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Merge pull request #6231 from paritytech/price_info_util

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price-info does not depend on util
This commit is contained in:
Marek Kotewicz 2017-08-08 20:56:12 +02:00 committed by GitHub
commit 80db43442e
4 changed files with 205 additions and 226 deletions
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2
Cargo.lock generated
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@ -2209,10 +2209,10 @@ dependencies = [
name = "price-info"
version = "1.7.0"
dependencies = [
"ethcore-util 1.8.0",
"fetch 0.1.0",
"futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
"log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
"parking_lot 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
"serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
]

2
price-info/Cargo.toml
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@ -13,4 +13,4 @@ log = "0.3"
serde_json = "1.0"
[dev-dependencies]
ethcore-util = { path = "../util" }
parking_lot = "0.4"

205
price-info/src/lib.rs
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@ -26,6 +26,207 @@ extern crate log;
pub extern crate fetch;
mod price_info;
use std::cmp;
use std::fmt;
use std::io;
use std::io::Read;
pub use price_info::*;
use fetch::{Client as FetchClient, Fetch};
use futures::Future;
use serde_json::Value;
/// Current ETH price information.
#[derive(Debug)]
pub struct PriceInfo {
/// Current ETH price in USD.
pub ethusd: f32,
}
/// Price info error.
#[derive(Debug)]
pub enum Error {
/// The API returned an unexpected status code.
StatusCode(&'static str),
/// The API returned an unexpected status content.
UnexpectedResponse(String),
/// There was an error when trying to reach the API.
Fetch(fetch::Error),
/// IO error when reading API response.
Io(io::Error),
}
impl From<io::Error> for Error {
fn from(err: io::Error) -> Self { Error::Io(err) }
}
impl From<fetch::Error> for Error {
fn from(err: fetch::Error) -> Self { Error::Fetch(err) }
}
/// A client to get the current ETH price using an external API.
pub struct Client<F = FetchClient> {
api_endpoint: String,
fetch: F,
}
impl<F> fmt::Debug for Client<F> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_struct("price_info::Client")
.field("api_endpoint", &self.api_endpoint)
.finish()
}
}
impl<F> cmp::PartialEq for Client<F> {
fn eq(&self, other: &Client<F>) -> bool {
self.api_endpoint == other.api_endpoint
}
}
impl<F: Fetch> Client<F> {
/// Creates a new instance of the `Client` given a `fetch::Client`.
pub fn new(fetch: F) -> Client<F> {
let api_endpoint = "http://api.etherscan.io/api?module=stats&action=ethprice".to_owned();
Client { api_endpoint, fetch }
}
/// Gets the current ETH price and calls `set_price` with the result.
pub fn get<G: Fn(PriceInfo) + Sync + Send + 'static>(&self, set_price: G) {
self.fetch.forget(self.fetch.fetch(&self.api_endpoint)
.map_err(|err| Error::Fetch(err))
.and_then(move |mut response| {
if !response.is_success() {
return Err(Error::StatusCode(response.status().canonical_reason().unwrap_or("unknown")));
}
let mut result = String::new();
response.read_to_string(&mut result)?;
let value: Option<Value> = serde_json::from_str(&result).ok();
let ethusd = value
.as_ref()
.and_then(|value| value.pointer("/result/ethusd"))
.and_then(|obj| obj.as_str())
.and_then(|s| s.parse().ok());
match ethusd {
Some(ethusd) => {
set_price(PriceInfo { ethusd });
Ok(())
},
None => Err(Error::UnexpectedResponse(result)),
}
})
.map_err(|err| {
warn!("Failed to auto-update latest ETH price: {:?}", err);
err
})
);
}
}
#[cfg(test)]
mod test {
extern crate parking_lot;
use self::parking_lot::Mutex;
