Make it explicit when using nonversioned encoding

17 files changed, 57 insertions, 57 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 2a89fa1a..fb8b4f5c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1080,7 +1080,6 @@ dependencies = [
  "parse_duration",
  "prometheus",
  "rand 0.8.5",
- "rmp-serde",
  "serde",
  "serde_bytes",
  "serde_json",
@@ -1156,7 +1155,6 @@ dependencies = [
  "hex",
  "opentelemetry",
  "rand 0.8.5",
- "rmp-serde",
  "serde",
  "serde_bytes",
  "tokio",
@@ -1200,7 +1198,6 @@ dependencies = [
  "netapp",
  "opentelemetry",
  "rand 0.8.5",
- "rmp-serde",
  "serde",
  "serde_bytes",
  "tokio",
@@ -1229,7 +1226,6 @@ dependencies = [
  "pnet_datalink",
  "rand 0.8.5",
  "reqwest",
- "rmp-serde",
  "schemars",
  "serde",
  "serde_bytes",
@@ -1255,7 +1251,6 @@ dependencies = [
  "hexdump",
  "opentelemetry",
  "rand 0.8.5",
- "rmp-serde",
  "serde",
  "serde_bytes",
  "tokio",
diff --git a/Cargo.nix b/Cargo.nix
index e0064d08..79601cdd 100644
--- a/Cargo.nix
+++ b/Cargo.nix
@@ -32,7 +32,7 @@ args@{
   ignoreLockHash,
 }:
 let
-  nixifiedLockHash = "f277e0cfb8bb74ed78c99c8e75821c5066b4b8250e9c14d34d0cca70a38c6cab";
+  nixifiedLockHash = "b6aeefc112eb232904b24398f4e5da776c8ee2c13d427a26dbdf1732205d4fc9";
   workspaceSrc = if args.workspaceSrc == null then ./. else args.workspaceSrc;
   currentLockHash = builtins.hashFile "sha256" (workspaceSrc + /Cargo.lock);
   lockHashIgnored = if ignoreLockHash
@@ -1539,7 +1539,6 @@ in
       parse_duration = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".parse_duration."2.1.1" { inherit profileName; }).out;
       ${ if rootFeatures' ? "garage/default" || rootFeatures' ? "garage/metrics" || rootFeatures' ? "garage/prometheus" then "prometheus" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".prometheus."0.13.0" { inherit profileName; }).out;
       rand = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rand."0.8.5" { inherit profileName; }).out;
-      rmp_serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rmp-serde."0.15.5" { inherit profileName; }).out;
       serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.137" { inherit profileName; }).out;
       serde_bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.5" { inherit profileName; }).out;
       structopt = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".structopt."0.3.26" { inherit profileName; }).out;
@@ -1639,7 +1638,6 @@ in
       hex = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".hex."0.4.3" { inherit profileName; }).out;
       opentelemetry = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".opentelemetry."0.17.0" { inherit profileName; }).out;
       rand = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rand."0.8.5" { inherit profileName; }).out;
-      rmp_serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rmp-serde."0.15.5" { inherit profileName; }).out;
       serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.137" { inherit profileName; }).out;
       serde_bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.5" { inherit profileName; }).out;
       tokio = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".tokio."1.17.0" { inherit profileName; }).out;
@@ -1710,7 +1708,6 @@ in
       netapp = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".netapp."0.5.2" { inherit profileName; }).out;
       opentelemetry = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".opentelemetry."0.17.0" { inherit profileName; }).out;
       rand = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rand."0.8.5" { inherit profileName; }).out;
-      rmp_serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rmp-serde."0.15.5" { inherit profileName; }).out;
       serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.137" { inherit profileName; }).out;
       serde_bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.5" { inherit profileName; }).out;
       tokio = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".tokio."1.17.0" { inherit profileName; }).out;
@@ -1752,7 +1749,6 @@ in
       pnet_datalink = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".pnet_datalink."0.28.0" { inherit profileName; }).out;
       rand = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rand."0.8.5" { inherit profileName; }).out;
       ${ if rootFeatures' ? "garage/consul-discovery" || rootFeatures' ? "garage_rpc/consul-discovery" || rootFeatures' ? "garage_rpc/reqwest" then "reqwest" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".reqwest."0.11.12" { inherit profileName; }).out;
-      rmp_serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rmp-serde."0.15.5" { inherit profileName; }).out;
       ${ if rootFeatures' ? "garage/kubernetes-discovery" || rootFeatures' ? "garage_rpc/kubernetes-discovery" || rootFeatures' ? "garage_rpc/schemars" then "schemars" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".schemars."0.8.8" { inherit profileName; }).out;
       serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.137" { inherit profileName; }).out;
       serde_bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.5" { inherit profileName; }).out;
@@ -1781,7 +1777,6 @@ in
       hexdump = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".hexdump."0.1.1" { inherit profileName; }).out;
       opentelemetry = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".opentelemetry."0.17.0" { inherit profileName; }).out;
       rand = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rand."0.8.5" { inherit profileName; }).out;
-      rmp_serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".rmp-serde."0.15.5" { inherit profileName; }).out;
       serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.137" { inherit profileName; }).out;
       serde_bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.5" { inherit profileName; }).out;
       tokio = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".tokio."1.17.0" { inherit profileName; }).out;
diff --git a/src/block/Cargo.toml b/src/block/Cargo.toml
index cbd58d32..1e4eb64e 100644
--- a/src/block/Cargo.toml
+++ b/src/block/Cargo.toml
@@ -31,7 +31,6 @@ rand = "0.8"
 async-compression = { version = "0.3", features = ["tokio", "zstd"] }
 zstd = { version = "0.9", default-features = false }
 
-rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
 serde_bytes = "0.11"
 
diff --git a/src/garage/Cargo.toml b/src/garage/Cargo.toml
index 337699ca..b43b0242 100644
--- a/src/garage/Cargo.toml
+++ b/src/garage/Cargo.toml
@@ -42,7 +42,6 @@ rand = "0.8"
 async-trait = "0.1.7"
 sodiumoxide = { version = "0.2.5-0", package = "kuska-sodiumoxide" }
 
-rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
 serde_bytes = "0.11"
 structopt = { version = "0.3", default-features = false }
diff --git a/src/garage/repair/online.rs b/src/garage/repair/online.rs
index 7120972c..627e3bf3 100644
--- a/src/garage/repair/online.rs
+++ b/src/garage/repair/online.rs
@@ -12,6 +12,7 @@ use garage_model::s3::version_table::*;
 use garage_table::*;
 use garage_util::background::*;
 use garage_util::error::Error;
+use garage_util::migrate::Migrate;
 
 use crate::*;
 
@@ -100,7 +101,7 @@ impl Worker for RepairVersionsWorker {
 			}
 		};
 
-		let version = rmp_serde::decode::from_read_ref::<_, Version>(&item_bytes)?;
+		let version = Version::decode(&item_bytes).ok_or_message("Cannot decode Version")?;
 		if !version.deleted.get() {
 			let object = self
 				.garage
@@ -180,7 +181,7 @@ impl Worker for RepairBlockrefsWorker {
 				}
 			};
 
-		let block_ref = rmp_serde::decode::from_read_ref::<_, BlockRef>(&item_bytes)?;
+		let block_ref = BlockRef::decode(&item_bytes).ok_or_message("Cannot decode BlockRef")?;
 		if !block_ref.deleted.get() {
 			let version = self
 				.garage
diff --git a/src/model/Cargo.toml b/src/model/Cargo.toml
index 3d3fb693..323c2d64 100644
--- a/src/model/Cargo.toml
+++ b/src/model/Cargo.toml
@@ -30,7 +30,6 @@ tracing = "0.1.30"
 rand = "0.8"
 zstd = { version = "0.9", default-features = false }
 
-rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
 serde_bytes = "0.11"
 
diff --git a/src/model/index_counter.rs b/src/model/index_counter.rs
index 3cd3083a..35d6596d 100644
--- a/src/model/index_counter.rs
+++ b/src/model/index_counter.rs
@@ -279,8 +279,8 @@ impl<T: CountedItem> IndexCounter<T> {
 
 			info!("zeroing old counters... ({})", hex::encode(&batch[0].0));
 			for (local_counter_k, local_counter) in batch {
-				let mut local_counter =
-					rmp_serde::decode::from_read_ref::<_, LocalCounterEntry<T>>(&local_counter)?;
+				let mut local_counter = LocalCounterEntry::<T>::decode(&local_counter)
+					.ok_or_message("Cannot decode local counter entry")?;
 
