receiving server logs

ClickHouse · Oct 9, 2022 · ed2384c · ed2384c
1 parent 9782b5c
commit ed2384c
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Showing 2 changed files with 35 additions and 0 deletions.
diff --git a/clickhouse/client.cpp b/clickhouse/client.cpp
@@ -430,6 +430,25 @@ bool Client::Impl::ReceivePacket(uint64_t* server_packet) {
         return false;
     }
 
+    case ServerCodes::Log: {
+        // log tag
+        if (!WireFormat::SkipString(*input_)) {
+            return false;
+        }
+        Block block;
+
+        // Use uncompressed stream since log blocks usually contain only one row
+        if (!ReadBlock(*input_, &block)) {
+            return false;
+        }
+
+        if (events_) {
+            events_->OnServerLog(block);
+        }
+
+        return true;
+    }
+
     default:
         throw UnimplementedError("unimplemented " + std::to_string((int)packet_type));
         break;

diff --git a/clickhouse/query.h b/clickhouse/query.h
@@ -66,6 +66,8 @@ class QueryEvents {
 
     virtual void OnProgress(const Progress& progress) = 0;
 
+    virtual void OnServerLog(const Block& block) = 0;
+
     virtual void OnFinish() = 0;
 };
 
@@ -74,6 +76,7 @@ using ExceptionCallback        = std::function<void(const Exception& e)>;
 using ProgressCallback         = std::function<void(const Progress& progress)>;
 using SelectCallback           = std::function<void(const Block& block)>;
 using SelectCancelableCallback = std::function<bool(const Block& block)>;
+using SelectServerLogCallback  = std::function<bool(const Block& block)>;
 
 
 class Query : public QueryEvents {
@@ -116,6 +119,12 @@ class Query : public QueryEvents {
         return *this;
     }
 
+    /// Set handler for receiving a server log of query exceution.
+    inline Query& OnServerLog(SelectServerLogCallback cb) {
+        select_server_log_cb_ = std::move(cb);
+        return *this;
+    }
+
     static const std::string default_query_id;
 
 private:
@@ -149,6 +158,12 @@ class Query : public QueryEvents {
         }
     }
 
+    void OnServerLog(const Block& block) override {
+        if (select_server_log_cb_) {
+            select_server_log_cb_(block);
+        }
+    }
+
     void OnFinish() override {
     }
 
@@ -159,6 +174,7 @@ class Query : public QueryEvents {
     ProgressCallback progress_cb_;
     SelectCallback select_cb_;
     SelectCancelableCallback select_cancelable_cb_;
+    SelectServerLogCallback select_server_log_cb_;
 };
 
 }