Initial revision of FileBackup class. This class manages the backup

and restoring of files.


git-svn-id: https://svn.microneil.com/svn/SNFUtility/trunk@3 aa37657e-1934-4a5f-aa6d-2d8eab27ff7c

Common/FileBackup.cpp

+// FileBackup.cpp
+//
+// Copyright (C) 2011, ARM Research Labs, LLC.
+// See www.armresearch.com for the copyright terms.
+//
+// This file implements the common functionality for the configuration
+// utilities.
+
+#include <iostream>
+#include <stdexcept>
+#include <fstream>
+#include <vector>
+
+#include <cerrno>
+#include <cstring>
+#include <cstdio>
+
+#include "FileBackup.hpp"
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Configuration. ////////////////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////
+// End of configuration. /////////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+FileBackup::FileBackup(std::string Suffix) :
+    BackupSuffix(Suffix) {
+
+}    
+
+void
+FileBackup::CopyFile(std::string From, std::string To) {
+
+    std::ifstream Input;
+
+    Input.open(From.c_str());
+    if (!Input) {
+	std::string Temp;
+
+	Temp = "Error opening the file " + From;
+	Temp += " to read from:  ";
+	Temp += strerror(errno);
+	throw std::runtime_error(Temp);
+    }
+
+    std::ofstream Output;
+
+    Output.open(To.c_str(), std::ios::trunc);
+    if (!Output) {
+	std::string Temp;
+
+	Temp = "Error opening the file " + To;
+	Temp += " to copy to:  ";
+	Temp += strerror(errno);
+	throw std::runtime_error(Temp);
+    }
+
+    if (!Input.eof()) {                                                         // Copy if there are characters.
+                                                                                // Copying an empty file causes
+        Output << Input.rdbuf();                                                // failbit to be set.
+
+    }
+
+    if (Output.bad() || Output.fail()) {
+	std::string Temp;
+
+	Temp = "Error copying " + From;
+	Temp += " to " + To;
+	Temp += ":  ";
+	Temp += strerror(errno);
+	throw std::runtime_error(Temp);
+    }
+
+    Input.close();
+    if (!Input) {
+	std::string Temp;
+
+	Temp = "Error closing the file " + From;
+	Temp += ":  ";
+	Temp += strerror(errno);
+	throw std::runtime_error(Temp);
+    }
+
+    Output.close();
+    if (!Output) {
+	std::string Temp;
+
+	Temp = "Error closing the file " + To;
+	Temp += ":  ";
+	Temp += strerror(errno);
+	throw std::runtime_error(Temp);
+    }
+
+}
+
+std::string
+FileBackup::GetBackupFileName(std::string File) {
+
+    return File + BackupSuffix;
+
+}
+
+void
+FileBackup::CreateBackupFile(std::string File) {
+
+    try {
+
+	CopyFile(File, GetBackupFileName(File));
+
+    } catch (std::exception &e) {
+	std::string Temp;
+
+	Temp = "Error making a backup of " + File;
+	Temp += ":  ";
+	Temp += e.what();
+	throw std::runtime_error(Temp);
+
+    }
+
+    BackedUpFile.push_back(File);                                               // Save the name.
+
+}
+
+bool
+FileBackup::RemoveAllBackupFiles() {
+
+    bool ErrorOccurred = false;
+
+    for (FilenameContainer::iterator iFile = BackedUpFile.begin();
+	 iFile != BackedUpFile.end();
+	 iFile++) {
+	std::string BackupFileName;
+
+	BackupFileName = GetBackupFileName(*iFile);
+
+        if (0 != remove(BackupFileName.c_str())) {                              // Delete the backup file.
+
+	    std::cerr << "Unable to remove backup file " << BackupFileName
+		      << ":  " << strerror(errno) << "\n";
+
+	    ErrorOccurred = true;
+
+	}
+
+    }
+
+    return ErrorOccurred;    
+
+}
+
+bool
+FileBackup::RestoreAllFilesFromBackup() {
+
+    bool ErrorOccurred = false;
+
+    for (FilenameContainer::iterator iFile = BackedUpFile.begin();
+	 iFile != BackedUpFile.end();
+	 iFile++) {
+	std::string BackupFileName;
+
+	BackupFileName = GetBackupFileName(*iFile);
+
+	try {
+
+	    CopyFile(BackupFileName, *iFile);
+
+	} catch (std::exception &e) {
+
+	    std::cerr << "Error restoring " << *iFile << " from backup "
+		      << BackupFileName << ":  " << e.what() << " \n";
+
+	    ErrorOccurred = true;
+
+	}
+
+    }
+
+    return ErrorOccurred;    
+
+}

