Resolve conflicts with main

Cargo.lock

@@ -112,9 +112,9 @@ dependencies = [
 
 [[package]]
 name = "actix-rt"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28f32d40287d3f402ae0028a9d54bef51af15c8769492826a69d28f81893151d"
+checksum = "24eda4e2a6e042aa4e55ac438a2ae052d3b5da0ecf83d7411e1a368946925208"
 dependencies = [
  "futures-core",
  "tokio",
@@ -123,9 +123,9 @@ dependencies = [
 
 [[package]]
 name = "actix-server"
-version = "2.3.0"
+version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3eb13e7eef0423ea6eab0e59f6c72e7cb46d33691ad56a726b3cd07ddec2c2d4"
+checksum = "b02303ce8d4e8be5b855af6cf3c3a08f3eff26880faad82bab679c22d3650cb5"
 dependencies = [
  "actix-rt",
  "actix-service",
@@ -1482,9 +1482,9 @@ dependencies = [
 
 [[package]]
 name = "io-uring"
-version = "0.5.13"
+version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd1e1a01cfb924fd8c5c43b6827965db394f5a3a16c599ce03452266e1cf984c"
+checksum = "595a0399f411a508feb2ec1e970a4a30c249351e30208960d58298de8660b0e5"
 dependencies = [
  "bitflags 1.3.2",
  "libc",
@@ -1653,9 +1653,9 @@ checksum = "6c8640c5d730cb13ebd907d8d04b52f55ac9a2eec55b440c8892f40d56c76c1d"
 
 [[package]]
 name = "metrics"
-version = "0.22.3"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2be3cbd384d4e955b231c895ce10685e3d8260c5ccffae898c96c723b0772835"
+checksum = "884adb57038347dfbaf2d5065887b6cf4312330dc8e94bc30a1a839bd79d3261"
 dependencies = [
  "ahash",
  "portable-atomic",
@@ -1663,9 +1663,9 @@ dependencies = [
 
 [[package]]
 name = "metrics-exporter-prometheus"
-version = "0.14.0"
+version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d58e362dc7206e9456ddbcdbd53c71ba441020e62104703075a69151e38d85f"
+checksum = "26eb45aff37b45cff885538e1dcbd6c2b462c04fe84ce0155ea469f325672c98"
 dependencies = [
  "base64 0.22.1",
  "http-body-util",
@@ -1683,9 +1683,9 @@ dependencies = [
 
 [[package]]
 name = "metrics-util"
-version = "0.16.3"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b07a5eb561b8cbc16be2d216faf7757f9baf3bfb94dbb0fae3df8387a5bb47f"
+checksum = "4259040465c955f9f2f1a4a8a16dc46726169bca0f88e8fb2dbeced487c3e828"
 dependencies = [
  "crossbeam-epoch",
  "crossbeam-utils",
@@ -1809,9 +1809,9 @@ checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
 
 [[package]]
 name = "opentelemetry"
-version = "0.22.0"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "900d57987be3f2aeb70d385fff9b27fb74c5723cc9a52d904d4f9c807a0667bf"
+checksum = "1b69a91d4893e713e06f724597ad630f1fa76057a5e1026c0ca67054a9032a76"
 dependencies = [
  "futures-core",
  "futures-sink",
@@ -1819,21 +1819,19 @@ dependencies = [
  "once_cell",
  "pin-project-lite",
  "thiserror",
- "urlencoding",
 ]
 
 [[package]]
 name = "opentelemetry-otlp"
-version = "0.15.0"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a016b8d9495c639af2145ac22387dcb88e44118e45320d9238fbf4e7889abcb"
+checksum = "a94c69209c05319cdf7460c6d4c055ed102be242a0a6245835d7bc42c6ec7f54"
 dependencies = [
  "async-trait",
  "futures-core",
  "http 0.2.12",
  "opentelemetry",
  "opentelemetry-proto",
- "opentelemetry-semantic-conventions",
  "opentelemetry_sdk",
  "prost",
  "thiserror",
@@ -1843,9 +1841,9 @@ dependencies = [
 
