From 2de6b7537d37dff82afe5563704949e9d4131a52 Mon Sep 17 00:00:00 2001
From: Mattes D <github@xoft.cz>
Date: Sun, 1 Dec 2019 14:41:46 +0100
Subject: BlockTypePalette: Refactored for usage in both directions.

Improves index() lookup speeds and allows BlockTypePalette to be used in place of ProtocolBlockTypePalette.
---
 src/BlockTypePalette.cpp | 75 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 55 insertions(+), 20 deletions(-)

(limited to 'src/BlockTypePalette.cpp')

diff --git a/src/BlockTypePalette.cpp b/src/BlockTypePalette.cpp
index fabf5698e..f0f54b7c1 100644
--- a/src/BlockTypePalette.cpp
+++ b/src/BlockTypePalette.cpp
@@ -4,9 +4,9 @@
 
 
 
-BlockTypePalette::BlockTypePalette()
+BlockTypePalette::BlockTypePalette():
+	mMaxIndex(0)
 {
-	// Nothing needed yet
 }
 
 
@@ -22,8 +22,10 @@ UInt32 BlockTypePalette::index(const AString & aBlockTypeName, const BlockState
 	}
 
 	// Not found, append:
-	mPalette.push_back(std::make_pair(aBlockTypeName, aBlockState));
-	return static_cast<UInt32>(mPalette.size() - 1);
+	auto index = mMaxIndex++;
+	mBlockToNumber[aBlockTypeName][aBlockState] = index;
+	mNumberToBlock[index] = {aBlockTypeName, aBlockState};
+	return index;
 }
 
 
@@ -32,16 +34,17 @@ UInt32 BlockTypePalette::index(const AString & aBlockTypeName, const BlockState
 
 std::pair<UInt32, bool> BlockTypePalette::maybeIndex(const AString & aBlockTypeName, const BlockState & aBlockState) const
 {
-	auto count = mPalette.size();
-	for (size_t idx = 0; idx < count; ++idx)
+	auto itr1 = mBlockToNumber.find(aBlockTypeName);
+	if (itr1 == mBlockToNumber.end())
 	{
-		const auto & entry = mPalette[idx];
-		if ((entry.first == aBlockTypeName) && (entry.second == aBlockState))
-		{
-			return std::make_pair(static_cast<UInt32>(idx), true);
-		}
+		return {0, false};
+	}
+	auto itr2 = itr1->second.find(aBlockState);
+	if (itr2 == itr1->second.end())
+	{
+		return {0, false};
 	}
-	return std::make_pair(0, false);
+	return {itr2->second, true};
 }
 
 
@@ -50,7 +53,7 @@ std::pair<UInt32, bool> BlockTypePalette::maybeIndex(const AString & aBlockTypeN
 
 UInt32 BlockTypePalette::count() const
 {
-	return static_cast<UInt32>(mPalette.size());
+	return static_cast<UInt32>(mNumberToBlock.size());
 }
 
 
@@ -59,22 +62,54 @@ UInt32 BlockTypePalette::count() const
 
 const std::pair<AString, BlockState> & BlockTypePalette::entry(UInt32 aIndex) const
 {
-	ASSERT(aIndex < mPalette.size());
-	return mPalette[aIndex];
+	auto itr = mNumberToBlock.find(aIndex);
+	if (itr == mNumberToBlock.end())
+	{
+		throw NoSuchIndexException(aIndex);
+	}
+	return itr->second;
 }
 
 
 
 
 
-std::map<UInt32, UInt32> BlockTypePalette::createTransformMap(const BlockTypePalette & aOther)
+std::map<UInt32, UInt32> BlockTypePalette::createTransformMapAddMissing(const BlockTypePalette & aFrom)
 {
 	std::map<UInt32, UInt32> res;
-	auto numIndices = aOther.count();
-	for (UInt32 idx = 0; idx < numIndices; ++idx)
+	for (const auto & fromEntry: aFrom.mNumberToBlock)
 	{
-		const auto & e = aOther.mPalette[idx];
-		res[idx] = index(e.first, e.second);
+		auto fromIndex = fromEntry.first;
+		const auto & blockTypeName = fromEntry.second.first;
+		const auto & blockState = fromEntry.second.second;
+		res[fromIndex] = index(blockTypeName, blockState);
+	}
+	return res;
+}
+
+
+
+
+
+std::map<UInt32, UInt32> BlockTypePalette::createTransformMapWithFallback(const BlockTypePalette & aFrom, UInt32 aFallbackIndex) const
+{
+	std::map<UInt32, UInt32> res;
+	for (const auto & fromEntry: aFrom.mNumberToBlock)
+	{
+		auto fromIndex = fromEntry.first;
+		const auto & blockTypeName = fromEntry.second.first;
+		const auto & blockState = fromEntry.second.second;
+		auto thisIndex = maybeIndex(blockTypeName, blockState);
+		if (thisIndex.second)
+		{
+			// The entry was found in this
+			res[fromIndex] = thisIndex.first;
+		}
+		else
+		{
+			// The entry was NOT found in this, replace with fallback:
+			res[fromIndex] = aFallbackIndex;
+		}
 	}
 	return res;
 }
-- 
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