Key-Value Logger Solana Program

A Solana program built with Anchor that demonstrates different logging methods through key-value pair operations. Includes a TypeScript client for interaction and event monitoring.

Overview

This program showcases three logging methodologies on Solana:

1. Simple text logging with msg!
2. Structured binary logging with sol_log_data
3. Anchor's structured events with emit!

Features:

• Stores operation count in a Program Derived Address (PDA)
• Swaps key/value pairs in subsequent operations
• Provides comprehensive TypeScript client integration
• Supports real-time event monitoring

Project Structure

my_anchor_project/
├── programs/
│   └── my_anchor_project/
│       └── src/
│           └── lib.rs         # Program logic
├── app/
│   └── key-value-client.ts    # TS client implementation
├── migrations/
│   ├── deploy.ts              # Deployment scripts
│   ├── fetchTxData.js         # Transaction inspector
│   └── solListener.js         # Event listener
├── target/
│   └── idl/
│       └── my_anchor_project.json  # Generated IDL
├── Anchor.toml                # Config
├── Cargo.toml                 # Rust dependencies
└── README.md                  # Documentation

Prerequisites

• Rust (v1.65.0+)
• Solana CLI (v1.18.4+)
• Anchor CLI
• Node.js (v18.x+)
• npm/yarn

🚀 Quick Start

1. Clone repository & install dependencies:

git clone https://github.com/your-username/my_anchor_project.git
cd my_anchor_project
npm install

2. Set up Solana devnet environment:

solana config set --url devnet
solana-keygen new

3. Build and deploy:

anchor build
anchor deploy

4. Run client with test data:

node app/key-value-client.js "temperature" "23.5°C"

Program Instructions

initialize

• Creates PDA with seed "logger"
• Sets initial nonce to 0

log_key_value

1. Accepts key/value pair (max 32 bytes each)
2. Increments nonce
3. Logs data using all three methods
4. Triggers swap_and_log with swapped values

📊 Logging Comparison

Method	Format	Size Limit	Decoding	Use Case
msg!	Plain text	512 bytes	Direct read	Simple debugging
sol_log_data	Binary	10KB	Manual deserialization	Structured large data
Anchor Events	JSON (IDL)	10KB	Automatic via client	Production applications

Event Types

// Original submission
struct KeyValueEvent {
    key: String,
    value: String,
    nonce: u64,
}

// After swap operation
struct KeyValueSwappedEvent {
    swapped_key: String,
    swapped_value: String,
    nonce: u64,
}

Client API

interface KeyValueClient {
  initialize(): Promise<TransactionSignature>;
  logKeyValue(key: string, value: string): Promise<TransactionSignature>;
  subscribeToLogs(callback: (log: any) => void): void;
  decodeBinaryLog(data: string): { key: string; value: string; nonce: number };
}

Monitoring Tools

Real-time Listener

node migrations/solListener.js

Transaction Inspector

node migrations/fetchTxData.js 5VERv8NMvzbJMEkV8xnrLkEaWRtSz9ChKDcpq3Mxcs3poaH9g4KdYL4iPEgfQ25238huKGnMHCUnmN4VbSv7nD9

EVM Developer Notes

1. Account Model: Unlike EVM's contract storage, Solana requires explicit account passing
2. PDAs: Program-controlled addresses (no private keys) for deterministic account access
3. Log Limits: Maximum 10KB per log entry across all methods
4. Gas Costs: Logging impacts compute units - binary logs are most efficient

License

MIT License - See LICENSE for details