REdis Serialization Protocol

RESP (Redis Serialization Protocol) is a simple protocol used by Redis to communicate between the client and server. It's a text-based protocol that is easy to understand and implement.

Here's a brief overview of how it works:

1. Simple Strings: Strings are sent as lines terminated by \r\n. For example, +OK\r\n represents the string "OK".

   These are used to transmit non-binary safe strings and are prefixed with a + sign. They cannot contain a CR or LF character (basically, newlines are not allowed). Simple Strings are typically used for sending status replies. For example, +OK\r\n is a Simple String representing the string "OK".

2. Errors: Errors are also sent as strings, but start with a -. For example, -Error message\r\n.

3. Integers: Integers are sent as a string of digits, prefixed by a :. For example, :1000\r\n represents the integer 1000.

4. Bulk Strings: Bulk strings are binary safe and have a length prefix to specify their length. For example, $6\r\nfoobar\r\n represents the string "foobar".

   These are used to transmit binary-safe strings and are prefixed with a $ sign followed by the length of the string. Bulk Strings can contain any kind of data, including binary data, and can be as long as 512MB.

5. Arrays: Arrays are sent as a prefix with the number of elements, followed by the elements themselves. For example, *2\r\n$3\r\nfoo\r\n$3\r\nbar\r\n represents the array ["foo", "bar"].

   arrays are prefixed with an asterisk (*) followed by the number of elements in the array.

6. Null Values: RESP has special representations for null values. A null Bulk String is represented as "$-1\r\n", and a null Array is represented as "*-1\r\n"

Request-Response Model: RESP is used in a request-response model. A client sends a request to the server, the server processes the request and then sends a response back to the client.

Pipelining: RESP supports pipelining. This means a client can send multiple requests to the server without waiting for the responses. The server will then send the responses back in the same order as the requests.

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