Redesign DataNodes

This commit is contained in:
Sebastian Messmer 2014-12-10 16:48:00 +01:00
parent 0b2b527b4d
commit b33cf908fa
9 changed files with 256 additions and 72 deletions

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@ -10,6 +10,7 @@ namespace onblocks {
class BlobStoreOnBlocks: public BlobStore { class BlobStoreOnBlocks: public BlobStore {
public: public:
//Should be a multiple of 16. The DataNodeView classes have a header of 16 bytes and the block key length (inner data nodes store a list of block keys) is 16 bytes.
static constexpr size_t BLOCKSIZE = 4096; static constexpr size_t BLOCKSIZE = 4096;
BlobStoreOnBlocks(std::unique_ptr<blockstore::BlockStore> blockStore); BlobStoreOnBlocks(std::unique_ptr<blockstore::BlockStore> blockStore);

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@ -2,20 +2,93 @@
using std::unique_ptr; using std::unique_ptr;
using blockstore::Block; using blockstore::Block;
using blockstore::Data;
namespace blobstore { namespace blobstore {
namespace onblocks { namespace onblocks {
DataInnerNode::DataInnerNode(unique_ptr<Block> block) DataInnerNode::DataInnerNode(DataNodeView view)
: DataNode(std::move(block)) { : DataNode(std::move(view)) {
} }
DataInnerNode::~DataInnerNode() { DataInnerNode::~DataInnerNode() {
} }
void DataInnerNode::InitializeEmptyInnerNode() { void DataInnerNode::InitializeNewInnerNode() {
InnerNodeHeader* header = (InnerNodeHeader*)_block->data(); *_node.MagicNumber() = _node.magicNumberNodeWithChildren;
header->nodeHeader.magicNumber = DataNode::magicNumberInnerNode; *_node.Size() = 0;
}
void DataInnerNode::read(off_t offset, size_t count, Data *result) {
assert(count <= result->size());
const uint64_t end = offset + count;
assert(end <= numBytesInThisNode());
uint8_t *target = (uint8_t*)result->data();
ChildEntry *child = ChildContainingFirstByteAfterOffset(offset);
off_t blockrelative_offset = offset - numBytesInLeftwardSiblings(child);
uint64_t already_read_bytes = readFromChild(child, blockrelative_offset, count, target);
while(numBytesInChildAndLeftwardSiblings(child) < end) {
++child;
already_read_bytes += readFromChild(child, 0, count, target + already_read_bytes);
};
assert(already_read_bytes == count);
}
uint64_t DataInnerNode::readFromChild(const ChildEntry *child, off_t inner_offset, size_t count, uint8_t *target) {
uint64_t readable_bytes = std::min(count, numBytesInChild(child) - inner_offset);
//TODO READ...
return readable_bytes;
}
DataInnerNode::ChildEntry *DataInnerNode::ChildContainingFirstByteAfterOffset(off_t offset) {
uint32_t offset_blocks = offset / _node.BLOCKSIZE_BYTES;
return
std::upper_bound(ChildrenBegin(), ChildrenEnd(), offset_blocks, [](uint32_t offset_blocks, const ChildEntry &child) {
return offset_blocks < child.numBlocksInThisAndLeftwardNodes;
});
}
uint64_t DataInnerNode::numBytesInThisNode() {
return numBytesInChildAndLeftwardSiblings(ChildrenLast());
}
uint64_t DataInnerNode::numBytesInChild(const ChildEntry *child) {
return numBytesInChildAndLeftwardSiblings(child) - numBytesInLeftwardSiblings(child);
}
uint64_t DataInnerNode::numBytesInLeftwardSiblings(const ChildEntry *child) {
if (child == ChildrenBegin()) {
return 0;
}
return numBytesInChildAndLeftwardSiblings(child-1);
}
uint64_t DataInnerNode::numBytesInChildAndLeftwardSiblings(const ChildEntry *child) {
return (uint64_t)child->numBlocksInThisAndLeftwardNodes * _node.BLOCKSIZE_BYTES;
}
DataInnerNode::ChildEntry *DataInnerNode::ChildrenBegin() {
return _node.DataBegin<ChildEntry>();
}
DataInnerNode::ChildEntry *DataInnerNode::ChildrenEnd() {
return ChildrenBegin() + *_node.Size();
}
DataInnerNode::ChildEntry *DataInnerNode::ChildrenLast() {
return ChildrenEnd()-1;
}
void DataInnerNode::write(off_t offset, size_t count, const Data &data) {
//assert(count <= data.size());
//assert(offset+count <= _node->DATASIZE_BYTES);
//std::memcpy(_node->DataBegin()+offset, result.data(), count);
} }
} }

