Merge pull request #545 from radixdlt/ledger-lookup-epoch-perf

Optimized epoch and epoch + round based ledger state lookups
radixdlt · Oct 20, 2023 · 6c8c9a6 · 6c8c9a6
2 parents ab1ab54 + c16647d
commit 6c8c9a6
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,7 +1,7 @@
 ## 1.1.1 - Babylon
 Release Date: _unreleased_
 
-TBA
+- Fixed `epoch [+ round]` based ledger state lookups.
 
 ## 1.1.0 - Babylon
 Release Date: _unreleased_

diff --git a/src/RadixDlt.NetworkGateway.PostgresIntegration/DbQueryExtensions.cs b/src/RadixDlt.NetworkGateway.PostgresIntegration/DbQueryExtensions.cs
@@ -162,37 +162,18 @@ public static IQueryable<LedgerTransaction> GetFirstLedgerTransactionAfterTimest
     }
 
     /// <summary>
-    /// Returns most recently committed ledger transaction at or before given epoch and round.
+    /// Returns ledger transaction committed at given epoch and round.
     /// </summary>
     /// <remarks>
     /// A LedgerTransaction row contains large blobs, so you must SELECT the fields you need after using this, and not pull down the whole
     /// ledger transaction row, to avoid possible performance issues.
     /// </remarks>
-    public static IQueryable<LedgerTransaction> GetLatestLedgerTransactionAtEpochRound<TDbContext>(this TDbContext dbContext, long epoch, long round)
+    public static IQueryable<LedgerTransaction> GetLedgerTransactionAtEpochAndRound<TDbContext>(this TDbContext dbContext, long epoch, long round)
         where TDbContext : CommonDbContext
     {
         return dbContext
             .LedgerTransactions
-            .Where(lt => lt.Epoch == epoch && lt.RoundInEpoch >= round && lt.IndexInRound == 0)
-            .OrderByDescending(lt => lt.StateVersion)
-            .Take(1)
-            .AnnotateMetricName();
-    }
-
-    /// <summary>
-    /// Returns the first committed ledger transaction at or after given epoch and round.
-    /// </summary>
-    /// <remarks>
-    /// A LedgerTransaction row contains large blobs, so you must SELECT the fields you need after using this, and not pull down the whole
-    /// ledger transaction row, to avoid possible performance issues.
-    /// </remarks>
-    public static IQueryable<LedgerTransaction> GetFirstLedgerTransactionAtEpochRound<TDbContext>(this TDbContext dbContext, long epoch, long round)
-        where TDbContext : CommonDbContext
-    {
-        return dbContext
-            .LedgerTransactions
-            .Where(lt => lt.Epoch >= epoch && lt.RoundInEpoch >= round && lt.IndexInRound == 0)
-            .OrderBy(lt => lt.StateVersion)
+            .Where(lt => lt.Epoch == epoch && lt.RoundInEpoch == round && lt.IndexInRound == 0)
             .Take(1)
             .AnnotateMetricName();
     }

diff --git a/src/RadixDlt.NetworkGateway.PostgresIntegration/Services/LedgerStateQuerier.cs b/src/RadixDlt.NetworkGateway.PostgresIntegration/Services/LedgerStateQuerier.cs
@@ -188,7 +188,7 @@ public LedgerStateQuerier(
         }
         else if (fromLedgerStateIdentifier?.HasEpoch() == true)
         {
-            ledgerStateReport = await GetLedgerStateAfterEpochAndRound(fromLedgerStateIdentifier.Epoch.Value, fromLedgerStateIdentifier.Round ?? 0, token);
+            ledgerStateReport = await GetLedgerStateAtEpochAndRound(fromLedgerStateIdentifier.Epoch.Value, fromLedgerStateIdentifier.Round ?? 1, token);
         }
 
         return ledgerStateReport?.LedgerState;
@@ -300,7 +300,7 @@ private async Task<LedgerStateReport> GetLedgerState(GatewayModel.LedgerStateSel
         }
         else if (at?.HasEpoch() == true)
         {
-            result = await GetLedgerStateAtEpochAndRound(at.Epoch.Value, at.Round ?? 0, token);
+            result = await GetLedgerStateAtEpochAndRound(at.Epoch.Value, at.Round ?? 1, token);
         }
         else
         {
@@ -372,23 +372,11 @@ private async Task<LedgerStateReport> GetLedgerStateAfterTimestamp(DateTime time
 
     private async Task<LedgerStateReport> GetLedgerStateAtEpochAndRound(long epoch, long round, CancellationToken token)
     {
-        var ledgerState = await SelectLedgerStateFromQuery(_dbContext.GetLatestLedgerTransactionAtEpochRound(epoch, round), false, token);
+        var ledgerState = await SelectLedgerStateFromQuery(_dbContext.GetLedgerTransactionAtEpochAndRound(epoch, round), false, token);
 
         if (ledgerState == null)
         {
-            throw InvalidRequestException.FromOtherError($"Epoch {epoch} is beyond the end of the known ledger");
-        }
-
-        return ledgerState;
-    }
-
-    private async Task<LedgerStateReport> GetLedgerStateAfterEpochAndRound(long epoch, long round, CancellationToken token)
-    {
-        var ledgerState = await SelectLedgerStateFromQuery(_dbContext.GetFirstLedgerTransactionAtEpochRound(epoch, round), false, token);
-
-        if (ledgerState == null)
-        {
-            throw InvalidRequestException.FromOtherError($"Epoch {epoch} round {round} is beyond the end of the known ledger");
+            throw InvalidRequestException.FromOtherError($"Epoch {epoch} round {round} is beyond the end of the known ledger or invalid");
         }
 
         return ledgerState;