优化和收尾

chusql-storage/src/protocol.rs

@@ -22,42 +22,104 @@ pub struct SchemaColumn {
     pub ty: ColumnType,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+/// 一列的统计（随数据字典一起走）
+pub struct ColumnStatWire {
+    pub name: String,
+    /// 不同值个数；`capped` 为真时它只是下界
+    pub distinct: u64,
+    #[serde(default)]
+    pub capped: bool,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+/// 一条索引定义
+pub struct IndexWire {
+    pub column: String,
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(tag = "method", rename_all = "snake_case")]
 /// 请求：method 字段决定类型
 pub enum Request {
     Ping,
-    Scan { table: String },
+    Scan {
+        table: String,
+    },
+    /// 插一行；要不要写索引由表上的索引决定（调用方不用管）
     Insert {
         table: String,
         row: Row,
-        #[serde(default)]
-        key: Option<i64>,
     },
-    LookupByIndex { table: String, key: i64 },
-    ReplaceAll { table: String, rows: Vec<Row> },
+    /// 一批行一起插：一次 WAL、一次 fsync
+    InsertBatch {
+        table: String,
+        rows: Vec<Row>,
+    },
+    /// 按 id 批量删行
+    DeleteKeys {
+        table: String,
+        keys: Vec<i64>,
+    },
+    /// 按某一列的索引取一行（列名默认 "id"，兼容老客户端）
+    LookupByIndex {
+        table: String,
+        #[serde(default = "default_id_column")]
+        column: String,
+        key: i64,
+    },
+    ReplaceAll {
+        table: String,
+        rows: Vec<Row>,
+    },
     ListTables,
-    DescribeTable { table: String },
+    DescribeTable {
+        table: String,
+    },
     CreateTable {
         table: String,
         columns: Vec<SchemaColumn>,
     },
-    DropTable { table: String },
-    ListCatalog
+    DropTable {
+        table: String,
+    },
+    ListCatalog,
+    /// 给某一列建索引（要求这一列整数取值唯一）
+    CreateIndex {
+        table: String,
+        column: String,
+    },
+    /// 去掉某一列的索引
+    DropIndex {
+        table: String,
+        column: String,
+    },
+}
+
+/// 没写 column 时按 `id` 算
+fn default_id_column() -> String {
+    "id".to_string()
 }
 
 #[derive(Debug, Serialize, Deserialize)]
-#[serde(tag = "status", rename_all = "lowercase")]
+#[serde(tag = "status", rename_all = "snake_case")]
 /// 响应：status 字段决定类型
 pub enum Response {
     Pong,
     Rows { rows: Vec<Row> },
     Tables { tables: Vec<String> },
     Schema {
+        table: String,
         columns: Vec<SchemaColumn>,
         #[serde(default)]
         row_count: u64,
+        #[serde(default)]
+        indexes: Vec<IndexWire>,
+        #[serde(default)]
+        stats: Vec<ColumnStatWire>,
     },
+    /// 这一列没有索引 —— 调用方应该退回全表扫描
+    NoIndex,
     Ok,
     Error { message: String },
     Catalog { schemas: Vec<TableSchemaWire> },
@@ -69,4 +131,8 @@ pub struct TableSchemaWire {
     pub columns: Vec<SchemaColumn>,
     #[serde(default)]
     pub row_count: u64,
+    #[serde(default)]
+    pub indexes: Vec<IndexWire>,
+    #[serde(default)]
+    pub stats: Vec<ColumnStatWire>,
 }