canic_backup/journal/
types.rs

1//! Module: journal::types
2//!
3//! Responsibility: define durable artifact journal state and transitions.
4//! Does not own: persistence, resume reporting, or full journal validation.
5//! Boundary: exposes typed journal records consumed by backup workflows.
6
7use crate::journal::JournalValidationError;
8
9use serde::{Deserialize, Serialize};
10
11///
12/// DownloadJournal
13///
14/// Durable artifact download journal for one backup run.
15/// Owned by backup journaling and consumed by resume and integrity checks.
16///
17
18#[derive(Clone, Debug, Deserialize, Serialize)]
19#[serde(deny_unknown_fields)]
20pub struct DownloadJournal {
21    pub journal_version: u16,
22    pub backup_id: String,
23    pub discovery_topology_hash: String,
24    pub pre_snapshot_topology_hash: String,
25    pub operation_metrics: DownloadOperationMetrics,
26    pub artifacts: Vec<ArtifactJournalEntry>,
27}
28
29///
30/// DownloadOperationMetrics
31///
32/// Counters for artifact download lifecycle progress.
33/// Owned by backup journaling and reported in resume summaries.
34///
35
36#[derive(Clone, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
37#[serde(deny_unknown_fields)]
38pub struct DownloadOperationMetrics {
39    pub target_count: usize,
40    pub snapshot_create_started: usize,
41    pub snapshot_create_completed: usize,
42    pub snapshot_download_started: usize,
43    pub snapshot_download_completed: usize,
44    pub checksum_verify_started: usize,
45    pub checksum_verify_completed: usize,
46    pub artifact_finalize_started: usize,
47    pub artifact_finalize_completed: usize,
48}
49
50///
51/// ArtifactJournalEntry
52///
53/// Durable journal entry for one snapshot artifact.
54/// Owned by backup journaling and advanced by snapshot download workflows.
55///
56
57#[derive(Clone, Debug, Deserialize, Serialize)]
58#[serde(deny_unknown_fields)]
59pub struct ArtifactJournalEntry {
60    pub canister_id: String,
61    pub snapshot_id: String,
62    pub state: ArtifactState,
63    #[serde(deserialize_with = "crate::serialization::required_option")]
64    pub temp_path: Option<String>,
65    pub artifact_path: String,
66    pub checksum_algorithm: String,
67    #[serde(deserialize_with = "crate::serialization::required_option")]
68    pub checksum: Option<String>,
69    pub updated_at: String,
70}
71
72impl ArtifactJournalEntry {
73    /// Return the idempotent action needed to resume this artifact.
74    #[must_use]
75    pub const fn resume_action(&self) -> ResumeAction {
76        match self.state {
77            ArtifactState::Created => ResumeAction::Download,
78            ArtifactState::Downloaded => ResumeAction::VerifyChecksum,
79            ArtifactState::ChecksumVerified => ResumeAction::Finalize,
80            ArtifactState::Durable => ResumeAction::Skip,
81        }
82    }
83
84    /// Advance this artifact to a later journal state.
85    pub fn advance_to(
86        &mut self,
87        next_state: ArtifactState,
88        updated_at: String,
89    ) -> Result<(), JournalValidationError> {
90        if !self.state.can_advance_to(next_state) {
91            return Err(JournalValidationError::InvalidStateTransition {
92                from: self.state,
93                to: next_state,
94            });
95        }
96
97        self.state = next_state;
98        self.updated_at = updated_at;
99        Ok(())
100    }
101}
102
103///
104/// ArtifactState
105///
106/// Monotonic durable state for one snapshot artifact.
107/// Owned by backup journaling and used to derive idempotent resume actions.
108///
109
110#[derive(Clone, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
111pub enum ArtifactState {
112    Created,
113    Downloaded,
114    ChecksumVerified,
115    Durable,
116}
117
118impl ArtifactState {
119    /// Return whether this state can advance monotonically to `next`.
120    #[must_use]
121    pub const fn can_advance_to(self, next: Self) -> bool {
122        self.as_order() <= next.as_order()
123    }
124
125    /// Return the stable ordering used by the journal state machine.
126    const fn as_order(self) -> u8 {
127        match self {
128            Self::Created => 0,
129            Self::Downloaded => 1,
130            Self::ChecksumVerified => 2,
131            Self::Durable => 3,
132        }
133    }
134}
135
136///
137/// ResumeAction
138///
139/// Next idempotent action needed to resume an artifact download.
140/// Owned by backup journaling and derived from artifact state.
141///
142
143#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
144pub enum ResumeAction {
145    Download,
146    VerifyChecksum,
147    Finalize,
148    Skip,
149}
canic_backup/journal/types.rs

canic_backup/journal/
types.rs
