Shallow Snapshots

Quick Reference

Shallow snapshots are like Git’s shallow clone - maintain current state while removing old history. Essential for privacy compliance, storage optimization, and performance.

Basic Usage

const  = new ();
// ... extensive editing history ...
 
// Regular snapshot - full history
const  = .({ : "snapshot" });
 
// Shallow snapshot - trimmed history
const  = .({
  : "shallow-snapshot",
  : .(),
});
 
// Typically 70-90% smaller
.(`Size reduction: ${100 - (. / . * 100)}%`);

Content Redaction

const  = new ();
const  = .("content");
 
// Sensitive data added
.(0, "SSN: 123-45-6789. ");
.(18, "Public info.");
 
// Redact sensitive part
.(0, 18);
 
// Create clean snapshot
const  = .({
  : "shallow-snapshot",
  : .(),
});
// Sensitive data permanently removed from history

Synchronization Limitations

⚠️ Important: Peers can only sync if they have versions after the shallow snapshot point.

Common Patterns

Archive and Trim

async function (: ) {
  // 1. Archive full history
  const  = .({ : "snapshot" });
  await ();
  
  // 2. Create shallow for active use
  const  = .({
    : "shallow-snapshot",
    : .(),
  });
  
  return ;
}
 
async function (: ) {
  // Save to cold storage
}

Privacy-Aware Design

class  {
  constructor(private : ) {}
  
  async () {
    // Delete sensitive content
    this..("private").(0, this..("private").);
    
    // Create clean snapshot
    return this..({
      : "shallow-snapshot",
      : this..(),
    });
  }
}

Best Practices

Coordinate before trimming: Ensure all peers synchronized
Archive before deletion: Keep full history backup if needed

Encoding - Different export options
Version Tutorial - Managing document versions
Event Graph Walker - Algorithm powering shallow snapshots

Event Graph Walker (Eg-Walker)How to Choose the Right CRDT Types