prikk-store 0.0.1

Prikk storage crate scaffold.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

//! Read helpers for supported inverse planning.

use std::collections::{BTreeMap, HashSet};

use prikk_error::{PrikkError, Result};
use prikk_object::{
    BlobPayload, BlockPayload, CanonicalEncode, ObjectEnvelope, ObjectId, ObjectType,
    RefStatePayload,
};

use crate::layout::RepositoryLayout;
use crate::object_store::FileObjectStore;
use crate::refs::RefStore;
use crate::snapshot::SnapshotManifest;

/// Read the current target Block ID for a ref.
pub(super) fn current_target_block(
    layout: &RepositoryLayout,
    object_store: &FileObjectStore,
    ref_name: &str,
) -> Result<ObjectId> {
    let ref_store = RefStore::new(layout.clone());
    let ref_state_id = ref_store
        .read_current_ref_state_id(ref_name)?
        .ok_or_else(|| PrikkError::Integrity(format!("ref {ref_name} is not published")))?;
    let envelope = object_store
        .read_typed(ref_state_id, ObjectType::RefState)?
        .ok_or_else(|| {
            PrikkError::Integrity(format!(
                "ref {ref_name} points to missing RefState {ref_state_id}"
            ))
        })?;
    let ref_state = RefStatePayload::decode_canonical(&envelope.canonical_payload)?;
    if ref_state.ref_name != ref_name {
        return Err(PrikkError::Integrity(format!(
            "RefState name mismatch: expected {ref_name}, got {}",
            ref_state.ref_name
        )));
    }
    Ok(ref_state.target_object_id)
}

/// Return the single-parent chain from oldest to newest.
pub(super) fn single_parent_chain(
    object_store: &FileObjectStore,
    target: ObjectId,
) -> Result<Vec<ObjectId>> {
    let mut newest_first = Vec::new();
    let mut seen = HashSet::new();
    let mut current = Some(target);
    while let Some(block_id) = current {
        if !seen.insert(block_id) {
            return Err(PrikkError::Integrity(format!(
                "block parent chain contains a cycle at {block_id}"
            )));
        }
        let block = read_block(object_store, block_id)?;
        if block.parent_block_ids.len() > 1 {
            return Err(PrikkError::UnsupportedObjectType(format!(
                "inverse planning supports single-parent chains only; block has {} parents",
                block.parent_block_ids.len()
            )));
        }
        newest_first.push(block_id);
        current = block.parent_block_ids.first().copied();
    }
    newest_first.reverse();
    Ok(newest_first)
}

/// Read and decode a Block payload.
pub(super) fn read_block(
    object_store: &FileObjectStore,
    block_id: ObjectId,
) -> Result<BlockPayload> {
    let envelope = object_store
        .read_typed(block_id, ObjectType::Block)?
        .ok_or_else(|| PrikkError::Integrity(format!("missing Block {block_id}")))?;
    BlockPayload::decode_canonical(&envelope.canonical_payload)
}

/// Read a Patch envelope.
pub(super) fn read_patch(
    object_store: &FileObjectStore,
    patch_id: ObjectId,
) -> Result<ObjectEnvelope> {
    object_store
        .read_typed(patch_id, ObjectType::Patch)?
        .ok_or_else(|| PrikkError::Integrity(format!("missing Patch {patch_id}")))
}

/// Load a snapshot manifest into a path-to-bytes map.
pub(super) fn load_snapshot_files(
    object_store: &FileObjectStore,
    snapshot_blob_ref: ObjectId,
) -> Result<BTreeMap<String, Vec<u8>>> {
    let envelope = object_store
        .read_typed(snapshot_blob_ref, ObjectType::Blob)?
        .ok_or_else(|| {
            PrikkError::Integrity(format!("missing snapshot Blob {snapshot_blob_ref}"))
        })?;
    let blob = BlobPayload::decode_canonical(&envelope.canonical_payload)?;
    let manifest = SnapshotManifest::decode(&blob.bytes)?;
    let mut files = BTreeMap::new();
    for entry in manifest.files {
        files.insert(entry.path.as_str().to_string(), entry.bytes);
    }
    Ok(files)
}

/// Read raw bytes from a Blob object.
pub(super) fn read_blob_bytes(
    object_store: &FileObjectStore,
    blob_id: ObjectId,
) -> Result<Vec<u8>> {
    let envelope = object_store
        .read_typed(blob_id, ObjectType::Blob)?
        .ok_or_else(|| PrikkError::Integrity(format!("missing Blob {blob_id}")))?;
    let blob = BlobPayload::decode_canonical(&envelope.canonical_payload)?;
    Ok(blob.bytes)
}

/// Ensure bytes identify as the expected Blob object ID.
pub(super) fn ensure_blob_matches(bytes: &[u8], expected: ObjectId) -> Result<()> {
    let payload = BlobPayload {
        bytes: bytes.to_vec(),
    };
    let id = ObjectId::from_canonical_payload(ObjectType::Blob, 1, &payload.to_canonical_bytes()?);
    if id == expected {
        return Ok(());
    }
    Err(PrikkError::Integrity(format!(
        "operation old_blob_id mismatch: expected {expected}, got {id}"
    )))
}