example for connection.GetTyped() and a tuple with slice/array members

[zachgrayio]

So far I've been unable to work out how to implement MsgPack decoder for the simple tuple:

type Tuple struct {
	Key      string
	Value    []byte
}

and the examples don't really show how to do this. no matter what I try, I'm met with ER_INVALID_MSGPACK: Invalid MsgPack - packet body

Can someone point me in the right direction?

[zachgrayio]

Update for others who might be having similar issues:

Since I'm just storing a []byte as value, I used a simple string encoder and just cast the []byte value back and forth as needed. Thus the msgpack decode is trivial.

Secondly, while I didn't find it in any of the examples, I did realize that conn.SelectAsync is called under the hood by conn.GetTyped and it expects a tarantool.* Key wrapper around the key value; so changing my call to use tarantool.StringKey{mystring} solved the issue; it was a Key error, not an issue with the MsgPack encoding of my payload itself (I wasn't getting that far).

[oleg-jukovec]

Thank you for highlighting the problem. We probably need to add examples for StringKey, IntIntKey or a paragraph to the documentation: how-to use own key.

A quick example for the issue (just an example, we need to find an elegant solution):

diff --git a/config.lua b/config.lua
index abea457..cedd60d 100644
--- a/config.lua
+++ b/config.lua
@@ -11,6 +11,12 @@ box.once("init", function()
     })
     s:create_index('primary', {type = 'tree', parts = {1, 'uint'}, if_not_exists = true})
 
+    local s = box.schema.space.create('test_string_byte', {
+        id = 667,
+        if_not_exists = true,
+    })
+    s:create_index('primary', {type = 'tree', parts = {1, 'string'}, if_not_exists = true})
+
     local sp = box.schema.space.create('SQL_TEST', {
         id = 519,
         if_not_exists = true,
diff --git a/example_test.go b/example_test.go
index cd4c787..5d7d552 100644
--- a/example_test.go
+++ b/example_test.go
@@ -18,6 +18,32 @@ type Tuple struct {
        Name     string
 }
 
+type TupleStringByte struct {
+       Key             string
+       Value   []byte
+}
+
+func ExampleStringKey() {
+       conn := example_connect()
+       defer conn.Close()
+
+       _, err := conn.Replace("test_string_byte", []interface{}{"asd", []byte{0x01, 0x02, 0x03, 0x04, 0x00, 0x00}})
+       if err != nil {
+               fmt.Printf("error in replace is %v", err)
+               return
+       }
+
+       var res []TupleStringByte
+       err = conn.SelectTyped("test_string_byte", 0, 0, 100, tarantool.IterEq, tarantool.StringKey{"asd"}, &res)
+       if err != nil {
+               fmt.Printf("error in select is %v", err)
+               return
+       }
+       fmt.Printf("response is %#v\n", res)
+       // Output:
+       // response is []tarantool_test.TupleByte{tarantool_test.TupleByte{Key:"asd", Value:[]uint8{0x1, 0x2, 0x3, 0x4, 0x0, 0x0}}}
+}
+
 func example_connect() *tarantool.Connection {
        conn, err := tarantool.Connect(server, opts)
        if err != nil {