68 lines
2 KiB
Rust
68 lines
2 KiB
Rust
use std::convert::TryInto;
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use serde::{Deserialize, Serialize};
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/// Wrapper around progressively fetched items
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///
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/// The paginator is a wrapper around a list of items that are fetched
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/// in pages from the YouTube API (e.g. playlist items,
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/// video recommendations or comments).
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#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
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#[non_exhaustive]
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pub struct Paginator<T> {
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/// Total number of items if finite and known.
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///
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/// Note that this number may not be 100% accurate, as this is the
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/// number returned by the YouTube API at the initial fetch.
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///
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/// It is intended to be shown to the user (e.g. 1261 comments,
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/// 18 Videos) and for progress estimation.
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///
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/// Don't use this number to check if all items were fetched or for
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/// iterating over the items.
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pub count: Option<u64>,
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/// Content of the paginator
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pub items: Vec<T>,
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/// The continuation token is passed to the YouTube API to fetch
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/// more items.
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///
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/// If it is None, it means that no more items can be fetched.
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pub ctoken: Option<String>,
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}
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impl<T> Default for Paginator<T> {
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fn default() -> Self {
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Self {
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count: Some(0),
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items: Vec::new(),
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ctoken: None,
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}
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}
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}
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impl<T> Paginator<T> {
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pub(crate) fn new(count: Option<u64>, items: Vec<T>, ctoken: Option<String>) -> Self {
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Self {
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count: match ctoken {
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Some(_) => count,
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None => items.len().try_into().ok(),
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},
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items,
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ctoken,
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}
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}
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/// Check if the paginator is exhausted, meaning that no more
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/// items can be fetched.
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///
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/// Equivalent to `paginator.ctoken.is_none()`.
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pub fn is_exhausted(&self) -> bool {
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self.ctoken.is_none()
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}
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/// Check if the paginator does not contain any data, meaning that it
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/// is exhausted and does not contain any items.
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pub fn is_empty(&self) -> bool {
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self.items.is_empty() && self.is_exhausted()
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}
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}
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