Common/FileBackup.hpp

+// FileBackup.hpp
+//
+// Copyright (C) 2011 ARM Research Labs, LLC.
+// See www.armresearch.com for the copyright terms.
+//
+// This file defines the interface used by the FileBackup class.
+//
+
+#ifndef FileBackuphpp_included
+#define FileBackuphpp_included
+
+#include <string>
+#include <vector>
+
+/// FileBackup class.
+//
+// This class provides capability to manage the backup and restore of
+// disk files.
+//
+//////////////////////////////////////////////////////////////////////////////////////////////////////////
+class FileBackup {
+
+public:
+
+    /// Constructor.
+    //
+    // \param[in] Suffix is the suffix to append to create the name of
+    // the backup file.
+    //
+    FileBackup(std::string Suffix);
+
+    /// Create a backup of the specified file.
+    //
+    // This method creates a backup of the specified file The name of
+    // the link is the name of the file appended by the BackupSuffix
+    // data member.
+    //
+    // The file can be restored from the backup by RestoreFromBackup.
+    //
+    // \param[in] File is the file name to create a backup for.
+    //
+    // \throws std::runtime_error in case of error.
+    //
+    // \see RestoreAllFilesFromBackup().
+    //
+    void CreateBackupFile(std::string File);
+
+    /// Remove the backups of all the specified files.
+    //
+    // This method removes the backup of the files specified by the
+    // CreateBackup() method.
+    //
+    // If an error is encountered, a message is output to std::cerr.
+    //
+    // \returns true if all backups were removed with no error, false otherwise.
+    //
+    bool RemoveAllBackupFiles();
+
+    /// Restore the all the specified files from the backup.
+    //
+    // This method restores the backup of the files specified by the
+    // CreateBackupFile() method.
+    //
+    // If an error is encountered, a message is output to std::cerr.
+    //
+    // \returns true if all files were restored with no error, false otherwise.
+    //
+    // \see CreateBackupFile().
+    //
+    bool RestoreAllFilesFromBackup();
+
+private:
+
+    /// Get the name of the backup file.
+    //
+    // \param[in] File is the name of the file to back up.
+    //
+    // \returns the name of the backup file.
+    //
+    std::string GetBackupFileName(std::string File);
+
+    /// Copy a file.
+    //
+    // \param[in] From is the name of the file to copy from.
+    //
+    // \param[in] To is the name of the file to copy to.
+    //
+    // \throws runtime_error in case of error.
+    //
+    void CopyFile(std::string From, std::string To);
+
+    /// Suffix to append to the file name to obtain the backup file
+    /// name.
+    std::string BackupSuffix;
+
+    /// Typedef for container of names of files.
+    typedef std::vector<std::string> FilenameContainer;
+
+    /// Container of files that have backups.
+    FilenameContainer BackedUpFile;
+
+};
+
+#endif

Common/Makefile.am

 -DSNF_OSTYPE=\"$(SNF_OSTYPE)\"  -DDEFAULT_DATA_DIR=\"@datadir@/$(PACKAGE_NAME)\" \
 -DSBIN_DIR=\"$(DESTDIR)$(sbindir)\"
 
-noinst_LIBRARIES = 					\
+noinst_LIBRARIES = 					     \
 	libUtilityCommon.a
 
-libUtilityCommon_a_SOURCES =        			\
-	@top_srcdir@/SNFUtility/Common/UtilityConfig.cpp
+libUtilityCommon_a_SOURCES =        			     \
+	@top_srcdir@/SNFUtility/Common/UtilityConfig.cpp     \
+	@top_srcdir@/SNFUtility/Common/FileBackup.cpp
 
-noinst_HEADERS =                    			\
-	@top_srcdir@/SNFUtility/Common/UtilityConfig.hpp
+noinst_HEADERS =                    			     \
+	@top_srcdir@/SNFUtility/Common/UtilityConfig.hpp     \
+	@top_srcdir@/SNFUtility/Common/FileBackup.hpp
 
-EXTRA_DIST = 						\
-	Makefile.am					\
+EXTRA_DIST = 						     \
+	Makefile.am					     \
 	ChangeLog
 
 clean-local:

Common/UtilityConfig.cpp

 /// Help command-line input.
 const string HelpKey("-h");
 
-const std::string UtilityConfig::BackupSuffix("_snf_backup");
-
 //////////////////////////////////////////////////////////////////////////////////////////////////////////
 // End of configuration. /////////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////////////////////////////////

Common/UtilityConfig.hpp

     //
     void MkDir(std::string &Dir);
 
-    /// Create a backup link of the specified file.
-    //
-    // This method creates a backup of the specified file by creating
-    // a link to the file.  The name of the link is the name of the
-    // file appended by the BackupSuffix data member.
-    //
-    // The file can be restored from the backup link by
-    // RestoreFromBackupLink.
-    //
-    // \param[in] File is the file name to create a backup link for.
-    //
-    // \throws std::runtime_error in case of error.
-    //
-    // \see RestoreFromBackupLink.
-    //
-    void CreateBackupLink(std::string File);
-
-    /// Remove the backup link of the specified file.
-    //
-    // This method removes the backup link of the specified file by
-    // creating a link to the file.  The name of the link is the name
-    // of the file appended by the BackupSuffix data member.
-    //
-    // \param[in] File is the file name whose backup link is to be
-    // removed.
-    //
-    void RemoveBackupLink(std::string File);
-
-
-    /// Restore the specified file from the backup link.
-    //
-    // This method restores the specified from the backup link created
-    // by CreateBackupLink().
-    //
-    // \param[in] File is the file name whose backup link is to be
-    // removed.
-    //
-    // \see CreateBackupLink.
-    //
-    void RestoreFromBackupLink(std::string File);
-
     /// Restart the MTA.
     //
     // This function starts or restarts the MTA.
     static const std::string SampleIgnoreListFile; ///< Sample ignore list file.
     static const std::string SampleRulebaseScriptFile; ///< Sample rulebase script file.
 
-    static const std::string BackupSuffix; ///< Suffix appended to create backup file name.
-
     snfCFGData CFGData; ///< Configuration data.
 
     /// Operating system type.