Remove encryption option warning

Cargo.lock

@@ -403,6 +403,9 @@ name = "bytes"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b700ce4376041dcd0a327fd0097c41095743c4c8af8887265942faf1100bd040"
+dependencies = [
+ "serde",
+]
 
 [[package]]
 name = "bytestring"
@@ -495,6 +498,16 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "combine"
+version = "4.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2d47c1b11006b87e492b53b313bb699ce60e16613c4dddaa91f8f7c220ab2fa"
+dependencies = [
+ "bytes 1.0.1",
+ "memchr",
+]
+
 [[package]]
 name = "const_fn"
 version = "0.4.8"
@@ -1251,6 +1264,7 @@ dependencies = [
  "once_cell",
  "parking_lot",
  "prometheus",
+ "redis",
  "reqwest",
  "rustls",
  "serde",
@@ -1667,6 +1681,21 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "redis"
+version = "0.21.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3bbc1838d8d0b423f325d6fac80c5f19109c7d16c8c37c584893dc17cf71c63d"
+dependencies = [
+ "async-trait",
+ "combine",
+ "dtoa",
+ "itoa",
+ "percent-encoding",
+ "sha1",
+ "url",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.9"

Cargo.toml

@@ -26,7 +26,7 @@ arc-swap = "1"
 async-trait = "0.1"
 base64 = "0.13"
 bincode = "1"
-bytes = "1"
+bytes = { version = "1", features = [ "serde" ] }
 chacha20 = "0.7"
 chrono = { version = "0.4", features = [ "serde" ] }
 clap = { version = "3.0.0-beta.2", features = [ "wrap_help" ] }
@@ -42,6 +42,7 @@ maxminddb = "0.20"
 md-5 = "0.9"
 parking_lot = "0.11"
 prometheus = { version = "0.12", features = [ "process" ] }
+redis = "0.21"
 reqwest = { version = "0.11", default_features = false, features = [ "json", "stream", "rustls-tls" ] }
 rustls = "0.19"
 serde = "1"

settings.sample.yaml

@@ -66,12 +66,16 @@ metric_settings:
 # differently from the official client.
 extended_options:
   # Which cache type to use. By default, this is `on_disk`, but one can select
-  # `lfu` or `lru` to use a LFU or LRU in addition to the on-disk cache to
-  # improve lookup times. Generally speaking, using one is almost always better,
-  # but by how much depends on how much memory you let the node use, how large
-  # is your node, and which caching implementation you use.
+  # `lfu`, `lru`, or `redis` to use a LFU, LRU, or redis instance in addition
+  # to the on-disk cache to improve lookup times. Generally speaking, using one
+  # is almost always better, but by how much depends on how much memory you let
+  # the node use, how large is your node, and which caching implementation you
+  # use.
   # cache_type: on_disk
 
+  # The redis url to connect with. Does nothing if the cache type isn't`redis`.
+  # redis_url: "redis://127.0.0.1/"
+
   # The amount of memory the client should use when using an in-memory cache.
   # This does nothing if only the on-disk cache is used.
   # memory_quota: 0
@@ -89,8 +93,6 @@ extended_options:
   # "debug", "trace", and "off", which disables logging.
   # logging_level: info
 
-  # Warning: Experimental. Will cause problems.
-  #
   # Enables disk encryption where the key is stored in memory. In other words,
   # when the MD@H program is stopped, all cached files are irrecoverable.
   # Practically speaking, this isn't all too useful (and definitely hurts

src/cache/mem.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::Arc;
 
@@ -7,10 +8,67 @@ use bytes::Bytes;
 use futures::FutureExt;
 use lfu_cache::LfuCache;
 use lru::LruCache;
+use redis::{
+    Client as RedisClient, Commands, FromRedisValue, RedisError, RedisResult, ToRedisArgs,
+};
+use serde::{Deserialize, Serialize};
 use tokio::sync::mpsc::{channel, Receiver, Sender};
 use tokio::sync::Mutex;
+use tracing::warn;
 
