basic graphql server

.gitignore

@@ -21,3 +21,5 @@ dev-env/
 /data/
 tmp/
 .task/
+node_modules/
+package-lock.json

Taskfile.yaml

@@ -48,6 +48,20 @@ tasks:
       - a-file-not-exists-so-it-always-rerun
     cmd: python start_grpc_server.py
 
+  graphql:
+    dotenv:
+      - .env
+    sources:
+      - '*.py'
+      - 'chii/**/*.py'
+      - 'rpc/**/*.py'
+      - 'gql/**/*.py'
+      - 'gql/**/*.graphql'
+    generates:
+      - a-file-not-exists-so-it-always-rerun
+    cmds:
+      - uvicorn gql.app:app
+
   mypy: mypy --show-column-numbers chii rpc
 
   lint:

chii/compat/phpseralize.py

@@ -24,7 +24,7 @@
 import six
 
 
-def load(fp: BytesIO) -> Any:
+def __load(fp: BytesIO) -> Any:
     """Read a string from the open file object `fp` and interpret it as a
     data stream of PHP-serialized objects, reconstructing and returning
     the original object hierarchy.
@@ -34,7 +34,7 @@ def load(fp: BytesIO) -> Any:
     reading, a `StringIO` object (`BytesIO` on Python 3), or any other custom
     object that meets this interface.
 
-    `load` will read exactly one object from the stream.  See the docstring of
+    `__load` will read exactly one object from the stream.  See the docstring of
     the module for this chained behavior.
 
     If an object hook is given object-opcodes are supported in the serilization
@@ -116,7 +116,7 @@ def loads(data: bytes | str) -> Any:
     string must be a bytestring.
     """
     with BytesIO(six.ensure_binary(data)) as fp:
-        return load(fp)
+        return __load(fp)
 
 
 def dict_to_list(d: dict[int, Any]) -> list[Any]:

chii/config.py

@@ -29,6 +29,15 @@ def MYSQL_SYNC_DSN(self) -> str:
             self.MYSQL_DB,
         )
 
+    def MYSQL_ASYNC_DSN(self) -> str:
+        return "mysql+aiomysql://{}:{}@{}:{}/{}".format(
+            self.MYSQL_USER,
+            self.MYSQL_PASS,
+            self.MYSQL_HOST,
+            self.MYSQL_PORT,
+            self.MYSQL_DB,
+        )
+
 
 config = Settings()
 

chii/db/sa.py

@@ -1,3 +1,4 @@
+import logging.config
 import time
 
 from sqlalchemy import (
@@ -19,6 +20,7 @@
     update,
 )
 from sqlalchemy.dialects.mysql import insert
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
 from sqlalchemy.orm import joinedload, selectinload, sessionmaker, subqueryload
 from sslog import logger
 
@@ -58,6 +60,29 @@ def get(T, *where, order=None):
     return s
 
 
+if config.debug:
+    # redirect echo logger to sslog
+    logging.config.dictConfig(
+        {
+            "version": 1,
+            "handlers": {
+                "sslog": {
+                    "class": "sslog.InterceptHandler",
+                    "level": "DEBUG",
+                }
+            },
+            "loggers": {
+                "": {"level": "INFO", "handlers": ["sslog"]},
+                "sqlalchemy.engine.Engine": {
+                    "level": "INFO",
+                    "handlers": ["sslog"],
+                    "propagate": False,
+                },
+            },
+        }
+    )
+
+
 def sync_session_maker():
     engine = create_engine(
         config.MYSQL_SYNC_DSN,
@@ -75,6 +100,19 @@ def sync_session_maker():
     return sessionmaker(engine)
 
