readyset-data: Reduce logging of unknown collations to once per process

The author didn't expect that this error would fire once per row during
snapshotting.

Change-Id: If85cf7a6e72567d6994911889f1751b2f74e0834
Reviewed-on: https://gerrit.readyset.name/c/readyset/+/9716
Tested-by: Buildkite CI
Reviewed-by: Michael Zink <[email protected]>

Author: rs-sac

Cargo.lock

@@ -159,6 +159,7 @@ itoa = "1.0"
 lazy_static = "1.4.0"
 left-right = "0.11"
 libc = "0.2"
+log-once = "0.4.1"
 lru = "0.14.0"
 machine-uid = "0.5"
 md5 = "0.7.0"

Cargo.toml

@@ -45,6 +45,7 @@ cidr = { workspace = true }
 postgres-types = { workspace = true, features = ["with-cidr-0_2"] }
 vec1 = { workspace = true }
 yore = { workspace = true }
+log-once = { workspace = true }
 
 # Local dependencies
 nom-sql = { path = "../nom-sql" }

readyset-data/Cargo.toml

@@ -4,10 +4,10 @@ use std::hash::Hash;
 
 use icu::collator::options::{CollatorOptions, Strength};
 use icu::collator::{Collator, CollatorBorrowed};
+use log_once::error_once;
 use serde::{Deserialize, Serialize};
 use strum::{EnumCount, FromRepr};
 use test_strategy::Arbitrary;
-use tracing::error;
 
 use crate::{Dialect, SqlEngine};
 
@@ -148,7 +148,7 @@ impl Collation {
     /// return a reasonable default for the dialect.
     pub fn get_or_default(dialect: Dialect, collation: &str) -> Self {
         Self::try_get(dialect, collation).unwrap_or_else(|| {
-            error!("Unknown {} collation {}", dialect.engine(), collation);
+            error_once!("Unknown {} collation {}", dialect.engine(), collation);
             Self::default_for(dialect)
         })
     }