-type CacheValue = (Bytes, ImageMetadata, u64);
+#[derive(Clone, Serialize, Deserialize)]
+pub struct CacheValue {
+    data: Bytes,
+    metadata: ImageMetadata,
+    on_disk_size: u64,
+}
+
+impl CacheValue {
+    #[inline]
+    fn new(data: Bytes, metadata: ImageMetadata, on_disk_size: u64) -> Self {
+        Self {
+            data,
+            metadata,
+            on_disk_size,
+        }
+    }
+}
+
+impl FromRedisValue for CacheValue {
+    fn from_redis_value(v: &redis::Value) -> RedisResult<Self> {
+        use bincode::ErrorKind;
+
+        if let redis::Value::Data(data) = v {
+            bincode::deserialize(data).map_err(|err| match *err {
+                ErrorKind::Io(e) => RedisError::from(e),
+                ErrorKind::Custom(e) => RedisError::from((
+                    redis::ErrorKind::ResponseError,
+                    "bincode deserialize failed",
+                    e,
+                )),
+                e => RedisError::from((
+                    redis::ErrorKind::ResponseError,
+                    "bincode deserialized failed",
+                    e.to_string(),
+                )),
+            })
+        } else {
+            Err(RedisError::from((
+                redis::ErrorKind::TypeError,
+                "Got non data type from redis db",
+            )))
+        }
+    }
+}
+
+impl ToRedisArgs for CacheValue {
+    fn write_redis_args<W>(&self, out: &mut W)
+    where
+        W: ?Sized + redis::RedisWrite,
+    {
+        out.write_arg(&bincode::serialize(self).expect("serialization to work"))
+    }
+}
 
 /// Use LRU as the eviction strategy
 pub type Lru = LruCache<CacheKey, CacheValue>;
@@ -18,22 +76,27 @@ pub type Lru = LruCache<CacheKey, CacheValue>;
 pub type Lfu = LfuCache<CacheKey, CacheValue>;
 
 /// Adapter trait for memory cache backends
+pub trait InternalMemoryCacheInitializer: InternalMemoryCache {
+    fn new() -> Self;
+}
+
 pub trait InternalMemoryCache: Sync + Send {
-    fn unbounded() -> Self;
-    fn get(&mut self, key: &CacheKey) -> Option<&CacheValue>;
+    fn get(&mut self, key: &CacheKey) -> Option<Cow<CacheValue>>;
     fn push(&mut self, key: CacheKey, data: CacheValue);
     fn pop(&mut self) -> Option<(CacheKey, CacheValue)>;
 }
 
-impl InternalMemoryCache for Lfu {
+impl InternalMemoryCacheInitializer for Lfu {
     #[inline]
-    fn unbounded() -> Self {
+    fn new() -> Self {
         Self::unbounded()
     }
+}
 
+impl InternalMemoryCache for Lfu {
     #[inline]
-    fn get(&mut self, key: &CacheKey) -> Option<&CacheValue> {
-        self.get(key)
+    fn get(&mut self, key: &CacheKey) -> Option<Cow<CacheValue>> {
+        self.get(key).map(Cow::Borrowed)
     }
 
     #[inline]
@@ -47,15 +110,17 @@ impl InternalMemoryCache for Lfu {
     }
 }
 
-impl InternalMemoryCache for Lru {
+impl InternalMemoryCacheInitializer for Lru {
     #[inline]
-    fn unbounded() -> Self {
+    fn new() -> Self {
         Self::unbounded()
     }
+}
 
+impl InternalMemoryCache for Lru {
     #[inline]
-    fn get(&mut self, key: &CacheKey) -> Option<&CacheValue> {
-        self.get(key)
+    fn get(&mut self, key: &CacheKey) -> Option<Cow<CacheValue>> {
+        self.get(key).map(Cow::Borrowed)
     }
 
