lib

Core libraries for Radroots
git clone https://radroots.dev/git/lib.git
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authored_draft_pair.rs (1490B)

      1 //! Atomic installation of two opaque authored revisions, without effects.
      2 
      3 use crate::{
      4     Error,
      5     authored_draft::{AuthoredDraft, AuthoredDraftRevision},
      6 };
      7 
      8 /// A fixed pair of distinct drafts belonging to one author.
      9 ///
     10 /// Both expected heads use the existing single-draft compare-and-swap contract.
     11 /// A backend must install both revisions or neither. Only an exact replay of
     12 /// both existing revisions succeeds as replay; a partially existing pair is a
     13 /// conflict. Historical replay does not establish current head ownership.
     14 #[derive(Clone, Debug, Eq, PartialEq)]
     15 pub struct AuthoredDraftPair {
     16     drafts: [AuthoredDraft; 2],
     17     expected_heads: [Option<AuthoredDraftRevision>; 2],
     18 }
     19 
     20 impl AuthoredDraftPair {
     21     pub fn new(
     22         first: AuthoredDraft,
     23         first_expected: Option<AuthoredDraftRevision>,
     24         second: AuthoredDraft,
     25         second_expected: Option<AuthoredDraftRevision>,
     26     ) -> Result<Self, Error> {
     27         first.validate()?;
     28         second.validate()?;
     29         if first.draft_id() == second.draft_id() || first.author() != second.author() {
     30             return Err(Error::InvalidAuthoredDraft);
     31         }
     32         Ok(Self {
     33             drafts: [first, second],
     34             expected_heads: [first_expected, second_expected],
     35         })
     36     }
     37 
     38     pub const fn drafts(&self) -> &[AuthoredDraft; 2] {
     39         &self.drafts
     40     }
     41 
     42     pub const fn expected_heads(&self) -> &[Option<AuthoredDraftRevision>; 2] {
     43         &self.expected_heads
     44     }
     45 }