YT-21942: Fix some bugs in adaptive row count mechanics

k-pogorelov · k-pogorelov · commit faff5fbac2a6 · 2025-06-23T22:42:43.000+03:00
commit_hash:e4863185d0a54cb33733e0741baf20b7aa2cd612
diff --git a/yt/yt/client/table_client/adapters.cpp b/yt/yt/client/table_client/adapters.cpp
@@ -225,7 +225,7 @@ void PipeReaderToWriterByBatches(
     try {
         TPeriodicYielder yielder(TDuration::Seconds(1));
 
-        while (auto batch = reader->Read(options)) {
+        for (bool isFirstBatch = true; auto batch = reader->Read(options); isFirstBatch = false) {
             yielder.TryYield();
 
             if (batch->IsEmpty()) {
@@ -251,7 +251,7 @@ void PipeReaderToWriterByBatches(
                     .ThrowOnError();
             }
 
-            if (optionsUpdater) {
+            if (optionsUpdater && !isFirstBatch) {
                 options.MaxRowsPerRead = rowsRead;
                 optionsUpdater(&options, timer.GetElapsedTime());
             }

Original file line number	Diff line number	Diff line change
`@@ -225,7 +225,7 @@ void PipeReaderToWriterByBatches(`
`225`	`225`	`try {`
`226`	`226`	`TPeriodicYielder yielder(TDuration::Seconds(1));`
`227`	`227`
`228`		`- while (auto batch = reader->Read(options)) {`
	`228`	`+ for (bool isFirstBatch = true; auto batch = reader->Read(options); isFirstBatch = false) {`
`229`	`229`	`yielder.TryYield();`
`230`	`230`
`231`	`231`	`if (batch->IsEmpty()) {`
`@@ -251,7 +251,7 @@ void PipeReaderToWriterByBatches(`
`251`	`251`	`.ThrowOnError();`
`252`	`252`	`}`
`253`	`253`
`254`		`- if (optionsUpdater) {`
	`254`	`+ if (optionsUpdater && !isFirstBatch) {`
`255`	`255`	`options.MaxRowsPerRead = rowsRead;`
`256`	`256`	`optionsUpdater(&options, timer.GetElapsedTime());`
`257`	`257`	`}`