Struct PrefetchItem 

pub struct PrefetchItem {
    pub key: String,
    pub size: u64,
    pub ranges: Option<Vec<[u64; 2]>>,
}

Wire format for POST /prefetch: Content-Type: application/x-ndjson, one PrefetchItem JSON object per \n-terminated line. There is no wrapper type — the body is a stream of lines, parsed and enqueued incrementally so the server never buffers the whole batch.

One key to warm, whole-object or ranged.

Fields

key: String

size: u64

The object’s file size, supplied by the caller. Both triggers already know it: Partition.file_size (persisted in PostgreSQL) for query/write warming, and PartitionWriteResult.file_size for the write path. Supplying it lets the server drive fills through prefetch_blocks(key, file_size, indices) with no origin HEAD (prefetch targets cold objects, so a server-side size() would force an avoidable HEAD).

Contract: this must be the object’s exact current size. The server trusts it without verification; an undersized value stores a truncated final block under the same block key demand reads use. RangeCache mitigates this with a hit-path length guard that detects and refetches a wrong-length block on the next correctly-sized read. An oversized value is safe — the origin GET past EOF fails and nothing is stored.

ranges: Option<Vec<[u64; 2]>>

None or empty = warm the whole object [0, size). Present = warm only these ranges (validated against size).

Trait Implementations

impl Clone for PrefetchItem

fn clone(&self) -> PrefetchItem

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PrefetchItem

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for PrefetchItem

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for PrefetchItem

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

where __S: Serializer,

Serialize this value into the given Serde serializer.