go-sqlite3-hak5/backup_test.go

291 lines
9.7 KiB
Go

// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.
package sqlite3
import (
"database/sql"
"fmt"
"os"
"testing"
"time"
)
// The number of rows of test data to create in the source database.
// Can be used to control how many pages are available to be backed up.
const testRowCount = 100
// The maximum number of seconds after which the page-by-page backup is considered to have taken too long.
const usePagePerStepsTimeoutSeconds = 30
// Test the backup functionality.
func testBackup(t *testing.T, testRowCount int, usePerPageSteps bool) {
// This function will be called multiple times.
// It uses sql.Register(), which requires the name parameter value to be unique.
// There does not currently appear to be a way to unregister a registered driver, however.
// So generate a database driver name that will likely be unique.
var driverName = fmt.Sprintf("sqlite3_testBackup_%v_%v_%v", testRowCount, usePerPageSteps, time.Now().UnixNano())
// The driver's connection will be needed in order to perform the backup.
driverConns := []*SQLiteConn{}
sql.Register(driverName, &SQLiteDriver{
ConnectHook: func(conn *SQLiteConn) error {
driverConns = append(driverConns, conn)
return nil
},
})
// Connect to the source database.
srcTempFilename := TempFilename(t)
defer os.Remove(srcTempFilename)
srcDb, err := sql.Open(driverName, srcTempFilename)
if err != nil {
t.Fatal("Failed to open the source database:", err)
}
defer srcDb.Close()
err = srcDb.Ping()
if err != nil {
t.Fatal("Failed to connect to the source database:", err)
}
// Connect to the destination database.
destTempFilename := TempFilename(t)
defer os.Remove(destTempFilename)
destDb, err := sql.Open(driverName, destTempFilename)
if err != nil {
t.Fatal("Failed to open the destination database:", err)
}
defer destDb.Close()
err = destDb.Ping()
if err != nil {
t.Fatal("Failed to connect to the destination database:", err)
}
// Check the driver connections.
if len(driverConns) != 2 {
t.Fatalf("Expected 2 driver connections, but found %v.", len(driverConns))
}
srcDbDriverConn := driverConns[0]
if srcDbDriverConn == nil {
t.Fatal("The source database driver connection is nil.")
}
destDbDriverConn := driverConns[1]
if destDbDriverConn == nil {
t.Fatal("The destination database driver connection is nil.")
}
// Generate some test data for the given ID.
var generateTestData = func(id int) string {
return fmt.Sprintf("test-%v", id)
}
// Populate the source database with a test table containing some test data.
tx, err := srcDb.Begin()
if err != nil {
t.Fatal("Failed to begin a transaction when populating the source database:", err)
}
_, err = srcDb.Exec("CREATE TABLE test (id INTEGER PRIMARY KEY, value TEXT)")
if err != nil {
tx.Rollback()
t.Fatal("Failed to create the source database \"test\" table:", err)
}
for id := 0; id < testRowCount; id++ {
_, err = srcDb.Exec("INSERT INTO test (id, value) VALUES (?, ?)", id, generateTestData(id))
if err != nil {
tx.Rollback()
t.Fatal("Failed to insert a row into the source database \"test\" table:", err)
}
}
err = tx.Commit()
if err != nil {
t.Fatal("Failed to populate the source database:", err)
}
// Confirm that the destination database is initially empty.
var destTableCount int
err = destDb.QueryRow("SELECT COUNT(*) FROM sqlite_master WHERE type = 'table'").Scan(&destTableCount)
if err != nil {
t.Fatal("Failed to check the destination table count:", err)
}
if destTableCount != 0 {
t.Fatalf("The destination database is not empty; %v table(s) found.", destTableCount)
}
// Prepare to perform the backup.
backup, err := destDbDriverConn.Backup("main", srcDbDriverConn, "main")
if err != nil {
t.Fatal("Failed to initialize the backup:", err)
}
// Allow the initial page count and remaining values to be retrieved.
// According to <https://www.sqlite.org/c3ref/backup_finish.html>, the page count and remaining values are "... only updated by sqlite3_backup_step()."
isDone, err := backup.Step(0)
if err != nil {
t.Fatal("Unable to perform an initial 0-page backup step:", err)
}
if isDone {
t.Fatal("Backup is unexpectedly done.")