 [[package]]
 name = "opentelemetry-proto"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a8fddc9b68f5b80dae9d6f510b88e02396f006ad48cac349411fbecc80caae4"
+checksum = "984806e6cf27f2b49282e2a05e288f30594f3dbc74eb7a6e99422bc48ed78162"
 dependencies = [
  "opentelemetry",
  "opentelemetry_sdk",
@@ -1853,24 +1851,18 @@ dependencies = [
  "tonic 0.11.0",
 ]
 
-[[package]]
-name = "opentelemetry-semantic-conventions"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9ab5bd6c42fb9349dcf28af2ba9a0667f697f9bdcca045d39f2cec5543e2910"
-
 [[package]]
 name = "opentelemetry_sdk"
-version = "0.22.1"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e90c7113be649e31e9a0f8b5ee24ed7a16923b322c3c5ab6367469c049d6b7e"
+checksum = "ae312d58eaa90a82d2e627fd86e075cf5230b3f11794e2ed74199ebbe572d4fd"
 dependencies = [
  "async-trait",
- "crossbeam-channel",
  "futures-channel",
  "futures-executor",
  "futures-util",
  "glob",
+ "lazy_static",
  "once_cell",
  "opentelemetry",
  "ordered-float",
@@ -1997,7 +1989,7 @@ dependencies = [
 
 [[package]]
 name = "pict-rs"
-version = "0.5.15"
+version = "0.5.16"
 dependencies = [
  "actix-form-data",
  "actix-web",
@@ -2649,12 +2641,6 @@ dependencies = [
  "pin-utils",
 ]
 
-[[package]]
-name = "scoped-tls"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1cf6437eb19a8f4a6cc0f7dca544973b0b78843adbfeb3683d1a94a0024a294"
-
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
@@ -3138,14 +3124,14 @@ dependencies = [
 
 [[package]]
 name = "tokio-uring"
-version = "0.4.0"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d5e02bb137e030b3a547c65a3bd2f1836d66a97369fdcc69034002b10e155ef"
+checksum = "748482e3e13584a34664a710168ad5068e8cb1d968aa4ffa887e83ca6dd27967"
 dependencies = [
  "bytes",
+ "futures-util",
  "io-uring",
  "libc",
- "scoped-tls",
  "slab",
  "socket2 0.4.10",
  "tokio",
@@ -3355,9 +3341,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-opentelemetry"
-version = "0.23.0"
+version = "0.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9be14ba1bbe4ab79e9229f7f89fab8d120b865859f10527f31c033e599d2284"
+checksum = "f68803492bf28ab40aeccaecc7021096bd256baf7ca77c3d425d89b35a7be4e4"
 dependencies = [
  "js-sys",
  "once_cell",
@@ -3465,12 +3451,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "urlencoding"
-version = "2.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "daf8dba3b7eb870caf1ddeed7bc9d2a049f3cfdfae7cb521b087cc33ae4c49da"
-
 [[package]]
 name = "utf8parse"
 version = "0.2.2"

