Refactor privilege handling

src/core/database_privileges/base.rs

@@ -0,0 +1,103 @@
+//! This module contains some base datastructures and functionality for dealing with
+//! database privileges in MySQL.
+
+use std::fmt;
+
+use crate::core::protocol::{MySQLDatabase, MySQLUser};
+use serde::{Deserialize, Serialize};
+
+/// This is the list of fields that are used to fetch the db + user + privileges
+/// from the `db` table in the database. If you need to add or remove privilege
+/// fields, this is a good place to start.
+pub const DATABASE_PRIVILEGE_FIELDS: [&str; 13] = [
+    "Db",
+    "User",
+    "select_priv",
+    "insert_priv",
+    "update_priv",
+    "delete_priv",
+    "create_priv",
+    "drop_priv",
+    "alter_priv",
+    "index_priv",
+    "create_tmp_table_priv",
+    "lock_tables_priv",
+    "references_priv",
+];
+
+// NOTE: ord is needed for BTreeSet to accept the type, but it
+//       doesn't have any natural implementation semantics.
+
+/// Representation of the set of privileges for a single user on a single database.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
+pub struct DatabasePrivilegeRow {
+    // TODO: don't store the db and user here, let the type be stored in a mapping
+    pub db: MySQLDatabase,
+    pub user: MySQLUser,
+    pub select_priv: bool,
+    pub insert_priv: bool,
+    pub update_priv: bool,
+    pub delete_priv: bool,
+    pub create_priv: bool,
+    pub drop_priv: bool,
+    pub alter_priv: bool,
+    pub index_priv: bool,
+    pub create_tmp_table_priv: bool,
+    pub lock_tables_priv: bool,
+    pub references_priv: bool,
+}
+
+impl DatabasePrivilegeRow {
+    /// Gets the value of a privilege by its name as a &str.
+    pub fn get_privilege_by_name(&self, name: &str) -> Option<bool> {
+        match name {
+            "select_priv" => Some(self.select_priv),
+            "insert_priv" => Some(self.insert_priv),
+            "update_priv" => Some(self.update_priv),
+            "delete_priv" => Some(self.delete_priv),
+            "create_priv" => Some(self.create_priv),
+            "drop_priv" => Some(self.drop_priv),
+            "alter_priv" => Some(self.alter_priv),
+            "index_priv" => Some(self.index_priv),
+            "create_tmp_table_priv" => Some(self.create_tmp_table_priv),
+            "lock_tables_priv" => Some(self.lock_tables_priv),
+            "references_priv" => Some(self.references_priv),
+            _ => None,
+        }
+    }
+}
+
+impl fmt::Display for DatabasePrivilegeRow {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for field in DATABASE_PRIVILEGE_FIELDS.into_iter().skip(2) {
+            if self.get_privilege_by_name(field).unwrap() {
+                f.write_str(db_priv_field_human_readable_name(field).as_str())?;
+                f.write_str(": Y\n")?;
+            } else {
+                f.write_str(db_priv_field_human_readable_name(field).as_str())?;
+                f.write_str(": N\n")?;
+            }
+        }
+        Ok(())
+    }
+}
+
+/// Converts a database privilege field name to a human-readable name.
+pub fn db_priv_field_human_readable_name(name: &str) -> String {
+    match name {
+        "Db" => "Database".to_owned(),
+        "User" => "User".to_owned(),
+        "select_priv" => "Select".to_owned(),
+        "insert_priv" => "Insert".to_owned(),
+        "update_priv" => "Update".to_owned(),
+        "delete_priv" => "Delete".to_owned(),
+        "create_priv" => "Create".to_owned(),
+        "drop_priv" => "Drop".to_owned(),
+        "alter_priv" => "Alter".to_owned(),
+        "index_priv" => "Index".to_owned(),
+        "create_tmp_table_priv" => "Temp".to_owned(),
+        "lock_tables_priv" => "Lock".to_owned(),
+        "references_priv" => "References".to_owned(),
+        _ => format!("Unknown({})", name),
+    }
+}