add conditional put

This commit is contained in:
Sebastian Hugentobler 2022-03-30 09:36:59 +02:00
parent b4fcbdfef8
commit 547b7b375a
Signed by: shu
GPG Key ID: BB32CF3CA052C2F0
7 changed files with 87 additions and 21 deletions

View File

@ -1,3 +1,4 @@
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};
use thiserror::Error;
@ -25,6 +26,23 @@ pub struct Account {
pub is_active: bool,
}
impl Account {
pub fn hash_string(&self) -> String {
let mut hasher = DefaultHasher::new();
self.hash(&mut hasher);
format!("{:x}", hasher.finish())
}
}
impl Hash for Account {
fn hash<H: Hasher>(&self, state: &mut H) {
self.number.hash(state);
self.owner.hash(state);
self.balance.to_string().hash(state);
self.is_active.hash(state);
}
}
impl Default for Account {
fn default() -> Self {
Account {
@ -42,12 +60,6 @@ impl PartialEq for Account {
}
}
impl Hash for Account {
fn hash<H: Hasher>(&self, state: &mut H) {
self.number.hash(state);
}
}
impl Account {
#[cfg(test)]
pub fn new() -> Self {

View File

@ -13,11 +13,11 @@ impl Bank {
Default::default()
}
pub fn account_action<F: Fn(&mut Account) -> Result<f64, AccountError>>(
pub fn account_action<F: Fn(&mut Account) -> Result<R, AccountError>, R>(
bank: RwLockReadGuard<'_, Bank>,
nr: &str,
action: F,
) -> Result<f64, AccountError> {
) -> Result<R, AccountError> {
match bank.accounts.get(nr) {
None => Err(AccountError::NotFound),
Some(account) => {

View File

@ -27,8 +27,14 @@ pub async fn fetch_account(host: &str, nr: &str) -> Result<JsonAccount, FetchErr
}
}
pub async fn set_balance(host: &str, nr: &str, balance: f64) -> Result<(), FetchError> {
pub async fn set_balance(
host: &str,
nr: &str,
balance: f64,
etag: String,
) -> Result<(), FetchError> {
let data = JsValue::from_str(&format!("amount={}", balance));
client::put(&format! {"{}/accounts/{}", host, nr}, data).await?;
client::put(&format! {"{}/accounts/{}", host, nr}, data, Some(etag)).await?;
Ok(())
}

View File

@ -53,7 +53,7 @@ pub async fn get_json(url: &str) -> Result<Option<String>, FetchError> {
Ok(text.as_string())
}
pub async fn put(url: &str, data: JsValue) -> Result<(), FetchError> {
pub async fn put(url: &str, data: JsValue, if_match: Option<String>) -> Result<(), FetchError> {
let mut opts = RequestInit::new();
opts.method("PUT");
opts.mode(RequestMode::Cors);
@ -63,6 +63,11 @@ pub async fn put(url: &str, data: JsValue) -> Result<(), FetchError> {
request
.headers()
.set("Content-Type", "application/x-www-form-urlencoded")?;
if let Some(etag) = if_match {
request.headers().set("If-match", &etag)?;
}
self::send_request(request).await?;
Ok(())

View File

@ -77,8 +77,17 @@ impl Component for Main {
true
}
Event::SetBalance(balance, nr) => {
let acc = bank::account::Account {
number: nr.clone(),
owner: self.selected_owner.clone(),
balance: self.selected_balance,
is_active: true,
};
let hash = acc.hash_string();
ctx.link().send_future(async move {
match api::set_balance("http://localhost:8000", &nr, balance).await {
match api::set_balance("http://localhost:8000", &nr, balance, hash).await {
Err(e) => Event::ShowError(e.to_string()),
Ok(_) => Event::SelectAccountNr(nr),
}

View File

@ -1,9 +1,7 @@
use actix_web::{put, web, HttpResponse, Responder, Result};
use actix_web::{put, web, HttpRequest, HttpResponse, Responder, Result};
use bank::account::AccountError;
use serde::Serialize;
use bank::bank::Bank;
use crate::handlers::error::HttpAccountError;
use crate::handlers::AmountData;
use crate::AppState;
@ -18,6 +16,7 @@ pub async fn route(
info: web::Path<String>,
form: web::Form<AmountData>,
data: web::Data<AppState>,
req: HttpRequest,
) -> Result<impl Responder> {
let nr = info.into_inner();
let amount = form.amount;
@ -29,11 +28,22 @@ pub async fn route(
info!("updating account {}...", nr);
let bank = data.bank.read().unwrap();
match Bank::account_action(bank, &nr, |account| {
match bank.accounts.get(&nr) {
None => Err(HttpAccountError(AccountError::NotFound).into()),
Some(account) => {
let mut account = account.write().unwrap();
let hash = account.hash_string();
if let Some(etag) = req.headers().get("If-Match") {
let etag = etag.to_str().unwrap_or("");
if etag != hash {
Ok(HttpResponse::PreconditionFailed().finish())
} else {
account.balance = amount;
Ok(amount)
}) {
Err(e) => Err(HttpAccountError(e).into()),
Ok(_) => Ok(HttpResponse::Ok().finish()),
Ok(HttpResponse::Ok().finish())
}
} else {
Ok(HttpResponse::PreconditionRequired().finish())
}
}
}
}

View File

@ -155,6 +155,30 @@ mod tests {
.set_form(&payload)
.to_request();
let resp = test::call_service(&app, req).await;
assert_eq!(resp.status(), StatusCode::PRECONDITION_REQUIRED);
let payload = AmountData { amount: 10_f64 };
let req = test::TestRequest::put()
.uri(&format!("/accounts/{}", nr))
.append_header((actix_web::http::header::IF_MATCH, "I aspire to be an etag"))
.set_form(&payload)
.to_request();
let resp = test::call_service(&app, req).await;
assert_eq!(resp.status(), StatusCode::PRECONDITION_FAILED);
let acc = bank::account::Account {
number: nr.to_string(),
owner: "aaa".to_string(),
balance: 5_f64,
is_active: true
};
let payload = AmountData { amount: 10_f64 };
let req = test::TestRequest::put()
.uri(&format!("/accounts/{}", nr))
.append_header((actix_web::http::header::IF_MATCH, acc.hash_string()))
.set_form(&payload)
.to_request();
let resp = test::call_service(&app, req).await;
assert!(resp.status().is_success());
let req = test::TestRequest::put()