 				for (_, tv) in local_counter.values.iter_mut() {
 					tv.0 = std::cmp::max(tv.0 + 1, now);
@@ -335,9 +335,8 @@ impl<T: CountedItem> IndexCounter<T> {
 				let local_counter_key = self.table.data.tree_key(pk, sk);
 				let mut local_counter = match self.local_counter.get(&local_counter_key)? {
 					Some(old_bytes) => {
-						let ent = rmp_serde::decode::from_read_ref::<_, LocalCounterEntry<T>>(
-							&old_bytes,
-						)?;
+						let ent = LocalCounterEntry::<T>::decode(&old_bytes)
+							.ok_or_message("Cannot decode local counter entry")?;
 						assert!(ent.pk == *pk);
 						assert!(ent.sk == *sk);
 						ent
diff --git a/src/model/migrate.rs b/src/model/migrate.rs
index cd6ad26a..6b4c3eed 100644
--- a/src/model/migrate.rs
+++ b/src/model/migrate.rs
@@ -2,6 +2,7 @@ use std::sync::Arc;
 
 use garage_util::crdt::*;
 use garage_util::data::*;
+use garage_util::encode::nonversioned_decode;
 use garage_util::error::Error as GarageError;
 use garage_util::time::*;
 
@@ -28,8 +29,8 @@ impl Migrate {
 		let mut old_buckets = vec![];
 		for res in tree.iter().map_err(GarageError::from)? {
 			let (_k, v) = res.map_err(GarageError::from)?;
-			let bucket = rmp_serde::decode::from_read_ref::<_, old_bucket::Bucket>(&v[..])
-				.map_err(GarageError::from)?;
+			let bucket =
+				nonversioned_decode::<old_bucket::Bucket>(&v[..]).map_err(GarageError::from)?;
 			old_buckets.push(bucket);
 		}
 
diff --git a/src/rpc/Cargo.toml b/src/rpc/Cargo.toml
index b87374ad..e9a0929a 100644
--- a/src/rpc/Cargo.toml
+++ b/src/rpc/Cargo.toml
@@ -25,7 +25,6 @@ rand = "0.8"
 sodiumoxide = { version = "0.2.5-0", package = "kuska-sodiumoxide" }
 
 async-trait = "0.1.7"
-rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
 serde_bytes = "0.11"
 serde_json = "1.0"
diff --git a/src/rpc/layout.rs b/src/rpc/layout.rs
index de4117a6..1030e3a6 100644
--- a/src/rpc/layout.rs
+++ b/src/rpc/layout.rs
@@ -5,6 +5,7 @@ use serde::{Deserialize, Serialize};
 
 use garage_util::crdt::{AutoCrdt, Crdt, LwwMap};
 use garage_util::data::*;
+use garage_util::encode::nonversioned_encode;
 use garage_util::error::*;
 
 use crate::ring::*;
@@ -70,7 +71,7 @@ impl NodeRole {
 impl ClusterLayout {
 	pub fn new(replication_factor: usize) -> Self {
 		let empty_lwwmap = LwwMap::new();
-		let empty_lwwmap_hash = blake2sum(&rmp_to_vec_all_named(&empty_lwwmap).unwrap()[..]);
+		let empty_lwwmap_hash = blake2sum(&nonversioned_encode(&empty_lwwmap).unwrap()[..]);
 
 		ClusterLayout {
 			version: 0,
@@ -92,7 +93,7 @@ impl ClusterLayout {
 			Ordering::Equal => {
 				self.staging.merge(&other.staging);
 
-				let new_staging_hash = blake2sum(&rmp_to_vec_all_named(&self.staging).unwrap()[..]);
+				let new_staging_hash = blake2sum(&nonversioned_encode(&self.staging).unwrap()[..]);
 				let changed = new_staging_hash != self.staging_hash;
 
 				self.staging_hash = new_staging_hash;
@@ -127,7 +128,7 @@ To know the correct value of the new layout version, invoke `garage layout show`
 		}
 
 		self.staging.clear();
-		self.staging_hash = blake2sum(&rmp_to_vec_all_named(&self.staging).unwrap()[..]);
+		self.staging_hash = blake2sum(&nonversioned_encode(&self.staging).unwrap()[..]);
 
 		self.version += 1;
 
@@ -151,7 +152,7 @@ To know the correct value of the new layout version, invoke `garage layout show`
 		}
 
 		self.staging.clear();
-		self.staging_hash = blake2sum(&rmp_to_vec_all_named(&self.staging).unwrap()[..]);
+		self.staging_hash = blake2sum(&nonversioned_encode(&self.staging).unwrap()[..]);
 
 		self.version += 1;
 
