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bytecodealliance
GitHub Repository: bytecodealliance/wasmtime
Path: blob/main/crates/wasi-keyvalue/wit/deps/keyvalue/batch.wit
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/// A keyvalue interface that provides batch operations.
/// 
/// A batch operation is an operation that operates on multiple keys at once.
/// 
/// Batch operations are useful for reducing network round-trip time. For example, if you want to
/// get the values associated with 100 keys, you can either do 100 get operations or you can do 1
/// batch get operation. The batch operation is faster because it only needs to make 1 network call
/// instead of 100.
/// 
/// A batch operation does not guarantee atomicity, meaning that if the batch operation fails, some
/// of the keys may have been modified and some may not. 
/// 
/// This interface does has the same consistency guarantees as the `store` interface, meaning that
/// you should be able to "read your writes."
/// 
/// Please note that this interface is bare functions that take a reference to a bucket. This is to
/// get around the current lack of a way to "extend" a resource with additional methods inside of
/// wit. Future version of the interface will instead extend these methods on the base `bucket`
/// resource.
interface batch {
    use store.{bucket, error};

    /// Get the key-value pairs associated with the keys in the store. It returns a list of
    /// key-value pairs.
    ///
    /// If any of the keys do not exist in the store, it returns a `none` value for that pair in the
    /// list.
    /// 
    /// MAY show an out-of-date value if there are concurrent writes to the store.
    /// 
    /// If any other error occurs, it returns an `Err(error)`.
    get-many: func(bucket: borrow<bucket>, keys: list<string>) -> result<list<option<tuple<string, list<u8>>>>, error>;

    /// Set the values associated with the keys in the store. If the key already exists in the
    /// store, it overwrites the value. 
    /// 
    /// Note that the key-value pairs are not guaranteed to be set in the order they are provided. 
    ///
    /// If any of the keys do not exist in the store, it creates a new key-value pair.
    /// 
    /// If any other error occurs, it returns an `Err(error)`. When an error occurs, it does not
    /// rollback the key-value pairs that were already set. Thus, this batch operation does not
    /// guarantee atomicity, implying that some key-value pairs could be set while others might
    /// fail. 
    /// 
    /// Other concurrent operations may also be able to see the partial results.
    set-many: func(bucket: borrow<bucket>, key-values: list<tuple<string, list<u8>>>) -> result<_, error>;

    /// Delete the key-value pairs associated with the keys in the store.
    /// 
    /// Note that the key-value pairs are not guaranteed to be deleted in the order they are
    /// provided.
    /// 
    /// If any of the keys do not exist in the store, it skips the key.
    /// 
    /// If any other error occurs, it returns an `Err(error)`. When an error occurs, it does not
    /// rollback the key-value pairs that were already deleted. Thus, this batch operation does not
    /// guarantee atomicity, implying that some key-value pairs could be deleted while others might
    /// fail.
    /// 
    /// Other concurrent operations may also be able to see the partial results.
    delete-many: func(bucket: borrow<bucket>, keys: list<string>) -> result<_, error>;
}