     #[inline]
@@ -69,6 +134,22 @@ impl InternalMemoryCache for Lru {
     }
 }
 
+impl InternalMemoryCache for RedisClient {
+    fn get(&mut self, key: &CacheKey) -> Option<Cow<CacheValue>> {
+        Commands::get(self, key).ok().map(Cow::Owned)
+    }
+
+    fn push(&mut self, key: CacheKey, data: CacheValue) {
+        if let Err(e) = Commands::set::<_, _, ()>(self, key, data) {
+            warn!("Failed to push to redis: {}", e);
+        }
+    }
+
+    fn pop(&mut self) -> Option<(CacheKey, CacheValue)> {
+        unimplemented!("redis should handle its own memory")
+    }
+}
+
 /// Memory accelerated disk cache. Uses the internal cache implementation in
 /// memory to speed up reads.
 pub struct MemoryCache<MemoryCacheImpl, ColdCache> {
@@ -80,7 +161,7 @@ pub struct MemoryCache<MemoryCacheImpl, ColdCache> {
 
 impl<MemoryCacheImpl, ColdCache> MemoryCache<MemoryCacheImpl, ColdCache>
 where
-    MemoryCacheImpl: 'static + InternalMemoryCache,
+    MemoryCacheImpl: 'static + InternalMemoryCacheInitializer,
     ColdCache: 'static + Cache,
 {
     pub fn new(inner: ColdCache, max_mem_size: crate::units::Bytes) -> Arc<Self> {
@@ -88,7 +169,7 @@ where
         let new_self = Arc::new(Self {
             inner,
             cur_mem_size: AtomicU64::new(0),
-            mem_cache: Mutex::new(MemoryCacheImpl::unbounded()),
+            mem_cache: Mutex::new(MemoryCacheImpl::new()),
             master_sender: tx,
         });
 
@@ -113,7 +194,7 @@ where
             Self {
                 inner,
                 cur_mem_size: AtomicU64::new(0),
-                mem_cache: Mutex::new(MemoryCacheImpl::unbounded()),
+                mem_cache: Mutex::new(MemoryCacheImpl::new()),
                 master_sender: tx,
             },
             rx,
@@ -121,6 +202,21 @@ where
     }
 }
 
+impl<MemoryCacheImpl, ColdCache> MemoryCache<MemoryCacheImpl, ColdCache>
+where
+    MemoryCacheImpl: 'static + InternalMemoryCache,
+    ColdCache: 'static + Cache,
+{
+    pub fn new_with_cache(inner: ColdCache, init_mem_cache: MemoryCacheImpl) -> Self {
+        Self {
+            inner,
+            cur_mem_size: AtomicU64::new(0),
+            mem_cache: Mutex::new(init_mem_cache),
+            master_sender: channel(1).0,
+        }
+    }
+}
+
 async fn internal_cache_listener<MemoryCacheImpl, ColdCache>(
     cache: Arc<MemoryCache<MemoryCacheImpl, ColdCache>>,
     max_mem_size: crate::units::Bytes,
@@ -146,16 +242,20 @@ async fn internal_cache_listener<MemoryCacheImpl, ColdCache>(
             .mem_cache
             .lock()
             .await
-            .push(key, (data, metadata, on_disk_size));
+            .push(key, CacheValue::new(data, metadata, on_disk_size));
 