@@ -180,7 +181,7 @@ To know the correct value of the new layout version, invoke `garage layout show`
 	/// returns true if consistent, false if error
 	pub fn check(&self) -> bool {
 		// Check that the hash of the staging data is correct
-		let staging_hash = blake2sum(&rmp_to_vec_all_named(&self.staging).unwrap()[..]);
+		let staging_hash = blake2sum(&nonversioned_encode(&self.staging).unwrap()[..]);
 		if staging_hash != self.staging_hash {
 			return false;
 		}
diff --git a/src/table/Cargo.toml b/src/table/Cargo.toml
index e1a74553..3911c945 100644
--- a/src/table/Cargo.toml
+++ b/src/table/Cargo.toml
@@ -28,7 +28,6 @@ hexdump = "0.1"
 tracing = "0.1.30"
 rand = "0.8"
 
-rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
 serde_bytes = "0.11"
 
diff --git a/src/table/merkle.rs b/src/table/merkle.rs
index 2d593e6d..e86d0251 100644
--- a/src/table/merkle.rs
+++ b/src/table/merkle.rs
@@ -10,6 +10,7 @@ use garage_db as db;
 
 use garage_util::background::*;
 use garage_util::data::*;
+use garage_util::encode::{nonversioned_decode, nonversioned_encode};
 use garage_util::error::Error;
 
 use garage_rpc::ring::*;
@@ -67,7 +68,7 @@ pub enum MerkleNode {
 
 impl<F: TableSchema, R: TableReplication> MerkleUpdater<F, R> {
 	pub(crate) fn new(data: Arc<TableData<F, R>>) -> Arc<Self> {
-		let empty_node_hash = blake2sum(&rmp_to_vec_all_named(&MerkleNode::Empty).unwrap()[..]);
+		let empty_node_hash = blake2sum(&nonversioned_encode(&MerkleNode::Empty).unwrap()[..]);
 
 		Arc::new(Self {
 			data,
@@ -273,7 +274,7 @@ impl<F: TableSchema, R: TableReplication> MerkleUpdater<F, R> {
 			tx.remove(&self.data.merkle_tree, k.encode())?;
 			Ok(self.empty_node_hash)
 		} else {
-			let vby = rmp_to_vec_all_named(v).map_err(|e| db::TxError::Abort(e.into()))?;
+			let vby = nonversioned_encode(v).map_err(|e| db::TxError::Abort(e.into()))?;
 			let rethash = blake2sum(&vby[..]);
 			tx.insert(&self.data.merkle_tree, k.encode(), vby)?;
 			Ok(rethash)
@@ -364,7 +365,7 @@ impl MerkleNode {
 	fn decode_opt(ent: &Option<db::Value>) -> Result<Self, Error> {
 		match ent {
 			None => Ok(MerkleNode::Empty),
-			Some(v) => Ok(rmp_serde::decode::from_read_ref::<_, MerkleNode>(&v[..])?),
+			Some(v) => Ok(nonversioned_decode::<MerkleNode>(&v[..])?),
 		}
 	}
 
diff --git a/src/table/sync.rs b/src/table/sync.rs
index 29e7aa89..c66c863f 100644
--- a/src/table/sync.rs
+++ b/src/table/sync.rs
@@ -14,6 +14,7 @@ use tokio::sync::{mpsc, watch};
 
 use garage_util::background::*;
 use garage_util::data::*;
+use garage_util::encode::nonversioned_encode;
 use garage_util::error::{Error, OkOrMessage};
 
 use garage_rpc::ring::*;
@@ -615,7 +616,7 @@ impl<F: TableSchema, R: TableReplication> Worker for SyncWorker<F, R> {
 // ---- UTIL ----
 
 fn hash_of_merkle_node(x: &MerkleNode) -> Result<Hash, Error> {
-	Ok(blake2sum(&rmp_to_vec_all_named(x)?[..]))
+	Ok(blake2sum(&nonversioned_encode(x)?[..]))
 }
 
 fn join_ordered<'a, K: Ord + Eq, V1, V2>(
diff --git a/src/util/data.rs b/src/util/data.rs
index 7715c2cc..b2a52e25 100644
--- a/src/util/data.rs
+++ b/src/util/data.rs
@@ -141,21 +141,6 @@ pub fn gen_uuid() -> Uuid {
 	rand::thread_rng().gen::<[u8; 32]>().into()
 }
 
