The databas_core crate defines a comprehensive error type system for storage operations, corruption detection, and constraint violations.
StorageError
The main error enum for all storage-level operations.
pub enum StorageError {
Io(std::io::Error),
Corruption(CorruptionError),
Constraint(ConstraintError),
InvalidArgument(InvalidArgumentError),
LimitExceeded(LimitExceededError),
Internal(InternalError),
}
Io Errors
Wraps standard I/O errors from file operations.
StorageError::Io(std::io::Error)
- File cannot be opened or created
- Read/write operations fail
- Disk space exhausted
- Permission denied
Corruption Errors
Database file corruption detected during validation.
StorageError::Corruption(CorruptionError)
Constraint Errors
Database constraint violations.
StorageError::Constraint(ConstraintError)
Invalid Argument Errors
Invalid parameters passed to API functions.
StorageError::InvalidArgument(InvalidArgumentError)
Limit Exceeded Errors
Resource limits exceeded.
StorageError::LimitExceeded(LimitExceededError)
Internal Errors
Internal invariant violations (should not occur in correct code).
StorageError::Internal(InternalError)
CorruptionError
Detailed information about database file corruption.
pub struct CorruptionError {
pub component: CorruptionComponent,
pub page_id: Option<u64>,
pub kind: CorruptionKind,
}
The database component where corruption was detected.
The page ID where corruption occurred, if applicable.
The specific type of corruption detected.
CorruptionComponent
pub enum CorruptionComponent {
DatabaseHeader,
DiskPage,
TablePage,
TableLeafPage,
TableInteriorPage,
BTree,
}
- DatabaseHeader - Page 0 header corruption
- DiskPage - Generic page-level corruption
- TablePage - Table page structure corruption
- TableLeafPage - B-tree leaf page corruption
- TableInteriorPage - B-tree interior page corruption
- BTree - B-tree structure invariant violation
CorruptionKind
pub enum CorruptionKind {
InvalidFileSize { size: u64, page_size: usize },
InvalidChecksum,
InvalidHeaderMagic,
InvalidHeaderPageSize { expected: usize, actual: u16 },
HeaderPageCountMismatch { expected: u64, actual: u64 },
HeaderPageCountZero,
InvalidPageType { page_type: u8 },
InvalidCellContentStart,
SlotIndexOutOfBounds,
SlotDirectoryOverlapsCellContent,
SlotDirectoryExceedsPageSize,
CellTooShort,
CellPayloadOutOfBounds,
CellContentUnderflow,
MalformedCell { slot_index: u16 },
}
File-Level Corruption
InvalidFileSize
InvalidFileSize { size: u64, page_size: usize }
"databas format1\0"
InvalidHeaderPageSize
InvalidHeaderPageSize { expected: usize, actual: u16 }
HeaderPageCountMismatch { expected: u64, actual: u64 }
Page Structure Corruption
InvalidPageType
InvalidPageType { page_type: u8 }
13 - Leaf table page5 - Interior table page
InvalidCellContentStart
Cell content area start offset is invalid (zero or exceeds page size).
SlotIndexOutOfBounds
Slot array index exceeds the cell count.
SlotDirectoryOverlapsCellContent
SlotDirectoryOverlapsCellContent
SlotDirectoryExceedsPageSize
Cell Corruption
CellTooShort
A cell is shorter than the minimum valid cell size.
CellPayloadOutOfBounds
Cell payload extends beyond the page boundary.
CellContentUnderflow
Cell content area pointer underflowed during allocation.
MalformedCell
MalformedCell { slot_index: u16 }
ConstraintError
Database constraint violations during data operations.
pub enum ConstraintError {
DuplicateRowId { row_id: u64 },
}
DuplicateRowId { row_id: u64 }
InvalidArgumentError
Invalid arguments passed to API functions.
pub enum InvalidArgumentError {
InvalidPageId { page_id: u64 },
}
InvalidPageId { page_id: u64 }
LimitExceededError
Resource or size limits exceeded.
pub enum LimitExceededError {
CellTooLarge { len: usize, max: usize },
PageFull { needed: usize, available: usize },
CacheCapacityExhausted,
}
CellTooLarge { len: usize, max: usize }
PageFull { needed: usize, available: usize }
InternalError
Internal invariant violations that indicate a bug in the database code.
pub enum InternalError {
InvariantViolation(InvariantViolation),
}
InvariantViolation
pub enum InvariantViolation {
InvalidFrameCount { frame_count: usize },
PinnedPageDuringFlush { page_id: u64 },
CorruptPageTableEntry { page_id: u64, frame_id: usize, frame_count: usize },
}
InvalidFrameCount { frame_count: usize }
PinnedPageDuringFlush { page_id: u64 }
CorruptPageTableEntry { page_id: u64, frame_id: usize, frame_count: usize }
Error Handling Example
use databas_core::disk_manager::DiskManager;
use databas_core::error::{StorageError, CorruptionKind};
fn open_database(path: &Path) -> Result<DiskManager, StorageError> {
match DiskManager::new(path) {
Ok(dm) => Ok(dm),
Err(StorageError::Corruption(err)) => {
match err.kind {
CorruptionKind::InvalidHeaderMagic => {
eprintln!("Not a valid databas file");
Err(StorageError::Corruption(err))
}
CorruptionKind::InvalidChecksum => {
eprintln!("Database file is corrupted");
Err(StorageError::Corruption(err))
}
_ => Err(StorageError::Corruption(err))
}
}
Err(e) => Err(e)
}
}
Display Implementation
All error types implement Display for human-readable error messages:
let err = StorageError::Corruption(CorruptionError {
component: CorruptionComponent::DatabaseHeader,
page_id: Some(0),
kind: CorruptionKind::InvalidHeaderMagic,
});
println!("{}", err);
// Output: "corruption in DatabaseHeader (page 0): invalid magic"