From bfe30a972359bbcf253f46e9486e304188df7a18 Mon Sep 17 00:00:00 2001
From: Artem Zuikov <chertus@gmail.com>
Date: Thu, 25 Jun 2020 22:26:03 +0300
Subject: [PATCH] remove a trick with expression continuation

---
 .../ExpressionBlockInputStream.cpp            | 29 -------------------
 src/Interpreters/ExpressionActions.cpp        | 16 ++++------
 src/Interpreters/ExpressionActions.h          |  2 +-
 .../InflatingExpressionTransform.cpp          |  6 ++--
 .../Transforms/InflatingExpressionTransform.h |  1 -
 5 files changed, 9 insertions(+), 45 deletions(-)

diff --git a/src/DataStreams/ExpressionBlockInputStream.cpp b/src/DataStreams/ExpressionBlockInputStream.cpp
index cce02af8262..9673395a21a 100644
--- a/src/DataStreams/ExpressionBlockInputStream.cpp
+++ b/src/DataStreams/ExpressionBlockInputStream.cpp
@@ -44,33 +44,4 @@ Block ExpressionBlockInputStream::readImpl()
     return res;
 }
 
-Block InflatingExpressionBlockInputStream::readImpl()
-{
-    if (!initialized)
-    {
-        if (expression->resultIsAlwaysEmpty())
-            return {};
-
-        initialized = true;
-    }
-
-    Block res;
-    bool keep_going = not_processed && not_processed->empty(); /// There's data inside expression.
-
-    if (!not_processed || keep_going)
-    {
-        not_processed.reset();
-
-        res = children.back()->read();
-        if (res || keep_going)
-            expression->execute(res, not_processed, action_number);
-    }
-    else
-    {
-        res = std::move(not_processed->block);
-        expression->execute(res, not_processed, action_number);
-    }
-    return res;
-}
-
 }
diff --git a/src/Interpreters/ExpressionActions.cpp b/src/Interpreters/ExpressionActions.cpp
index 0a99fcd6f21..845c1c789f7 100644
--- a/src/Interpreters/ExpressionActions.cpp
+++ b/src/Interpreters/ExpressionActions.cpp
@@ -676,19 +676,13 @@ void ExpressionActions::execute(Block & block, bool dry_run) const
     }
 }
 
-/// @warning It's a tricky method that allows to continue ONLY ONE action in reason of one-to-many ALL JOIN logic.
-void ExpressionActions::execute(Block & block, ExtraBlockPtr & not_processed, size_t & start_action) const
+void ExpressionActions::execute(Block & block, ExtraBlockPtr & not_processed) const
 {
-    size_t i = start_action;
-    start_action = 0;
-    for (; i < actions.size(); ++i)
-    {
-        actions[i].execute(block, false, not_processed);
-        checkLimits(block);
+    if (actions.size() != 1)
+        throw Exception("Continuation over multiple expressions is not supported", ErrorCodes::LOGICAL_ERROR);
 
-        if (not_processed)
-            start_action = i;
-    }
+    actions[0].execute(block, false, not_processed);
+    checkLimits(block);
 }
 
 bool ExpressionActions::hasJoinOrArrayJoin() const
diff --git a/src/Interpreters/ExpressionActions.h b/src/Interpreters/ExpressionActions.h
index 8f66e6c5c3a..89f10184bd8 100644
--- a/src/Interpreters/ExpressionActions.h
+++ b/src/Interpreters/ExpressionActions.h
@@ -212,7 +212,7 @@ public:
     void execute(Block & block, bool dry_run = false) const;
 
     /// Execute the expression on the block with continuation.
-    void execute(Block & block, ExtraBlockPtr & not_processed, size_t & start_action) const;
+    void execute(Block & block, ExtraBlockPtr & not_processed) const;
 
     bool hasJoinOrArrayJoin() const;
 
diff --git a/src/Processors/Transforms/InflatingExpressionTransform.cpp b/src/Processors/Transforms/InflatingExpressionTransform.cpp
index de4e93ef8d2..5fc5bdc2304 100644
--- a/src/Processors/Transforms/InflatingExpressionTransform.cpp
+++ b/src/Processors/Transforms/InflatingExpressionTransform.cpp
@@ -59,7 +59,7 @@ Block InflatingExpressionTransform::readExecute(Chunk & chunk)
             res = getInputPort().getHeader().cloneWithColumns(chunk.detachColumns());
 
         if (res)
-            expression->execute(res, not_processed, action_number);
+            expression->execute(res, not_processed);
     }
     else if (not_processed->empty()) /// There's not processed data inside expression.
     {
@@ -67,12 +67,12 @@ Block InflatingExpressionTransform::readExecute(Chunk & chunk)
             res = getInputPort().getHeader().cloneWithColumns(chunk.detachColumns());
 
         not_processed.reset();
-        expression->execute(res, not_processed, action_number);
+        expression->execute(res, not_processed);
     }
     else
     {
         res = std::move(not_processed->block);
-        expression->execute(res, not_processed, action_number);
+        expression->execute(res, not_processed);
     }
     return res;
 }
diff --git a/src/Processors/Transforms/InflatingExpressionTransform.h b/src/Processors/Transforms/InflatingExpressionTransform.h
index b490d0699ad..ee77eaee19c 100644
--- a/src/Processors/Transforms/InflatingExpressionTransform.h
+++ b/src/Processors/Transforms/InflatingExpressionTransform.h
@@ -27,7 +27,6 @@ private:
     bool initialized = false;
 
     ExtraBlockPtr not_processed;
-    size_t action_number = 0;
 
     Block readExecute(Chunk & chunk);
 };