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "pict-rs"
 description = "A simple image hosting service"
-version = "0.5.15"
+version = "0.5.16"
 authors = ["asonix <asonix@asonix.dog>"]
 license = "AGPL-3.0"
 readme = "README.md"
@@ -37,13 +37,13 @@ diesel-derive-enum = { version = "2.1.0", features = ["postgres"] }
 futures-core = "0.3"
 hex = "0.4.3"
 md-5 = "0.10.5"
-metrics = "0.22.0"
+metrics = "0.23.0"
-metrics-exporter-prometheus = { version = "0.14.0", default-features = false, features = ["http-listener"] }
+metrics-exporter-prometheus = { version = "0.15.0", default-features = false, features = ["http-listener"] }
 mime = "0.3.1"
 nanorand = { version = "0.7", optional = true }
-opentelemetry_sdk = { version = "0.22", features = ["rt-tokio"] }
+opentelemetry_sdk = { version = "0.23", features = ["rt-tokio"] }
-opentelemetry = "0.22"
+opentelemetry = "0.23"
-opentelemetry-otlp = "0.15"
+opentelemetry-otlp = "0.16"
 pin-project-lite = "0.2.7"
 refinery = { version = "0.8.10", features = ["tokio-postgres", "postgres"] }
 reqwest = { version = "0.12.0", default-features = false, features = ["json", "rustls-tls-no-provider", "stream"] }
@@ -70,7 +70,7 @@ time = { version = "0.3.0", features = ["serde", "serde-well-known"] }
 tokio = { version = "1", features = ["full", "tracing"] }
 tokio-postgres = { version = "0.7.10", features = ["with-uuid-1", "with-time-0_3", "with-serde_json-1"] }
 tokio-postgres-generic-rustls = { version = "0.1.0", default-features = false, features = ["aws-lc-rs"] }
-tokio-uring = { version = "0.4", optional = true, features = ["bytes"] }
+tokio-uring = { version = "0.5", optional = true, features = ["bytes"] }
 tokio-util = { version = "0.7", default-features = false, features = [
   "codec",
   "io",
@@ -79,7 +79,7 @@ toml = "0.8.0"
 tracing = "0.1.15"
 tracing-error = "0.2.0"
 tracing-log = "0.2.0"
-tracing-opentelemetry = "0.23"
+tracing-opentelemetry = "0.24"
 tracing-subscriber = { version = "0.3.0", features = [
   "ansi",
   "env-filter",
@@ -96,7 +96,7 @@ webpki-roots = "0.26.0"
 [dependencies.tracing-actix-web]
 version = "0.7.10"
 default-features = false
-features = ["opentelemetry_0_22"]
+features = ["opentelemetry_0_23"]
 
 [patch.crates-io]
 reqwest = { git = "https://github.com/asonix/reqwest", branch = "asonix/limit-openssl-probe" }

pict-rs.nix

@@ -11,7 +11,7 @@
 
 rustPlatform.buildRustPackage {
   pname = "pict-rs";
-  version = "0.5.15";
+  version = "0.5.16";
   src = ./.;
 
   cargoLock = {

releases/0.5.16.md

@@ -0,0 +1,46 @@
+# pict-rs 0.5.16
+
+pict-rs is a simple image hosting microservice, designed to handle storing and retrieving images,
+animations, and videos, as well as providing basic image processing functionality.
+
+## Overview
+
+pict-rs 0.5.16 includes a couple bugfixes for parsing query paramters, better handling of proxied
+media, clearer postgres errors, and updated dependencies.
+
+### Fixes
+
+- [Query Fixes](#query-fixes)
+- [Better Concurrent Proxies](#better-concurrent-proxies)
+
+
+### Changes
+
+- [Improved Postgres Errors](#improved-postgres-errors)
+
+
+## Upgrade Notes
+
+There are no significant changes from 0.5.15. Upgrading should be a simple as pulling a new version
+of pict-rs.
+
+
+## Descriptions
+
+### Query Fixes
+
+A couple boolean query parameters were not getting parsed properly, this impacted ?backgrounded for
+image downloads and ?force for pruning media. pict-rs 0.5.16 resolves this.
+
+
+### Better Concurrent Proxies
+
+When the same proxy endpoint was accessed more than once concurrently, only one request would end up
+succeeding. Now pict-rs better handles when multiple concurrent requests are made.
+
+
+### Improved Postgres Errors
+
+In some postgres errors, it is difficult to tell whether an error originated from within the
+postgres client or the postgres server. pict-rs 0.5.16 now includes extra context when displaying
+postgres errors to help discern this.

src/file.rs

@@ -167,10 +167,10 @@ mod io_uring {
             while let Some(res) = stream.next().await {
                 tracing::trace!("write_from_stream while: looping");
 
-                let mut buf = res?;
+                let buf = res?;
 
                 let len = buf.len();
-                let mut position = 0;
+                let mut position: usize = 0;
 
                 loop {
                     tracing::trace!("write_from_stream: looping");
@@ -179,9 +179,8 @@ mod io_uring {
                         break;
                     }
 
-                    let position_u64: u64 = position.try_into().unwrap();
+                    let (res, _buf) = self
-                    let (res, slice) = self
+                        .write_at(buf.slice(position..), cursor + (position as u64))
-                        .write_at(buf.slice(position..len), cursor + position_u64)
                         .await;
 
                     let n = res?;
@@ -190,12 +189,10 @@ mod io_uring {
                     }
 
                     position += n;
-
-                    buf = slice.into_inner();
                 }
 