}
// Check that the page count and remaining values are reasonable.
initialPageCount := backup.PageCount()
if initialPageCount <= 0 {
t.Fatalf("Unexpected initial page count value: %v", initialPageCount)
}
initialRemaining := backup.Remaining()
if initialRemaining <= 0 {
t.Fatalf("Unexpected initial remaining value: %v", initialRemaining)
}
if initialRemaining != initialPageCount {
t.Fatalf("Initial remaining value differs from the initial page count value; remaining: %v; page count: %v", initialRemaining, initialPageCount)
}
// Perform the backup.
if usePerPageSteps {
var startTime = time.Now().Unix()
// Test backing-up using a page-by-page approach.
var latestRemaining = initialRemaining
for {
// Perform the backup step.
isDone, err = backup.Step(1)
if err != nil {
t.Fatal("Failed to perform a backup step:", err)
}
// The page count should remain unchanged from its initial value.
currentPageCount := backup.PageCount()
if currentPageCount != initialPageCount {
t.Fatalf("Current page count differs from the initial page count; initial page count: %v; current page count: %v", initialPageCount, currentPageCount)
}
// There should now be one less page remaining.
currentRemaining := backup.Remaining()
expectedRemaining := latestRemaining - 1
if currentRemaining != expectedRemaining {
t.Fatalf("Unexpected remaining value; expected remaining value: %v; actual remaining value: %v", expectedRemaining, currentRemaining)
}
latestRemaining = currentRemaining
if isDone {
break
}
// Limit the runtime of the backup attempt.
if (time.Now().Unix() - startTime) > usePagePerStepsTimeoutSeconds {
t.Fatal("Backup is taking longer than expected.")
}
}
} else {
// Test the copying of all remaining pages.
isDone, err = backup.Step(-1)
if err != nil {
t.Fatal("Failed to perform a backup step:", err)
}
if !isDone {
t.Fatal("Backup is unexpectedly not done.")
}
}
// Check that the page count and remaining values are reasonable.
finalPageCount := backup.PageCount()
if finalPageCount != initialPageCount {
t.Fatalf("Final page count differs from the initial page count; initial page count: %v; final page count: %v", initialPageCount, finalPageCount)
}
finalRemaining := backup.Remaining()
if finalRemaining != 0 {
t.Fatalf("Unexpected remaining value: %v", finalRemaining)
}
// Finish the backup.
err = backup.Finish()
if err != nil {
t.Fatal("Failed to finish backup:", err)
}
// Confirm that the "test" table now exists in the destination database.
var doesTestTableExist bool
err = destDb.QueryRow("SELECT EXISTS (SELECT 1 FROM sqlite_master WHERE type = 'table' AND name = 'test' LIMIT 1) AS test_table_exists").Scan(&doesTestTableExist)
if err != nil {
t.Fatal("Failed to check if the \"test\" table exists in the destination database:", err)
}
if !doesTestTableExist {
t.Fatal("The \"test\" table could not be found in the destination database.")
}
// Confirm that the number of rows in the destination database's "test" table matches that of the source table.
var actualTestTableRowCount int
err = destDb.QueryRow("SELECT COUNT(*) FROM test").Scan(&actualTestTableRowCount)
if err != nil {
t.Fatal("Failed to determine the rowcount of the \"test\" table in the destination database:", err)
}
if testRowCount != actualTestTableRowCount {
t.Fatalf("Unexpected destination \"test\" table row count; expected: %v; found: %v", testRowCount, actualTestTableRowCount)
}
// Check each of the rows in the destination database.
for id := 0; id < testRowCount; id++ {
var checkedValue string
err = destDb.QueryRow("SELECT value FROM test WHERE id = ?", id).Scan(&checkedValue)
if err != nil {
t.Fatal("Failed to query the \"test\" table in the destination database:", err)
}
var expectedValue = generateTestData(id)
if checkedValue != expectedValue {
t.Fatalf("Unexpected value in the \"test\" table in the destination database; expected value: %v; actual value: %v", expectedValue, checkedValue)
}
}
}
func TestBackupStepByStep(t *testing.T) {
testBackup(t, testRowCount, true)
}
func TestBackupAllRemainingPages(t *testing.T) {
testBackup(t, testRowCount, false)
}
// Test the error reporting when preparing to perform a backup.
func TestBackupError(t *testing.T) {
const driverName = "sqlite3_TestBackupError"
// The driver's connection will be needed in order to perform the backup.
var dbDriverConn *SQLiteConn
sql.Register(driverName, &SQLiteDriver{
ConnectHook: func(conn *SQLiteConn) error {
dbDriverConn = conn
return nil
},
})
// Connect to the database.
dbTempFilename := TempFilename(t)
defer os.Remove(dbTempFilename)
db, err := sql.Open(driverName, dbTempFilename)
if err != nil {
t.Fatal("Failed to open the database:", err)
}
defer db.Close()
db.Ping()
// Need the driver connection in order to perform the backup.
if dbDriverConn == nil {
t.Fatal("Failed to get the driver connection.")
}
// Prepare to perform the backup.
// Intentionally using the same connection for both the source and destination databases, to trigger an error result.
backup, err := dbDriverConn.Backup("main", dbDriverConn, "main")
if err == nil {
t.Fatal("Failed to get the expected error result.")
}
const expectedError = "source and destination must be distinct"
if err.Error() != expectedError {
t.Fatalf("Unexpected error message; expected value: \"%v\"; actual value: \"%v\"", expectedError, err.Error())
}
if backup != nil {
t.Fatal("Failed to get the expected nil backup result.")
}
}