi
+    assert all(
+        x in flag_day.citation.lower() for x in ("wikipedia", "flag")
+    ), "Expected citation to be inferred"
+    assert flag_day.content_hash
+
+    # Now, check adding a different file but same metadata
+    # (emulating main text vs supplemental information)
+    # will be seen as a different doc
+    flag_day_content = await anyio.Path(stub_data_dir / "flag_day.html").read_bytes()
+    assert len(flag_day_content) >= 1000, "Expected long file to test truncation"
+    await anyio.Path(tmp_path / "flag_day.html").write_bytes(flag_day_content[:-100])
+    assert await docs.aadd(
+        tmp_path / "flag_day.html", dockey="flag_day_shorter", doi=common_doi
+    )
+    assert len(set(docs.docs.keys())) == 3, "Expected a third document to be added"
+    shorter_flag_day = docs.docs["flag_day_shorter"]
+    assert isinstance(shorter_flag_day, DocDetails)
+    assert shorter_flag_day.doi == common_doi
+    assert all(
+        x in shorter_flag_day.citation.lower() for x in ("wikipedia", "flag")
+    ), "Expected citation to be inferred"
+    assert shorter_flag_day.content_hash
+    assert flag_day.content_hash != shorter_flag_day.content_hash
+    assert flag_day.doc_id != shorter_flag_day.doc_id
 
 
 @pytest.mark.asyncio
@@ -939,6 +970,7 @@ async def test_pdf_reader_w_no_match_doc_details(stub_data_dir: Path) -> None:
         "Wellawatte et al, XAI Review, 2023",
     )
     (doc_details,) = docs.docs.values()
+    assert doc_details.content_hash == "41f786fcc56d27ff0c1507153fae3774"
     assert doc_details.docname == docname, "Added name should match between details"
     # doc will be a DocDetails object, but nothing can be found
     # thus, we retain the prior citation data
@@ -1028,10 +1060,12 @@ async def test_pdf_reader_match_doc_details(stub_data_dir: Path) -> None:
         fields=["author", "journal", "citation_count"],
     )
     (doc_details,) = docs.docs.values()
+    assert doc_details.content_hash == "41f786fcc56d27ff0c1507153fae3774"
     assert doc_details.docname == docname, "Added name should match between details"
     # Crossref is non-deterministic in its ordering for results
+    # (it can give DOI '10.1021/acs.jctc.2c01235' or DOI '10.26434/chemrxiv-2022-qfv02')
     # thus we need to capture both possible dockeys
-    assert doc_details.dockey in {"d7763485f06aabde", "5300ef1d5fb960d7"}
+    assert doc_details.dockey in {"8ce7ddba9c9dcae6", "a353fa2478475c9c"}
     assert isinstance(doc_details, DocDetails)
     # note year is unknown because citation string is only parsed for authors/title/doi
     # AND we do not request it back from the metadata sources