Added logic for working with Tarantool schema via Box

- Implemented the `box.Schema()` method that returns a `Schema` object for schema-related operations

CHANGELOG.md

@@ -11,6 +11,7 @@ Versioning](http://semver.org/spec/v2.0.0.html) except to the first release.
 ### Added
 
 - Extend box with replication information (#427).
+- Implemented box.schema.user operations requests and sugar interface.
 
 ### Changed
 

box/box.go

@@ -17,6 +17,12 @@ func New(conn tarantool.Doer) *Box {
 	}
 }
 
+// Schema returns a new Schema instance, providing access to schema-related operations.
+// It uses the connection from the Box instance to communicate with Tarantool.
+func (b *Box) Schema() *Schema {
+	return NewSchema(b.conn)
+}
+
 // Info retrieves the current information of the Tarantool instance.
 // It calls the "box.info" function and parses the result into the Info structure.
 func (b *Box) Info() (Info, error) {

box/info.go

@@ -112,18 +112,14 @@ func (ir *InfoResponse) DecodeMsgpack(d *msgpack.Decoder) error {
 // InfoRequest represents a request to retrieve information about the Tarantool instance.
 // It implements the tarantool.Request interface.
 type InfoRequest struct {
-	baseRequest
-}
-
-// Body method is used to serialize the request's body.
-// It is part of the tarantool.Request interface implementation.
-func (i InfoRequest) Body(res tarantool.SchemaResolver, enc *msgpack.Encoder) error {
-	return i.impl.Body(res, enc)
+	*tarantool.CallRequest // Underlying Tarantool call request.
 }
 
 // NewInfoRequest returns a new empty info request.
 func NewInfoRequest() InfoRequest {
-	req := InfoRequest{}
-	req.impl = newCall("box.info")
-	return req
+	callReq := tarantool.NewCallRequest("box.info")
+
+	return InfoRequest{
+		callReq,
+	}
 }

box/schema.go

@@ -0,0 +1,21 @@
+package box
+
+import "github.com/tarantool/go-tarantool/v2"
+
+// Schema represents the schema-related operations in Tarantool.
+// It holds a connection to interact with the Tarantool instance.
+type Schema struct {
+	conn tarantool.Doer // Connection interface for interacting with Tarantool.
+}
+
+// NewSchema creates a new Schema instance with the provided Tarantool connection.
+// It initializes a Schema object that can be used for schema-related operations
+// such as managing users, tables, and other schema elements in the Tarantool instance.
+func NewSchema(conn tarantool.Doer) *Schema {
+	return &Schema{conn: conn} // Pass the connection to the Schema.
+}
+
+// User returns a new SchemaUser instance, allowing schema-related user operations.
+func (s *Schema) User() *SchemaUser {
+	return NewSchemaUser(s.conn)
+}

