大改，整理项目结构，完成rust ffi调用，写好tcp接口

chusql-core/storage/src/protocol.rs

@@ -0,0 +1,236 @@
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+// 协议：Haskell 与 Rust 之间的请求 / 响应类型。
+
+pub type Row = HashMap<String, serde_json::Value>;
+
+pub const USERS_TABLE: &str = "__chusql_users";
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct Account {
+    pub id: i64,
+    pub user: String,
+    pub password_hash: String,
+    pub revision: u64,
+    #[serde(default)]
+    pub registered_at: String,
+    #[serde(default)]
+    pub last_login_at: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct SchemaColumn {
+    pub name: String,
+    pub ty: String,
+    #[serde(default = "default_true")]
+    pub nullable: bool,
+    #[serde(default)]
+    pub default: Option<serde_json::Value>,
+    #[serde(default)]
+    pub auto_increment: bool,
+    #[serde(default)]
+    pub primary_key: bool,
+    #[serde(default)]
+    pub unique: bool,
+    #[serde(default)]
+    pub check: Option<String>,
+}
+
+impl Default for SchemaColumn {
+    /// 列定义的默认值
+    fn default() -> Self {
+        SchemaColumn {
+            name: String::new(),
+            ty: String::new(),
+            nullable: true,
+            default: None,
+            auto_increment: false,
+            primary_key: false,
+            unique: false,
+            check: None,
+        }
+    }
+}
+
+/// serde 里缺省为真
+fn default_true() -> bool {
+    true
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct ColumnStatWire {
+    pub name: String,
+    pub distinct: u64,
+    #[serde(default)]
+    pub capped: bool,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct IndexWire {
+    pub column: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "method", rename_all = "snake_case")]
+pub enum Request {
+    AccountsList,
+    AccountCreate { user: String, password_hash: String },
+    AccountReset { user: String, password_hash: String },
+    AccountLogin {
+        user: String,
+        #[serde(default)]
+        at: Option<String>,
+    },
+    AccountDrop { user: String },
+    Ping,
+    Scan {
+        table: String,
+        #[serde(default)]
+        columns: Option<Vec<String>>,
+    },
+    Insert {
+        table: String,
+        row: Row,
+    },
+    InsertBatch {
+        table: String,
+        rows: Vec<Row>,
+    },
+    DeleteKeys {
+        table: String,
+        keys: Vec<i64>,
+    },
+    LookupByIndex {
+        table: String,
+        #[serde(default = "default_id_column")]
+        column: String,
+        key: serde_json::Value,
+    },
+    RangeByIndex {
+        table: String,
+        column: String,
+        #[serde(default)]
+        lo: Option<serde_json::Value>,
+        #[serde(default = "default_true")]
+        lo_inclusive: bool,
+        #[serde(default)]
+        hi: Option<serde_json::Value>,
+        #[serde(default = "default_true")]
+        hi_inclusive: bool,
+    },
+    ReplaceAll {
+        table: String,
+        rows: Vec<Row>,
+    },
+    ListTables,
+    DescribeTable {
+        table: String,
+    },
+    CreateTable {
+        table: String,
+        columns: Vec<SchemaColumn>,
+    },
+    DropTable {
+        table: String,
+    },
+    ListCatalog,
+    CreateIndex {
+        table: String,
+        column: String,
+    },
+    DropIndex {
+        table: String,
+        column: String,
+    },
+    DropColumn {
+        table: String,
+        column: String,
+    },
+    Compact {
+        table: String,
+    },
+    ReplaceSchema {
+        table: String,
+        columns: Vec<SchemaColumn>,
+        rows: Vec<Row>,
+    },
+}
+
+impl Request {
+    /// 拒绝可能影响文件路径的列名
+    pub fn valid_columns(&self) -> bool {
+        let valid = |name: &str| !name.is_empty()
+            && name.chars().all(|c| c.is_ascii_alphanumeric() || c == '_');
+        match self {
+            Self::CreateIndex { column, .. } | Self::DropIndex { column, .. }
+            | Self::DropColumn { column, .. } | Self::LookupByIndex { column, .. }
+            | Self::RangeByIndex { column, .. } => valid(column),
+            Self::CreateTable { columns, .. } => columns.iter().all(|c| valid(&c.name)),
+            Self::ReplaceSchema { columns, .. } => columns.iter().all(|c| valid(&c.name)),
+            _ => true,
+        }
+    }
+    /// 普通表操作的统一访问边界
+    pub fn table(&self) -> Option<&str> {
+        match self {
+            Self::Scan { table, .. } | Self::Insert { table, .. }
+            | Self::InsertBatch { table, .. } | Self::DeleteKeys { table, .. }
+            | Self::LookupByIndex { table, .. } | Self::ReplaceAll { table, .. }
+            | Self::RangeByIndex { table, .. }
+            | Self::DescribeTable { table } | Self::CreateTable { table, .. }
+            | Self::DropTable { table } | Self::CreateIndex { table, .. }
+            | Self::DropIndex { table, .. } | Self::DropColumn { table, .. }
+            | Self::Compact { table }
+            | Self::ReplaceSchema { table, .. } => Some(table),
+            Self::Ping | Self::ListTables | Self::ListCatalog | Self::AccountsList
+            | Self::AccountCreate { .. } | Self::AccountReset { .. } | Self::AccountLogin { .. }
+            | Self::AccountDrop { .. } => None,
+        }
+    }
+}
+
+/// 是不是保留系统表名
+pub fn reserved_table(table: &str) -> bool {
+    table.to_ascii_lowercase().starts_with("__chusql_")
+}
+
+/// 没写 column 时按 `id` 算
+fn default_id_column() -> String {
+    "id".to_string()
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "status", rename_all = "snake_case")]
+pub enum Response {
+    Accounts { accounts: Vec<Account> },
+    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>,
+    },
+    NoIndex,
+    Ok,
+    Error { message: String },
+    Catalog { schemas: Vec<TableSchemaWire> },
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct TableSchemaWire {
+    pub table: String,
+    pub columns: Vec<SchemaColumn>,
+    #[serde(default)]
+    pub row_count: u64,
+    #[serde(default)]
+    pub indexes: Vec<IndexWire>,
+    #[serde(default)]
+    pub stats: Vec<ColumnStatWire>,
+}