refactor: make RegionOptions and MergeOutput serializable (#4180)

* chore: make RegionOptions serializable and add region_dir in CompactionRegion

* refactor: make `PickerOutput` and `MergeOutput` serializable and deserializable

* refactor: remove Serialize and Deserialize from PickerOutput

* chore: revert changes for file.rs

* chore: revert changes for compactor.rs and compaction.rs

---------

Co-authored-by: tison <[email protected]>

src/mito2/src/compaction/compactor.rs

@@ -19,6 +19,7 @@ use std::time::Duration;
 use api::v1::region::compact_request;
 use common_telemetry::info;
 use object_store::manager::ObjectStoreManager;
+use serde::{Deserialize, Serialize};
 use smallvec::SmallVec;
 use snafu::{OptionExt, ResultExt};
 use store_api::metadata::RegionMetadataRef;
@@ -174,7 +175,7 @@ pub async fn open_compaction_region(
 }
 
 /// `[MergeOutput]` represents the output of merging SST files.
-#[derive(Default, Clone, Debug)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize)]
 pub struct MergeOutput {
     pub files_to_add: Vec<FileMeta>,
     pub files_to_remove: Vec<FileMeta>,

src/mito2/src/region/options.rs

@@ -22,7 +22,7 @@ use std::time::Duration;
 use common_base::readable_size::ReadableSize;
 use common_wal::options::{WalOptions, WAL_OPTIONS_KEY};
 use serde::de::Error as _;
-use serde::{Deserialize, Deserializer};
+use serde::{Deserialize, Deserializer, Serialize};
 use serde_json::Value;
 use serde_with::{serde_as, with_prefix, DisplayFromStr};
 use snafu::{ensure, ResultExt};
@@ -36,7 +36,7 @@ const DEFAULT_INDEX_SEGMENT_ROW_COUNT: usize = 1024;
 /// Options that affect the entire region.
 ///
 /// Users need to specify the options while creating/opening a region.
-#[derive(Debug, Default, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default)]
 pub struct RegionOptions {
     /// Region SST files TTL.
@@ -102,7 +102,7 @@ impl TryFrom<&HashMap<String, String>> for RegionOptions {
 }
 
 /// Options for compactions
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(tag = "compaction.type")]
 #[serde(rename_all = "snake_case")]
 pub enum CompactionOptions {
@@ -127,7 +127,7 @@ impl Default for CompactionOptions {
 
 /// Time window compaction options.
 #[serde_as]
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default)]
 pub struct TwcsOptions {
     /// Max num of files that can be kept in active writing time window.
@@ -195,7 +195,7 @@ impl Default for RegionOptionsWithoutEnum {
 with_prefix!(prefix_inverted_index "index.inverted_index.");
 
 /// Options for index.
-#[derive(Debug, Clone, PartialEq, Eq, Default, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Default, Serialize, Deserialize)]
 #[serde(default)]
 pub struct IndexOptions {
     /// Options for the inverted index.
@@ -205,7 +205,7 @@ pub struct IndexOptions {
 
 /// Options for the inverted index.
 #[serde_as]
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default)]
 pub struct InvertedIndexOptions {
     /// The column ids that should be ignored when building the inverted index.
@@ -228,7 +228,7 @@ impl Default for InvertedIndexOptions {
 }
 
 /// Options for region level memtable.
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(tag = "memtable.type", rename_all = "snake_case")]
 pub enum MemtableOptions {
     TimeSeries,
@@ -240,7 +240,7 @@ with_prefix!(prefix_partition_tree "memtable.partition_tree.");
 
 /// Partition tree memtable options.
 #[serde_as]
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default)]
 pub struct PartitionTreeOptions {
     /// Max keys in an index shard.