 
+def async_session_maker():
+    engine = create_async_engine(
+        config.MYSQL_ASYNC_DSN(),
+        pool_recycle=14400,
+        pool_size=10,
+        max_overflow=20,
+        echo=config.debug,
+        execution_options={"statement_timeout": config.MYSQL_STMT_TIMEOUT},
+    )
+
+    return async_sessionmaker(engine)
+
+
 def before_cursor_execute(
     conn: Connection, cursor, statement, parameters, context, executemany
 ):

chii/db/tables.py

@@ -91,7 +91,7 @@ class ChiiTimeline:
             )
         },
     )
-    dateline: int = field(
+    created_at: int = field(
         default_factory=lambda: int(time.time()),
         metadata={
             "sa": Column(
@@ -111,7 +111,10 @@ class ChiiTimeline:
 
 # type helper for ChiiTimeline.uid.desc()
 ChiiTimeline_column_id: Column[int] = cast(Column[int], ChiiTimeline.id)
+ChiiTimeline_column_cat: Column[int] = cast(Column[int], ChiiTimeline.cat)
+ChiiTimeline_column_type: Column[int] = cast(Column[int], ChiiTimeline.type)
 ChiiTimeline_column_uid: Column[int] = cast(Column[int], ChiiTimeline.uid)
+ChiiTimeline_column_created_at: Column[int] = cast(Column[int], ChiiTimeline.created_at)
 
 
 class HTMLEscapedString(types.TypeDecorator):

gql/app.py

@@ -0,0 +1,86 @@
+from pathlib import Path
+from typing import Any, Iterator
+
+from ariadne import ObjectType, QueryType, gql, make_executable_schema
+from ariadne.asgi import GraphQL
+from sqlalchemy import select
+from starlette.applications import Starlette
+from starlette.routing import Mount
+
+from chii.compat import phpseralize
+from chii.const import CollectionType
+from chii.db import sa
+from chii.db.tables import ChiiTimeline, ChiiTimeline_column_cat, ChiiTimeline_column_id
+from chii.timeline import TimelineCat
+from gql.model import CollectTimeline
+from gql.rules import depth_limit_validator
+
+# Define types using Schema Definition Language (https://graphql.org/learn/schema/)
+# Wrapping string in gql function provides validation and better error traceback
+type_defs = gql(
+    Path(__file__, "..", "schema.graphql").resolve().read_text(encoding="utf8")
+)
+
+CreateSession = sa.async_session_maker()
+
+# Map resolver functions to Query fields using QueryType
+gql_query = QueryType()
+
+
+# Resolvers are simple python functions
+@gql_query.field("timeline_collection")
+async def timeline_collection(*_: Any) -> list[CollectTimeline]:
+    async with CreateSession() as session:
+        rows: Iterator[ChiiTimeline] = await session.scalars(
+            select(ChiiTimeline)
+            .where(ChiiTimeline_column_cat == TimelineCat.Subject)
+            .order_by(ChiiTimeline_column_id.desc())
+            .limit(10)
+        )
+
+        result = []
+        for row in rows:
+            meme = phpseralize.loads(row.memo.encode())
+            if not row.batch:
+                result.append(
+                    CollectTimeline(
+                        id=row.id,
+                        action=CollectionType.wish,
+                        user_id=row.uid,
+                        subject_id=[int(meme["subject_id"])],
+                        created_at=row.created_at,
+                    )
+                )
+            else:
+                result.append(
+                    CollectTimeline(
+                        id=row.id,
+                        action=CollectionType.wish,
+                        user_id=row.uid,
+                        subject_id=[int(x) for x in meme],
+                        created_at=row.created_at,
+                    )
+                )
+
+        return result
+
+
+# Map resolver functions to custom type fields using ObjectType
+gql_collect_timeline = ObjectType("CollectTimeline")
+
+# Create executable GraphQL schema
+schema = make_executable_schema(type_defs, gql_query, gql_collect_timeline)
+
+app = Starlette(
+    debug=True,
+    routes=[
+        Mount(
+            "/graphql",
+            GraphQL(
+                schema,
+                debug=True,
+                validation_rules=[depth_limit_validator(max_depth=5)],
+            ),
+        ),
+    ],
+)

gql/model.py

@@ -0,0 +1,9 @@
+from typing import TypedDict
+
+
+class CollectTimeline(TypedDict):
+    id: int
+    action: int
+    user_id: int
+    subject_id: list[int]
+    created_at: int

