Struct LogicalFieldId 

pub struct LogicalFieldId { /* private fields */ }

Globally unique identifier for a column in the storage engine.

A LogicalFieldId combines three components into a single 64-bit value:

• Namespace (16 bits): Category of data (user, system, MVCC)
• Table ID (16 bits): Which table the column belongs to
• Field ID (32 bits): Which column within the table

This design prevents ID collisions across different tables and data categories while keeping identifiers compact and easy to pass around.

Bit Layout

|-------- 64 bits total --------|
| namespace | table_id | field_id |
|  16 bits  | 16 bits  | 32 bits  |

Construction

Use the constructor methods rather than directly manipulating bits:

• LogicalFieldId::for_user - User-defined columns
• LogicalFieldId::for_mvcc_created_by - MVCC created_by metadata
• LogicalFieldId::for_mvcc_deleted_by - MVCC deleted_by metadata
• LogicalFieldId::from_parts - Custom construction

Thread Safety

LogicalFieldId is Copy and thread-safe.

Implementations

impl LogicalFieldId

pub const fn new() -> Self

Returns an instance with zero initialized data.

impl LogicalFieldId

pub const fn into_bytes(self) -> [u8; 8]

Returns the underlying bits.

Layout

The returned byte array is layed out in the same way as described here.

pub const fn from_bytes(bytes: [u8; 8]) -> Self

Converts the given bytes directly into the bitfield struct.

impl LogicalFieldId

pub fn field_id(&self) -> <B32 as Specifier>::InOut

Returns the value of field_id. Column identifier within the table (32 bits).

Supports up to ~4.3 billion columns per table. Field ID 0 is reserved for row ID columns.

pub fn field_id_or_err( &self, ) -> Result<<B32 as Specifier>::InOut, InvalidBitPattern<<B32 as Specifier>::Bytes>>

Returns the value of field_id.

Errors

If the returned value contains an invalid bit pattern for field_id. Column identifier within the table (32 bits).

Supports up to ~4.3 billion columns per table. Field ID 0 is reserved for row ID columns.

pub fn with_field_id(self, new_val: <B32 as Specifier>::InOut) -> Self

Returns a copy of the bitfield with the value of field_id set to the given value.

Panics

If the given value is out of bounds for field_id. Column identifier within the table (32 bits).

Supports up to ~4.3 billion columns per table. Field ID 0 is reserved for row ID columns.

pub fn with_field_id_checked( self, new_val: <B32 as Specifier>::InOut, ) -> Result<Self, OutOfBounds>

Returns a copy of the bitfield with the value of field_id set to the given value.

Errors

If the given value is out of bounds for field_id. Column identifier within the table (32 bits).

Supports up to ~4.3 billion columns per table. Field ID 0 is reserved for row ID columns.

pub fn set_field_id(&mut self, new_val: <B32 as Specifier>::InOut)

Sets the value of field_id to the given value.

Panics

If the given value is out of bounds for field_id. Column identifier within the table (32 bits).

Supports up to ~4.3 billion columns per table. Field ID 0 is reserved for row ID columns.

pub fn set_field_id_checked( &mut self, new_val: <B32 as Specifier>::InOut, ) -> Result<(), OutOfBounds>

Sets the value of field_id to the given value.

Errors

If the given value is out of bounds for field_id. Column identifier within the table (32 bits).

Supports up to ~4.3 billion columns per table. Field ID 0 is reserved for row ID columns.

pub fn table_id(&self) -> <B16 as Specifier>::InOut

Returns the value of table_id. Table identifier (16 bits).

Supports up to 65,535 tables. Table ID 0 is reserved for the system catalog.

pub fn table_id_or_err( &self, ) -> Result<<B16 as Specifier>::InOut, InvalidBitPattern<<B16 as Specifier>::Bytes>>

Returns the value of table_id.

Errors

If the returned value contains an invalid bit pattern for table_id. Table identifier (16 bits).

Supports up to 65,535 tables. Table ID 0 is reserved for the system catalog.

pub fn with_table_id(self, new_val: <B16 as Specifier>::InOut) -> Self

Returns a copy of the bitfield with the value of table_id set to the given value.

Panics

If the given value is out of bounds for table_id. Table identifier (16 bits).

Supports up to 65,535 tables. Table ID 0 is reserved for the system catalog.

pub fn with_table_id_checked( self, new_val: <B16 as Specifier>::InOut, ) -> Result<Self, OutOfBounds>

Returns a copy of the bitfield with the value of table_id set to the given value.

Errors

If the given value is out of bounds for table_id. Table identifier (16 bits).

Supports up to 65,535 tables. Table ID 0 is reserved for the system catalog.

pub fn set_table_id(&mut self, new_val: <B16 as Specifier>::InOut)

Sets the value of table_id to the given value.

Panics

If the given value is out of bounds for table_id. Table identifier (16 bits).

Supports up to 65,535 tables. Table ID 0 is reserved for the system catalog.

pub fn set_table_id_checked( &mut self, new_val: <B16 as Specifier>::InOut, ) -> Result<(), OutOfBounds>

Sets the value of table_id to the given value.

Errors

If the given value is out of bounds for table_id. Table identifier (16 bits).

Supports up to 65,535 tables. Table ID 0 is reserved for the system catalog.

pub fn namespace(&self) -> <LogicalStorageNamespace as Specifier>::InOut

Returns the value of namespace. Data category (16 bits).

Determines whether this ID refers to user data, system metadata, or MVCC tracking.

pub fn namespace_or_err( &self, ) -> Result<<LogicalStorageNamespace as Specifier>::InOut, InvalidBitPattern<<LogicalStorageNamespace as Specifier>::Bytes>>

Returns the value of namespace.

