What is the maximum length of vec in cosmwasm?

[99Kies]

What is the maximum length of vec in cosmwasm? I might set up a maximum of 15625 whitelists, but I'm concerned that this would exceed the vec length limit. Also the max block limit for our chain is 22MB.

this is my code:

#[cw_serde]
pub struct WhitelistConfig {
    pub addr: String,
}

#[cw_serde]
pub struct Whitelist {
    pub users: Vec<WhitelistConfig>,
}

impl Whitelist {
    pub fn is_whitelist(&self, addr: impl AsRef<str>) -> bool {
        let addr = addr.as_ref();
        self.users.iter().any(|a| a.addr == addr)
    }
}

[chipshort]

There is no explicit limit for vec length, but the limit you will most likely run into is the length limit for storage values.

So you need to make sure that when you serialize your value and save it in storage, the serialized value is smaller than that limit. I would recommand to keep a little buffer in-between, in case we ever need to lower the limit in the future.

Also keep in mind that reading and writing storage takes more gas depending on the size of the value.

[webmaster128]

Looking at the use case above (what I can guess from it), it makes sense to store it in a cw-storage-plus Map where each address it a key. The value can be anything, e.g. a constant 1u32. Then you can do existence checks on the map very efficiently as it is only a single database lookup.