         // Pop if too large
         while cache.cur_mem_size.load(Ordering::Acquire) >= max_mem_size as u64 {
-            let popped = cache
-                .mem_cache
-                .lock()
-                .await
-                .pop()
-                .map(|(key, (bytes, metadata, size))| (key, bytes, metadata, size));
+            let popped = cache.mem_cache.lock().await.pop().map(
+                |(
+                    key,
+                    CacheValue {
+                        data,
+                        metadata,
+                        on_disk_size,
+                    },
+                )| (key, data, metadata, on_disk_size),
+            );
             if let Some((_, _, _, size)) = popped {
                 cache.cur_mem_size.fetch_sub(size as u64, Ordering::Release);
             } else {
@@ -181,12 +281,16 @@ where
         key: &CacheKey,
     ) -> Option<Result<(CacheStream, ImageMetadata), super::CacheError>> {
         match self.mem_cache.lock().now_or_never() {
-            Some(mut mem_cache) => match mem_cache.get(key).map(|(bytes, metadata, _)| {
-                Ok((CacheStream::Memory(MemStream(bytes.clone())), *metadata))
-            }) {
-                Some(v) => Some(v),
-                None => self.inner.get(key).await,
-            },
+            Some(mut mem_cache) => {
+                match mem_cache.get(key).map(Cow::into_owned).map(
+                    |CacheValue { data, metadata, .. }| {
+                        Ok((CacheStream::Memory(MemStream(data)), metadata))
+                    },
+                ) {
+                    Some(v) => Some(v),
+                    None => self.inner.get(key).await,
+                }
+            }
             None => self.inner.get(key).await,
         }
     }
@@ -206,10 +310,11 @@ where
 
 #[cfg(test)]
 mod test_util {
+    use std::borrow::Cow;
     use std::cell::RefCell;
     use std::collections::{BTreeMap, HashMap};
 
-    use super::{CacheValue, InternalMemoryCache};
+    use super::{CacheValue, InternalMemoryCache, InternalMemoryCacheInitializer};
     use crate::cache::{
         Cache, CacheEntry, CacheError, CacheKey, CacheStream, CallbackCache, ImageMetadata,
     };
@@ -275,13 +380,15 @@ mod test_util {
     #[derive(Default)]
     pub struct TestMemoryCache(pub BTreeMap<CacheKey, CacheValue>);
 
-    impl InternalMemoryCache for TestMemoryCache {
-        fn unbounded() -> Self {
+    impl InternalMemoryCacheInitializer for TestMemoryCache {
+        fn new() -> Self {
             Self::default()
         }
+    }
 
-        fn get(&mut self, key: &CacheKey) -> Option<&CacheValue> {
-            self.0.get(key)
+    impl InternalMemoryCache for TestMemoryCache {
+        fn get(&mut self, key: &CacheKey) -> Option<Cow<CacheValue>> {
+            self.0.get(key).map(Cow::Borrowed)
         }
 
         fn push(&mut self, key: CacheKey, data: CacheValue) {
@@ -306,7 +413,7 @@ mod cache_ops {
     use bytes::Bytes;
     use futures::{FutureExt, StreamExt};
 
-    use crate::cache::mem::InternalMemoryCache;
+    use crate::cache::mem::{CacheValue, InternalMemoryCache};
     use crate::cache::{Cache, CacheEntry, CacheKey, CacheStream, ImageMetadata, MemStream};
 
     use super::test_util::{TestDiskCache, TestMemoryCache};
@@ -326,7 +433,7 @@ mod cache_ops {
             last_modified: None,
         };
         let bytes = Bytes::from_static(b"abcd");
-        let value = (bytes.clone(), metadata.clone(), 34);
+        let value = CacheValue::new(bytes.clone(), metadata.clone(), 34);
 
         // Populate the cache, need to drop the lock else it's considered locked
         // when we actually call the cache

src/cache/mod.rs

@@ -12,6 +12,7 @@ use chacha20::Key;
 use chrono::{DateTime, FixedOffset};
 use futures::{Stream, StreamExt};
 use once_cell::sync::OnceCell;
+use redis::ToRedisArgs;
 use serde::{Deserialize, Serialize};
 use serde_repr::{Deserialize_repr, Serialize_repr};
 use thiserror::Error;
@@ -35,6 +36,15 @@ pub mod mem;
 #[derive(PartialEq, Eq, Hash, Clone, Debug, PartialOrd, Ord)]
 pub struct CacheKey(pub String, pub String, pub bool);
 