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, Ordering};
use fetch;
use fetch::Fetch;
use futures;
use futures::future::{Future, FutureResult};
use Client;
#[derive(Clone)]
struct FakeFetch(Option<String>, Arc<Mutex<u64>>);
impl Fetch for FakeFetch {
type Result = FutureResult<fetch::Response, fetch::Error>;
fn new() -> Result<Self, fetch::Error> where Self: Sized { Ok(FakeFetch(None, Default::default())) }
fn fetch_with_abort(&self, url: &str, _abort: fetch::Abort) -> Self::Result {
assert_eq!(url, "http://api.etherscan.io/api?module=stats&action=ethprice");
let mut val = self.1.lock();
*val = *val + 1;
if let Some(ref response) = self.0 {
let data = ::std::io::Cursor::new(response.clone());
futures::future::ok(fetch::Response::from_reader(data))
} else {
futures::future::ok(fetch::Response::not_found())
}
}
// this guarantees that the calls to price_info::Client::get will block for execution
fn forget<F, I, E>(&self, f: F) where
F: Future<Item=I, Error=E> + Send + 'static,
I: Send + 'static,
E: Send + 'static {
let _ = f.wait();
}
}
fn price_info_ok(response: &str) -> Client<FakeFetch> {
Client::new(FakeFetch(Some(response.to_owned()), Default::default()))
}
fn price_info_not_found() -> Client<FakeFetch> {
Client::new(FakeFetch::new().unwrap())
}
#[test]
fn should_get_price_info() {
// given
let response = r#"{
"status": "1",
"message": "OK",
"result": {
"ethbtc": "0.0891",
"ethbtc_timestamp": "1499894236",
"ethusd": "209.55",
"ethusd_timestamp": "1499894229"
}
}"#;
let price_info = price_info_ok(response);
// when
price_info.get(|price| {
// then
assert_eq!(price.ethusd, 209.55);
});
}
#[test]
fn should_not_call_set_price_if_response_is_malformed() {
// given
let response = "{}";
let price_info = price_info_ok(response);
let b = Arc::new(AtomicBool::new(false));
// when
let bb = b.clone();
price_info.get(move |_| {
bb.store(true, Ordering::Relaxed);
});
// then
assert_eq!(b.load(Ordering::Relaxed), false);
}
#[test]
fn should_not_call_set_price_if_response_is_invalid() {
// given
let price_info = price_info_not_found();
let b = Arc::new(AtomicBool::new(false));
// when
let bb = b.clone();
price_info.get(move |_| {
bb.store(true, Ordering::Relaxed);
});
// then
assert_eq!(b.load(Ordering::Relaxed), false);
}
}

222
price-info/src/price_info.rs
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@ -1,222 +0,0 @@
// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
use std::cmp;
use std::fmt;
use std::io;
use std::io::Read;
use std::str::FromStr;
use fetch;
use fetch::{Client as FetchClient, Fetch};
use futures::Future;
use serde_json;
use serde_json::Value;
/// Current ETH price information.
#[derive(Debug)]
pub struct PriceInfo {
/// Current ETH price in USD.
pub ethusd: f32,
}
/// Price info error.
#[derive(Debug)]
pub enum Error {
/// The API returned an unexpected status code or content.
UnexpectedResponse(&'static str, String),
/// There was an error when trying to reach the API.
Fetch(fetch::Error),
/// IO error when reading API response.
Io(io::Error),
}
impl From<io::Error> for Error {
fn from(err: io::Error) -> Self { Error::Io(err) }
}
impl From<fetch::Error> for Error {
fn from(err: fetch::Error) -> Self { Error::Fetch(err) }
}
/// A client to get the current ETH price using an external API.
pub struct Client<F = FetchClient> {
api_endpoint: String,
fetch: F,
}
impl<F> fmt::Debug for Client<F> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_struct("price_info::Client")
.field("api_endpoint", &self.api_endpoint)
.finish()
}
}
impl<F> cmp::PartialEq for Client<F> {
fn eq(&self, other: &Client<F>) -> bool {
self.api_endpoint == other.api_endpoint
}
}
impl<F: Fetch> Client<F> {
/// Creates a new instance of the `Client` given a `fetch::Client`.
