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extern crate chrono;
#[macro_use]
extern crate hyper;
#[macro_use]
extern crate log;
extern crate reqwest;
extern crate serde;
#[macro_use]
extern crate serde_derive;
extern crate serde_json;
extern crate serde_urlencoded;
pub mod error;
pub mod response;
pub mod api;
pub mod prelude;
pub mod client;
pub mod tests;
pub use client::Client;
pub use error::Error;
pub use prelude::*;
use serde::Serialize;
use serde::de::DeserializeOwned;
use std::fmt;
pub trait Endpoint: Serialize {
type ResponseType: std::fmt::Debug + Clone + DeserializeOwned;
const URL: &'static str;
}
pub trait PageableEndpoint
where
Self: Endpoint + std::marker::Sized,
<Self as Endpoint>::ResponseType: IntoIterator + Clone,
<<Self as Endpoint>::ResponseType as std::iter::IntoIterator>::Item: Clone + fmt::Debug,
{
fn pager(self, client: Client) -> Pager<Self>;
fn page_mut(&mut self) -> &mut Option<usize>;
fn limit_mut(&mut self) -> &mut Option<usize>;
}
#[derive(Clone, Debug)]
pub struct Pager<T>
where
T: Endpoint,
<T as Endpoint>::ResponseType: IntoIterator + Clone + std::fmt::Debug,
<<T as Endpoint>::ResponseType as std::iter::IntoIterator>::Item: Clone + fmt::Debug,
{
client: Client,
shifted: usize,
endpoint: T,
data: Vec<<<T as Endpoint>::ResponseType as IntoIterator>::Item>,
}
impl<T> Pager<T>
where
T: Endpoint + PageableEndpoint,
T: Clone + fmt::Debug,
<T as Endpoint>::ResponseType: IntoIterator + Clone + fmt::Debug,
<<T as Endpoint>::ResponseType as std::iter::IntoIterator>::Item: Clone + fmt::Debug,
{
pub fn new(
client: Client,
mut endpoint: T,
start: Option<usize>,
limit: Option<usize>,
) -> Self {
match (endpoint.page_mut(), start) {
(&mut None, None) => *endpoint.page_mut() = Some(0),
(&mut None, Some(_)) => *endpoint.page_mut() = start,
_ => {}
}
match (endpoint.limit_mut(), limit) {
(&mut None, None) => *endpoint.limit_mut() = Some(750),
(&mut None, Some(_)) => *endpoint.limit_mut() = limit,
_ => {}
}
debug!(
"initialize new pager: page: {}, limit {}",
endpoint.page_mut().unwrap(),
endpoint.limit_mut().unwrap(),
);
Self {
client: client,
data: Vec::new(),
shifted: 0,
endpoint: endpoint,
}
}
fn page_mut(&mut self) -> usize {
self.endpoint.page_mut().unwrap()
}
fn limit_mut(&mut self) -> usize {
self.endpoint.limit_mut().unwrap()
}
fn next_page(&mut self) {
*self.endpoint.page_mut() = Some(self.page_mut() + 1);
}
}
impl<T> Iterator for Pager<T>
where
T: Endpoint,
T: PageableEndpoint + Clone + std::fmt::Debug,
<T as Endpoint>::ResponseType: IntoIterator,
<<T as Endpoint>::ResponseType as std::iter::IntoIterator>::Item: Clone + fmt::Debug,
{
type Item = Result<<<T as Endpoint>::ResponseType as IntoIterator>::Item, error::Error>;
fn next(&mut self) -> Option<Self::Item> {
match self.data.pop() {
Some(i) => {
debug!("returning from buffer");
self.shifted += 1;
debug!(
"buffer: remaining/shifted: {}/{}",
self.data.len(),
self.shifted,
);
Some(Ok(i))
}
None => {
debug!("expected shifted: {}", self.page_mut() * self.limit_mut());
debug!("actually shifted: {}", self.shifted);
if self.page_mut() * self.limit_mut() > self.shifted {
debug!("reached the last page");
return None;
}
debug!("fetching new data");
let res = self.client.execute(self.endpoint.clone());
self.next_page();
match res {
Ok(res) => {
for var in res.into_iter() {
self.data.push(var);
}
debug!("filled buffer with {} entries", self.data.len());
self.next()
}
Err(e) => Some(Err(e)),
}
}
}
}
}