Errors

If the returned value contains an invalid bit pattern for namespace. Data category (16 bits).

Determines whether this ID refers to user data, system metadata, or MVCC tracking.

pub fn with_namespace( self, new_val: <LogicalStorageNamespace as Specifier>::InOut, ) -> Self

Returns a copy of the bitfield with the value of namespace set to the given value.

Panics

If the given value is out of bounds for namespace. Data category (16 bits).

Determines whether this ID refers to user data, system metadata, or MVCC tracking.

pub fn with_namespace_checked( self, new_val: <LogicalStorageNamespace as Specifier>::InOut, ) -> Result<Self, OutOfBounds>

Returns a copy of the bitfield with the value of namespace set to the given value.

Errors

If the given value is out of bounds for namespace. Data category (16 bits).

Determines whether this ID refers to user data, system metadata, or MVCC tracking.

pub fn set_namespace( &mut self, new_val: <LogicalStorageNamespace as Specifier>::InOut, )

Sets the value of namespace to the given value.

Panics

If the given value is out of bounds for namespace. Data category (16 bits).

Determines whether this ID refers to user data, system metadata, or MVCC tracking.

pub fn set_namespace_checked( &mut self, new_val: <LogicalStorageNamespace as Specifier>::InOut, ) -> Result<(), OutOfBounds>

Sets the value of namespace to the given value.

Errors

If the given value is out of bounds for namespace. Data category (16 bits).

Determines whether this ID refers to user data, system metadata, or MVCC tracking.

impl LogicalFieldId

pub fn from_parts( namespace: LogicalStorageNamespace, table_id: TableId, field_id: FieldId, ) -> Self

Construct a LogicalFieldId from individual components.

This is the most general constructor. Use the convenience methods (for_user, for_mvcc_created_by, etc.) for common cases.

pub fn for_user(table_id: TableId, field_id: FieldId) -> Self

Create an ID for a user-defined column.

This is the most common constructor for regular table columns. It uses the UserData namespace.

pub fn for_user_table_0(field_id: FieldId) -> Self

Create an ID for a user column in table 0.

This is a convenience method for tests and examples that use the default table ID.

pub fn for_mvcc_created_by(table_id: TableId) -> Self

Create an ID for the MVCC created_by column of a table.

Each table has a created_by column that tracks which transaction inserted each row. The field ID is always u32::MAX as a sentinel value.

pub fn for_mvcc_deleted_by(table_id: TableId) -> Self

Create an ID for the MVCC deleted_by column of a table.

Each table has a deleted_by column that tracks which transaction deleted each row (or TXN_ID_NONE if not deleted). The field ID is always u32::MAX - 1 as a sentinel value.

Trait Implementations

impl CheckTotalSizeMultipleOf8 for LogicalFieldId

type Size = TotalSize<BitCount</// Globally unique identifier for a column in the storage engine. /// /// A `LogicalFieldId` combines three components into a single 64-bit value: /// - **Namespace** (16 bits): Category of data (user, system, MVCC) /// - **Table ID** (16 bits): Which table the column belongs to /// - **Field ID** (32 bits): Which column within the table /// /// This design prevents ID collisions across different tables and data categories while /// keeping identifiers compact and easy to pass around. /// /// # Bit Layout /// /// ```text /// |-------- 64 bits total --------| /// | namespace | table_id | field_id | /// | 16 bits | 16 bits | 32 bits | /// ``` /// /// # Construction /// /// Use the constructor methods rather than directly manipulating bits: /// - [`LogicalFieldId::for_user`] - User-defined columns /// - [`LogicalFieldId::for_mvcc_created_by`] - MVCC created_by metadata /// - [`LogicalFieldId::for_mvcc_deleted_by`] - MVCC deleted_by metadata /// - [`LogicalFieldId::from_parts`] - Custom construction /// /// # Thread Safety /// /// `LogicalFieldId` is `Copy` and thread-safe. #[bitfield] #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Default)] #[repr(u64)] pub struct LogicalFieldId { /// Column identifier within the table (32 bits). /// /// Supports up to ~4.3 billion columns per table. Field ID `0` is reserved for /// row ID columns. pub field_id: B32, /// Table identifier (16 bits). /// /// Supports up to 65,535 tables. Table ID `0` is reserved for the system catalog. pub table_id: B16, /// Data category (16 bits). /// /// Determines whether this ID refers to user data, system metadata, or MVCC tracking. pub namespace: LogicalStorageNamespace, }>>

impl Clone for LogicalFieldId

fn clone(&self) -> LogicalFieldId

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LogicalFieldId

fn fmt(&self, __bf_f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LogicalFieldId

fn default() -> LogicalFieldId

Returns the “default value” for a type.

impl From<[u8; 8]> for LogicalFieldId

fn from(bytes: [u8; 8]) -> Self

Converts to this type from the input type.

impl From<LogicalFieldId> for [u8; 8]

fn from(bytes: LogicalFieldId) -> Self

Converts to this type from the input type.

impl From<LogicalFieldId> for u64

where BitCount<{ _ }>: IsU64Compatible,

fn from(__bf_bitfield: LogicalFieldId) -> Self

Converts to this type from the input type.

impl From<u64> for LogicalFieldId

where BitCount<{ _ }>: IsU64Compatible,

fn from(__bf_prim: u64) -> Self

Converts to this type from the input type.

impl Hash for LogicalFieldId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for LogicalFieldId

fn eq(&self, other: &LogicalFieldId) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for LogicalFieldId

impl Eq for LogicalFieldId

impl StructuralPartialEq for LogicalFieldId