Enum JournalRecordV54 

pub enum JournalRecordV54 {
    EndBlock,
    Mutation {
        object_id: u64,
        mutation: MutationV54,
    },
    Commit,
    Discard(u64),
    DidFlushDevice(u64),
    DataChecksums(Range<u64>, ChecksumsV38, bool),
}

Variants

EndBlock

Indicates no more records in this block.

Mutation

Mutation for a particular object. object_id here is for the collection i.e. the store or allocator.

Fields

object_id: u64

mutation: MutationV54

Commit

Commits records in the transaction.

Discard(u64)

Discard all mutations with offsets greater than or equal to the given offset.

DidFlushDevice(u64)

Indicates the device was flushed at the given journal offset. Note that this really means that at this point in the journal offset, we can be certain that there’s no remaining buffered data in the block device; the buffers and the disk contents are consistent. We insert one of these records after a flush along with the next transaction to go through. If that never comes (either due to graceful or hard shutdown), the journal reset on the next mount will serve the same purpose and count as a flush, although it is necessary to defensively flush the device before replaying the journal (if possible, i.e. not read-only) in case the block device connection was reused.

DataChecksums(Range<u64>, ChecksumsV38, bool)

Checksums for a data range written by this transaction. A transaction is only valid if these checksums are right. The range is the device offset the checksums are for.

A boolean indicates whether this range is being written to for the first time. For overwrite extents, we only check the checksums for a block if it has been written to for the first time since the last flush, because otherwise we can’t roll it back anyway so it doesn’t matter. For copy-on-write extents, the bool is always true.

Trait Implementations

impl Clone for JournalRecordV54

fn clone(&self) -> JournalRecordV54

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for JournalRecordV54

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for JournalRecordV54

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<JournalRecordV40> for JournalRecordV54

fn from(item: JournalRecordV40) -> Self

Converts to this type from the input type.

impl From<JournalRecordV41> for JournalRecordV54

fn from(item: JournalRecordV41) -> Self

Converts to this type from the input type.

impl From<JournalRecordV42> for JournalRecordV54

fn from(item: JournalRecordV42) -> Self

Converts to this type from the input type.

impl From<JournalRecordV43> for JournalRecordV54

fn from(item: JournalRecordV43) -> Self

Converts to this type from the input type.

impl From<JournalRecordV46> for JournalRecordV54

fn from(item: JournalRecordV46) -> Self

Converts to this type from the input type.

impl From<JournalRecordV47> for JournalRecordV54

fn from(item: JournalRecordV47) -> Self

Converts to this type from the input type.

impl From<JournalRecordV49> for JournalRecordV54

fn from(item: JournalRecordV49) -> Self

Converts to this type from the input type.

impl From<JournalRecordV50> for JournalRecordV54

fn from(from: JournalRecordV50) -> Self

Converts to this type from the input type.

impl Serialize for JournalRecordV54

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TypeFingerprint for JournalRecordV54

fn fingerprint() -> String

impl Versioned for JournalRecordV54

fn max_serialized_size() -> Option<u64>

Maximum size of a serialized version of this type. Serialization and deserialization will fail if the limit is exceeded. If None, there is no limit. None is preferred over u64::MAX because serializing and deserializing with a limit has runtime overhead.

fn deserialize_from<R>(reader: &mut R, _version: Version) -> Result<Self>

where R: Read + ?Sized, for<'de> Self: Deserialize<'de>,

fn serialize_into<W>(&self, writer: &mut W) -> Result<()>

where W: Write, Self: Serialize,

impl VersionedLatest for JournalRecordV54

fn deserialize_from_version<R>(reader: &mut R, version: Version) -> Result<Self>

where R: Read, Self: Sized,

Deserializes from a given version format and upgrades to the latest version.

fn deserialize_with_version<R>(reader: &mut R) -> Result<(Self, Version)>

where R: Read, Self: Sized,

Like deserialize_from_version but reads Version from reader first, then uses it to deserialize self.

fn serialize_with_version<W>(&self, writer: &mut W) -> Result<()>

where W: Write, Self: Sized,

Like serialize_into but serialized Version first, then self.