(entities) Adds change provider entity and mysql backed store for it

entity/BUILD.bazel

@@ -2,7 +2,10 @@ load("@rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "entity",
-    srcs = ["request.go"],
+    srcs = [
+        "change_provider.go",
+        "request.go",
+    ],
     importpath = "github.com/uber/submitqueue/entity",
     visibility = ["//visibility:public"],
 )

entity/change_provider.go

@@ -0,0 +1,15 @@
+package entity
+
+// ChangeProvider represents a code change from an external provider (e.g., a GitHub pull request or Gerrit changelist)
+// along with its associated metadata. The object is immutable after creation.
+type ChangeProvider struct {
+	// RequestID is the globally unique identifier for the land request. Format: "<queue>/<counter_value>".
+	RequestID string
+	// ChangeProviderSrc defines the source of the change. For e.g. - Github, Gitlab etc.
+	ChangeProviderSrc string
+	// ChangeProviderID is the identifier specified by the change provider source. For e.g. - Github PR ID etc.
+	ChangeProviderID string
+	// Metadata is the interesting data from the change provider that we want to store.
+	// This is a freeform JSON object.
+	Metadata map[string]string
+}

extension/storage/BUILD.bazel

@@ -3,6 +3,7 @@ load("@rules_go//go:def.bzl", "go_library")
 go_library(
     name = "storage",
     srcs = [
+        "change_provider_store.go",
         "request_store.go",
         "storage.go",
     ],

extension/storage/change_provider_store.go

@@ -0,0 +1,26 @@
+package storage
+
+import (
+	"context"
+
+	"github.com/uber/submitqueue/entity"
+)
+
+// ChangeProviderStore is an interface that defines methods for managing change provider information in the database.
+type ChangeProviderStore interface {
+	// Get retrieves information about a change by ID.
+	// Returns ErrNotFound if the change provider is not found.
+	//
+	// Note: The order of ChangeProvider entities here is not guaranteed to
+	// be the same as the request to which it belongs. The caller is repsonsible
+	// for inspecting and mapping the result of this function to the
+	// order of changes within the original request.
+	//
+	Get(ctx context.Context, requestID string) ([]entity.ChangeProvider, error)
+
+	// Create creates a new change provider.
+	Create(ctx context.Context, changeProvider entity.ChangeProvider) error
+
+	// There is no update function since once created, data is only ever read from this
+	// store.
+}

extension/storage/mysql/BUILD.bazel

@@ -3,6 +3,7 @@ load("@rules_go//go:def.bzl", "go_library")
 go_library(
     name = "mysql",
     srcs = [
+        "change_provider_store.go",
         "request_store.go",
         "storage.go",
     ],

extension/storage/mysql/change_provider_store.go

@@ -0,0 +1,88 @@
+package mysql
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/go-sql-driver/mysql"
+
+	"github.com/uber/submitqueue/entity"
+	"github.com/uber/submitqueue/extension/storage"
+)
+
+type changeProviderStore struct {
+	db *sql.DB
+}
+
+// NewChangeProviderStore creates a new MySQL-backed ChangeProviderStore.
+func NewChangeProviderStore(db *sql.DB) storage.ChangeProviderStore {
+	return &changeProviderStore{db: db}
+}
+
+// Get retrieves change provider(s) by request ID. Returns ErrNotFound if the change provider is not found.
+//
+// Note: The order of ChangeProvider entities returned here is not guaranteed
+// to be the same as the request to which it belongs. The caller is repsonsible
+// for inspecting and mapping the result of this function to the
+// order of changes within the original request.
+//
+func (s *changeProviderStore) Get(ctx context.Context, requestID string) ([]entity.ChangeProvider, error) {
+	rows, err := s.db.QueryContext(ctx,
+		"SELECT request_id, change_provider_src, change_provider_id, metadata FROM change_provider WHERE request_id = ?",
+		requestID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get change provider entities requestID=%s from the database: %w", requestID, err)
+	}
+	defer rows.Close()
+
+	var results []entity.ChangeProvider
+	for rows.Next() {
+		var cp entity.ChangeProvider
+		var metadataJSON []byte
+
+		if err := rows.Scan(&cp.RequestID, &cp.ChangeProviderSrc, &cp.ChangeProviderID, &metadataJSON); err != nil {
+			return nil, fmt.Errorf("failed to scan change provider entity requestID=%s from the database: %w", requestID, err)
+		}
+
+		if err := json.Unmarshal(metadataJSON, &cp.Metadata); err != nil {
+			return nil, fmt.Errorf("failed to unmarshal metadata for change provider entity requestID=%s from the database: %w", requestID, err)
+		}
+
+		results = append(results, cp)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("failed to iterate change provider entities requestID=%s from the database: %w", requestID, err)
+	}
+
+	if len(results) == 0 {
+		return nil, storage.WrapNotFound(fmt.Errorf("change provider entity requestID=%s", requestID))
+	}
+
+	return results, nil
+}
+
+// Create creates a new change provider. Returns ErrAlreadyExists if the entry already exists.
+func (s *changeProviderStore) Create(ctx context.Context, changeProvider entity.ChangeProvider) error {
+	metadataJSON, err := json.Marshal(changeProvider.Metadata)
+	if err != nil {
+		return fmt.Errorf("failed to marshal metadata id=%s for Create change provider entity: %w", changeProvider.RequestID, err)
+	}
+
+	_, err = s.db.ExecContext(ctx,
+		"INSERT INTO change_provider (request_id, change_provider_src, change_provider_id, metadata) VALUES (?, ?, ?, ?)",
+		changeProvider.RequestID, changeProvider.ChangeProviderSrc, changeProvider.ChangeProviderID, metadataJSON,
+	)
+	if err != nil {
+		var mysqlErr *mysql.MySQLError
+		if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
+			return fmt.Errorf("change provider entity id=%s: %w", changeProvider.RequestID, storage.ErrAlreadyExists)
+		}
+		return fmt.Errorf("failed to insert change provider entity id=%s: %w", changeProvider.RequestID, err)
+	}
+
+	return nil
+}

