refactor(nix-compat): Move serialization machinery into wire.

This groups most `wire` feature gated logic into a single module.
The nix_daemon module will be gated by a feature that adds
nix-compat-derive as a dependency.

All of this is a way to break the crate2nix dependency cycle between
nix-compat and nix-compat-derive(which depends on nix-compat for its
doctests).

Change-Id: I95938a6f280c11967371ff21f8b5a19e6d3d3805
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12761
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>

tvix/nix-compat-derive-tests/tests/read_derive.rs

@@ -1,7 +1,7 @@
 use std::str::FromStr;
 
-use nix_compat::nix_daemon::de::mock::{Builder, Error};
+use nix_compat::wire::de::mock::{Builder, Error};
-use nix_compat::nix_daemon::de::NixRead;
+use nix_compat::wire::de::NixRead;
 use nix_compat_derive::NixDeserialize;
 
 #[derive(Debug, PartialEq, Eq, NixDeserialize)]

tvix/nix-compat-derive-tests/tests/ui/deserialize_bad_type.stderr

@@ -15,7 +15,7 @@ error[E0277]: the trait bound `BadType: NixDeserialize` is not satisfied
             u64
             usize
 note: required by a bound in `try_read_value`
- --> $WORKSPACE/nix-compat/src/nix_daemon/de/mod.rs
+ --> $WORKSPACE/nix-compat/src/wire/de/mod.rs
   |
   |     fn try_read_value<V: NixDeserialize>(
   |                          ^^^^^^^^^^^^^^ required by this bound in `NixRead::try_read_value`

tvix/nix-compat-derive-tests/tests/ui/deserialize_from_str_error_not_display.stderr

@@ -7,7 +7,7 @@ error[E0277]: `()` doesn't implement `std::fmt::Display`
   = help: the trait `std::fmt::Display` is not implemented for `()`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 note: required by a bound in `invalid_data`
- --> $WORKSPACE/nix-compat/src/nix_daemon/de/mod.rs
+ --> $WORKSPACE/nix-compat/src/wire/de/mod.rs
   |
   |     fn invalid_data<T: fmt::Display>(msg: T) -> Self {
   |                        ^^^^^^^^^^^^ required by this bound in `Error::invalid_data`

tvix/nix-compat-derive-tests/tests/ui/deserialize_remote_missing_attr.stderr

@@ -1,5 +1,6 @@
 error: Missing from_str, from or try_from attribute
-  --> tests/ui/deserialize_remote_missing_attr.rs:10:25
+  --> tests/ui/deserialize_remote_missing_attr.rs:11:5
    |
-10 | nix_deserialize_remote!(#[nix()] Value);
+11 | /     #[nix()]
-   |                         ^^^^^^^^^^^^^^
+12 | |     Value
+   | |_________^

tvix/nix-compat-derive-tests/tests/ui/deserialize_try_from_error_not_display.stderr

@@ -7,7 +7,7 @@ error[E0277]: `()` doesn't implement `std::fmt::Display`
   = help: the trait `std::fmt::Display` is not implemented for `()`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 note: required by a bound in `invalid_data`
- --> $WORKSPACE/nix-compat/src/nix_daemon/de/mod.rs
+ --> $WORKSPACE/nix-compat/src/wire/de/mod.rs
   |
   |     fn invalid_data<T: fmt::Display>(msg: T) -> Self {
   |                        ^^^^^^^^^^^^ required by this bound in `Error::invalid_data`

tvix/nix-compat-derive-tests/tests/write_derive.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 
-use nix_compat::nix_daemon::ser::{
+use nix_compat::wire::ser::{
     mock::{Builder, Error},
     NixWrite as _,
 };

tvix/nix-compat-derive/src/de.rs

@@ -58,12 +58,12 @@ fn nix_deserialize_impl(
 
     quote! {
         #[automatically_derived]
-        impl #impl_generics #crate_path::nix_daemon::de::NixDeserialize for #ty #ty_generics
+        impl #impl_generics #crate_path::wire::de::NixDeserialize for #ty #ty_generics
             #where_clause
         {
             #[allow(clippy::manual_async_fn)]
             fn try_deserialize<R>(reader: &mut R) -> impl ::std::future::Future<Output=Result<Option<Self>, R::Error>> + Send + '_
-                where R: ?Sized + #crate_path::nix_daemon::de::NixRead + Send,
+                where R: ?Sized + #crate_path::wire::de::NixRead + Send,
             {
                 #body
             }
@@ -253,7 +253,7 @@ fn nix_deserialize_try_from(crate_path: &Path, ty: &Type) -> TokenStream {
     quote_spanned! {
         ty.span() =>
         async move {
-            use #crate_path::nix_daemon::de::Error;
+            use #crate_path::wire::de::Error;
             if let Some(item) = reader.try_read_value::<#ty>().await? {
                 <Self as ::std::convert::TryFrom<#ty>>::try_from(item)
                     .map_err(Error::invalid_data)
@@ -269,7 +269,7 @@ fn nix_deserialize_from_str(crate_path: &Path, span: Span) -> TokenStream {
     quote_spanned! {
         span =>
         async move {
-            use #crate_path::nix_daemon::de::Error;
+            use #crate_path::wire::de::Error;
             if let Some(buf) = reader.try_read_bytes().await? {
                 let s = ::std::str::from_utf8(&buf)
                     .map_err(Error::invalid_data)?;

