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wire/
transfer_plan.rs

1// SPDX-License-Identifier: Apache-2.0
2//! Shared repository transfer planning primitives.
3//!
4//! The wire protocol still carries the existing push/pull messages. This
5//! module gives local and hosted sync paths one Rust-native vocabulary for the
6//! Heddle object lane: content-addressed objects that can ride the native pack,
7//! and signed sidecars that must use the out-of-pack verification paths.
8
9use objects::{object::ChangeId, store::ObjectStore};
10
11use crate::{
12    ObjectInfo, ObjectType, ObjectTypeBucket, PlannedObject, Result, StateClosureOptions,
13    enumerate_state_closure_plan_with_options,
14};
15
16#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
17pub enum GitLaneTransferIntent {
18    /// This transfer contains only Heddle content-addressed objects and
19    /// sidecars; no Git-lane work is expected.
20    #[default]
21    HeddleObjectsOnly,
22    /// Hosted Git-lane pack streaming remains on the current implementation.
23    /// The shared transfer plan records that fact without taking ownership of
24    /// reachable Git pack construction.
25    ExistingImplementation,
26    /// Placeholder for the future Sley facade boundary. Heddle should not grow
27    /// a second reachable-pack planner locally; once Sley exposes the needed
28    /// facade, this intent can become an executable Git-lane plan.
29    BlockedOnSleyReachablePackPlanning,
30}
31
32#[derive(Debug, Clone, PartialEq, Eq)]
33pub struct RepositoryTransferPlan<T = PlannedObject> {
34    pub partitions: TransferPartitions<T>,
35    pub stats: TransferPlanStats,
36    pub git_lane: GitLaneTransferIntent,
37}
38
39#[derive(Debug, Clone, PartialEq, Eq)]
40pub struct TransferPartitions<T = PlannedObject> {
41    pub packable_objects: Vec<T>,
42    pub sidecar_objects: Vec<T>,
43}
44
45#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
46pub struct TransferPlanStats {
47    pub total_objects: usize,
48    pub packable_objects: usize,
49    pub sidecar_objects: usize,
50    pub blobs: usize,
51    pub trees: usize,
52    pub states: usize,
53    pub actions: usize,
54    pub redactions: usize,
55    pub state_visibilities: usize,
56}
57
58impl RepositoryTransferPlan<PlannedObject> {
59    pub fn from_state_closure_plan(
60        store: &impl ObjectStore,
61        root: ChangeId,
62        options: StateClosureOptions,
63        git_lane: GitLaneTransferIntent,
64    ) -> Result<Self> {
65        let objects = enumerate_state_closure_plan_with_options(store, root, options)?;
66        Ok(Self::from_planned_objects(objects, git_lane))
67    }
68
69    pub fn from_planned_objects(
70        objects: impl IntoIterator<Item = PlannedObject>,
71        git_lane: GitLaneTransferIntent,
72    ) -> Self {
73        build_plan(objects, planned_object_type, git_lane)
74    }
75}
76
77impl RepositoryTransferPlan<ObjectInfo> {
78    pub fn from_object_infos(
79        objects: impl IntoIterator<Item = ObjectInfo>,
80        git_lane: GitLaneTransferIntent,
81    ) -> Self {
82        build_plan(objects, object_info_type, git_lane)
83    }
84}
85
86impl<T> RepositoryTransferPlan<T> {
87    pub fn requires_native_pack(&self, include_full_closure: bool) -> bool {
88        include_full_closure || self.stats.packable_objects > 0
89    }
90
91    pub fn is_heddle_only(&self) -> bool {
92        self.git_lane == GitLaneTransferIntent::HeddleObjectsOnly
93    }
94}
95
96impl<T> TransferPartitions<T> {
97    pub fn is_empty(&self) -> bool {
98        self.packable_objects.is_empty() && self.sidecar_objects.is_empty()
99    }
100
101    pub fn len(&self) -> usize {
102        self.packable_objects.len() + self.sidecar_objects.len()
103    }
104
105    pub fn iter(&self) -> impl Iterator<Item = &T> {
106        self.packable_objects
107            .iter()
108            .chain(self.sidecar_objects.iter())
109    }
110
111    pub fn is_sidecar_object_type(obj_type: ObjectType) -> bool {
112        !obj_type.packable()
113    }
114}
115
116impl<T> Default for TransferPartitions<T> {
117    fn default() -> Self {
118        Self {
119            packable_objects: Vec::new(),
120            sidecar_objects: Vec::new(),
121        }
122    }
123}
124
125impl TransferPlanStats {
126    fn record(&mut self, obj_type: ObjectType) {
127        self.total_objects += 1;
128        if TransferPartitions::<()>::is_sidecar_object_type(obj_type) {
129            self.sidecar_objects += 1;
130        } else {
131            self.packable_objects += 1;
132        }
133        match obj_type.bucket() {
134            ObjectTypeBucket::Blob => self.blobs += 1,