extension/storage/mysql/schema/change_provider.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS change_provider (
+    request_id VARCHAR(255) NOT NULL,
+    change_provider_src VARCHAR(255) NOT NULL,
+    change_provider_id VARCHAR(255) NOT NULL,
+    metadata JSON NOT NUll,
+    PRIMARY KEY (request_id,change_provider_src,change_provider_id)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

extension/storage/mysql/storage.go

@@ -28,8 +28,9 @@ type MySQLParameters struct {
 }
 
 type mysqlStorage struct {
-	db           *sql.DB
-	requestStore storage.RequestStore
+	db                  *sql.DB
+	requestStore        storage.RequestStore
+	changeProviderStore storage.ChangeProviderStore
 }
 
 // NewStorage creates a new MySQL storage.
@@ -50,8 +51,9 @@ func NewStorage(p MySQLParameters) (storage.Storage, error) {
 	}
 
 	return &mysqlStorage{
-		db:           db,
-		requestStore: NewRequestStore(db),
+		db:                  db,
+		requestStore:        NewRequestStore(db),
+		changeProviderStore: NewChangeProviderStore(db),
 	}, nil
 }
 
@@ -60,6 +62,11 @@ func (f *mysqlStorage) GetRequestStore() storage.RequestStore {
 	return f.requestStore
 }
 
+// GetChangeProviderStore returns the MySQL-backed ChangeProviderStore.
+func (f *mysqlStorage) GetChangeProviderStore() storage.ChangeProviderStore {
+	return f.changeProviderStore
+}
+
 // Close closes the underlying database connection.
 func (f *mysqlStorage) Close() error {
 	return f.db.Close()

extension/storage/storage.go

@@ -29,6 +29,9 @@ type Storage interface {
 	// GetRequestStore returns the RequestStore instance.
 	GetRequestStore() RequestStore
 
+	// GetChangeProviderStore returns the ChangeProviderStore instance.
+	GetChangeProviderStore() ChangeProviderStore
+
 	// Close closes the storage and all underlying connections. Should only be called once at the end of the program.
 	Close() error
 }

gateway/controller/land_test.go

@@ -38,24 +38,48 @@ func (m *mockRequestStore) UpdateState(ctx context.Context, id string, version i
 	return nil
 }
 
+type mockChangeProviderStore struct {
+	createFunc func(ctx context.Context, changeProvider entity.ChangeProvider) error
+}
+
+func (m *mockChangeProviderStore) Get(ctx context.Context, requestID string) ([]entity.ChangeProvider, error) {
+	return nil, nil
+}
+
+func (m *mockChangeProviderStore) Create(ctx context.Context, changeProvider entity.ChangeProvider) error {
+	return m.createFunc(ctx, changeProvider)
+}
+
 type mockStorage struct {
-	requestStore storage.RequestStore
+	requestStore        storage.RequestStore
+	changeProviderStore storage.ChangeProviderStore
 }
 
 func (m *mockStorage) GetRequestStore() storage.RequestStore {
 	return m.requestStore
 }
 
