[masklinn]

> Isn't length + pointer... Basically a Pascal string? Unless I am mistaken.

Length + pointer is a record string, a pascal string has the length at the head of the buffer, behind the pointer.

[nopurpose]

Many years ago when reading Redis code I saw the same pattern: they pass around simple pointer to data, but there is a fixed length metadata just before that.

[masklinn]

I assume it’s either Antirez’s sds or a variant / ancestor thereof, yes. It stores a control block at the head of the string, but the pointer points past that block, so it has metadata but “is” a C string.