mirror of
https://github.com/nostr-protocol/nips.git
synced 2024-11-10 14:19:08 -05:00
52 lines
1.7 KiB
Markdown
52 lines
1.7 KiB
Markdown
NIP-34a
|
|
=======
|
|
|
|
Oldest First
|
|
------------
|
|
|
|
`draft` `optional` `author:arthurfranca`
|
|
|
|
Events with older `created_at` are retrieved first.
|
|
|
|
## Implementation
|
|
|
|
`Relay` computes `nip34a` field once upon receiving the event.
|
|
|
|
The lower the `created_at`, the higher `nip34a` will be.
|
|
|
|
### Javascript
|
|
|
|
```js
|
|
// Use this same value even if your programming language allows a higher one
|
|
const maxDateNowSeconds = 8640000000000 // 8.64e15 ms / 1000
|
|
// Equals 17280000000000. It is ok because it is lower than Number.MAX_SAFE_INTEGER
|
|
// We multiply by 2 because of "ts = seconds + maxDateNowSeconds" below
|
|
const maxTs = maxDateNowSeconds * 2
|
|
const maxSecondsLength = maxTs.toString().length
|
|
|
|
function getNip34a (createdAt, id = '') {
|
|
// The id length must always be the same to not affect sorting
|
|
if (id.length !== 64) { throw new Error('Wrong id length') }
|
|
let seconds = Math.trunc(createdAt) // Make sure it is int instead of float
|
|
seconds = Math.max(seconds, -maxDateNowSeconds) // Keep min limit
|
|
seconds = Math.min(seconds, maxDateNowSeconds) // Keep max limit
|
|
// Allow negative createdAt but remove minus sign
|
|
// because '-2' string timestamp is wrongly higher than '-1'
|
|
let ts = seconds + maxDateNowSeconds
|
|
// Make it lower the greater the ts is (the newer the createdAt is)
|
|
ts = maxTs - ts
|
|
// '10' is wrongly lower then '2' while '10' is higher than padded '02'
|
|
const paddedTsSeconds = ts.toString().padStart(maxSecondsLength, '0')
|
|
|
|
// Event id is used as a fixed length unique identifier
|
|
return `${paddedTsSeconds}${id}`
|
|
}
|
|
|
|
event.nip34a = getNip34a(event.created_at, event.id)
|
|
```
|
|
|
|
## Notes
|
|
|
|
This implementation should be updated if we find out a popular programming
|
|
language doesn't support 17280000000000 int.
|