From bbae6d83c6d7ea25f17965fd68062f0cab3da5e4 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Wed, 23 Aug 2023 00:26:20 +0100
Subject: Cache the Hook name/column relation for non-subclass multi-row
 selects

---
 slicer/db/sqlSelectDeserializer.cpp | 78 ++++++++++++++++++++++++++++++-------
 slicer/db/sqlSelectDeserializer.h   | 13 +++++--
 2 files changed, 72 insertions(+), 19 deletions(-)

diff --git a/slicer/db/sqlSelectDeserializer.cpp b/slicer/db/sqlSelectDeserializer.cpp
index e11493e..8081d76 100644
--- a/slicer/db/sqlSelectDeserializer.cpp
+++ b/slicer/db/sqlSelectDeserializer.cpp
@@ -5,6 +5,7 @@
 #include <memory>
 #include <selectcommand.h>
 #include <slicer/common.h>
+#include <slicer/hookMap.h>
 #include <slicer/modelParts.h>
 #include <utility>
 
@@ -58,10 +59,53 @@ namespace Slicer {
 		}
 	}
 
+	void
+	SqlSelectDeserializer::fillLowerColumnNameCache()
+	{
+		BOOST_ASSERT(lowerColumnNames.empty());
+		lowerColumnNames.reserve(columnCount);
+		orderedColumns.reserve(columnCount);
+		for (auto col = 0U; col < columnCount; col += 1) {
+			const DB::Column & c = (*cmd)[col];
+			lowerColumnNames.emplace_back(to_lower_copy(c.name));
+		}
+	}
+
+	const DB::Column *
+	SqlSelectDeserializer::searchOrFilleColumnCache(size_t idx, const HookCommon * hook)
+	{
+		if (idx < orderedColumns.size()) {
+			return orderedColumns[idx];
+		}
+		BOOST_ASSERT(idx == orderedColumns.size());
+		if (const auto itr = std::find(lowerColumnNames.begin(), lowerColumnNames.end(), hook->nameLower);
+				itr != lowerColumnNames.end()) {
+			return orderedColumns.emplace_back(&(*cmd)[static_cast<unsigned int>(itr - lowerColumnNames.begin())]);
+		}
+		else {
+			return orderedColumns.emplace_back(nullptr);
+		}
+	}
+
+	namespace {
+		void
+		assignFromColumn(ModelPartParam fmp, const DB::Column & c)
+		{
+			BOOST_ASSERT(fmp);
+			BOOST_ASSERT(!c.isNull());
+			fmp->Create();
+			fmp->SetValue(SqlSource(c));
+			fmp->Complete();
+		}
+	}
+
 	void
 	SqlSelectDeserializer::DeserializeSequence(ModelPartParam omp)
 	{
 		omp->OnAnonChild([this](auto && mp, auto &&) {
+			if (!typeIdColIdx && lowerColumnNames.empty()) {
+				fillLowerColumnNameCache();
+			}
 			while (cmd->fetch()) {
 				DeserializeRow(mp);
 			}
@@ -92,20 +136,26 @@ namespace Slicer {
 				case Slicer::ModelPartType::Complex: {
 					auto apply = [this](auto && rcmp) {
 						rcmp->Create();
-						for (auto col = 0U; col < columnCount; col += 1) {
-							const DB::Column & c = (*cmd)[col];
-							if (!c.isNull()) {
-								rcmp->OnChild(
-										[&c](auto && fmp, auto &&) {
-											if (fmp) {
-												fmp->Create();
-												fmp->SetValue(SqlSource(c));
-												fmp->Complete();
-											}
-										},
-										c.name, nullptr, false);
+						if (typeIdColIdx || lowerColumnNames.empty()) {
+							for (auto col = 0U; col < columnCount; col += 1) {
+								const DB::Column & c = (*cmd)[col];
+								if (!c.isNull()) {
+									rcmp->OnChild(
+											[&c](auto && fmp, auto &&) {
+												assignFromColumn(fmp, c);
+											},
+											c.name, nullptr, false);
+								}
 							}
 						}
+						else {
+							rcmp->OnEachChild([idx = 0U, this](auto &&, auto && fmp, auto && hook) mutable {
+								if (auto c = searchOrFilleColumnCache(idx, hook); c && !c->isNull()) {
+									assignFromColumn(fmp, *c);
+								}
+								++idx;
+							});
+						}
 						rcmp->Complete();
 					};
 					if (typeIdColIdx) {
@@ -116,12 +166,10 @@ namespace Slicer {
 					apply(rmp);
 				} break;
 				case Slicer::ModelPartType::Simple: {
-					rmp->Create();
 					const DB::Column & c = (*cmd)[0];
 					if (!c.isNull()) {
-						rmp->SetValue(SqlSource(c));
+						assignFromColumn(rmp, c);
 					}
-					rmp->Complete();
 				} break;
 				default:
 					throw UnsupportedModelType();
diff --git a/slicer/db/sqlSelectDeserializer.h b/slicer/db/sqlSelectDeserializer.h
index f8fce08..b911fb1 100644
--- a/slicer/db/sqlSelectDeserializer.h
+++ b/slicer/db/sqlSelectDeserializer.h
@@ -9,6 +9,7 @@
 
 namespace DB {
 	class SelectCommand;
+	class Column;
 }
 
 namespace Slicer {
@@ -20,15 +21,19 @@ namespace Slicer {
 		void Deserialize(ModelPartForRootParam) override;
 
 	protected:
-		void DLL_PRIVATE DeserializeSimple(ModelPartParam);
-		void DLL_PRIVATE DeserializeObject(ModelPartParam);
-		void DLL_PRIVATE DeserializeSequence(ModelPartParam);
-		void DLL_PRIVATE DeserializeRow(ModelPartParam);
+		DLL_PRIVATE void DeserializeSimple(ModelPartParam);
+		DLL_PRIVATE void DeserializeObject(ModelPartParam);
+		DLL_PRIVATE void DeserializeSequence(ModelPartParam);
+		DLL_PRIVATE void DeserializeRow(ModelPartParam);
+		DLL_PRIVATE void fillLowerColumnNameCache();
+		DLL_PRIVATE inline const DB::Column * searchOrFilleColumnCache(size_t idx, const HookCommon * hook);
 
 		DB::SelectCommand * cmd;
 		unsigned int columnCount;
 		std::optional<std::string> typeIdColName;
 		std::optional<unsigned int> typeIdColIdx;
+		std::vector<std::string> lowerColumnNames;
+		std::vector<const DB::Column *> orderedColumns;
 	};
 }
 
-- 
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