-// RMP serialization with names of fields and variants
-
-/// Serialize to MessagePack
-pub fn rmp_to_vec_all_named<T>(val: &T) -> Result<Vec<u8>, rmp_serde::encode::Error>
-where
-	T: Serialize + ?Sized,
-{
-	let mut wr = Vec::with_capacity(128);
-	let mut se = rmp_serde::Serializer::new(&mut wr)
-		.with_struct_map()
-		.with_string_variants();
-	val.serialize(&mut se)?;
-	Ok(wr)
-}
-
 /// Serialize to JSON, truncating long result
 pub fn debug_serialize<T: Serialize>(x: T) -> String {
 	match serde_json::to_string(&x) {
diff --git a/src/util/encode.rs b/src/util/encode.rs
new file mode 100644
index 00000000..724e482a
--- /dev/null
+++ b/src/util/encode.rs
@@ -0,0 +1,26 @@
+use serde::{Deserialize, Serialize};
+
+/// Serialize to MessagePacki, without versionning
+/// (see garage_util::migrate for functions that manage versionned
+/// data formats)
+pub fn nonversioned_encode<T>(val: &T) -> Result<Vec<u8>, rmp_serde::encode::Error>
+where
+	T: Serialize + ?Sized,
+{
+	let mut wr = Vec::with_capacity(128);
+	let mut se = rmp_serde::Serializer::new(&mut wr)
+		.with_struct_map()
+		.with_string_variants();
+	val.serialize(&mut se)?;
+	Ok(wr)
+}
+
+/// Deserialize from MessagePacki, without versionning
+/// (see garage_util::migrate for functions that manage versionned
+/// data formats)
+pub fn nonversioned_decode<T>(bytes: &[u8]) -> Result<T, rmp_serde::decode::Error>
+where
+	T: for<'de> Deserialize<'de> + ?Sized,
+{
+	rmp_serde::decode::from_read_ref::<_, T>(bytes)
+}
diff --git a/src/util/lib.rs b/src/util/lib.rs
index fd3d5c7b..be82061f 100644
--- a/src/util/lib.rs
+++ b/src/util/lib.rs
@@ -8,6 +8,7 @@ pub mod background;
 pub mod config;
 pub mod crdt;
 pub mod data;
+pub mod encode;
 pub mod error;
 pub mod formater;
 pub mod metrics;
diff --git a/src/util/migrate.rs b/src/util/migrate.rs
index 199c68f6..f6028bf4 100644
--- a/src/util/migrate.rs
+++ b/src/util/migrate.rs
@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 pub trait Migrate: Serialize + for<'de> Deserialize<'de> + 'static {
 	/// A sequence of bytes to add at the beginning of the serialized
 	/// string, to identify that the data is of this version.
-	const MARKER: &'static [u8] = b"";
+	const VERSION_MARKER: &'static [u8] = b"";
 
 	/// The previous version of this data type, from which items of this version
 	/// can be migrated. Set `type Previous = NoPrevious` to indicate that this datatype
@@ -15,10 +15,9 @@ pub trait Migrate: Serialize + for<'de> Deserialize<'de> + 'static {
 	fn migrate(previous: Self::Previous) -> Self;
 
 	fn decode(bytes: &[u8]) -> Option<Self> {
-		if bytes.len() >= Self::MARKER.len() && &bytes[..Self::MARKER.len()] == Self::MARKER {
-			if let Ok(value) =
-				rmp_serde::decode::from_read_ref::<_, Self>(&bytes[Self::MARKER.len()..])
-			{
+		let marker_len = Self::VERSION_MARKER.len();
+		if bytes.len() >= marker_len && &bytes[..marker_len] == Self::VERSION_MARKER {
+			if let Ok(value) = rmp_serde::decode::from_read_ref::<_, Self>(&bytes[marker_len..]) {
 				return Some(value);
 			}
 		}
@@ -28,7 +27,7 @@ pub trait Migrate: Serialize + for<'de> Deserialize<'de> + 'static {
 
 	fn encode(&self) -> Result<Vec<u8>, rmp_serde::encode::Error> {
 		let mut wr = Vec::with_capacity(128);
-		wr.extend_from_slice(Self::MARKER);
+		wr.extend_from_slice(Self::VERSION_MARKER);
 		let mut se = rmp_serde::Serializer::new(&mut wr)
 			.with_struct_map()
 			.with_string_variants();
@@ -40,13 +39,13 @@ pub trait Migrate: Serialize + for<'de> Deserialize<'de> + 'static {
 pub trait InitialFormat: Serialize + for<'de> Deserialize<'de> + 'static {
 	/// A sequence of bytes to add at the beginning of the serialized
 	/// string, to identify that the data is of this version.
-	const MARKER: &'static [u8] = b"";
+	const VERSION_MARKER: &'static [u8] = b"";
 }
 
 // ----
 
 impl<T: InitialFormat> Migrate for T {
-	const MARKER: &'static [u8] = <T as InitialFormat>::MARKER;
+	const VERSION_MARKER: &'static [u8] = <T as InitialFormat>::VERSION_MARKER;
 
 	type Previous = NoPrevious;