-                let position: u64 = position.try_into().unwrap();
+                let len: u64 = len.try_into().unwrap();
-                cursor += position;
+                cursor += len;
             }
 
             self.inner.sync_all().await?;
@@ -220,7 +217,7 @@ mod io_uring {
         }
 
         async fn write_at<T: IoBuf>(&self, buf: T, pos: u64) -> BufResult<usize, T> {
-            self.inner.write_at(buf, pos).await
+            self.inner.write_at(buf, pos).submit().await
         }
     }
 

src/lib.rs

@@ -74,7 +74,10 @@ use self::{
     middleware::{Deadline, Internal, Log, Metrics, Payload},
     migrate_store::migrate_store,
     queue::queue_generate,
-    repo::{sled::SledRepo, Alias, ArcRepo, DeleteToken, Hash, Repo, UploadId, UploadResult},
+    repo::{
+        sled::SledRepo, Alias, ArcRepo, DeleteToken, Hash, ProxyAlreadyExists, Repo, UploadId,
+        UploadResult,
+    },
     serde_str::Serde,
     state::State,
     store::{file_store::FileStore, object_store::ObjectStore, Store},
@@ -1286,11 +1289,28 @@ async fn proxy_alias_from_query<S: Store + 'static>(
             } else if !state.config.server.read_only {
                 let stream = download_stream(proxy.as_str(), state).await?;
 
-                let (alias, _, _) = ingest_inline(stream, state, &Default::default()).await?;
+                // some time has passed, see if we've proxied elsewhere
-
+                if let Some(alias) = state.repo.related(proxy.clone()).await? {
-                state.repo.relate_url(proxy, alias.clone()).await?;
-
                     alias
+                } else {
+                    let (alias, token, _) =
+                        ingest_inline(stream, state, &Default::default()).await?;
+
+                    // last check, do we succeed or fail to relate the proxy alias
+                    if let Err(ProxyAlreadyExists) =
+                        state.repo.relate_url(proxy.clone(), alias.clone()).await?
+                    {
+                        queue::cleanup_alias(&state.repo, alias, token).await?;
+
+                        state
+                            .repo
+                            .related(proxy)
+                            .await?
+                            .ok_or(UploadError::MissingAlias)?
+                    } else {
+                        alias
+                    }
+                }
             } else {
                 return Err(UploadError::ReadOnly.into());
             };

src/repo.rs

@@ -46,6 +46,8 @@ pub(crate) struct HashAlreadyExists;
 pub(crate) struct AliasAlreadyExists;
 #[derive(Debug)]
 pub(crate) struct VariantAlreadyExists;
+#[derive(Debug)]
+pub(crate) struct ProxyAlreadyExists;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub(crate) struct UploadId {
@@ -151,7 +153,11 @@ impl<T> BaseRepo for Arc<T> where T: BaseRepo {}
 
 #[async_trait::async_trait(?Send)]
 pub(crate) trait ProxyRepo: BaseRepo {
-    async fn relate_url(&self, url: Url, alias: Alias) -> Result<(), RepoError>;
+    async fn relate_url(
+        &self,
+        url: Url,
+        alias: Alias,
+    ) -> Result<Result<(), ProxyAlreadyExists>, RepoError>;
 
     async fn related(&self, url: Url) -> Result<Option<Alias>, RepoError>;
 
@@ -163,7 +169,11 @@ impl<T> ProxyRepo for Arc<T>
 where
     T: ProxyRepo,
 {
-    async fn relate_url(&self, url: Url, alias: Alias) -> Result<(), RepoError> {
+    async fn relate_url(
+        &self,
+        url: Url,
+        alias: Alias,
+    ) -> Result<Result<(), ProxyAlreadyExists>, RepoError> {
         T::relate_url(self, url, alias).await
     }
 

