use async_trait::async_trait;
use futures_util::FutureExt;
use futures_util::StreamExt;
use futures::stream;
use lazy_static::lazy_static;
use log::error;
use mobc_redis::redis;
use mobc_redis::redis::AsyncCommands;
use serde_json::json;
use mobc::Pool;
use mobc_redis::RedisConnectionManager;
use crate::database::{Storage, Result, StorageError, ErrorKind, MicropubChannel};
use crate::indieauth::User;
struct RedisScripts {
edit_post: redis::Script
}
impl From<mobc_redis::redis::RedisError> for StorageError {
fn from(err: mobc_redis::redis::RedisError) -> Self {
Self {
msg: format!("{}", err),
source: Some(Box::new(err)),
kind: ErrorKind::Backend
}
}
}
impl From<mobc::Error<mobc_redis::redis::RedisError>> for StorageError {
fn from(err: mobc::Error<mobc_redis::redis::RedisError>) -> Self {
Self {
msg: format!("{}", err),
source: Some(Box::new(err)),
kind: ErrorKind::Backend
}
}
}
lazy_static! {
static ref SCRIPTS: RedisScripts = RedisScripts {
edit_post: redis::Script::new(include_str!("./edit_post.lua"))
};
}
#[derive(Clone)]
pub struct RedisStorage {
redis: mobc::Pool<RedisConnectionManager>,
}
fn filter_post(mut post: serde_json::Value, user: &'_ Option<String>) -> Option<serde_json::Value> {
if post["properties"]["deleted"][0].is_string() {
return Some(json!({
"type": post["type"],
"properties": {
"deleted": post["properties"]["deleted"]
}
}));
}
let empty_vec: Vec<serde_json::Value> = vec![];
let author = post["properties"]["author"].as_array().unwrap_or(&empty_vec).iter().map(|i| i.as_str().unwrap().to_string());
let visibility = post["properties"]["visibility"][0].as_str().unwrap_or("public");
let mut audience = author.chain(post["properties"]["audience"].as_array().unwrap_or(&empty_vec).iter().map(|i| i.as_str().unwrap().to_string()));
if (visibility == "private" && !audience.any(|i| Some(i) == *user)) || (visibility == "protected" && user.is_none()) {
return None
}
if post["properties"]["location"].is_array() {
let location_visibility = post["properties"]["location-visibility"][0].as_str().unwrap_or("private");
let mut author = post["properties"]["author"].as_array().unwrap_or(&empty_vec).iter().map(|i| i.as_str().unwrap().to_string());
if location_visibility == "private" && !author.any(|i| Some(i) == *user) {
post["properties"].as_object_mut().unwrap().remove("location");
}
}
Some(post)
}
#[async_trait]
impl Storage for RedisStorage {
async fn delete_post<'a>(&self, url: &'a str) -> Result<()> {
let mut conn = self.redis.get().await?;
Ok(conn.hdel::<&str, &str, ()>("posts", url).await?)
}
async fn post_exists(&self, url: &str) -> Result<bool> {
let mut conn = self.redis.get().await?;
Ok(conn.hexists::<&str, &str, bool>(&"posts", url).await?)
}
async fn get_post(&self, url: &str) -> Result<Option<serde_json::Value>> {
let mut conn = self.redis.get().await?;
match conn.hget::<&str, &str, Option<String>>(&"posts", url).await? {
Some(val) => {
let parsed = serde_json::from_str::<serde_json::Value>(&val)?;
if let Some(new_url) = parsed["see_other"].as_str() {
match conn.hget::<&str, &str, Option<String>>(&"posts", new_url).await? {
Some(val) => Ok(Some(serde_json::from_str::<serde_json::Value>(&val)?)),
None => Ok(None)
}
} else {
Ok(Some(parsed))
}
},
None => Ok(None)
}
}
async fn get_channels(&self, user: &User) -> Result<Vec<MicropubChannel>> {
let mut conn = self.redis.get().await?;
let channels = conn.smembers::<String, Vec<String>>("channels_".to_string() + user.me.as_str()).await?;
// TODO: use streams here instead of this weird thing... how did I even write this?!
Ok(futures_util::future::join_all(channels.iter()
.map(|channel| self.get_post(channel)
.map(|result| result.unwrap())
.map(|post: Option<serde_json::Value>| {
if let Some(post) = post {
Some(MicropubChannel {
uid: post["properties"]["uid"][0].as_str().unwrap().to_string(),
name: post["properties"]["name"][0].as_str().unwrap().to_string()
})
} else { None }
})
).collect::<Vec<_>>()).await.into_iter().filter_map(|chan| chan).collect::<Vec<_>>())
}
async fn put_post<'a>(&self, post: &'a serde_json::Value) -> Result<()> {
let mut conn = self.redis.get().await?;
let key: &str;
match post["properties"]["uid"][0].as_str() {
Some(uid) => key = uid,
None => return Err(StorageError::new(ErrorKind::BadRequest, "post doesn't have a UID"))
}
conn.hset::<&str, &str, String, ()>(&"posts", key, post.to_string()).await?;
if post["properties"]["url"].is_array() {
for url in post["properties"]["url"].as_array().unwrap().iter().map(|i| i.as_str().unwrap().to_string()) {
if url != key {
conn.hset::<&str, &str, String, ()>(&"posts", &url, json!({"see_other": key}).to_string()).await?;
}
}
}
if post["type"].as_array().unwrap().iter().any(|i| i == "h-feed") {
// This is a feed. Add it to the channels array if it's not already there.
conn.sadd::<String, &str, ()>("channels_".to_string() + post["properties"]["author"][0].as_str().unwrap(), key).await?
