osbuild: experimentally switch to fastjsonschema

Just a quick draft to see what it would take to move to fastjson
schema.

osbuild/meta.py

@@ -31,7 +31,7 @@
 from collections import deque
 from typing import Any, Deque, Dict, List, Optional, Sequence, Set, Tuple, Union
 
-import jsonschema
+import fastjsonschema
 
 from .util import osrelease
 
@@ -55,8 +55,8 @@ def __init__(self, message: str):
 
     @classmethod
     def from_exception(cls, ex):
-        err = cls(ex.message)
-        err.path = ex.absolute_path
+        err = cls(str(ex))
+        #err.path = ex.absolute_path
         return err
 
     @property
@@ -217,9 +217,11 @@ class Schema:
     """
 
     def __init__(self, schema: Optional[Dict], name: Optional[str] = None):
+        if schema:
+            schema["schema"] = "http://json-schema.org/draft-04/schema"
         self.data = schema
         self.name = name
-        self._validator: Optional[jsonschema.Draft4Validator] = None
+        self._validator: Optional[fastjsonschema.CodeGeneratorDraft04] = None
 
     def check(self) -> ValidationResult:
         """Validate the `schema` data itself"""
@@ -243,10 +245,8 @@ def check(self) -> ValidationResult:
             return res
 
         try:
-            Validator = jsonschema.Draft4Validator
-            Validator.check_schema(self.data)
-            self._validator = Validator(self.data)
-        except jsonschema.exceptions.SchemaError as err:
+            self._validator = fastjsonschema.compile(self.data)
+        except fastjsonschema.JsonSchemaDefinitionException as err:
             res += ValidationError.from_exception(err)
 
         return res
@@ -266,8 +266,10 @@ def validate(self, target) -> ValidationResult:
         if not self._validator:
             raise RuntimeError("Trying to validate without validator.")
 
-        for error in self._validator.iter_errors(target):
-            res += ValidationError.from_exception(error)
+        try:
+            self._validator(target)
+        except fastjsonschema.JsonSchemaException as e:
+            res += ValidationError.from_exception(e)
 
         return res
 
@@ -278,11 +280,11 @@ def __bool__(self):
 META_JSON_SCHEMA = {
     "type": "object",
     "additionalProperties": False,
-    "propertyNames": {
-        "not": {
-            "const": "description",
-        },
-    },
+    #"propertyNames": {
+    #    "not": {
+    #        "const": "description",
+    #    },
+    #},
     "required": ["summary", "description"],
     "anyOf": [
         {

requirements.txt

@@ -1,2 +1,2 @@
-jsonschema
+fastjsonschema
 pytest

setup.py

@@ -7,7 +7,7 @@
     packages=["osbuild", "osbuild.formats", "osbuild.util","osbuild.solver"],
     license='Apache-2.0',
     install_requires=[
-        "jsonschema",
+        "fastjsonschema",
     ],
     entry_points={
         "console_scripts": [

test/mod/test_meta.py

@@ -323,20 +323,20 @@ def test_load_from_json_prefered(tmp_path):
     (
         # no description
         {"summary": "some", "schema": {}},
-        "'description' is a required property",
+        "data must contain ['description'] properties",
     ), (
         # no summary
         {"description": ["yes"], "schema": {}},
-        "'summary' is a required property",
+        "data must contain ['summary'] properties",        
     ), (
         # schema{,_2} missing
         {"summary": "some", "description": ["many", "strings"]},
-        " is not valid",
+        "data cannot be validated by any definition"
     ), (
         # capabilities of wrong type
         {"summary": "some", "description": ["many", "strings"], "schema": {},
          "capabilities": [1, "cap1"]},
-        " is not of type 'string'",
+        " must be string"
     ),
 ])
 def test_meta_json_validation_schema(test_input, expected_err):

tox.ini

@@ -14,7 +14,7 @@ description = "run osbuild unit tests"
 deps =
     pytest
     pytest-xdist
-    jsonschema
+    fastjsonschema
     mako
     iniparse
     pyyaml