use (or)json for DB bridge

Some initial testing with orjson indicates performance varies from
slightly better than pysqlite to about 2x slower depending on the type
of query.

Performance could be improved by building the Python list in rspy
instead of sending back json that needs to be decoded, but it may make
more sense to rewrite the hotspots in Rust instead. More testing is
required in any case.

pylib/anki/collection.py

@@ -266,8 +266,9 @@ crt=?, mod=?, scm=?, dty=?, usn=?, ls=?, conf=?""",
 
     def reopen(self) -> None:
         "Reconnect to DB (after changing threads, etc)."
+        raise Exception("fixme")
         if not self.db:
-            self.db = DBProxy(self.path)
+            #self.db = DBProxy(self.path)
             self.media.connect()
             self._openLog()
 

pylib/anki/dbproxy.py

@@ -1,12 +1,15 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-# fixme: lossy utf8 handling
-# fixme: progress
+from __future__ import annotations
 
-from sqlite3 import dbapi2 as sqlite
 from typing import Any, Iterable, List, Optional, Sequence, Union
 
+import anki
+
+# fixme: remember to null on close to avoid circular ref
+# fixme: progress
+
 # DBValue is actually Union[str, int, float, None], but if defined
 # that way, every call site needs to do a type check prior to using
 # the return values.
@@ -20,28 +23,29 @@ class DBProxy:
     # Lifecycle
     ###############
 
-    def __init__(self, path: str) -> None:
-        self._db = sqlite.connect(path, timeout=0)
+    def __init__(self, backend: anki.rsbackend.RustBackend, path: str) -> None:
+        self._backend = backend
         self._path = path
         self.mod = False
 
     def close(self) -> None:
-        self._db.close()
+        # fixme
+        pass
 
     # Transactions
     ###############
 
     def commit(self) -> None:
-        self._db.commit()
+        # fixme
+        pass
 
     def rollback(self) -> None:
-        self._db.rollback()
+        # fixme
+        pass
 
     def setAutocommit(self, autocommit: bool) -> None:
-        if autocommit:
-            self._db.isolation_level = None
-        else:
-            self._db.isolation_level = ""
+        # fixme
+        pass
 
     # Querying
     ################
@@ -55,16 +59,8 @@ class DBProxy:
             if s.startswith(stmt):
                 self.mod = True
         # fetch rows
-        curs = self._db.execute(sql, args)
-        if first_row_only:
-            row = curs.fetchone()
-            curs.close()
-            if row is not None:
-                return [row]
-            else:
-                return []
-        else:
-            return curs.fetchall()
+        # fixme: first_row_only
+        return self._backend.db_query_json(sql, args)
 
     # Query shortcuts
     ###################
@@ -98,8 +94,8 @@ class DBProxy:
 
     def executemany(self, sql: str, args: Iterable[Iterable[ValueForDB]]) -> None:
         self.mod = True
-        self._db.executemany(sql, args)
+        raise Exception("fixme")
 
     def executescript(self, sql: str) -> None:
         self.mod = True
-        self._db.executescript(sql)
+        raise Exception("fixme")

pylib/anki/rsbackend.py

@@ -18,6 +18,7 @@ from typing import (
     Any)
 
 import ankirspy  # pytype: disable=import-error
+import orjson
 
 import anki.backend_pb2 as pb
 import anki.buildinfo
@@ -421,6 +422,11 @@ class RustBackend:
 
         return map(sqlrow_to_tuple, output.rows)
 
+    def db_query_json(self, sql: str, args: Iterable[ValueForDB]) -> List[DBRow]:
+        input = orjson.dumps(dict(sql=sql, args=args))
+        output = self._backend.db_query(input)
+        return orjson.loads(output)
+
 def translate_string_in(
     key: TR, **kwargs: Union[str, int, float]
 ) -> pb.TranslateStringIn:

pylib/setup.py

@@ -21,6 +21,7 @@ setuptools.setup(
         "requests",
         "decorator",
         "protobuf",
+        "orjson",
         'psutil; sys_platform == "win32"',
         'distro; sys_platform != "darwin" and sys_platform != "win32"',
     ],