box/schema_user.go

@@ -0,0 +1,221 @@
+package box
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/tarantool/go-tarantool/v2"
+	"github.com/vmihailenco/msgpack/v5"
+)
+
+// SchemaUser provides methods to interact with schema-related user operations in Tarantool.
+type SchemaUser struct {
+	conn tarantool.Doer // Connection interface for interacting with Tarantool.
+}
+
+// NewSchemaUser creates a new SchemaUser instance with the provided Tarantool connection.
+// It initializes a SchemaUser object, which provides methods to perform user-related
+// schema operations (such as creating, modifying, or deleting users) in the Tarantool instance.
+func NewSchemaUser(conn tarantool.Doer) *SchemaUser {
+	return &SchemaUser{conn: conn}
+}
+
+// UserExistsRequest represents a request to check if a user exists in Tarantool.
+type UserExistsRequest struct {
+	*tarantool.CallRequest // Underlying Tarantool call request.
+}
+
+// UserExistsResponse represents the response to a user existence check.
+type UserExistsResponse struct {
+	Exists bool // True if the user exists, false otherwise.
+}
+
+// DecodeMsgpack decodes the response from a Msgpack-encoded byte slice.
+func (uer *UserExistsResponse) DecodeMsgpack(d *msgpack.Decoder) error {
+	arrayLen, err := d.DecodeArrayLen()
+	if err != nil {
+		return err
+	}
+
+	// Ensure that the response array contains exactly 1 element (the "Exists" field).
+	if arrayLen != 1 {
+		return fmt.Errorf("protocol violation; expected 1 array entry, got %d", arrayLen)
+	}
+
+	// Decode the boolean value indicating whether the user exists.
+	uer.Exists, err = d.DecodeBool()
+
+	return err
+}
+
+// NewUserExistsRequest creates a new request to check if a user exists.
+func NewUserExistsRequest(username string) UserExistsRequest {
+	callReq := tarantool.NewCallRequest("box.schema.user.exists").Args([]interface{}{username})
+
+	return UserExistsRequest{
+		callReq,
+	}
+}
+
+// Exists checks if the specified user exists in Tarantool.
+func (u *SchemaUser) Exists(ctx context.Context, username string) (bool, error) {
+	// Create a request and send it to Tarantool.
+	req := NewUserExistsRequest(username).Context(ctx)
+	resp := &UserExistsResponse{}
+
+	// Execute the request and parse the response.
+	err := u.conn.Do(req).GetTyped(resp)
+
+	return resp.Exists, err
+}
+
+// UserCreateOptions represents options for creating a user in Tarantool.
+type UserCreateOptions struct {
+	// IfNotExists - if true, prevents an error if the user already exists.
+	IfNotExists bool `msgpack:"if_not_exists"`
+	// Password for the new user.
+	Password string `msgpack:"password"`
+}
+
+// UserCreateRequest represents a request to create a new user in Tarantool.
+type UserCreateRequest struct {
+	*tarantool.CallRequest // Underlying Tarantool call request.
+}
+
+// NewUserCreateRequest creates a new request to create a user with specified options.
+func NewUserCreateRequest(username string, options UserCreateOptions) UserCreateRequest {
+	callReq := tarantool.NewCallRequest("box.schema.user.create").
+		Args([]interface{}{username, options})
+
+	return UserCreateRequest{
+		callReq,
+	}
+}
+
+// UserCreateResponse represents the response to a user creation request.
+type UserCreateResponse struct{}
+
+// DecodeMsgpack decodes the response for a user creation request.
+// In this case, the response does not contain any data.
+func (uer *UserCreateResponse) DecodeMsgpack(_ *msgpack.Decoder) error {
+	return nil
+}
+
+// Create creates a new user in Tarantool with the given username and options.
+func (u *SchemaUser) Create(ctx context.Context, username string, options UserCreateOptions) error {
+	// Create a request and send it to Tarantool.
+	req := NewUserCreateRequest(username, options).Context(ctx)
+	resp := &UserCreateResponse{}
+
+	// Execute the request and handle the response.
+	fut := u.conn.Do(req)
+
+	err := fut.GetTyped(resp)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// UserDropOptions represents options for dropping a user in Tarantool.
+type UserDropOptions struct {
+	IfExists bool `msgpack:"if_exists"` // If true, prevents an error if the user does not exist.
+}
+
+// UserDropRequest represents a request to drop a user from Tarantool.
+type UserDropRequest struct {
+	*tarantool.CallRequest // Underlying Tarantool call request.
+}
+
+// NewUserDropRequest creates a new request to drop a user with specified options.
+func NewUserDropRequest(username string, options UserDropOptions) UserDropRequest {
+	callReq := tarantool.NewCallRequest("box.schema.user.drop").
+		Args([]interface{}{username, options})
+
+	return UserDropRequest{
+		callReq,
+	}
+}
+
+// UserDropResponse represents the response to a user drop request.
+type UserDropResponse struct{}
+
+// Drop drops the specified user from Tarantool, with optional conditions.
+func (u *SchemaUser) Drop(ctx context.Context, username string, options UserDropOptions) error {
+	// Create a request and send it to Tarantool.
+	req := NewUserDropRequest(username, options).Context(ctx)
+	resp := &UserCreateResponse{}
+
+	// Execute the request and handle the response.
+	fut := u.conn.Do(req)
+
+	err := fut.GetTyped(resp)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// UserPasswordRequest represents a request to retrieve a user's password from Tarantool.
+type UserPasswordRequest struct {
+	*tarantool.CallRequest // Underlying Tarantool call request.
+}
+
+// NewUserPasswordRequest creates a new request to fetch the user's password.
+// It takes the username and constructs the request to Tarantool.
+func NewUserPasswordRequest(username string) UserPasswordRequest {
+	// Create a request to get the user's password.
+	callReq := tarantool.NewCallRequest("box.schema.user.password").Args([]interface{}{username})
+
+	return UserPasswordRequest{
+		callReq,
+	}
+}
+
+// UserPasswordResponse represents the response to the user password request.
+// It contains the password hash.
+type UserPasswordResponse struct {
+	Hash string // The password hash of the user.
+}
+
+// DecodeMsgpack decodes the response from Tarantool in Msgpack format.
+// It expects the response to be an array of length 1, containing the password hash string.
+func (upr *UserPasswordResponse) DecodeMsgpack(d *msgpack.Decoder) error {
+	// Decode the array length.
+	arrayLen, err := d.DecodeArrayLen()
+	if err != nil {
+		return err
+	}
+
+	// Ensure the array contains exactly 1 element (the password hash).
+	if arrayLen != 1 {
+		return fmt.Errorf("protocol violation; expected 1 array entry, got %d", arrayLen)
+	}
+
+	// Decode the string containing the password hash.
+	upr.Hash, err = d.DecodeString()
+
+	return err
+}
+
+// Password sends a request to retrieve the user's password from Tarantool.
+// It returns the password hash as a string or an error if the request fails.
+func (u *SchemaUser) Password(ctx context.Context, username string) (string, error) {
+	// Create the request and send it to Tarantool.
+	req := NewUserPasswordRequest(username).Context(ctx)
+	resp := &UserPasswordResponse{}
+
+	// Execute the request and handle the response.
+	fut := u.conn.Do(req)
+
+	// Get the decoded response.
+	err := fut.GetTyped(resp)
+	if err != nil {
+		return "", err
+	}
+
+	// Return the password hash.
+	return resp.Hash, nil
+}