src/repo/postgres.rs

@@ -47,8 +47,8 @@ use super::{
     notification_map::{NotificationEntry, NotificationMap},
     Alias, AliasAccessRepo, AliasAlreadyExists, AliasRepo, BaseRepo, DeleteToken, DetailsRepo,
     FullRepo, Hash, HashAlreadyExists, HashPage, HashRepo, JobId, JobResult, OrderedHash,
-    ProxyRepo, QueueRepo, RepoError, SettingsRepo, StoreMigrationRepo, UploadId, UploadRepo,
+    ProxyAlreadyExists, ProxyRepo, QueueRepo, RepoError, SettingsRepo, StoreMigrationRepo,
-    UploadResult, VariantAccessRepo, VariantAlreadyExists, VariantRepo,
+    UploadId, UploadRepo, UploadResult, VariantAccessRepo, VariantAlreadyExists, VariantRepo,
 };
 
 #[derive(Clone)]
@@ -103,33 +103,71 @@ pub(crate) enum ConnectPostgresError {
     BuildPool(#[source] PoolError),
 }
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug)]
 pub(crate) enum PostgresError {
-    #[error("Error in db pool")]
+    Pool(RunError),
-    Pool(#[source] RunError),
+    Diesel(diesel::result::Error),
-
+    Hex(hex::FromHexError),
-    #[error("Error in database")]
+    SerializeDetails(serde_json::Error),
-    Diesel(#[from] diesel::result::Error),
+    DeserializeDetails(serde_json::Error),
-
+    SerializeUploadResult(serde_json::Error),
-    #[error("Error deserializing hex value")]
+    DeserializeUploadResult(serde_json::Error),
-    Hex(#[source] hex::FromHexError),
-
-    #[error("Error serializing details")]
-    SerializeDetails(#[source] serde_json::Error),
-
-    #[error("Error deserializing details")]
-    DeserializeDetails(#[source] serde_json::Error),
-
-    #[error("Error serializing upload result")]
-    SerializeUploadResult(#[source] serde_json::Error),
-
-    #[error("Error deserializing upload result")]
-    DeserializeUploadResult(#[source] serde_json::Error),
-
-    #[error("Timed out waiting for postgres")]
     DbTimeout,
 }
 
+impl std::fmt::Display for PostgresError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Pool(_) => write!(f, "Error in db pool"),
+            Self::Diesel(e) => match e {
+                diesel::result::Error::DatabaseError(kind, _) => {
+                    write!(f, "Error in diesel: {kind:?}")
+                }
+                diesel::result::Error::InvalidCString(_) => {
+                    write!(f, "Error in diesel: Invalid c string")
+                }
+                diesel::result::Error::QueryBuilderError(_) => {
+                    write!(f, "Error in diesel: Query builder")
+                }
+                diesel::result::Error::SerializationError(_) => {
+                    write!(f, "Error in diesel: Serialization")
+                }
+                diesel::result::Error::DeserializationError(_) => {
+                    write!(f, "Error in diesel: Deserialization")
+                }
+                _ => write!(f, "Error in diesel"),
+            },
+            Self::Hex(_) => write!(f, "Error deserializing hex value"),
+            Self::SerializeDetails(_) => write!(f, "Error serializing details"),
+            Self::DeserializeDetails(_) => write!(f, "Error deserializing details"),
+            Self::SerializeUploadResult(_) => write!(f, "Error serializing upload result"),
+            Self::DeserializeUploadResult(_) => write!(f, "Error deserializing upload result"),
+            Self::DbTimeout => write!(f, "Timed out waiting for postgres"),
+        }
+    }
+}
+
+impl std::error::Error for PostgresError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            Self::Pool(e) => Some(e),
+            Self::Diesel(e) => Some(e),
+            Self::Hex(e) => Some(e),
+            Self::SerializeDetails(e) => Some(e),
+            Self::DeserializeDetails(e) => Some(e),
+            Self::SerializeUploadResult(e) => Some(e),
+            Self::DeserializeUploadResult(e) => Some(e),
+            Self::DbTimeout => None,
+        }
+    }
+}
+
+impl From<diesel::result::Error> for PostgresError {
+    fn from(value: diesel::result::Error) -> Self {
+        Self::Diesel(value)
+    }
+}
+
 #[derive(Debug, thiserror::Error)]
 pub(crate) enum TlsError {
     #[error("Couldn't read configured certificate file")]
@@ -1846,21 +1884,31 @@ impl StoreMigrationRepo for PostgresRepo {
 #[async_trait::async_trait(?Send)]
 impl ProxyRepo for PostgresRepo {
     #[tracing::instrument(level = "debug", skip(self))]
-    async fn relate_url(&self, input_url: Url, input_alias: Alias) -> Result<(), RepoError> {
+    async fn relate_url(
+        &self,
+        input_url: Url,
+        input_alias: Alias,
+    ) -> Result<Result<(), ProxyAlreadyExists>, RepoError> {
         use schema::proxies::dsl::*;
 
