Task 798: .VSVNBAK File Format
Task 798: .VSVNBAK File Format
File Format Specifications for .VSVNBAK
The .VSVNBAK file extension corresponds to the backup format used by VisualSVN Server for Subversion repositories. This format is proprietary and designed for creating restore points of repositories. It supports both full and incremental backups, where full backups capture the entire repository state, and incremental backups capture only changes since the previous backup. The internal structure of .VSVNBAK files is not publicly documented in detail, as it is managed through VisualSVN Server's backup and restore features. Based on available information, the format likely involves a compressed representation of a repository hotcopy (a consistent snapshot created via tools like svnadmin hotcopy), but specific byte-level headers, encoding, or internal data organization are not disclosed in technical resources. Restoration requires VisualSVN Server tools, such as the Restore-SvnRepository PowerShell cmdlet or the server's graphical interface.
1. List of Properties Intrinsic to the .VSVNBAK File Format
The properties of the .VSVNBAK format are primarily conveyed through the filename convention and high-level metadata, as the internal file contents are opaque without proprietary tools. No detailed binary specifications (e.g., headers or fields) are available publicly. The identified properties include:
- File Extension: .vsvnbak (case-insensitive, typically lowercase).
- Filename Format: Follows the pattern
<RepositoryName>-<YYYY-MM-DD>-<HHMMSS>-(full|incremental).vsvnbak, where: <RepositoryName>is the name of the backed-up Subversion repository.<YYYY-MM-DD>and<HHMMSS>represent the backup creation date and time.(full|incremental)indicates the backup type.- Backup Type: Either "full" (complete repository state) or "incremental" (changes since the last backup).
- Creation Timestamp: Embedded in the filename as date and time components.
- Repository Name: Extracted from the filename prefix.
- Chain Dependency (for incremental backups): Requires a preceding full backup and subsequent incrementals for complete restoration.
- Version Compatibility: Supported in VisualSVN Server versions 3.6 and later.
- Contents: Repository data, including revisions, file system structure, and metadata; full backups are self-contained, while incrementals form a chain.
These properties are intrinsic to the format's design within the VisualSVN ecosystem but are not stored as extractable metadata inside the file without specialized software.
2. Two Direct Download Links for .VSVNBAK Files
No public direct download links for .VSVNBAK files were identified through extensive searches across web resources, including documentation sites, forums, and repositories like GitHub. This format is used for private repository backups, and samples are not typically shared publicly due to their sensitive nature (containing version control data). If samples are required for development, they must be generated using VisualSVN Server by creating a backup of a test repository.
3. Ghost Blog Embedded HTML JavaScript for Drag-and-Drop .VSVNBAK File Analysis
The following is an HTML snippet with embedded JavaScript that can be embedded in a Ghost blog post. It allows users to drag and drop a .VSVNBAK file, parses the filename to extract properties (since internal decoding is not feasible without proprietary specifications), and displays them on screen. Note that file contents are not read or modified due to the opaque format.
4. Python Class for Handling .VSVNBAK Files
The following Python class opens a .VSVNBAK file, parses the filename for properties (as internal decoding is not possible), prints them to the console, and provides placeholder methods for read/write operations. Actual decoding and writing are noted as unsupported due to the proprietary format.
import os
class VSVNBAKHandler:
def __init__(self, filepath):
self.filepath = filepath
self.properties = self._parse_filename()
def _parse_filename(self):
filename = os.path.basename(self.filepath)
if not filename.lower().endswith('.vsvnbak'):
raise ValueError("Invalid file extension")
parts = filename.rsplit('.', 1)[0].split('-')
if len(parts) < 5:
raise ValueError("Invalid filename format")
repo_name = '-'.join(parts[:-4])
year, month, day_time_type = parts[-4], parts[-3], parts[-2:]
day = day_time_type[0]
time_type = '-'.join(day_time_type[1:])
backup_time, backup_type = time_type.split('-') if '-' in time_type else ('', time_type)
return {
'File Extension': '.vsvnbak',
'Repository Name': repo_name,
'Backup Date': f"{year}-{month}-{day}",
'Backup Time': backup_time,
'Backup Type': backup_type,
'Version Compatibility': 'VisualSVN Server 3.6+'
}
def open_and_decode(self):
# Placeholder: Actual decode not possible without specs
print("Opening and decoding .VSVNBAK file (filename-based properties only):")
self.print_properties()
def read(self):
# Placeholder: Cannot read internal data
print("Reading internal data not supported for proprietary format.")
