Refactor WAL Replay Loop and Improve EOF Handling in `ReplayCommand`

[ayushsatyam146]

The ReplayCommand function, which processes WAL segments during recovery, currently uses an infinite for {} loop. This loop relies on checking for io.EOF as its primary exit condition, which is explicitly flagged in a TODO comment as needing a "more elegant solution" and "handled in a better way."

Relevant section of code is below

// TODO: Replace this infinite loop with a more elegant solution
    for {
      // Read CRC32 (4 bytes) + entrySize (4 bytes)
      if _, err := io.ReadFull(reader, bb1h); err != nil {
        // TODO: this terminating connection should be handled in a better way
        // and the loop should not be infinite.
        // Edge case: this EOF error can happen even in the next step when
        // we are reading the WAL element from the file.
        if err == io.EOF {
          break
        }
        file.Close()
        return fmt.Errorf("error reading WAL: %w", err)
      }

• Refactor Loop Structure: Replace the for {} loop with a more idiomatic Go pattern for reading from an io.Reader until EOF.
• Explicit EOF Handling: Ensure io.EOF is handled precisely where it's expected – when no more full entries can be read. This means distinguishing between a clean end of file and an actual I/O error.
• Ensure better logging and error handling and stuff error message with segment name, byte offset etc. for better debugging.

Setup Instructions

1. setup DiceDB server locally from the source - instructions
2. setup DiceDB Go SDK locally from the source - instructions
3. setup DiceDB CLI locally from the source - instructions
4. refer to the Pointing to local checked-out dicedb-gosection inREADME`.

Start the DiceDB server

$ go run main.go --log-level debug

Follow the contribution guidelines

These are general guidelines to follow before you submit a patch. Please mark them as done once you complete them

• [ ] please go through the CONTRIBUTING guide
• [ ] follow LOGGING best practices
• [ ] follow Golang best practices
• [ ] run make lint on your local copy of the codebase

[prabhavdogra]

@ayushsatyam146 I’m excited to pick this up

[ayushsatyam146]

Please go ahead @prabhavdogra