feat(history): add the event-log schema, writer, and reader

Cargo.toml

@@ -19,10 +19,11 @@
 exclude = ["dev/msrvcheck", "python"]
 members = [
     "ballista-cli",
+    "ballista/api-types",
     "ballista/client",
     "ballista/core",
     "ballista/executor",
-    "ballista/api-types",
+    "ballista/history",
     "ballista/scheduler",
     "benchmarks",
     "chaos-testing",

ballista/api-types/src/dto.rs

@@ -19,6 +19,7 @@
 //! server, so both serialize byte-identical JSON.
 
 use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
 
 /// Summary of one job, served by `GET /api/jobs` and `GET /api/job/{job_id}`.
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -164,3 +165,10 @@ pub enum PlanFormat {
     /// `?plan_format=metrics` => indent with aggregated metrics
     Metrics,
 }
+
+/// Session config for one job, as flat key/value pairs. Served by
+/// `GET /api/job/{job_id}/config`.
+///
+/// A `BTreeMap` so key order is deterministic: the same job must serialize
+/// identically whether it is served live or replayed from a stored log.
+pub type JobConfig = BTreeMap<String, String>;

ballista/history/Cargo.toml

@@ -0,0 +1,38 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+[package]
+name = "ballista-history"
+description = "Event-log schema, writer, and reader for the Ballista history server"
+license = "Apache-2.0"
+version = "54.0.0"
+homepage = "https://datafusion.apache.org/ballista/"
+repository = "https://github.com/apache/datafusion-ballista"
+authors = ["Apache DataFusion <dev@datafusion.apache.org>"]
+edition = { workspace = true }
+rust-version = { workspace = true }
+
+[dependencies]
+ballista-api-types = { path = "../api-types", version = "54.0.0" }
+log = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { version = "1", features = ["raw_value"] }
+tokio = { workspace = true, features = ["fs", "io-util", "macros", "rt", "sync"] }
+
+[dev-dependencies]
+tempfile = { workspace = true }
+tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }