Added incr_by

src/cmd/string.rs

@@ -1,6 +1,12 @@
 use crate::{connection::Connection, error::Error, value::Value};
+use std::convert::TryInto;
 use bytes::Bytes;
 
+pub fn incr_by(conn: &Connection, args: &[Bytes]) -> Result<Value, Error> {
+    let by: i64 = (&Value::Blob(args[2].to_owned())).try_into()?;
+    conn.db().incr(&args[1], by)
+}
+
 pub fn incr(conn: &Connection, args: &[Bytes]) -> Result<Value, Error> {
     conn.db().incr(&args[1], 1)
 }

src/db/mod.rs

@@ -49,8 +49,8 @@ impl Db {
                 Ok(val.into())
             }
             None => {
-                entries.insert(key.clone(), "1".into());
-                Ok((1_i64).into())
+                entries.insert(key.clone(), incr_by.into());
+                Ok((incr_by  as i64).into())
             }
         }
     }

src/dispatcher.rs

@@ -52,6 +52,11 @@ dispatcher! {
         ["write" "denyoom" "fast"],
         2,
     },
+    incrby {
+        cmd::string::incr_by,
+        ["write" "denyoom" "fast"],
+        3,
+    },
     set {
         cmd::string::set,
         ["random" "loading" "stale"],