Fix storing bug

This bug would sometimes appear in the revaultd functional tests.
The problem was that we would check if the signature was in the db,
then if it wasn't there, try to insert it. The problem with this is
that between the check and the insertion someone else might have
inserted the signature.
Here we remove the second check altoghether, and recognize if there
were any duplicates from the eventual error at insertion.

src/db/mod.rs

@@ -11,7 +11,7 @@ use schema::SCHEMA;
 
 use std::{collections::BTreeMap, fmt};
 
-use tokio_postgres::{types::Type, Client, NoTls};
+use tokio_postgres::{error::SqlState, types::Type, Client, NoTls};
 
 pub const DB_VERSION: i32 = 0;
 
@@ -90,30 +90,36 @@ pub async fn store_sig(
  let client = establish_connection(config).await?;
  let sig = signature.serialize_der();
 
- // Make sure it's not here already
- let statement = client
- .prepare_typed(
- "SELECT signature FROM signatures WHERE signature = $1",
- &[Type::BYTEA],
- )
- .await?;
- if !client.query(&statement, &[&sig.as_ref()]).await?.is_empty() {
- return Err(DbError::Duplicate);
- }
-
  let statement = client
  .prepare_typed(
  "INSERT INTO signatures (txid, pubkey, signature) VALUES ($1, $2, $3) \
  ON CONFLICT(txid, pubkey) DO UPDATE SET signature=$3",
  &[Type::BYTEA, Type::BYTEA, Type::BYTEA],
  )
  .await?;
- client
+
+ if let Err(e) = client
  .execute(
  &statement,
  &[&txid.as_ref(), &pubkey.serialize().as_ref(), &sig.as_ref()],
  )
- .await?;
+ .await
+ {
+ log::debug!("We have a statement error in store_sig: {:?}", e);
+ if let Some(e) = e.as_db_error() {
+ log::debug!(
+ "We have a db error {:?} with code {:?}",
+ e.clone(),
+ e.clone().code()
+ );
+ if *e.code() == SqlState::UNIQUE_VIOLATION {
+ // Ah, it was trying to insert a signature that was there already.
+ // Alright.
+ return Err(DbError::Duplicate);
+ }
+ }
+ return Err(e.into());
+ }
 
  Ok(())
 }