Parse the request body once per request in the validators

src/mock_vws/_flask_server/vwq.py

@@ -137,7 +137,7 @@ def query() -> Response:
 
     databases = get_all_cloud_databases()
     request_body = request.stream.read()
-    run_query_validators(
+    validated_query = run_query_validators(
         request_headers=dict(request.headers),
         request_body=request_body,
         request_method=request.method,
@@ -147,11 +147,7 @@ def query() -> Response:
     date = email.utils.formatdate(timeval=None, localtime=False, usegmt=True)
 
     response_text = get_query_match_response_text(
-        request_headers=dict(request.headers),
-        request_body=request_body,
-        request_method=request.method,
-        request_path=request.path,
-        databases=databases,
+        validated_query=validated_query,
         query_match_checker=query_match_checker,
     )
 

src/mock_vws/_query_tools.py

@@ -2,65 +2,39 @@
 
 import base64
 import uuid
-from collections.abc import Iterable, Mapping
 from typing import Any
 
 from beartype import beartype
 
 from mock_vws._base64_decoding import decode_base64
 from mock_vws._constants import ResultCodes, TargetStatuses
-from mock_vws._database_matchers import get_database_matching_client_keys
 from mock_vws._matching import matching_targets
 from mock_vws._mock_common import json_dump
-from mock_vws._query_validators.multipart import parse_multipart
-from mock_vws.database import CloudDatabase
+from mock_vws._query_validators import ValidatedQuery
 from mock_vws.image_matchers import ImageMatcher
 
 
 @beartype
 def get_query_match_response_text(
     *,
-    request_headers: Mapping[str, str],
-    request_body: bytes,
-    request_method: str,
-    request_path: str,
-    databases: Iterable[CloudDatabase],
+    validated_query: ValidatedQuery,
     query_match_checker: ImageMatcher,
 ) -> str:
     """
     Args:
-        request_path: The path of the request.
-        request_headers: The headers sent with the request.
-        request_body: The body of the request.
-        request_method: The HTTP method of the request.
-        databases: All Vuforia databases.
+        validated_query: The database and the parsed body which the query
+            validators resolved the request to.
         query_match_checker: A callable which takes two image values and
             returns a match score, or ``None`` if they do not match.
 
     Returns:
         The response text for a query endpoint request.
     """
-    fields, files = parse_multipart(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-
-    max_num_results = fields.get(key="max_num_results", default="1")
-    include_target_data = fields.get(
-        key="include_target_data",
-        default="top",
-    ).lower()
-
-    image_part = files["image"]
-    image_value = image_part.stream.read()
-
-    database = get_database_matching_client_keys(
-        request_headers=request_headers,
-        request_body=request_body,
-        request_method=request_method,
-        request_path=request_path,
-        databases=databases,
-    )
+    fields = validated_query.form.fields
+    max_num_results = fields.get("max_num_results", "1")
+    include_target_data = fields.get("include_target_data", "top").lower()
+    image_value = validated_query.form.files["image"]
+    database = validated_query.database
 
     matches_best_first = matching_targets(
         matcher=query_match_checker,

src/mock_vws/_query_validators/__init__.py

@@ -1,9 +1,14 @@
 """Input validators to use in the mock query API."""
 
 from collections.abc import Iterable, Mapping
+from dataclasses import dataclass
 
 from beartype import beartype
 
+from mock_vws._query_validators.multipart import (
+    MultipartForm,
+    parse_multipart,
+)
 from mock_vws.database import CloudDatabase
 
 from .accept_header_validators import validate_accept_header
@@ -38,6 +43,24 @@
 from .project_state_validators import validate_project_state
 
 
+@beartype
+@dataclass(frozen=True, kw_only=True)
+class ValidatedQuery:
+    """What the validators learn about a query request which passes them.
+
+    Args:
+        database: The database which the request's client keys belong to.
+        form: The parsed body of the request.
+
+    Attributes:
+        database: The database which the request's client keys belong to.
+        form: The parsed body of the request.
+    """
+
+    database: CloudDatabase
+    form: MultipartForm
+
+
 @beartype
 def run_query_validators(
     *,
@@ -46,15 +69,28 @@ def run_query_validators(
     request_body: bytes,
     request_method: str,
     databases: Iterable[CloudDatabase],
-) -> None:
+) -> ValidatedQuery:
     """Run all validators.
 
