seaplane 0.8.0

The Seaplane Rust SDK
Documentation 
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//! This module contains types for performing range queries across metadata services that use the
//! paging mechanism.

use crate::{base64::Base64Encoded, impl_base64};

/// The directory from which to perform a given range query, excluding the trailing slash, encoded
/// in url-safe base64
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct Directory {
    inner: Base64Encoded,
}
impl_base64!(Directory);

/// The full context with which to perform a range query
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct RangeQueryContext<T> {
    /// The directory, if any, within which to perform the range query.
    dir: Option<Directory>,
    /// The lower bound on the page of results to return.
    from: Option<T>,
}

// This has to be hand implemented to avoid an incorrect Default bound on T
impl<T> Default for RangeQueryContext<T> {
    fn default() -> Self { Self { dir: None, from: None } }
}

impl<T> RangeQueryContext<T> {
    /// Creates a blank context, suitable for querying the root directory at the first available key
    pub fn new() -> Self { Self::default() }

    /// Set the directory within which to perform the query
    pub fn set_directory(&mut self, dir: Directory) { self.dir = Some(dir); }

    /// Set the key to use when beginning the next page of the query
    pub fn set_from(&mut self, next_key: T) { self.from = Some(next_key); }

    pub fn directory(&self) -> &Option<Directory> { &self.dir }

    pub fn from(&self) -> &Option<T> { &self.from }
}