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@ -9,14 +9,32 @@ namespace onblocks {
class DataInnerNode: public DataNode { class DataInnerNode: public DataNode {
public: public:
DataInnerNode(std::unique_ptr<blockstore::Block> block); DataInnerNode(DataNodeView block);
virtual ~DataInnerNode(); virtual ~DataInnerNode();
struct InnerNodeHeader { struct ChildEntry {
NodeHeader nodeHeader; uint32_t numBlocksInThisAndLeftwardNodes;
uint8_t key[Key::KEYLENGTH_BINARY];
}; };
void InitializeEmptyInnerNode(); void InitializeNewInnerNode();
void read(off_t offset, size_t count, blockstore::Data *result) override;
void write(off_t offset, size_t count, const blockstore::Data &data) override;
uint64_t numBytesInThisNode() override;
private:
ChildEntry *ChildrenBegin();
ChildEntry *ChildrenEnd();
ChildEntry *ChildrenLast();
uint64_t readFromChild(const ChildEntry *child, off_t inner_offset, size_t count, uint8_t *target);
ChildEntry *ChildContainingFirstByteAfterOffset(off_t offset);
uint64_t numBytesInChildAndLeftwardSiblings(const ChildEntry *child);
uint64_t numBytesInLeftwardSiblings(const ChildEntry *child);
uint64_t numBytesInChild(const ChildEntry *child);
}; };
} }

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@ -2,20 +2,37 @@
using std::unique_ptr; using std::unique_ptr;
using blockstore::Block; using blockstore::Block;
using blockstore::Data;
namespace blobstore { namespace blobstore {
namespace onblocks { namespace onblocks {
DataLeafNode::DataLeafNode(unique_ptr<Block> block) DataLeafNode::DataLeafNode(DataNodeView view)
: DataNode(std::move(block)) { : DataNode(std::move(view)) {
} }
DataLeafNode::~DataLeafNode() { DataLeafNode::~DataLeafNode() {
} }
void DataLeafNode::InitializeEmptyLeaf() { void DataLeafNode::read(off_t offset, size_t count, Data *result) {
LeafHeader *header = (LeafHeader*)_block->data(); assert(count <= result->size());
header->nodeHeader.magicNumber = DataNode::magicNumberLeaf; assert(offset+count <= _node.DATASIZE_BYTES);
std::memcpy(result->data(), _node.DataBegin<unsigned char>()+offset, count);
}
void DataLeafNode::write(off_t offset, size_t count, const Data &data) {
assert(count <= data.size());
assert(offset+count <= _node.DATASIZE_BYTES);
std::memcpy(_node.DataBegin<unsigned char>()+offset, data.data(), count);
}
void DataLeafNode::InitializeNewLeafNode() {
*_node.MagicNumber() = _node.magicNumberLeaf;
*_node.Size() = 0;
}
uint64_t DataLeafNode::numBytesInThisNode() {
return *_node.Size();
} }
} }

