plugmem_arena/
error.rs

1//! The crate-wide error type.
2//!
3//! All four storage structures share one error enum: capacity problems are
4//! always typed errors, never panics, and a caller embedding several
5//! structures (the plugmem engine does) handles one type.
6
7use crate::arena::PAGE_BYTES;
8use crate::chunk::CHUNK_PAYLOAD;
9
10/// Errors returned by storage operations. No operation in this crate panics
11/// on resource exhaustion — capacity problems are always typed errors.
12/// (Contract violations — a wrong key length, an out-of-range id — panic,
13/// because they are caller bugs, not runtime conditions; each method
14/// documents its panics.)
15#[derive(Clone, Copy, Debug, PartialEq, Eq, thiserror::Error)]
16#[cfg_attr(feature = "serde", derive(serde::Serialize))]
17pub enum Error {
18    /// Growing a byte pool would exceed the structure's configured
19    /// `max_bytes` ceiling.
20    #[error("capacity exceeded: pool would grow past {max_bytes} bytes")]
21    CapacityExceeded {
22        /// The configured ceiling that would have been crossed.
23        max_bytes: usize,
24    },
25    /// The [`Slot`](crate::Slot) layout constants are invalid.
26    #[error(
27        "invalid slot layout: size {size}, key_len {key_len} (require 1 <= key_len <= size <= {PAGE_BYTES})"
28    )]
29    BadSlot {
30        /// Declared [`Slot::SIZE`](crate::Slot::SIZE).
31        size: usize,
32        /// Declared [`Slot::KEY_LEN`](crate::Slot::KEY_LEN).
33        key_len: usize,
34    },
35    /// [`ArenaCfg::shards`](crate::ArenaCfg::shards) is not a non-zero power
36    /// of two.
37    #[error("shard count must be a non-zero power of two, got {got}")]
38    BadShardCount {
39        /// The rejected shard count.
40        got: usize,
41    },
42    /// A blob passed to [`BlobHeap::push`](crate::BlobHeap::push) is longer
43    /// than the configured [`max_blob`](crate::BlobHeapCfg::max_blob).
44    #[error("blob of {len} bytes exceeds the configured max_blob of {max_blob} bytes")]
45    BlobTooLarge {
46        /// Length of the rejected blob.
47        len: usize,
48        /// The configured per-blob ceiling.
49        max_blob: usize,
50    },
51    /// A value passed to [`ChunkPool::push`](crate::ChunkPool::push) is
52    /// longer than a chunk's payload ([`CHUNK_PAYLOAD`] bytes) and can never
53    /// fit without crossing a chunk boundary.
54    #[error("value of {len} bytes exceeds the chunk payload of {CHUNK_PAYLOAD} bytes")]
55    ValueTooLarge {
56        /// Length of the rejected value.
57        len: usize,
58    },
59    /// A serialized image failed load-time validation (`load` methods).
60    ///
61    /// The message names the violated invariant. Loading never panics on
62    /// arbitrary bytes — every inconsistency maps to this variant.
63    #[error("corrupt image: {0}")]
64    Corrupt(&'static str),
65}
plugmem_arena/error.rs

plugmem_arena/
error.rs
