Ticket #4760: mythtv-4760-database_backup_using_script-20080627.patch

libs/libmyth/dbutil.h

@@ -44 +44 @@
                                  QString extension = ".sql");
     QString GetBackupDirectory();
 
+    bool DoBackup(QString backupScript, QString &filename);
     bool DoBackup(QString &filename);
 
     QString m_versionString;

libs/libmyth/dbutil.cpp

@@ -157 +157 @@
 /** \fn DBUtil::BackupDB(QString)
  *  \brief Requests a backup of the database.
  *
+ *   If the DatabaseBackupScript exists in the ShareDir, it will be executed.
+ *   All required database information will be made available as name=value
+ *   pairs in a temporary file whose filename will be passed to the backup
+ *   script.  The script may parse this file to obtain the required information
+ *   to run a backup program, such as mysqldump or mysqlhotcopy.
+ *
+ *   If the DatabaseBackupScript does not exist, a backup will be performed
+ *   using mysqldump directly.  The database password will be passed in a
+ *   temporary file so it does not have to be specified on the command line.
+ *
  *   Care should be taken in calling this function.  It has the potential to
  *   corrupt in-progress recordings or interfere with playback.
  */
@@ -169 +179 @@
         return true;
     }
 
+    QString backupScript = gContext->GetSetting("DatabaseBackupScript",
+                   gContext->GetShareDir() + "database_mythconverg_backup.pl");
+
+    if (!QFile::exists(backupScript))
+    {
+        VERBOSE(VB_IMPORTANT, QString("Database backup script does "
+                              "not exist: %1").arg(backupScript));
+        backupScript = QString::null;
+    }
+
     bool result = false;
     MSqlQuery query(MSqlQuery::InitCon());
 
@@ -176 +196 @@
                                 QDateTime::currentDateTime()
                                 .toString("yyyy-MM-dd hh:mm:ss"), NULL);
 
-    result = DoBackup(filename);
+    if (backupScript.isEmpty())
+        result = DoBackup(filename);
+    else
+        result = DoBackup(backupScript, filename);
 
     gContext->SaveSettingOnHost("BackupDBLastRunEnd",
                                 QDateTime::currentDateTime()
@@ -295 +318 @@
     return directory;
 }
 
+/** \fn DBUtil::DoBackup(QString, QString)
+ *  \brief Creates a backup of the database by executing the backupScript.
+ *
+ *   This function executes the specified backup script to create a database
+ *   backup.  This is the preferred approach for creating the backup.
+ */
+bool DBUtil::DoBackup(QString backupScript, QString &filename)
+{
+    DatabaseParams dbParams = gContext->GetDatabaseParams();
+    QString     dbSchemaVer = gContext->GetSetting("DBSchemaVer");
+    QString backupDirectory = GetBackupDirectory();
+    QString  backupFilename = CreateBackupFilename(dbParams.dbName + "-" +
+                                                   dbSchemaVer, ".sql");
+    QString      scriptArgs = gContext->GetSetting("BackupDBScriptArgs");
+
+    // Create a temporary file containing the database information
+    QString tempDatabaseConfFile = createTempFile(
+                                         "/tmp/mythtv_db_backup_conf_XXXXXX");
+    FILE *fp;
+    if (!(fp = fopen(tempDatabaseConfFile.ascii(), "w")))
+    {
+        VERBOSE(VB_IMPORTANT, LOC_ERR + QString("Unable to create temporary "
+                "configuration file for creating DB backup: %1")
+                .arg(tempDatabaseConfFile.ascii()));
+        VERBOSE(VB_IMPORTANT, LOC_ERR + "Attempting backup, anyway.");
+        tempDatabaseConfFile = "";
+    }
+    else
+    {
+        chmod(tempDatabaseConfFile.ascii(), S_IRUSR);
+        fprintf(fp, QString("DBHostName=%1\n"
+                            "DBPort=%2\n")
+                            .arg(dbParams.dbHostName).arg(dbParams.dbPort));
+        fprintf(fp, QString("DBUserName=%1\n"
+                            "DBPassword=%2\n")
+                            .arg(dbParams.dbUserName).arg(dbParams.dbPassword));
+        fprintf(fp, QString("DBName=%1\n"
+                            "DBSchemaVer=%2\n")
+                            .arg(dbParams.dbName).arg(dbSchemaVer));
+        fprintf(fp, QString("DBBackupDirectory=%1\n"
+                            "DBBackupFilename=%2\n")
+                            .arg(backupDirectory)
+                            .arg(backupFilename));
+        if (fclose(fp))
+            VERBOSE(VB_IMPORTANT, LOC_ERR + QString("Error closing %1: %2")
+                    .arg(tempDatabaseConfFile.ascii()).arg(strerror(errno)));
+    }
+
+    if (!scriptArgs.isEmpty())
+    {
+        scriptArgs.prepend(" ");
+    }
+
+    QString command = backupScript + scriptArgs + " " + tempDatabaseConfFile;
+    VERBOSE(VB_IMPORTANT, QString("Backing up database with script: %1")
+            .arg(backupScript));
+    uint status = system(command.ascii());
+
+    unlink(tempDatabaseConfFile.ascii());
+
+    if (status)
+    {
+        VERBOSE(VB_IMPORTANT, LOC_ERR +
+                QString("Error backing up database: %1 (%2)")
+                .arg(command.ascii()).arg(status));
+        filename = "__FAILED__";
+        return false;
+    }
+
+    VERBOSE(VB_IMPORTANT, "Database Backup complete.");
+
+    QDir dir(backupDirectory, backupFilename + "*");
+    uint numfiles = dir.count();
+    if (numfiles < 1)
+    {
+        // If no file begins with the suggested filename, don't show the backup
+        // filename in the GUI message -- the script probably used some other
+        // filename
+        filename = "";
+        VERBOSE(VB_FILE, LOC_ERR + QString("No files beginning with the "
+                "suggested database backup filename (%1) were found in %2.")
+                .arg(backupFilename).arg(backupDirectory));
+    }
+    else
+    {
+        filename = dir.path() + "/" + dir[0];;
+        if (numfiles > 1)
+            VERBOSE(VB_FILE, LOC_ERR + QString("Multiple files beginning with "
+                    "the suggested database backup filename (%1) were found "
+                    "in %2.  Assuming the first is the backup.")
+                    .arg(backupFilename).arg(backupDirectory));
+    }
+    if (!filename.isEmpty())
+        VERBOSE(VB_IMPORTANT, QString("Backed up database to file: %1")
+                .arg(filename));
+    return true;
+}
+
 /** \fn DBUtil::DoBackup(QString)
  *  \brief Creates a backup of the database.
+ *
+ *   This fallback function is used only if the database backup script cannot
+ *   be found.
  */
 bool DBUtil::DoBackup(QString &filename)
 {