def write(self, new_properties):
# Placeholder: Cannot write without format specs
print("Writing to .VSVNBAK not supported.")
def print_properties(self):
for key, value in self.properties.items():
print(f"{key}: {value}")
# Example usage:
# handler = VSVNBAKHandler('path/to/MyRepo-2025-12-17-120000-full.vsvnbak')
# handler.open_and_decode()
5. Java Class for Handling .VSVNBAK Files
The following Java class provides similar functionality: opens the file, parses the filename, prints properties, with placeholders for read/write.
import java.io.File;
import java.util.HashMap;
import java.util.Map;
public class VSVNBAKHandler {
private String filepath;
private Map<String, String> properties;
public VSVNBAKHandler(String filepath) {
this.filepath = filepath;
this.properties = parseFilename();
}
private Map<String, String> parseFilename() {
File file = new File(filepath);
String filename = file.getName();
if (!filename.toLowerCase().endsWith(".vsvnbak")) {
throw new IllegalArgumentException("Invalid file extension");
}
String baseName = filename.substring(0, filename.lastIndexOf('.'));
String[] parts = baseName.split("-");
if (parts.length < 5) {
throw new IllegalArgumentException("Invalid filename format");
}
String repoName = String.join("-", java.util.Arrays.copyOfRange(parts, 0, parts.length - 4));
String year = parts[parts.length - 4];
String month = parts[parts.length - 3];
String day = parts[parts.length - 2];
String timeType = parts[parts.length - 1];
String[] timeTypeParts = timeType.split("-", 2);
String backupTime = timeTypeParts.length > 1 ? timeTypeParts[0] : "";
String backupType = timeTypeParts.length > 1 ? timeTypeParts[1] : timeTypeParts[0];
Map<String, String> props = new HashMap<>();
props.put("File Extension", ".vsvnbak");
props.put("Repository Name", repoName);
props.put("Backup Date", year + "-" + month + "-" + day);
props.put("Backup Time", backupTime);
props.put("Backup Type", backupType);
props.put("Version Compatibility", "VisualSVN Server 3.6+");
return props;
}
public void openAndDecode() {
// Placeholder: Decode not possible
System.out.println("Opening and decoding .VSVNBAK file (filename-based properties only):");
printProperties();
}
public void read() {
// Placeholder
System.out.println("Reading internal data not supported for proprietary format.");
}
public void write(Map<String, String> newProperties) {
// Placeholder
System.out.println("Writing to .VSVNBAK not supported.");
}
public void printProperties() {
properties.forEach((key, value) -> System.out.println(key + ": " + value));
}
// Example usage:
// public static void main(String[] args) {
// VSVNBAKHandler handler = new VSVNBAKHandler("path/to/MyRepo-2025-12-17-120000-full.vsvnbak");
// handler.openAndDecode();
// }
}
6. JavaScript Class for Handling .VSVNBAK Files
The following JavaScript class (for Node.js) opens the file via filesystem, parses the filename, prints properties to console, with placeholders.
