PubkeyIndexMap: consider using [48]u8 as key

[twoeths]

from @spiral-ladder comment #28 (comment)

note that this is also used in bun binding so need to assess how it affect performance there

export fn pubkeyIndexMapGet(nbr_ptr: u64, key: [*c]const u8, key_length: c_uint) c_uint {
    if (key_length != PUBKEY_INDEX_MAP_KEY_SIZE) {
        return NOT_FOUND_INDEX;
    }
    const instance_ptr: *PubkeyIndexMapU32 = @ptrFromInt(nbr_ptr);
    const value = instance_ptr.get(key[0..key_length]) orelse return NOT_FOUND_INDEX;
    return value;
}

[spiral-ladder]

So, I was working on the main STF, and found that AutoHashMap does not support strings as keys since a very long time ago. I've switched it to StringHashMap in my (wip) state transition PR here. Not sure yet how this impacts the Bun bindings.

[twoeths]

AutoHashMap does not support strings as keys

@spiral-ladder the current implementation used [48]u8 as key already and should work fine as in unit tests, it's only the interface using []const u8 so not sure why it's a blocker there

since I already used a@memcpy in the implementation, looks like switching to [48]u8 should not affect Bun binding's performance

pub fn set(self: *@This(), key: []const u8, value: Val) !void {
    if (key.len != PUBKEY_INDEX_MAP_KEY_SIZE) {
        return error.InvalidKeyLen;
    }
    var fixed_key: Key = undefined;
    @memcpy(&fixed_key, key);
    try self.map.put(fixed_key, value);
}