         let mut conn = self.get_connection().await?;
 
-        diesel::insert_into(proxies)
+        let res = diesel::insert_into(proxies)
             .values((url.eq(input_url.as_str()), alias.eq(&input_alias)))
             .execute(&mut conn)
             .with_metrics(crate::init_metrics::POSTGRES_PROXY_RELATE_URL)
             .with_timeout(Duration::from_secs(5))
             .await
-            .map_err(|_| PostgresError::DbTimeout)?
+            .map_err(|_| PostgresError::DbTimeout)?;
-            .map_err(PostgresError::Diesel)?;
 
-        Ok(())
+        match res {
+            Ok(_) => Ok(Ok(())),
+            Err(diesel::result::Error::DatabaseError(
+                diesel::result::DatabaseErrorKind::UniqueViolation,
+                _,
+            )) => Ok(Err(ProxyAlreadyExists)),
+            Err(e) => Err(PostgresError::Diesel(e).into()),
+        }
     }
 
     #[tracing::instrument(level = "debug", skip(self))]

src/repo/sled.rs

@@ -26,8 +26,8 @@ use super::{
     notification_map::{NotificationEntry, NotificationMap},
     Alias, AliasAccessRepo, AliasAlreadyExists, AliasRepo, BaseRepo, DeleteToken, Details,
     DetailsRepo, FullRepo, HashAlreadyExists, HashPage, HashRepo, JobId, JobResult, OrderedHash,
-    ProxyRepo, QueueRepo, RepoError, SettingsRepo, StoreMigrationRepo, UploadId, UploadRepo,
+    ProxyAlreadyExists, ProxyRepo, QueueRepo, RepoError, SettingsRepo, StoreMigrationRepo,
-    UploadResult, VariantAccessRepo, VariantAlreadyExists, VariantRepo,
+    UploadId, UploadRepo, UploadResult, VariantAccessRepo, VariantAlreadyExists, VariantRepo,
 };
 
 macro_rules! b {
@@ -218,20 +218,32 @@ impl FullRepo for SledRepo {
 
 #[async_trait::async_trait(?Send)]
 impl ProxyRepo for SledRepo {
-    async fn relate_url(&self, url: Url, alias: Alias) -> Result<(), RepoError> {
+    async fn relate_url(
+        &self,
+        url: Url,
+        alias: Alias,
+    ) -> Result<Result<(), ProxyAlreadyExists>, RepoError> {
         let proxy = self.proxy.clone();
         let inverse_proxy = self.inverse_proxy.clone();
 
-        crate::sync::spawn_blocking("sled-io", move || {
+        let res = crate::sync::spawn_blocking("sled-io", move || {
-            proxy.insert(url.as_str().as_bytes(), alias.to_bytes())?;
+            match proxy.compare_and_swap(
+                url.as_str().as_bytes(),
+                Option::<sled::IVec>::None,
+                Some(alias.to_bytes()),
+            )? {
+                Ok(_) => {
                     inverse_proxy.insert(alias.to_bytes(), url.as_str().as_bytes())?;
 
-            Ok(()) as Result<(), SledError>
+                    Ok(Ok(())) as Result<Result<(), ProxyAlreadyExists>, SledError>
+                }
+                Err(_) => Ok(Err(ProxyAlreadyExists)),
+            }
         })
         .await
         .map_err(|_| RepoError::Canceled)??;
 
-        Ok(())
+        Ok(res)
     }
 
     async fn related(&self, url: Url) -> Result<Option<Alias>, RepoError> {