Struct Record 

pub struct Record {
    pub container: PathBuf,
    pub content_name: String,
    pub started: u64,
    pub write_backs: u64,
    pub agreed: Option<u32>,
}

What a session remembers across a crash.

Deliberately small. Concept 6.3 removed the content file digest this used to carry: the container records a CRC-32 for its content file already, so recovery compares against the container rather than against a second copy of the fact that can drift from it — and drift is likeliest at the moment this file is consulted.

Record::agreed is not that digest coming back, and the difference is worth being exact about. The removed one answered has the content file changed, which the container can answer better. This one answers which side changed, which nothing can answer without a record, because both sides are only visible now and the question is about then. It is a note of a past moment rather than a cached copy of a present fact, so there is nothing for it to drift from: if it is stale, the answer it gives — that the container is not where we left it — is the true one.

Fields

container: PathBuf

Where the container was when the session opened, resolved. It may have moved or gone since, which concept 6.4 requires recovery to survive rather than fail at the rename.

content_name: String

The content file’s name inside the container, which is also its name inside content/ and therefore what decides which application opens it.

started: u64

When the session opened, in seconds since the Unix epoch.

A number rather than a formatted timestamp, because nothing in the tool needs to render it: concept 6.3 shows a person the content file’s own modification time, which comes from the filesystem. Storing it this way keeps a date-formatting dependency out of a crate that would otherwise have no use for one.

write_backs: u64

How many write-backs this session has performed, which concept 6.2 shows beside the session.

agreed: Option<u32>

The container’s content file CRC-32 at the last moment this session and the container were known to agree: the extraction, or the most recent write-back.

What it is for is telling which side moved. A content file that differs from its container is either an edit that never landed or a container that changed underneath a dead session, and those want opposite treatment — the first is the person’s own work and goes back, the second is a conflict only they can settle. Comparing the two sides now cannot separate them, because both are only observable in the present.

None for a session written by a build that did not record it, and for one whose container could not be read at the time. Recovery treats that as not known to agree, which is the cautious direction: it asks.

Trait Implementations

impl Clone for Record

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Record

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

Formats the value using the given formatter.

impl Eq for Record

impl PartialEq for Record

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Record