Merge pull request #417 from codecrafters-io/TropicolX-patch-62

Revise "Empty RDB transfer #cf8" (stage 52)

Author: TropicolX

stage_descriptions/replication-10-cf8.md

@@ -1,28 +1,27 @@
-In this stage, you'll add support for sending an empty RDB file as a master. This is part of the "full resynchronization" process.
+In this stage, you'll add support for sending an empty RDB file as a master. 
 
-### Full resynchronization
+### Full Resynchronization
 
-When a replica connects to a master for the first time, it sends a `PSYNC ? -1` command. This is the replica's way of
-telling the master that it doesn't have any data yet, and needs to be fully resynchronized.
+When a replica connects to a master for the first time, it sends a `PSYNC ? -1` command. This is the replica's way of telling the master that it doesn't have any data yet and needs to be fully resynchronized.
 
-The master acknowledges this by sending a `FULLRESYNC` response to the replica.
+The master responds in two steps:
 
-After sending the `FULLRESYNC` response, the master will then send a RDB file of its current state to the replica. The replica is expected to load the file into memory, replacing its current state.
+- It acknowledges with a `FULLRESYNC` response (Handled in a previous stage)
+- It sends a snapshot of its current state as an [RDB file](https://rdb.fnordig.de/file_format.html).
 
-For the purposes of this challenge, you don't have to actually construct an RDB file. We'll assume that the master's database is always empty,
-and just hardcode an empty RDB file to send to the replica.
+The replica is expected to load the file into memory and replace its current state with the master's data.
 
-You can find the hex representation of an empty RDB file [here](https://github.com/codecrafters-io/redis-tester/blob/main/internal/assets/empty_rdb_hex.md).
+For this challenge, you don’t need to build an RDB file yourself. Instead, you can hardcode an empty RDB file, since we’ll assume the master’s database is always empty.
 
-The tester will accept any valid RDB file that is empty, you don't need to send the exact file above.
+You can find the hex and base64 representation of an empty RDB file [here](https://github.com/codecrafters-io/redis-tester/blob/main/internal/assets/empty_rdb_hex.md). You need to decode these into binary contents before sending them to the replica.
 
 The file is sent using the following format:
 
 ```
 $<length_of_file>\r\n<binary_contents_of_file>
 ```
 
-(This is similar to how [Bulk Strings](https://redis.io/topics/protocol#resp-bulk-strings) are encoded, but without the trailing `\r\n`)
+This is similar to how [bulk strings](https://redis.io/topics/protocol#resp-bulk-strings) are encoded, but without the trailing `\r\n`.
 
 ### Tests
 
@@ -32,22 +31,22 @@ The tester will execute your program like this:
 ./your_program.sh --port <PORT>
 ```
 
-It'll then connect to your TCP server as a replica and execute the following commands:
+It will then connect to your TCP server as a replica and execute the following commands:
 
-1. `PING` (expecting `+PONG\r\n` back)
-2. `REPLCONF listening-port <PORT>` (expecting `+OK\r\n` back)
-3. `REPLCONF capa eof capa psync2` (expecting `+OK\r\n` back)
-4. `PSYNC ? -1` (expecting `+FULLRESYNC <REPL_ID> 0\r\n` back)
+1. `PING` - expecting `+PONG\r\n`
+2. `REPLCONF listening-port <PORT>` - expecting `+OK\r\n`
+3. `REPLCONF capa eof capa psync2` - expecting `+OK\r\n`
+4. `PSYNC ? -1` - expecting `+FULLRESYNC <REPL_ID> 0\r\n`
 
-After receiving a response to the last command, the tester will expect to receive an empty RDB file from your server.
+After the last response, the tester will expect to receive an empty RDB file from your server.
+
+The tester will accept any valid RDB file that is empty.
 
 ### Notes
 
-- The [RDB file link](https://github.com/codecrafters-io/redis-tester/blob/main/internal/assets/empty_rdb_hex.md) contains hex & base64 representations
-  of the file. You need to decode these into binary contents before sending it to the replica.
 - The RDB file should be sent like this: `$<length>\r\n<contents>`
   - `<length>` is the length of the file in bytes
   - `<contents>` is the binary contents of the file
-  - Note that this is NOT a RESP bulk string, it doesn't contain a `\r\n` at the end
+  - Note that this is NOT a RESP bulk string and doesn't contain a `\r\n` at the end.
 - If you want to learn more about the RDB file format, read [this blog post](https://rdb.fnordig.de/file_format.html). This challenge
   has a separate extension dedicated to reading RDB files.