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Improve code decreasing tree depth

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This commit is contained in:
Sebastian Messmer 2016-07-15 16:23:00 +02:00
parent b1b90b8c3d
commit 582917c1f5
3 changed files with 23 additions and 6 deletions
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25
src/blobstore/implementations/onblocks/datatreestore/impl/LeafTraverser.cpp
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@ -10,6 +10,7 @@ using std::vector;
using boost::none;
using cpputils::Data;
using cpputils::unique_ref;
using cpputils::dynamic_pointer_move;
using blobstore::onblocks::datanodestore::DataNodeStore;
using blobstore::onblocks::datanodestore::DataNode;
using blobstore::onblocks::datanodestore::DataInnerNode;
@ -196,16 +197,30 @@ namespace blobstore {
unique_ref<DataNode> LeafTraverser::_whileRootHasOnlyOneChildReplaceRootWithItsChild(unique_ref<DataNode> root) {
DataInnerNode *inner = dynamic_cast<DataInnerNode*>(root.get());
if (inner != nullptr && inner->numChildren() == 1) {
auto child = _nodeStore->load(inner->getChild(0)->key());
ASSERT(child != none, "Couldn't load first child of root node");
auto newRoot = _nodeStore->overwriteNodeWith(std::move(root), **child);
_nodeStore->remove(std::move(*child));
return _whileRootHasOnlyOneChildReplaceRootWithItsChild(std::move(newRoot));
auto newRoot = _whileRootHasOnlyOneChildRemoveRootReturnChild(inner->getChild(0)->key());
auto result = _nodeStore->overwriteNodeWith(std::move(root), *newRoot);
_nodeStore->remove(std::move(newRoot));
return result;
} else {
return root;
}
}
unique_ref<DataNode> LeafTraverser::_whileRootHasOnlyOneChildRemoveRootReturnChild(const blockstore::Key &key) {
auto current = _nodeStore->load(key);
ASSERT(current != none, "Node not found");
auto inner = dynamic_pointer_move<DataInnerNode>(*current);
if (inner == none) {
return std::move(*current);
} else if ((*inner)->numChildren() == 1) {
auto result = _whileRootHasOnlyOneChildRemoveRootReturnChild((*inner)->getChild(0)->key());
_nodeStore->remove(std::move(*inner));
return result;
} else {
return std::move(*inner);
}
}
}
}
}

2
src/blobstore/implementations/onblocks/datatreestore/impl/LeafTraverser.h
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@ -5,6 +5,7 @@
#include <cpp-utils/macros.h>
#include <cpp-utils/pointer/unique_ref.h>
#include <cpp-utils/data/Data.h>
#include <blockstore/utils/Key.h>
namespace blobstore {
namespace onblocks {
@ -50,6 +51,7 @@ namespace blobstore {
uint32_t _maxLeavesForTreeDepth(uint8_t depth) const;
std::function<cpputils::Data (uint32_t index)> _createMaxSizeLeaf() const;
cpputils::unique_ref<datanodestore::DataNode> _whileRootHasOnlyOneChildReplaceRootWithItsChild(cpputils::unique_ref<datanodestore::DataNode> root);
cpputils::unique_ref<datanodestore::DataNode> _whileRootHasOnlyOneChildRemoveRootReturnChild(const blockstore::Key &key);
DISALLOW_COPY_AND_ASSIGN(LeafTraverser);
};

2
test/blobstore/implementations/onblocks/datatreestore/DataTreeTest_Performance.cpp
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@ -464,6 +464,6 @@ TEST_F(DataTreeTest_Performance, ResizeNumBytes_DecreaseTreeDepth_2to0) {
EXPECT_EQ(5u, blockStore->loadedBlocks().size()); // load new last leaf (+inner node), load second inner node to remove its subtree, then 2x load first child of root to replace root with its child.
EXPECT_EQ(0u, blockStore->createdBlocks());
EXPECT_EQ(3u + maxChildrenPerInnerNode, blockStore->removedBlocks().size());
EXPECT_EQ(2u, blockStore->distinctWrittenBlocks().size()); // 2x rewrite root node to be a leaf
EXPECT_EQ(2u, blockStore->distinctWrittenBlocks().size()); // remove children from inner node and rewrite root node to be a leaf
EXPECT_EQ(0u, blockStore->resizedBlocks().size());
}