Enum Volatility 

pub enum Volatility {
    Stable,
    Grows,
    Rewritten,
}

How much a region’s contents move between requests.

This exists because a provider caches by prefix: an entry is readable next time only when every byte in front of it is unchanged, so a block that moves invalidates everything behind it however stable that later content is. The arrangement that pays is stable content first and churn last.

A region’s RegionKind cannot answer this. A pinned region sounds immutable and is written constantly - context_write into a findings region is an ordinary move, and tool routing sends read results straight into one. A compact-history region sounds settled and gains an entry every time compaction fires. Inferring stability from the kind put churn at the front of the prefix and cost a measured 456,860 cache-write tokens against zero reads (issue #474).

So the blueprint says. The author knows whether a region is set once at spawn or written every turn, and nothing else does.

Variants

Stable

Written rarely or never after setup: a task, a system prompt, a convention the run does not revise. Sorted to the front, where it forms the prefix everything else caches behind.

Grows

Appended to, with existing entries left alone: a findings list, a bibliography, a transcript of what has been read. Sorted after the stable content, and split into chunks so the settled head of it can be cached while only the tail is re-sent.

Rewritten

Existing content changes in place: a scratchpad, a key-value store whose keys are overwritten, anything rebuilt each turn. Sorted last, where it invalidates nothing but itself.

The default, and deliberately the pessimistic one: a blueprint that declares nothing must never be made worse by this, and an optimistic default is exactly how inferring stability from the kind went wrong.

Trait Implementations

impl Clone for Volatility

fn clone(&self) -> Volatility

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Volatility

impl Debug for Volatility

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

Formats the value using the given formatter.

impl Default for Volatility

fn default() -> Volatility

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Volatility

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Volatility

impl PartialEq for Volatility

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Volatility

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Volatility