135            ObjectTypeBucket::Tree => self.trees += 1,
136            ObjectTypeBucket::State => self.states += 1,
137            ObjectTypeBucket::Action => self.actions += 1,
138            ObjectTypeBucket::Redaction => self.redactions += 1,
139            ObjectTypeBucket::StateVisibility => self.state_visibilities += 1,
140        }
141    }
142}
143
144fn build_plan<T>(
145    objects: impl IntoIterator<Item = T>,
146    object_type: fn(&T) -> ObjectType,
147    git_lane: GitLaneTransferIntent,
148) -> RepositoryTransferPlan<T> {
149    let mut partitions = TransferPartitions::default();
150    let mut stats = TransferPlanStats::default();
151
152    for object in objects {
153        let obj_type = object_type(&object);
154        stats.record(obj_type);
155        if TransferPartitions::<T>::is_sidecar_object_type(obj_type) {
156            partitions.sidecar_objects.push(object);
157        } else {
158            partitions.packable_objects.push(object);
159        }
160    }
161
162    RepositoryTransferPlan {
163        partitions,
164        stats,
165        git_lane,
166    }
167}
168
169fn planned_object_type(object: &PlannedObject) -> ObjectType {
170    object.obj_type
171}
172
173fn object_info_type(object: &ObjectInfo) -> ObjectType {
174    object.obj_type
175}
176
177#[cfg(test)]
178mod tests {
179    use objects::object::{ChangeId, ContentHash};
180
181    use super::*;
182    use crate::ObjectId;
183
184    fn hash(byte: u8) -> ContentHash {
185        ContentHash::from_bytes([byte; 32])
186    }
187
188    #[test]
189    fn partitions_split_native_pack_objects_from_sidecars() {
190        let state = ChangeId::from_bytes([9; 16]);
191        let plan = RepositoryTransferPlan::from_planned_objects(
192            vec![
193                PlannedObject {
194                    id: ObjectId::Hash(hash(1)),
195                    obj_type: ObjectType::Blob,
196                },
197                PlannedObject {
198                    id: ObjectId::Hash(hash(2)),
199                    obj_type: ObjectType::Tree,
200                },
201                PlannedObject {
202                    id: ObjectId::Hash(hash(1)),
203                    obj_type: ObjectType::Redaction,
204                },
205                PlannedObject {
206                    id: ObjectId::ChangeId(state),
207                    obj_type: ObjectType::StateVisibility,
208                },
209            ],
210            GitLaneTransferIntent::HeddleObjectsOnly,
211        );
212
213        assert_eq!(plan.partitions.packable_objects.len(), 2);
214        assert_eq!(plan.partitions.sidecar_objects.len(), 2);
215        assert_eq!(plan.stats.total_objects, 4);
216        assert_eq!(plan.stats.packable_objects, 2);
217        assert_eq!(plan.stats.sidecar_objects, 2);
218        assert_eq!(plan.stats.blobs, 1);
219        assert_eq!(plan.stats.trees, 1);
220        assert_eq!(plan.stats.redactions, 1);
221        assert_eq!(plan.stats.state_visibilities, 1);
222        assert!(plan.requires_native_pack(false));
223    }
224
225    #[test]
226    fn sidecar_only_plan_does_not_require_native_pack() {
227        let state = ChangeId::from_bytes([3; 16]);
228        let plan = RepositoryTransferPlan::from_object_infos(
229            vec![ObjectInfo {
230                id: ObjectId::ChangeId(state),
231                obj_type: ObjectType::StateVisibility,
232                size: 128,
233                delta_base: None,
234            }],
235            GitLaneTransferIntent::HeddleObjectsOnly,
236        );
237
238        assert!(!plan.requires_native_pack(false));
239        assert!(plan.requires_native_pack(true));
240        assert_eq!(plan.stats.packable_objects, 0);
241        assert_eq!(plan.stats.sidecar_objects, 1);
242    }
243
244    #[test]
245    fn git_lane_intents_name_current_and_sley_gated_paths() {
246        let hosted = RepositoryTransferPlan::from_planned_objects(
247            Vec::<PlannedObject>::new(),
248            GitLaneTransferIntent::ExistingImplementation,
249        );
250        let sley_blocked = RepositoryTransferPlan::from_planned_objects(
251            Vec::<PlannedObject>::new(),
252            GitLaneTransferIntent::BlockedOnSleyReachablePackPlanning,
253        );
254
255        assert_eq!(
256            hosted.git_lane,
257            GitLaneTransferIntent::ExistingImplementation
258        );
259        assert_eq!(
260            sley_blocked.git_lane,
261            GitLaneTransferIntent::BlockedOnSleyReachablePackPlanning
262        );
263        assert!(!hosted.is_heddle_only());
264        assert!(!sley_blocked.is_heddle_only());
265    }
266}