const fs = require('fs');
const path = require('path');
class VSVNBAKHandler {
constructor(filepath) {
this.filepath = filepath;
this.properties = this.parseFilename();
}
parseFilename() {
const filename = path.basename(this.filepath);
if (!filename.toLowerCase().endsWith('.vsvnbak')) {
throw new Error('Invalid file extension');
}
const baseName = filename.slice(0, -9); // Remove .vsvnbak
const parts = baseName.split('-');
if (parts.length < 5) {
throw new Error('Invalid filename format');
}
const repoName = parts.slice(0, parts.length - 4).join('-');
const year = parts[parts.length - 4];
const month = parts[parts.length - 3];
const day = parts[parts.length - 2];
const timeType = parts[parts.length - 1];
const [backupTime, backupType] = timeType.includes('-') ? timeType.split('-') : ['', timeType];
return {
'File Extension': '.vsvnbak',
'Repository Name': repoName,
'Backup Date': `${year}-${month}-${day}`,
'Backup Time': backupTime,
'Backup Type': backupType,
'Version Compatibility': 'VisualSVN Server 3.6+'
};
}
openAndDecode() {
// Placeholder
console.log('Opening and decoding .VSVNBAK file (filename-based properties only):');
this.printProperties();
}
read() {
// Placeholder
console.log('Reading internal data not supported for proprietary format.');
}
write(newProperties) {
// Placeholder
console.log('Writing to .VSVNBAK not supported.');
}
printProperties() {
for (const [key, value] of Object.entries(this.properties)) {
console.log(`${key}: ${value}`);
}
}
}
// Example usage:
// const handler = new VSVNBAKHandler('path/to/MyRepo-2025-12-17-120000-full.vsvnbak');
// handler.openAndDecode();
7. C Class for Handling .VSVNBAK Files
In C, classes are not native, so the following uses a struct with functions to simulate class behavior. It parses the filename, prints properties, with placeholders for read/write.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct {
char* filepath;
char* file_extension;
char* repo_name;
char* backup_date;
char* backup_time;
char* backup_type;
char* version_compat;
} VSVNBAKHandler;
VSVNBAKHandler* create_handler(const char* filepath) {
VSVNBAKHandler* handler = (VSVNBAKHandler*)malloc(sizeof(VSVNBAKHandler));
handler->filepath = strdup(filepath);
char* filename = strrchr(filepath, '/');
filename = filename ? filename + 1 : (char*)filepath;
if (strcasestr(filename, ".vsvnbak") == NULL) {
free(handler);
fprintf(stderr, "Invalid file extension\n");
return NULL;
}
char* base_name = strdup(filename);
base_name[strlen(base_name) - 9] = '\0'; // Remove .vsvnbak
char* parts[10];
int part_count = 0;
char* token = strtok(base_name, "-");
while (token && part_count < 10) {
parts[part_count++] = token;
token = strtok(NULL, "-");
}
if (part_count < 5) {
free(base_name);
free(handler);
fprintf(stderr, "Invalid filename format\n");
return NULL;
}
int repo_len = 0;
for (int i = 0; i < part_count - 4; i++) {
repo_len += strlen(parts[i]) + 1;
}
handler->repo_name = (char*)malloc(repo_len);
strcpy(handler->repo_name, parts[0]);
for (int i = 1; i < part_count - 4; i++) {
strcat(handler->repo_name, "-");
strcat(handler->repo_name, parts[i]);
}
char* year = parts[part_count - 4];
char* month = parts[part_count - 3];
char* day = parts[part_count - 2];
char* time_type = parts[part_count - 1];
char* time_delim = strchr(time_type, '-');
char* backup_time = time_type;
char* backup_type = time_delim ? time_delim + 1 : time_type;
if (time_delim) *time_delim = '\0';
handler->backup_date = (char*)malloc(11);
sprintf(handler->backup_date, "%s-%s-%s", year, month, day);
handler->backup_time = strdup(backup_time);
handler->backup_type = strdup(backup_type);
handler->file_extension = strdup(".vsvnbak");
handler->version_compat = strdup("VisualSVN Server 3.6+");
free(base_name);
return handler;
}
void open_and_decode(VSVNBAKHandler* handler) {
// Placeholder
printf("Opening and decoding .VSVNBAK file (filename-based properties only):\n");
print_properties(handler);
}
void read(VSVNBAKHandler* handler) {
// Placeholder
printf("Reading internal data not supported for proprietary format.\n");
}
void write(VSVNBAKHandler* handler, /* new props */) {
// Placeholder
printf("Writing to .VSVNBAK not supported.\n");
}
void print_properties(VSVNBAKHandler* handler) {
printf("File Extension: %s\n", handler->file_extension);
printf("Repository Name: %s\n", handler->repo_name);
printf("Backup Date: %s\n", handler->backup_date);
printf("Backup Time: %s\n", handler->backup_time);
printf("Backup Type: %s\n", handler->backup_type);
printf("Version Compatibility: %s\n", handler->version_compat);
}
void destroy_handler(VSVNBAKHandler* handler) {
free(handler->filepath);
free(handler->file_extension);
free(handler->repo_name);
free(handler->backup_date);
free(handler->backup_time);
free(handler->backup_type);
free(handler->version_compat);
free(handler);
}
// Example usage:
// int main() {
// VSVNBAKHandler* handler = create_handler("path/to/MyRepo-2025-12-17-120000-full.vsvnbak");
// if (handler) {
// open_and_decode(handler);
// destroy_handler(handler);
// }
// return 0;
// }