}
Ok(())
}
async fn read_feed_with_limit<'a>(&self, url: &'a str, after: &'a Option<String>, limit: usize, user: &'a Option<String>) -> Result<Option<serde_json::Value>> {
let mut conn = self.redis.get().await?;
let mut feed;
match conn.hget::<&str, &str, Option<String>>(&"posts", url).await? {
Some(post) => feed = serde_json::from_str::<serde_json::Value>(&post)?,
None => return Ok(None)
}
if feed["see_other"].is_string() {
match conn.hget::<&str, &str, Option<String>>(&"posts", feed["see_other"].as_str().unwrap()).await? {
Some(post) => feed = serde_json::from_str::<serde_json::Value>(&post)?,
None => return Ok(None)
}
}
if let Some(post) = filter_post(feed, user) {
feed = post
} else {
return Err(StorageError::new(ErrorKind::PermissionDenied, "specified user cannot access this post"))
}
if feed["children"].is_array() {
let children = feed["children"].as_array().unwrap();
let posts_iter: Box<dyn std::iter::Iterator<Item = String> + Send>;
// TODO: refactor this to apply the skip on the &mut iterator
if let Some(after) = after {
posts_iter = Box::new(children.iter().map(|i| i.as_str().unwrap().to_string()).skip_while(move |i| i != after).skip(1));
} else {
posts_iter = Box::new(children.iter().map(|i| i.as_str().unwrap().to_string()));
}
let posts = stream::iter(posts_iter)
.map(|url| async move {
match self.redis.get().await {
Ok(mut conn) => match conn.hget::<&str, &str, Option<String>>("posts", &url).await {
Ok(post) => match post {
Some(post) => match serde_json::from_str::<serde_json::Value>(&post) {
Ok(post) => Some(post),
Err(err) => {
let err = StorageError::from(err);
error!("{}", err);
panic!("{}", err)
}
},
// Happens because of a broken link (result of an improper deletion?)
None => None,
},
Err(err) => {
let err = StorageError::from(err);
error!("{}", err);
panic!("{}", err)
}
},
// TODO: Instead of causing a panic, investigate how can you fail the whole stream
// Somehow fuse it maybe?
Err(err) => {
let err = StorageError::from(err);
error!("{}", err);
panic!("{}", err)
}
}
})
// TODO: determine the optimal value for this buffer
// It will probably depend on how often can you encounter a private post on the page
// It shouldn't be too large, or we'll start fetching too many posts from the database
// It MUST NOT be larger than the typical page size
// It MUST NOT be a significant amount of the connection pool size
.buffered(std::cmp::min(3, limit))
// Hack to unwrap the Option and sieve out broken links
// Broken links return None, and Stream::filter_map skips all Nones.
.filter_map(|post: Option<serde_json::Value>| async move { post })
.filter_map(|post| async move {
filter_post(post, user)
})
.take(limit);
// TODO: Instead of catching panics, find a way to make the whole stream fail with Result<Vec<serde_json::Value>>
match std::panic::AssertUnwindSafe(posts.collect::<Vec<serde_json::Value>>()).catch_unwind().await {
Ok(posts) => feed["children"] = json!(posts),
Err(_) => return Err(StorageError::new(ErrorKind::Other, "Unknown error encountered while assembling feed, see logs for more info"))
}
}
return Ok(Some(feed));
}
async fn update_post<'a>(&self, mut url: &'a str, update: serde_json::Value) -> Result<()> {
let mut conn = self.redis.get().await?;
if !conn.hexists::<&str, &str, bool>("posts", url).await.unwrap() {
return Err(StorageError::new(ErrorKind::NotFound, "can't edit a non-existent post"))
}
let post: serde_json::Value = serde_json::from_str(&conn.hget::<&str, &str, String>("posts", url).await?)?;
if let Some(new_url) = post["see_other"].as_str() {
url = new_url
}
Ok(SCRIPTS.edit_post.key("posts").arg(url).arg(update.to_string()).invoke_async::<_, ()>(&mut conn as &mut redis::aio::Connection).await?)
}
}
impl RedisStorage {
/// Create a new RedisDatabase that will connect to Redis at `redis_uri` to store data.
pub async fn new(redis_uri: String) -> Result<Self> {
match redis::Client::open(redis_uri) {
Ok(client) => Ok(Self { redis: Pool::builder().max_open(20).build(RedisConnectionManager::new(client)) }),
Err(e) => Err(e.into())
}
}
}
#[cfg(test)]
pub mod tests {
use std::{process};
use std::time::Duration;
use mobc_redis::redis;
pub async fn get_redis_instance() -> (tempdir::TempDir, process::Child, String) {
let tempdir = tempdir::TempDir::new("redis").expect("failed to create tempdir");
let socket = tempdir.path().join("redis.sock");
let redis_child = process::Command::new("redis-server")
.current_dir(&tempdir)
.arg("--port").arg("0")
.arg("--unixsocket").arg(&socket)
.stdout(process::Stdio::null())
.stderr(process::Stdio::null())
.spawn().expect("Failed to spawn Redis");
println!("redis+unix:///{}", socket.to_str().unwrap());
let uri = format!("redis+unix:///{}", socket.to_str().unwrap());
// There should be a slight delay, we need to wait for Redis to spin up
let client = redis::Client::open(uri.clone()).unwrap();
let millisecond = Duration::from_millis(1);
let mut retries: usize = 0;
const MAX_RETRIES: usize = 60 * 1000/*ms*/;
while let Err(err) = client.get_connection() {
if err.is_connection_refusal() {
async_std::task::sleep(millisecond).await;
retries += 1;
if retries > MAX_RETRIES {
panic!("Timeout waiting for Redis, last error: {}", err);
}
} else {
panic!("Could not connect: {}", err);
}
}
return (tempdir, redis_child, uri)
}
}