tvix/nix-compat-derive/src/ser.rs

@@ -55,13 +55,13 @@ fn nix_serialize_impl(
 
     quote! {
         #[automatically_derived]
-        impl #impl_generics #crate_path::nix_daemon::ser::NixSerialize for #ty #ty_generics
+        impl #impl_generics #crate_path::wire::ser::NixSerialize for #ty #ty_generics
             #where_clause
         {
             async fn serialize<W>(&self, writer: &mut W) -> std::result::Result<(), W::Error>
-                where W: #crate_path::nix_daemon::ser::NixWrite
+                where W: #crate_path::wire::ser::NixWrite
             {
-                use #crate_path::nix_daemon::ser::Error as _;
+                use #crate_path::wire::ser::Error as _;
                 #body
             }
         }
@@ -207,7 +207,7 @@ fn nix_serialize_try_into(crate_path: &Path, ty: &Type) -> TokenStream {
     quote_spanned! {
         ty.span() =>
         {
-            use #crate_path::nix_daemon::ser::Error;
+            use #crate_path::wire::ser::Error;
             let other : #ty = <Self as Clone>::clone(self).try_into().map_err(Error::unsupported_data)?;
             writer.write_value(&other).await
         }

tvix/nix-compat/src/lib.rs

@@ -18,5 +18,3 @@ pub mod wire;
 pub mod nix_daemon;
 #[cfg(feature = "wire")]
 pub use nix_daemon::worker_protocol;
-#[cfg(feature = "wire")]
-pub use nix_daemon::ProtocolVersion;

tvix/nix-compat/src/nix_daemon/mod.rs

@@ -1,7 +1 @@
 pub mod worker_protocol;
-
-mod protocol_version;
-pub use protocol_version::ProtocolVersion;
-
-pub mod de;
-pub mod ser;

tvix/nix-compat/src/nix_daemon/worker_protocol.rs

@@ -10,7 +10,7 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
 use crate::wire;
 
-use super::ProtocolVersion;
+use crate::wire::ProtocolVersion;
 
 static WORKER_MAGIC_1: u64 = 0x6e697863; // "nixc"
 static WORKER_MAGIC_2: u64 = 0x6478696f; // "dxio"

tvix/nix-compat/src/wire/de/bytes.rs

@@ -34,7 +34,7 @@ mod test {
     use rstest::rstest;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::de::{NixRead, NixReader};
+    use crate::wire::de::{NixRead, NixReader};
 
     #[rstest]
     #[case::empty("", &hex!("0000 0000 0000 0000"))]

tvix/nix-compat/src/wire/de/collections.rs

@@ -64,7 +64,7 @@ mod test {
     use rstest::rstest;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::de::{NixDeserialize, NixRead, NixReader};
+    use crate::wire::de::{NixDeserialize, NixRead, NixReader};
 
     #[rstest]
     #[case::empty(vec![], &hex!("0000 0000 0000 0000"))]

tvix/nix-compat/src/wire/de/int.rs

@@ -45,7 +45,7 @@ mod test {
     use rstest::rstest;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::de::{NixRead, NixReader};
+    use crate::wire::de::{NixRead, NixReader};
 
     #[rstest]
     #[case::simple_false(false, &hex!("0000 0000 0000 0000"))]

tvix/nix-compat/src/wire/de/mock.rs

@@ -6,7 +6,7 @@ use std::thread;
 use bytes::Bytes;
 use thiserror::Error;
 
-use crate::nix_daemon::ProtocolVersion;
+use crate::wire::ProtocolVersion;
 
 use super::NixRead;
 
@@ -189,7 +189,7 @@ mod test {
     use bytes::Bytes;
     use hex_literal::hex;
 
-    use crate::nix_daemon::de::NixRead;
+    use crate::wire::de::NixRead;
 
     use super::{Builder, Error};
 

tvix/nix-compat/src/wire/de/reader.rs

@@ -8,8 +8,7 @@ use bytes::{Buf, BufMut, Bytes, BytesMut};
 use pin_project_lite::pin_project;
 use tokio::io::{AsyncBufRead, AsyncRead, AsyncReadExt, ReadBuf};
 