+impl ToRedisArgs for CacheKey {
+    fn write_redis_args<W>(&self, out: &mut W)
+    where
+        W: ?Sized + redis::RedisWrite,
+    {
+        out.write_arg_fmt(self)
+    }
+}
+
 impl Display for CacheKey {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         if self.2 {

src/config.rs

@@ -109,6 +109,7 @@ pub struct Config {
     pub enable_metrics: bool,
     pub geoip_license_key: Option<ClientSecret>,
     pub proxy: Option<Url>,
+    pub redis_url: Option<Url>,
 }
 
 impl Config {
@@ -210,6 +211,7 @@ impl Config {
                 }
             }),
             proxy: cli_args.proxy,
+            redis_url: file_extended_options.redis_url,
         }
     }
 }
@@ -236,6 +238,7 @@ pub enum CacheType {
     OnDisk,
     Lru,
     Lfu,
+    Redis,
 }
 
 impl FromStr for CacheType {
@@ -246,6 +249,7 @@ impl FromStr for CacheType {
             "on_disk" => Ok(Self::OnDisk),
             "lru" => Ok(Self::Lru),
             "lfu" => Ok(Self::Lfu),
+            "redis" => Ok(Self::Redis),
             _ => Err(format!("Unknown option: {}", s)),
         }
     }
@@ -294,6 +298,7 @@ struct YamlExtendedOptions {
     enable_metrics: Option<bool>,
     logging_level: Option<LevelFilter>,
     cache_path: Option<PathBuf>,
+    redis_url: Option<Url>,
 }
 
 #[derive(Clap, Clone)]
@@ -341,7 +346,7 @@ struct CliArgs {
     #[clap(short, long)]
     pub config_path: Option<PathBuf>,
     /// Whether to use an in-memory cache in addition to the disk cache. Default
-    /// value is "on_disk", other options are "lfu" and "lru".
+    /// value is "on_disk", other options are "lfu", "lru", and "redis".
     #[clap(short = 't', long)]
     pub cache_type: Option<CacheType>,
     /// Whether or not to use a proxy for upstream requests. This affects all
@@ -457,6 +462,7 @@ mod config {
                 enable_metrics: None,
                 logging_level: Some(LevelFilter::Error),
                 cache_path: Some(PathBuf::from("b")),
+                redis_url: None,
             }),
         };
 

src/main.rs

@@ -21,6 +21,7 @@ use chacha20::Key;
 use config::Config;
 use maxminddb::geoip2;
 use parking_lot::RwLock;
+use redis::Client as RedisClient;
 use rustls::{NoClientAuth, ServerConfig};
 use sodiumoxide::crypto::stream::xchacha20::gen_key;
 use state::{RwLockServerState, ServerState};
@@ -81,6 +82,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
         .unstable_options
         .contains(&UnstableOptions::DisableTls);
     let bind_address = config.bind_address;
+    let redis_url = config.redis_url.clone();
 
     //
     // Logging and warnings
@@ -174,6 +176,14 @@ async fn main() -> Result<(), Box<dyn Error>> {
         CacheType::OnDisk => cache,
         CacheType::Lru => MemoryCache::<Lfu, _>::new(cache, memory_max_size),
         CacheType::Lfu => MemoryCache::<Lru, _>::new(cache, memory_max_size),
+        CacheType::Redis => {
+            let url = redis_url.unwrap_or_else(|| {
+                url::Url::parse("redis://127.0.0.1/").expect("default redis url to be parsable")
+            });
+            info!("Trying to connect to redis instance at {}", url);
+            let mem_cache = RedisClient::open(url)?;
+            Arc::new(MemoryCache::new_with_cache(cache, mem_cache))
+        }
     };
 
     let cache_0 = Arc::clone(&cache);
@@ -289,10 +299,6 @@ fn print_preamble_and_warnings(args: &Config) -> Result<(), Box<dyn Error>> {
         build_string
     );
 
-    if args.ephemeral_disk_encryption {
-        error!("Encrypted files are _very_ broken; caveat emptor!");
-    }
-
     if !args.unstable_options.is_empty() {
         warn!("Unstable options are enabled. These options should not be used in production!");
     }