+func (m *mockStorage) GetChangeProviderStore() storage.ChangeProviderStore {
+	return m.changeProviderStore
+}
+
 func (m *mockStorage) Close() error {
 	return nil
 }
 
 func TestNewLandController(t *testing.T) {
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			return nil
+	store := &mockStorage{
+		requestStore: &mockRequestStore{
+			createFunc: func(ctx context.Context, request entity.Request) error {
+				return nil
+			},
 		},
-	}}
+		changeProviderStore: &mockChangeProviderStore{
+			createFunc: func(ctx context.Context, changeProvider entity.ChangeProvider) error {
+				return nil
+			},
+		},
+	}
 	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
 		return 1, nil
 	}}
@@ -64,11 +88,18 @@ func TestNewLandController(t *testing.T) {
 }
 
 func TestLand_ReturnsSqid(t *testing.T) {
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			return nil
+	store := &mockStorage{
+		requestStore: &mockRequestStore{
+			createFunc: func(ctx context.Context, request entity.Request) error {
+				return nil
+			},
 		},
-	}}
+		changeProviderStore: &mockChangeProviderStore{
+			createFunc: func(ctx context.Context, changeProvider entity.ChangeProvider) error {
+				return nil
+			},
+		},
+	}
 	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
 		return 1, nil
 	}}
@@ -88,12 +119,19 @@ func TestLand_ReturnsSqid(t *testing.T) {
 func TestLand_PassesCorrectParametersToStore(t *testing.T) {
 	var capturedRequest entity.Request
 
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			capturedRequest = request
-			return nil
+	store := &mockStorage{
+		requestStore: &mockRequestStore{
+			createFunc: func(ctx context.Context, request entity.Request) error {
+				capturedRequest = request
+				return nil
+			},
 		},
-	}}
+		changeProviderStore: &mockChangeProviderStore{
+			createFunc: func(ctx context.Context, changeProvider entity.ChangeProvider) error {
+				return nil
+			},
+		},
+	}
 	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
 		return 42, nil
 	}}
@@ -119,11 +157,18 @@ func TestLand_PassesCorrectParametersToStore(t *testing.T) {
 }
 
 func TestLand_ReturnsErrorOnStorageFailure(t *testing.T) {
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			return fmt.Errorf("database connection failed")
+	store := &mockStorage{
+		requestStore: &mockRequestStore{
+			createFunc: func(ctx context.Context, request entity.Request) error {
+				return fmt.Errorf("database connection failed")
+			},
 		},
-	}}
+		changeProviderStore: &mockChangeProviderStore{
+			createFunc: func(ctx context.Context, changeProvider entity.ChangeProvider) error {
+				return nil
+			},
+		},
+	}
 	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
 		return 1, nil
 	}}
@@ -140,11 +185,18 @@ func TestLand_ReturnsErrorOnStorageFailure(t *testing.T) {
 }
 
 func TestLand_ReturnsErrorOnCounterFailure(t *testing.T) {
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			return nil
+	store := &mockStorage{
+		requestStore: &mockRequestStore{
+			createFunc: func(ctx context.Context, request entity.Request) error {
+				return nil
+			},
 		},
-	}}
+		changeProviderStore: &mockChangeProviderStore{
+			createFunc: func(ctx context.Context, changeProvider entity.ChangeProvider) error {
+				return nil
+			},
+		},
+	}
 	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
 		return 0, fmt.Errorf("counter unavailable")
 	}}
@@ -163,11 +215,18 @@ func TestLand_ReturnsErrorOnCounterFailure(t *testing.T) {
 func TestLand_CounterDomainIncludesQueue(t *testing.T) {
 	var capturedDomain string
 
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			return nil
+	store := &mockStorage{
+		requestStore: &mockRequestStore{
+			createFunc: func(ctx context.Context, request entity.Request) error {
+				return nil
+			},
 		},
-	}}
+		changeProviderStore: &mockChangeProviderStore{
+			createFunc: func(ctx context.Context, changeProvider entity.ChangeProvider) error {
+				return nil
+			},
+		},
+	}
 	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
 		capturedDomain = domain
 		return 1, nil