rslib/src/backend/dbproxy.rs

@@ -6,27 +6,85 @@ use crate::err::Result;
 use crate::storage::SqliteStorage;
 use rusqlite::types::{FromSql, FromSqlError, ToSql, ToSqlOutput, ValueRef};
 use serde_derive::{Deserialize, Serialize};
-//
-// #[derive(Deserialize)]
-// struct DBRequest {
-//     sql: String,
-//     args: Vec<SqlValue>,
-// }
-//
+
+// json implementation
+
+#[derive(Deserialize)]
+pub(super) struct DBRequest {
+    sql: String,
+    args: Vec<SqlValue>,
+}
+
 // #[derive(Serialize)]
-// struct DBResult {
+// pub(super) struct DBResult {
 //     rows: Vec<Vec<SqlValue>>,
 // }
-//
-// #[derive(Serialize, Deserialize, Debug)]
-// #[serde(untagged)]
-// enum SqlValue {
-//     Null,
-//     String(String),
-//     Int(i64),
-//     Float(f64),
-//     Blob(Vec<u8>),
-// }
+type DBResult = Vec<Vec<SqlValue>>;
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(untagged)]
+pub(super) enum SqlValue {
+    Null,
+    String(String),
+    Int(i64),
+    Double(f64),
+    Blob(Vec<u8>),
+}
+
+impl ToSql for SqlValue {
+    fn to_sql(&self) -> std::result::Result<ToSqlOutput<'_>, rusqlite::Error> {
+        let val = match self {
+            SqlValue::Null => ValueRef::Null,
+            SqlValue::String(v) => ValueRef::Text(v.as_bytes()),
+            SqlValue::Int(v) => ValueRef::Integer(*v),
+            SqlValue::Double(v) => ValueRef::Real(*v),
+            SqlValue::Blob(v) => ValueRef::Blob(&v),
+        };
+        Ok(ToSqlOutput::Borrowed(val))
+    }
+}
+
+impl FromSql for SqlValue {
+    fn column_result(value: ValueRef<'_>) -> std::result::Result<Self, FromSqlError> {
+        let val = match value {
+            ValueRef::Null => SqlValue::Null,
+            ValueRef::Integer(i) => SqlValue::Int(i),
+            ValueRef::Real(v) => SqlValue::Double(v),
+            ValueRef::Text(v) => SqlValue::String(String::from_utf8_lossy(v).to_string()),
+            ValueRef::Blob(v) => SqlValue::Blob(v.to_vec()),
+        };
+        Ok(val)
+    }
+}
+
+pub(super) fn db_query_json_str(db: &SqliteStorage, input: &[u8]) -> Result<String> {
+    let req: DBRequest = serde_json::from_slice(input)?;
+    let resp = db_query_json(db, req)?;
+    Ok(serde_json::to_string(&resp)?)
+}
+
+pub(super) fn db_query_json(db: &SqliteStorage, input: DBRequest) -> Result<DBResult> {
+    let mut stmt = db.db.prepare_cached(&input.sql)?;
+
+    let columns = stmt.column_count();
+
+    let mut rows = stmt.query(&input.args)?;
+
+    let mut output_rows = vec![];
+
+    while let Some(row) = rows.next()? {
+        let mut orow = Vec::with_capacity(columns);
+        for i in 0..columns {
+            let v: SqlValue = row.get(i)?;
+            orow.push(v);
+        }
+
+        output_rows.push(orow);
+    }
+
+    Ok(output_rows)
+}
+
 // protobuf implementation
 
 impl ToSql for pb::SqlValue {

rslib/src/backend/mod.rs

@@ -1,6 +1,7 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
+use crate::backend::dbproxy::db_query_json_str;
 use crate::backend::dbproxy::db_query_proto;
 use crate::backend_proto::backend_input::Value;
 use crate::backend_proto::{Empty, RenderedTemplateReplacement, SyncMediaIn};
@@ -497,6 +498,10 @@ impl Backend {
     fn db_query(&self, input: pb::DbQueryIn) -> Result<pb::DbQueryOut> {
         db_query_proto(&self.col, input)
     }
+
+    pub fn db_query_json(&self, input: &[u8]) -> Result<String> {
+        db_query_json_str(&self.col, input)
+    }
 }
 
 fn translate_arg_to_fluent_val(arg: &pb::TranslateArgValue) -> FluentValue {

rslib/src/storage/sqlite.rs

@@ -26,6 +26,7 @@ macro_rules! cached_sql {
     }};
 }
 
+// currently public for dbproxy
 #[derive(Debug)]
 pub struct SqliteStorage {
     // currently crate-visible for dbproxy

rspy/src/lib.rs

@@ -70,6 +70,13 @@ impl Backend {
             self.backend.set_progress_callback(Some(Box::new(func)));
         }
     }
+
+    fn db_query(&mut self, py: Python, input: &PyBytes) -> PyObject {
+        let in_bytes = input.as_bytes();
+        let out_string = self.backend.db_query_json(in_bytes).unwrap();
+        let out_obj = PyBytes::new(py, out_string.as_bytes());
+        out_obj.into()
+    }
 }
 
 // I18n backend