From f348a8f2acdea910e14e4820115f12cd09801172 Mon Sep 17 00:00:00 2001
From: Ryan Leckey <ryan@launchbadge.com>
Date: Thu, 18 Feb 2021 21:43:08 -0800
Subject: [PATCH] feat(mysql): expand MySqlTypeInfo, MySqlTypeId

---
 sqlx-mysql/src/type_id.rs   | 29 ++++++++++++++++++++++++----
 sqlx-mysql/src/type_info.rs | 38 +++++++++++++++++++++++--------------
 2 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/sqlx-mysql/src/type_id.rs b/sqlx-mysql/src/type_id.rs
index fe68bca6..4b3b18d9 100644
--- a/sqlx-mysql/src/type_id.rs
+++ b/sqlx-mysql/src/type_id.rs
@@ -1,5 +1,7 @@
+use crate::protocol::{ColumnDefinition, ColumnFlags};
+
 /// A unique identifier for a MySQL data type.
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(
     any(feature = "offline", feature = "serde"),
     derive(serde::Serialize, serde::Deserialize)
@@ -9,18 +11,32 @@ pub struct MySqlTypeId(u8, u8);
 // a flag byte which has the highest bit set to indicate the type is unsigned
 const UNSIGNED: u8 = 0x80;
 
+impl MySqlTypeId {
+    pub(crate) const fn new(def: &ColumnDefinition) -> Self {
+        Self(def.ty, if def.flags.contains(ColumnFlags::UNSIGNED) { UNSIGNED } else { 0 })
+    }
+
+    pub(crate) const fn ty(self) -> u8 {
+        self.0
+    }
+
+    pub(crate) const fn flags(self) -> u8 {
+        self.1
+    }
+}
+
 impl MySqlTypeId {
     /// Returns `true` if this is the `NULL` type.
     ///
     /// For MySQL, this occurs in types from parameters or when `NULL` is
     /// directly used in an expression by itself, such as `SELECT NULL`.
     ///
-    pub const fn is_null(&self) -> bool {
+    pub(crate) const fn is_null(&self) -> bool {
         matches!(*self, MySqlTypeId::NULL)
     }
 
     /// Returns `true` if this is an integer data type.
-    pub const fn is_integer(&self) -> bool {
+    pub(crate) const fn is_integer(&self) -> bool {
         matches!(
             *self,
             MySqlTypeId::TINYINT
@@ -36,8 +52,13 @@ impl MySqlTypeId {
         )
     }
 
+    /// Returns `true` if this is an unsigned data type.
+    pub(crate) const fn is_unsigned(&self) -> bool {
+        self.1 == UNSIGNED
+    }
+
     /// Returns the name for this MySQL data type.
-    pub const fn name(&self) -> &'static str {
+    pub(crate) const fn name(&self) -> &'static str {
         match *self {
             Self::NULL => "NULL",
 
diff --git a/sqlx-mysql/src/type_info.rs b/sqlx-mysql/src/type_info.rs
index 5906b7a4..fba4bf89 100644
--- a/sqlx-mysql/src/type_info.rs
+++ b/sqlx-mysql/src/type_info.rs
@@ -1,4 +1,7 @@
-use crate::MySqlTypeId;
+use sqlx_core::TypeInfo;
+
+use crate::protocol::ColumnDefinition;
+use crate::{MySql, MySqlTypeId};
 
 /// Provides information about a MySQL type.
 #[derive(Debug, Clone)]
@@ -8,11 +11,16 @@ use crate::MySqlTypeId;
 )]
 pub struct MySqlTypeInfo {
     id: MySqlTypeId,
-    flags: u16,
-    charset: u8,
+    charset: u16,
 
     // [max_size] for integer types, this is (M) in BIT(M) or TINYINT(M)
-    max_size: u8,
+    max_size: u32,
+}
+
+impl MySqlTypeInfo {
+    pub(crate) const fn new(def: &ColumnDefinition) -> Self {
+        Self { id: MySqlTypeId::new(def), charset: def.charset, max_size: def.max_size }
+    }
 }
 
 impl MySqlTypeInfo {
@@ -20,18 +28,20 @@ impl MySqlTypeInfo {
     pub const fn id(&self) -> MySqlTypeId {
         self.id
     }
+}
 
-    /// Returns `true` if this is the `NULL` type.
-    ///
-    /// For MySQL, this occurs in types from parameters or when `NULL` is
-    /// directly used in an expression by itself, such as `SELECT NULL`.
-    ///
-    pub const fn is_null(&self) -> bool {
-        self.id().is_null()
+impl TypeInfo for MySqlTypeInfo {
+    type Database = MySql;
+
+    fn id(&self) -> MySqlTypeId {
+        self.id()
     }
 
-    /// Returns the name for this MySQL data type.
-    pub const fn name(&self) -> &'static str {
-        self.id().name()
+    fn is_unknown(&self) -> bool {
+        self.id.is_null()
+    }
+
+    fn name(&self) -> &str {
+        self.id.name()
     }
 }