-use crate::nix_daemon::ProtocolVersion;
+use crate::wire::{ProtocolVersion, EMPTY_BYTES};
-use crate::wire::EMPTY_BYTES;
 
 use super::{Error, NixRead};
 
@@ -270,7 +269,7 @@ mod test {
     use tokio_test::io::Builder;
 
     use super::*;
-    use crate::nix_daemon::de::NixRead;
+    use crate::wire::de::NixRead;
 
     #[tokio::test]
     async fn test_read_u64() {

tvix/nix-compat/src/wire/mod.rs

@@ -3,3 +3,9 @@
 
 mod bytes;
 pub use bytes::*;
+
+mod protocol_version;
+pub use protocol_version::ProtocolVersion;
+
+pub mod de;
+pub mod ser;

tvix/nix-compat/src/wire/ser/bytes.rs

@@ -45,7 +45,7 @@ mod test {
     use tokio::io::AsyncWriteExt as _;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::ser::{NixWrite, NixWriter};
+    use crate::wire::ser::{NixWrite, NixWriter};
 
     #[rstest]
     #[case::empty("", &hex!("0000 0000 0000 0000"))]

tvix/nix-compat/src/wire/ser/collections.rs

@@ -53,7 +53,7 @@ mod test {
     use tokio::io::AsyncWriteExt as _;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::ser::{NixSerialize, NixWrite, NixWriter};
+    use crate::wire::ser::{NixSerialize, NixWrite, NixWriter};
 
     #[rstest]
     #[case::empty(vec![], &hex!("0000 0000 0000 0000"))]

tvix/nix-compat/src/wire/ser/int.rs

@@ -67,7 +67,7 @@ mod test {
     use tokio::io::AsyncWriteExt as _;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::ser::{NixWrite, NixWriter};
+    use crate::wire::ser::{NixWrite, NixWriter};
 
     #[rstest]
     #[case::simple_false(false, &hex!("0000 0000 0000 0000"))]

tvix/nix-compat/src/wire/ser/mock.rs

@@ -7,7 +7,7 @@ use std::thread;
 use ::proptest::prelude::TestCaseError;
 use thiserror::Error;
 
-use crate::nix_daemon::ProtocolVersion;
+use crate::wire::ProtocolVersion;
 
 use super::NixWrite;
 
@@ -491,11 +491,11 @@ mod test {
     use proptest::prelude::TestCaseError;
     use proptest::proptest;
 
-    use crate::nix_daemon::ser::mock::proptest::arb_extra_write;
+    use crate::wire::ser::mock::proptest::arb_extra_write;
-    use crate::nix_daemon::ser::mock::Operation;
+    use crate::wire::ser::mock::Operation;
-    use crate::nix_daemon::ser::mock::OperationType;
+    use crate::wire::ser::mock::OperationType;
-    use crate::nix_daemon::ser::Error as _;
+    use crate::wire::ser::Error as _;
-    use crate::nix_daemon::ser::NixWrite;
+    use crate::wire::ser::NixWrite;
 
     use super::{Builder, Error};
 

tvix/nix-compat/src/wire/ser/writer.rs

@@ -8,9 +8,7 @@ use bytes::{Buf, BufMut, BytesMut};
 use pin_project_lite::pin_project;
 use tokio::io::{AsyncWrite, AsyncWriteExt};
 
-use crate::nix_daemon::ProtocolVersion;
+use crate::wire::{padding_len, ProtocolVersion, EMPTY_BYTES};
-use crate::wire::padding_len;
-use crate::wire::EMPTY_BYTES;
 
 use super::{Error, NixWrite};
 
@@ -225,7 +223,7 @@ mod test {
     use tokio::io::AsyncWriteExt as _;
     use tokio_test::io::Builder;
 
-    use crate::nix_daemon::ser::NixWrite;
+    use crate::wire::ser::NixWrite;
 
     use super::NixWriter;
 

tvix/store/src/bin/tvix-store.rs

@@ -3,9 +3,9 @@ use clap::Subcommand;
 
 use futures::StreamExt;
 use futures::TryStreamExt;
-use nix_compat::nix_daemon::de::Error;
 use nix_compat::nixhash::CAHash;
 use nix_compat::nixhash::NixHash;
+use nix_compat::wire::de::Error;
 use nix_compat::{path_info::ExportedPathInfo, store_path::StorePath};
 use serde::Deserialize;
 use serde::Serialize;

users/picnoir/tvix-daemon/src/main.rs

@@ -3,8 +3,8 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio_listener::{self, SystemOptions, UserOptions};
 use tracing::{debug, error, info, instrument, Level};
 
+use nix_compat::wire::ProtocolVersion;
 use nix_compat::worker_protocol::{self, server_handshake_client, ClientSettings, Trust};
-use nix_compat::ProtocolVersion;
 
 #[derive(Parser, Debug)]
 struct Cli {