+    Vuforia reports one problem with a request even when the request has
+    more than one. Which problem it reports is decided by the order of the
+    validators here, so that order is the mock's record of Vuforia's error
+    precedence, verified against the real service.
+
+    The body is parsed once, after the ``Content-Type`` header which names
+    its boundary has been validated, and the parsed form is shared by every
+    validator which reads the body.
+
     Args:
         request_path: The path of the request.
         request_headers: The headers sent with the request.
         request_body: The body of the request.
         request_method: The HTTP method of the request.
         databases: All Vuforia databases.
+
+    Returns:
+        The database which the request's client keys belong to, and the
+        parsed body of the request.
     """
     validate_content_length_header_is_int(request_headers=request_headers)
     validate_content_length_header_not_too_large(
@@ -72,20 +108,14 @@ def run_query_validators(
         request_headers=request_headers,
         databases=databases,
     )
-    validate_authorization(
-        request_headers=request_headers,
-        request_body=request_body,
-        request_method=request_method,
-        request_path=request_path,
-        databases=databases,
-    )
-    validate_project_state(
+    database = validate_authorization(
         request_headers=request_headers,
         request_body=request_body,
         request_method=request_method,
         request_path=request_path,
         databases=databases,
     )
+    validate_project_state(database=database)
     validate_accept_header(request_headers=request_headers)
     validate_date_header_given(request_headers=request_headers)
     validate_date_format(request_headers=request_headers)
@@ -94,35 +124,16 @@ def run_query_validators(
         request_headers=request_headers,
         request_body=request_body,
     )
-    validate_extra_fields(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_image_field_given(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_image_is_image(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_image_format(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_image_dimensions(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_image_file_size(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_max_num_results(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    validate_include_target_data(
+    form = parse_multipart(
         request_headers=request_headers,
         request_body=request_body,
     )
+    validate_extra_fields(form=form)
+    validate_image_field_given(form=form)
+    validate_image_is_image(form=form)
+    validate_image_format(form=form)
+    validate_image_dimensions(form=form)
+    validate_image_file_size(form=form)
+    validate_max_num_results(form=form)
+    validate_include_target_data(form=form)
+    return ValidatedQuery(database=database, form=form)

src/mock_vws/_query_validators/auth_validators.py

@@ -115,7 +115,7 @@ def validate_authorization(
     request_body: bytes,
     request_method: str,
     databases: Iterable[CloudDatabase],
-) -> None:
+) -> CloudDatabase:
     """Validate the authorization header given to the query endpoint.
 
     Args:
@@ -125,12 +125,15 @@ def validate_authorization(
         request_method: The HTTP method of the request.
         databases: All Vuforia databases.
 
+    Returns:
+        The database which the request's client keys belong to.
+
     Raises:
         AuthenticationFailureError: The "Authorization" header is not as
             expected.
     """
     try:
-        get_database_matching_client_keys(
+        return get_database_matching_client_keys(
             request_headers=request_headers,
             request_body=request_body,
             request_method=request_method,

src/mock_vws/_query_validators/fields_validators.py

@@ -1,38 +1,26 @@
 """Validators for the fields given."""
 
 import logging
-from collections.abc import Mapping
 
 from beartype import beartype
 
 from mock_vws._query_validators.exceptions import UnknownParametersError
-from mock_vws._query_validators.multipart import parse_multipart
+from mock_vws._query_validators.multipart import MultipartForm
 
 _LOGGER = logging.getLogger(name=__name__)
 
 
 @beartype
-def validate_extra_fields(
-    *,
-    request_headers: Mapping[str, str],
-    request_body: bytes,
-) -> None:
+def validate_extra_fields(*, form: MultipartForm) -> None:
     """Validate that the no unknown fields are given.
 
     Args:
-        request_headers: The headers sent with the request.
-        request_body: The body of the request.
+        form: The parsed body of the request.
 
     Raises:
         UnknownParametersError: Extra fields are given.
-        NoContentDispositionError: A part of the body has no
-            ``Content-Disposition`` header.
     """
-    fields, files = parse_multipart(
-        request_headers=request_headers,
-        request_body=request_body,
-    )
-    parsed_keys = fields.keys() | files.keys()
+    parsed_keys = form.fields.keys() | form.files.keys()
     known_parameters = {"image", "max_num_results", "include_target_data"}
 
     if not parsed_keys - known_parameters: