ic_memory/
schema.rs

1use serde::{Deserialize, Serialize};
2
3///
4/// SchemaMetadata
5///
6/// Optional diagnostic metadata for an in-place store schema.
7///
8/// This metadata helps humans and frameworks diagnose which schema version was
9/// declared in each generation. It is bounded and validated for durable ledger
10/// encoding, but it does not perform application schema migrations or validate
11/// stable data semantics.
12///
13
14#[derive(Clone, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
15#[serde(deny_unknown_fields)]
16pub struct SchemaMetadata {
17    /// Optional in-place schema version.
18    pub(crate) schema_version: Option<u32>,
19}
20
21impl SchemaMetadata {
22    /// Construct schema metadata after validating the persisted encoding bounds.
23    pub fn new(schema_version: Option<u32>) -> Result<Self, SchemaMetadataError> {
24        let metadata = Self { schema_version };
25        metadata.validate()?;
26        Ok(metadata)
27    }
28
29    /// Validate schema metadata encoding rules.
30    pub fn validate(&self) -> Result<(), SchemaMetadataError> {
31        if self.schema_version == Some(0) {
32            return Err(SchemaMetadataError::InvalidVersion);
33        }
34        Ok(())
35    }
36
37    /// Return the optional in-place schema version.
38    #[must_use]
39    pub const fn schema_version(&self) -> Option<u32> {
40        self.schema_version
41    }
42}
43
44///
45/// SchemaMetadataError
46///
47/// Schema metadata validation failure.
48///
49
50#[non_exhaustive]
51#[derive(Clone, Debug, Eq, thiserror::Error, PartialEq)]
52pub enum SchemaMetadataError {
53    /// Schema version zero is reserved for absence.
54    #[error("schema_version must be greater than zero when present")]
55    InvalidVersion,
56}
ic_memory/schema.rs

ic_memory/
schema.rs