pub fn new(fetch: F) -> Client<F> {
let api_endpoint = "http://api.etherscan.io/api?module=stats&action=ethprice".to_owned();
Client { api_endpoint, fetch }
}
/// Gets the current ETH price and calls `set_price` with the result.
pub fn get<G: Fn(PriceInfo) + Sync + Send + 'static>(&self, set_price: G) {
self.fetch.forget(self.fetch.fetch(&self.api_endpoint)
.map_err(|err| Error::Fetch(err))
.and_then(move |mut response| {
let mut result = String::new();
response.read_to_string(&mut result)?;
if response.is_success() {
let value: Result<Value, _> = serde_json::from_str(&result);
if let Ok(v) = value {
let obj = v.pointer("/result/ethusd").and_then(|obj| {
match *obj {
Value::String(ref s) => FromStr::from_str(s).ok(),
_ => None,
}
});
if let Some(ethusd) = obj {
set_price(PriceInfo { ethusd });
return Ok(());
}
}
}
let status = response.status().canonical_reason().unwrap_or("unknown");
Err(Error::UnexpectedResponse(status, result))
})
.map_err(|err| {
warn!("Failed to auto-update latest ETH price: {:?}", err);
err
})
);
}
}
#[cfg(test)]
mod test {
extern crate ethcore_util as util;
use self::util::Mutex;
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, Ordering};
use fetch;
use fetch::Fetch;
use futures;
use futures::future::{Future, FutureResult};
use price_info::Client;
#[derive(Clone)]
struct FakeFetch(Option<String>, Arc<Mutex<u64>>);
impl Fetch for FakeFetch {
type Result = FutureResult<fetch::Response, fetch::Error>;
fn new() -> Result<Self, fetch::Error> where Self: Sized { Ok(FakeFetch(None, Default::default())) }
fn fetch_with_abort(&self, url: &str, _abort: fetch::Abort) -> Self::Result {
assert_eq!(url, "http://api.etherscan.io/api?module=stats&action=ethprice");
let mut val = self.1.lock();
*val = *val + 1;
if let Some(ref response) = self.0 {
let data = ::std::io::Cursor::new(response.clone());
futures::future::ok(fetch::Response::from_reader(data))
} else {
futures::future::ok(fetch::Response::not_found())
}
}
// this guarantees that the calls to price_info::Client::get will block for execution
fn forget<F, I, E>(&self, f: F) where
F: Future<Item=I, Error=E> + Send + 'static,
I: Send + 'static,
E: Send + 'static {
let _ = f.wait();
}
}
fn price_info_ok(response: &str) -> Client<FakeFetch> {
Client::new(FakeFetch(Some(response.to_owned()), Default::default()))
}
fn price_info_not_found() -> Client<FakeFetch> {
Client::new(FakeFetch::new().unwrap())
}
#[test]
fn should_get_price_info() {
// given
let response = r#"{
"status": "1",
"message": "OK",
"result": {
"ethbtc": "0.0891",
"ethbtc_timestamp": "1499894236",
"ethusd": "209.55",
"ethusd_timestamp": "1499894229"
}
}"#;
let price_info = price_info_ok(response);
// when
price_info.get(|price| {
// then
assert_eq!(price.ethusd, 209.55);
});
}
#[test]
fn should_not_call_set_price_if_response_is_malformed() {
// given
let response = "{}";
let price_info = price_info_ok(response);
let b = Arc::new(AtomicBool::new(false));
// when
let bb = b.clone();
price_info.get(move |_| {
bb.store(true, Ordering::Relaxed);
});
// then
assert_eq!(b.load(Ordering::Relaxed), false);
}
#[test]
fn should_not_call_set_price_if_response_is_invalid() {
// given
let price_info = price_info_not_found();
let b = Arc::new(AtomicBool::new(false));
// when
let bb = b.clone();
price_info.get(move |_| {
bb.store(true, Ordering::Relaxed);
});
// then
assert_eq!(b.load(Ordering::Relaxed), false);
}
}