Add `PageIter<T>` to abstract over iterating over pages

master
Paul Woolcock 6 years ago
parent 87a0c103e6
commit 0e8eb4e568
  1. 2
      src/entities/mod.rs
  2. 94
      src/entities/pageiter.rs

@ -6,6 +6,7 @@ pub mod instance;
pub mod list; pub mod list;
pub mod mention; pub mod mention;
pub mod notification; pub mod notification;
pub mod pageiter;
pub mod relationship; pub mod relationship;
pub mod report; pub mod report;
pub mod search_result; pub mod search_result;
@ -27,6 +28,7 @@ pub mod prelude {
pub use super::list::List; pub use super::list::List;
pub use super::mention::Mention; pub use super::mention::Mention;
pub use super::notification::Notification; pub use super::notification::Notification;
pub use super::pageiter::PageIter;
pub use super::relationship::Relationship; pub use super::relationship::Relationship;
pub use super::report::Report; pub use super::report::Report;
pub use super::search_result::SearchResult; pub use super::search_result::SearchResult;

@ -0,0 +1,94 @@
use page::Page;
use entities::{
account::Account,
notification::Notification,
relationship::Relationship,
report::Report,
status::{Emoji, Status}
};
use serde::Deserialize;
macro_rules! into_pageiter {
($typ:ty) => {
impl<'a> IntoIterator for Page<'a, $typ> {
type Item = $typ;
type IntoIter = PageIter<'a, $typ>;
fn into_iter(self) -> PageIter<'a, $typ> {
PageIter::new(self)
}
}
}
}
into_pageiter!(Status);
into_pageiter!(Account);
into_pageiter!(String);
into_pageiter!(Emoji);
into_pageiter!(Notification);
into_pageiter!(Report);
into_pageiter!(Relationship);
pub struct PageIter<'a, T: Clone + for<'de> Deserialize<'de>> {
page: Page<'a, T>,
buffer: Vec<T>,
cur_idx: usize,
use_initial: bool,
}
impl<'a, T: Clone + for<'de> Deserialize<'de>> PageIter<'a, T> {
fn new(page: Page<'a, T>) -> PageIter<'a, T> {
PageIter {
page: page,
buffer: vec![],
cur_idx: 0,
use_initial: true,
}
}
fn need_next_page(&self) -> bool {
self.buffer.is_empty() ||
self.cur_idx == self.buffer.len()
}
fn fill_next_page(&mut self) -> Option<()> {
let items = if let Ok(items) = self.page.next_page() {
items
} else {
return None;
};
if let Some(items) = items {
self.buffer = items;
self.cur_idx = 0;
Some(())
} else {
None
}
}
}
impl<'a, T: Clone+ for<'de> Deserialize<'de>> Iterator for PageIter<'a, T> {
type Item = T;
fn next(&mut self) -> Option<Self::Item> {
if self.use_initial {
let idx = self.cur_idx;
if self.cur_idx == self.page.initial_items.len() - 1 {
self.cur_idx = 0;
self.use_initial = false;
} else {
self.cur_idx += 1;
}
Some(self.page.initial_items[idx].clone())
} else {
if self.need_next_page() {
if self.fill_next_page().is_none() {
return None;
}
}
let idx = self.cur_idx;
self.cur_idx += 1;
Some(self.buffer[idx].clone())
}
}
}
Loading…
Cancel
Save