Add 'development/libs/barrel/' from commit 'f3b8ab47d3a3ad8d43dc2b89a5eec1c4e87b033d'

git-subtree-dir: development/libs/barrel
git-subtree-mainline: 518551bfa6ef7d6508b425afa4bfb3ddbd418141
git-subtree-split: f3b8ab47d3a3ad8d43dc2b89a5eec1c4e87b033d

1 files changed, 162 insertions, 0 deletions

diff --git a/development/libs/barrel/src/backend/mysql.rs b/development/libs/barrel/src/backend/mysql.rs
new file mode 100644
index 000000000000..5b27c69e334a
--- /dev/null
+++ b/development/libs/barrel/src/backend/mysql.rs
@@ -0,0 +1,162 @@
+//! MySQL implementation of a generator
+//!
+//! This module generates strings that are specific to MySQL
+//! databases. They should be thoroughly tested via unit testing
+
+use super::SqlGenerator;
+use crate::types::{BaseType, Type};
+
+/// A simple macro that will generate a schema prefix if it exists
+macro_rules! prefix {
+    ($schema:expr) => {
+        $schema
+            .map(|s| format!("`{}`.", s))
+            .unwrap_or_else(|| String::new())
+    };
+}
+
+/// MySQL generator backend
+pub struct MySql;
+impl SqlGenerator for MySql {
+    fn create_table(name: &str, schema: Option<&str>) -> String {
+        format!("CREATE TABLE {}`{}`", prefix!(schema), name)
+    }
+
+    fn create_table_if_not_exists(name: &str, schema: Option<&str>) -> String {
+        format!("CREATE TABLE {}`{}` IF NOT EXISTS", prefix!(schema), name)
+    }
+
+    fn drop_table(name: &str, schema: Option<&str>) -> String {
+        format!("DROP TABLE {}`{}`", prefix!(schema), name)
+    }
+
+    fn drop_table_if_exists(name: &str, schema: Option<&str>) -> String {
+        format!("DROP TABLE {}`{}` IF EXISTS", prefix!(schema), name)
+    }
+
+    fn rename_table(old: &str, new: &str, schema: Option<&str>) -> String {
+        let schema = prefix!(schema);
+        format!("RENAME TABLE {}`{}` TO {}`{}`", schema, old, schema, new)
+    }
+
+    fn alter_table(name: &str, schema: Option<&str>) -> String {
+        format!("ALTER TABLE {}`{}`", prefix!(schema), name)
+    }
+
+    fn add_column(ex: bool, schema: Option<&str>, name: &str, tt: &Type) -> String {
+        let bt: BaseType = tt.get_inner();
+        use self::BaseType::*;
+        let name = format!("`{}`", name);
+
+        #[cfg_attr(rustfmt, rustfmt_skip)] /* This shouldn't be formatted. It's too long */
+        format!(
+            "{}{}{}{}{}",
+            match bt {
+                Text => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Varchar(_) => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Primary => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Integer => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Float => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Double => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                UUID => unimplemented!(),
+                Json => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Boolean => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Date => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Binary => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Foreign(_, _, _) => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Custom(_) => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(bt, schema)),
+                Array(it) => format!("{}{} {}", MySql::prefix(ex), name, MySql::print_type(Array(Box::new(*it)), schema)),
+                Index(_) => unreachable!(),
+            },
+            match tt.primary {
+                true => " PRIMARY KEY",
+                false => "",
+            },
+            match (&tt.default).as_ref() {
+                Some(ref m) => format!(" DEFAULT '{}'", m),
+                _ => format!(""),
+            },
+            match tt.nullable {
+                true => "",
+                false => " NOT NULL",
+            },
+            match tt.unique {
+                true => " UNIQUE",
+                false => "",
+            },
+        )
+    }
+
+    fn drop_column(name: &str) -> String {
+        format!("DROP COLUMN `{}`", name)
+    }
+
+    fn rename_column(old: &str, new: &str) -> String {
+        format!("CHANGE COLUMN `{}` `{}`", old, new)
+    }
+
+    fn create_index(table: &str, schema: Option<&str>, name: &str, _type: &Type) -> String {
+        // FIXME: Implement Mysql specific index builder here
+        format!(
+            "CREATE {} INDEX `{}` ON {}`{}` ({})",
+            match _type.unique {
+                true => "UNIQUE",
+                false => "",
+            },
+            name,
+            prefix!(schema),
+            table,
+            match _type.inner {
+                BaseType::Index(ref cols) => cols
+                    .iter()
+                    .map(|col| format!("`{}`", col))
+                    .collect::<Vec<_>>()
+                    .join(", "),
+                _ => unreachable!(),
+            }
+        )
+    }
+
+    fn drop_index(name: &str) -> String {
+        format!("DROP INDEX `{}`", name)
+    }
+}
+
+impl MySql {
+    fn prefix(ex: bool) -> String {
+        match ex {
+            true => format!("ADD COLUMN "),
+            false => format!(""),
+        }
+    }
+
+    fn print_type(t: BaseType, schema: Option<&str>) -> String {
+        use self::BaseType::*;
+        match t {
+            Text => format!("TEXT"),
+            Varchar(l) => match l {
+                0 => format!("VARCHAR"), // For "0" remove the limit
+                _ => format!("VARCHAR({})", l),
+            },
+            /* "NOT NULL" is added here because normally primary keys are implicitly not-null */
+            Primary => format!("INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY"),
+            Integer => format!("INTEGER"),
+            Float => format!("FLOAT"),
+            Double => format!("DOUBLE"),
+            UUID => format!("CHAR(36)"),
+            Boolean => format!("BOOLEAN"),
+            Date => format!("DATE"),
+            Json => format!("JSON"),
+            Binary => format!("BYTEA"),
+            Foreign(s, t, refs) => format!(
+                "INTEGER REFERENCES {}{}({})",
+                prefix!(s),
+                t,
+                refs.0.join(",")
+            ),
+            Custom(t) => format!("{}", t),
+            Array(meh) => format!("{}[]", MySql::print_type(*meh, schema)),
+            Index(_) => unreachable!(),
+        }
+    }
+}