Added utility methods

Author: sfackler

src/postgres/lib.rs

@@ -0,0 +1,114 @@
+extern mod sql;
+
+use sql::{ToSqlStr, FromSqlStr};
+
+use std::str;
+use std::ptr;
+
+mod ffi {
+    use std::libc::{c_char, c_int, c_uint, c_void};
+
+    pub type PGconn = c_void;
+    pub type PGresult = c_void;
+    pub type OId = c_uint;
+
+    pub enum ConnStatusType {
+        CONNECTION_OK,
+        CONNECTION_BAD,
+        CONNECTION_STARTED,
+        CONNECTION_MADE,
+        CONNECTION_AWAITING_RESPONSE,
+        CONNECTION_AUTH_OK,
+        CONNECTION_SETENV,
+        CONNECTION_SSL_STARTUP,
+        CONNECTION_NEEDED
+    }
+
+    pub enum ExecStatusType {
+        PGRES_EMPTY_QUERY = 0,
+        PGRES_COMMAND_OK,
+        PGRES_TUPLES_OK,
+        PGRES_COPY_OUT,
+        PGRES_COPY_IN,
+        PGRES_BAD_RESPONSE,
+        PGRES_NONFATAL_ERROR,
+        PGRES_FATAL_ERROR,
+        PGRES_COPY_BOTH,
+        PGRES_SINGLE_TUPLE
+    }
+
+    #[link_args = "-lpq"]
+    extern "C" {
+        fn PQconnectdb(conninfo: *c_char) -> *PGconn;
+        fn PQfinish(conn: *PGconn);
+        fn PQstatus(conn: *PGconn) -> ConnStatusType;
+        fn PQerrorMessage(conn: *PGconn) -> *c_char;
+        fn PQexecParams(conn: *PGconn, command: *c_char, nParams: c_int,
+                        paramTypes: *OId, paramValues: **c_char,
+                        paramLengths: *c_int, paramFormats: *c_int,
+                        resultFormat: c_int) -> *PGresult;
+        fn PQresultStatus(res: *PGresult) -> ExecStatusType;
+        fn PQresultErrorMessage(res: *PGresult) -> *c_char;
+        fn PQclear(res: *PGresult);
+        fn PQntuples(res: *PGresult) -> c_int;
+    }
+}
+
+fn open(name: &str) -> Result<~Connection, ~str> {
+    unsafe {
+        let conn = ~Connection {conn: do name.as_c_str |c_name| {
+            ffi::PQconnectdb(c_name)
+        }};
+
+        match ffi::PQstatus(conn.conn) {
+            ffi::CONNECTION_OK => Ok(conn),
+            _ => Err(str::raw::from_c_str(ffi::PQerrorMessage(conn.conn)))
+        }
+    }
+}
+
+pub struct Connection {
+    priv conn: *ffi::PGconn
+}
+
+impl Drop for Connection {
+    fn drop(&self) {
+        unsafe {
+            ffi::PQfinish(self.conn)
+        }
+    }
+}
+
+impl Connection {
+    fn query(&self, query: &str, params: &[@ToSqlStr]) -> Result<~RowIterator, ~str> {
+        Err(~"foo")
+    }
+}
+
+pub struct RowIterator {
+    priv res: *ffi::PGresult,
+    priv row: Row
+}
+
+impl Drop for RowIterator {
+    fn drop(&self) {
+        unsafe {
+            ffi::PQclear(self.res)
+        }
+    }
+}
+
+impl<'self> Iterator<&'self Row<'self>> for RowIterator {
+    fn next(&mut self) -> Option<&'self Row> {
+        unsafe {
+            if ffi::PQntuples(self.res) == self. {
+                return None;
+            }
+        }
+    }
+}
+
+pub struct Row<'self> {
+    priv res: *ffi::PGresult,
+    priv row: uint
+}

src/postgres/test.rs

@@ -0,0 +1,6 @@
+extern mod postgres;
+
+#[test]
+fn test_conn() {
+	printfln!("%?", postgres::open("postgres://postgres@localhost"));
+}

src/sql/lib.rs

@@ -0,0 +1,44 @@
+
+// pub trait Connection<'self, R: Rows<'self>> {
+//     fn query(&self, query: &str, params: &[@ToSqlStr]) -> Result<~R, ~str>;
+// }
+
+// pub trait Rows<'self, R: Row, I: Iterator<&'self R>>: Container {
+//     fn iter(&self) -> I;
+// }
+
+// pub trait Row: Container {
+//     fn get<T: FromSqlStr>(&self) -> Option<T>;
+// }
+
+pub trait ToSqlStr {
+    fn to_sql_str(&self) -> ~str;
+}
+
+impl ToSqlStr for int {
+    fn to_sql_str(&self) -> ~str {
+        self.to_str()
+    }
+}
+
+impl ToSqlStr for uint {
+    fn to_sql_str(&self) -> ~str {
+        self.to_str()
+    }
+}
+
+pub trait FromSqlStr {
+    fn from_sql_str(&str) -> Option<Self>;
+}
+
+impl FromSqlStr for int {
+    fn from_sql_str(s: &str) -> Option<int> {
+        FromStr::from_str(s)
+    }
+}
+
+impl FromSqlStr for uint {
+    fn from_sql_str(s: &str) -> Option<uint> {
+        FromStr::from_str(s)
+    }
+}

src/sqlite3/lib.rs

@@ -78,6 +78,25 @@ impl Connection {
             _ => Err(self.get_error())
         }
     }
+
+    pub fn update(&self, query: &str) -> Result<uint, ~str> {
+        self.prepare(query).chain(|stmt| stmt.update())
+    }
+
+    pub fn query<T>(&self, query: &str, blk: &fn (&mut ResultIterator) -> T)
+            -> Result<T, ~str> {
+        let stmt = match self.prepare(query) {
+            Ok(stmt) => stmt,
+            Err(err) => return Err(err)
+        };
+
+        let mut it = match stmt.query() {
+            Ok(it) => it,
+            Err(err) => return Err(err)
+        };
+
+        Ok(blk(&mut it))
+    }
 }
 
 pub struct PreparedStatement<'self> {

src/sqlite3/test.rs

@@ -3,13 +3,15 @@ extern mod sqlite3;
 #[test]
 fn test() {
     let conn = sqlite3::open("db").unwrap();
-    conn.prepare("DROP TABLE IF EXISTS foo").unwrap().update();
-    conn.prepare("CREATE TABLE foo (
+    conn.update("DROP TABLE IF EXISTS foo");
+    conn.update("CREATE TABLE foo (
                     id  BIGINT PRIMARY KEY
-                  )").unwrap().update();
-    conn.prepare("INSERT INTO foo (id) VALUES (101), (102)").unwrap().update();
-    let stmt = conn.prepare("SELECT id FROM foo").unwrap();
-    for stmt.query().unwrap().advance |row| {
-        printfln!("%u %d", row.len(), row.get(0).get());
-    }
+                 )");
+    conn.update("INSERT INTO foo (id) VALUES (101), (102)");
+
+    do conn.query("SELECT id FROM foo") |it| {
+        for it.advance |row| {
+            printfln!("%u %d", row.len(), row.get(0).get());
+        }
+    };
 }