MarketBookRelease HOW

Example from file: examples/demos/lowlevel/01_general_operations.go

The MarketBookRelease() method terminates the Depth of Market (DOM) subscription that was previously opened by the MarketBookAdd() method. It is used for proper resource cleanup and closing the connection with the server.

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🧩 Code example

fmt.Println("\n6.3. MarketBookRelease() - Unsubscribe from DOM")
fmt.Println("    Cleaning up subscription...")

bookReleaseCtx, bookReleaseCancel := context.WithTimeout(context.Background(), 5*time.Second)
defer bookReleaseCancel()

marketBookReleaseReq := &pb.MarketBookReleaseRequest{
    Symbol: cfg.TestSymbol, // symbol from config.json (test_symbol)
}
marketBookReleaseData, err := account.MarketBookRelease(bookReleaseCtx, marketBookReleaseReq)
if err != nil {
    fmt.Printf("  ⚠️  Unsubscribe failed: %v\n", err)
    fmt.Println("     → Not critical - connection will close anyway")
} else {
    if marketBookReleaseData.Success {
        fmt.Println("  ✓ Unsubscribed successfully")
    } else {
        fmt.Println("  ⚠️  Unsubscribe reported unsuccessful")
    }
}

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🟢 Detailed Code Explanation

• Create context with timeout:

bookReleaseCtx, bookReleaseCancel := context.WithTimeout(context.Background(), 5*time.Second)
defer bookReleaseCancel()

A 5-second timeout prevents hanging when communicating with the server.

• Form the request:

marketBookReleaseReq := &pb.MarketBookReleaseRequest{ Symbol: cfg.TestSymbol }

Specify the symbol for which the DOM subscription was previously made.

• Send the request:

marketBookReleaseData, err := account.MarketBookRelease(bookReleaseCtx, marketBookReleaseReq)

A gRPC call is executed, requesting subscription closure.

• Error handling:

if err != nil {
    fmt.Printf("  ⚠️  Unsubscribe failed: %v\n", err)
    fmt.Println("     → Not critical - connection will close anyway")
}

Even if an error occurs, it's not critical — all subscriptions will be automatically closed when the session ends.

• Successful or unsuccessful unsubscribe:

if marketBookReleaseData.Success {
    fmt.Println("  ✓ Unsubscribed successfully")
} else {
    fmt.Println("  ⚠️  Unsubscribe reported unsuccessful")
}

If Success = true, the broker confirmed successful subscription closure.

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📦 What the Server Returns

message MarketBookReleaseData {
  bool Success = 1; // True if unsubscription was successful
}

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Output Examples

✅ Successful Unsubscribe

✓ Unsubscribed successfully

Unsubscribe Error

⚠️  Unsubscribe failed: subscription not found
     → Not critical - connection will close anyway

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🧠 What It's Used For

The MarketBookRelease() method is used for:

• properly terminating DOM subscription;
• freeing server resources;
• demonstrating the complete market depth workflow cycle (Add → Get → Release);
• ensuring clean connection closure in tests or demonstrations.

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💬 In Simple Terms

MarketBookRelease() is "disconnecting from the order book". If you subscribed to DOM via MarketBookAdd(), this call neatly closes the subscription, freeing the connection and preventing accumulation of excess resources on the server.