verifier.go

package pg2mysql

import (
	"errors"
	"fmt"
)

type Verifier interface {
	Verify() error
}

type verifier struct {
	src, dst DB
	watcher  VerifierWatcher
}

func NewVerifier(src, dst DB, watcher VerifierWatcher) Verifier {
	return &verifier{
		src:     src,
		dst:     dst,
		watcher: watcher,
	}
}

func (v *verifier) Verify() error {
	srcSchema, err := BuildSchema(v.src)
	if err != nil {
		return fmt.Errorf("failed to build source schema: %s", err)
	}

	var verifyErr error
	for _, table := range srcSchema.Tables {
		v.watcher.TableVerificationDidStart(table.Name)

		var missingRows int64
		var missingIDs []string
		err = EachMissingRow(v.src, v.dst, table, func(scanArgs []interface{}) error {
			if colIndex, _, getColErr := table.GetColumn("id"); getColErr == nil {
				if colID, ok := scanArgs[colIndex].(*interface{}); ok {
					missingIDs = append(missingIDs, fmt.Sprintf("%v", *colID))
				}
			}
			missingRows++

			return nil
		})
		if missingRows > 0 || err != nil {
			verifyErr = errors.New("verify failed")
		}
		if err != nil {
			v.watcher.TableVerificationDidFinishWithError(table.Name, err)
			continue
		}

		v.watcher.TableVerificationDidFinish(table.Name, missingRows, missingIDs)
	}

	return verifyErr
}