gql/rules.py

@@ -0,0 +1,120 @@
+from typing import Dict, Tuple
+
+from ariadne.contrib.tracing.utils import is_introspection_key
+from graphql import (
+    ASTValidationRule,
+    DefinitionNode,
+    FieldNode,
+    FragmentDefinitionNode,
+    FragmentSpreadNode,
+    GraphQLError,
+    InlineFragmentNode,
+    Node,
+    OperationDefinitionNode,
+    ValidationContext,
+)
+from graphql.validation.validate import ValidationAbortedError
+
+
+def depth_limit_validator(max_depth: int):
+    class DepthLimitValidator(ASTValidationRule):
+        def __init__(self, validation_context: ValidationContext):
+            document = validation_context.document
+            definitions = document.definitions
+
+            fragments = get_fragments(definitions)
+            queries = get_queries_and_mutations(definitions)
+            query_depths = {}
+
+            for name in queries:
+                query_depths[name] = determine_depth(
+                    node=queries[name],
+                    fragments=fragments,
+                    depth_so_far=0,
+                    max_depth=max_depth,
+                    context=validation_context,
+                    operation_name=name,
+                )
+            super().__init__(validation_context)
+
+    return DepthLimitValidator
+
+
+def get_fragments(
+    definitions: Tuple[DefinitionNode, ...],
+) -> Dict[str, FragmentDefinitionNode]:
+    fragments = {}
+    for definition in definitions:
+        if isinstance(definition, FragmentDefinitionNode):
+            fragments[definition.name.value] = definition
+    return fragments
+
+
+def get_queries_and_mutations(
+    definitions: Tuple[DefinitionNode, ...],
+) -> Dict[str, OperationDefinitionNode]:
+    operations = {}
+
+    for definition in definitions:
+        if isinstance(definition, OperationDefinitionNode):
+            operation = definition.name.value if definition.name else "anonymous"
+            operations[operation] = definition
+    return operations
+
+
+def determine_depth(
+    node: Node,
+    fragments: Dict[str, FragmentDefinitionNode],
+    depth_so_far: int,
+    max_depth: int,
+    context: ValidationContext,
+    operation_name: str,
+) -> int:
+    if depth_so_far > max_depth:
+        context.report_error(
+            GraphQLError(
+                f"'{operation_name}' exceeds maximum operation depth of {max_depth}.",
+                [node],
+            )
+        )
+        raise ValidationAbortedError
+    if isinstance(node, FieldNode):
+        should_ignore = is_introspection_key(node.name.value)
+
+        if should_ignore or not node.selection_set:
+            return 0
+        return 1 + max(
+            determine_depth(
+                node=selection,
+                fragments=fragments,
+                depth_so_far=depth_so_far + 1,
+                max_depth=max_depth,
+                context=context,
+                operation_name=operation_name,
+            )
+            for selection in node.selection_set.selections
+        )
+    if isinstance(node, FragmentSpreadNode):
+        return determine_depth(
+            node=fragments[node.name.value],
+            fragments=fragments,
+            depth_so_far=depth_so_far,
+            max_depth=max_depth,
+            context=context,
+            operation_name=operation_name,
+        )
+    if isinstance(
+        node, (InlineFragmentNode, FragmentDefinitionNode, OperationDefinitionNode)
+    ):
+        return max(
+            determine_depth(
+                node=selection,
+                fragments=fragments,
+                depth_so_far=depth_so_far,
+                max_depth=max_depth,
+                context=context,
+                operation_name=operation_name,
+            )
+            for selection in node.selection_set.selections
+        )
+    raise Exception(f"Depth crawler cannot handle: {node.kind}.")  # pragma: no cover

gql/schema.graphql

@@ -0,0 +1,12 @@
+type Query {
+  timeline_collection:[CollectTimeline!]!
+}
+
+type CollectTimeline {
+  id: Int!
+  action: Int!
+  user_id: Int!
+  subject_id: [Int!]!
+  # unix timestamp in seconds
+  created_at: Int!
+}