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@ -9,14 +9,16 @@ namespace onblocks {
class DataLeafNode: public DataNode { class DataLeafNode: public DataNode {
public: public:
DataLeafNode(std::unique_ptr<blockstore::Block> block); DataLeafNode(DataNodeView block);
virtual ~DataLeafNode(); virtual ~DataLeafNode();
struct LeafHeader { void read(off_t offset, size_t count, blockstore::Data *result) override;
NodeHeader nodeHeader; void write(off_t offset, size_t count, const blockstore::Data &data) override;
};
void InitializeNewLeafNode();
uint64_t numBytesInThisNode() override;
void InitializeEmptyLeaf();
}; };
} }

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@ -12,40 +12,38 @@ using std::runtime_error;
namespace blobstore { namespace blobstore {
namespace onblocks { namespace onblocks {
DataNode::DataNode(unique_ptr<Block> block) DataNode::DataNode(DataNodeView node)
: _block(std::move(block)) { : _node(std::move(node)) {
} }
DataNode::~DataNode() { DataNode::~DataNode() {
} }
void DataNode::flush() {
_block->flush();
}
unique_ptr<DataNode> DataNode::load(unique_ptr<Block> block) { unique_ptr<DataNode> DataNode::load(unique_ptr<Block> block) {
NodeHeader *header = (NodeHeader*)block->data(); DataNodeView node(std::move(block));
if (header->magicNumber == magicNumberInnerNode) {
return make_unique<DataInnerNode>(std::move(block)); if (*node.MagicNumber() == node.magicNumberNodeWithChildren) {
} else if (header->magicNumber == magicNumberLeaf) { return make_unique<DataInnerNode>(std::move(node));
return make_unique<DataLeafNode>(std::move(block)); } else if (*node.MagicNumber() == node.magicNumberLeaf) {
return make_unique<DataLeafNode>(std::move(node));
} else { } else {
//TODO Better exception //TODO Better exception
throw runtime_error("Invalid node magic number"); throw runtime_error("Invalid node magic number");
} }
} }
unique_ptr<DataInnerNode> DataNode::initializeNewInnerNode(unique_ptr<Block> block) { /*
unique_ptr<DataInnerNode> DataNodeView::initializeNewInnerNode(unique_ptr<Block> block) {
auto newNode = make_unique<DataInnerNode>(std::move(block)); auto newNode = make_unique<DataInnerNode>(std::move(block));
newNode->InitializeEmptyInnerNode(); newNode->InitializeEmptyInnerNode();
return newNode; return newNode;
} }
unique_ptr<DataLeafNode> DataNode::initializeNewLeafNode(unique_ptr<Block> block) { unique_ptr<DataLeafNode> DataNodeView::initializeNewLeafNode(unique_ptr<Block> block) {
auto newNode = make_unique<DataLeafNode>(std::move(block)); auto newNode = make_unique<DataLeafNode>(std::move(block));
newNode->InitializeEmptyLeaf(); newNode->InitializeEmptyLeaf();
return newNode; return newNode;
} }*/
} }
} }

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@ -2,40 +2,33 @@
#ifndef BLOBSTORE_IMPLEMENTATIONS_ONBLOCKS_IMPL_DATANODE_H_ #ifndef BLOBSTORE_IMPLEMENTATIONS_ONBLOCKS_IMPL_DATANODE_H_
#define BLOBSTORE_IMPLEMENTATIONS_ONBLOCKS_IMPL_DATANODE_H_ #define BLOBSTORE_IMPLEMENTATIONS_ONBLOCKS_IMPL_DATANODE_H_
#include "blockstore/interface/Block.h" #include "DataNodeView.h"
#include <memory> #include "blockstore/utils/Data.h"
namespace blobstore { namespace blobstore {
namespace onblocks { namespace onblocks {
class DataInnerNode;
class DataLeafNode;
class DataNode { class DataNode {
public: public:
virtual ~DataNode(); virtual ~DataNode();
static constexpr unsigned char magicNumberInnerNode = 0x01; //TODO MAke read, numBytesInThisNode const
static constexpr unsigned char magicNumberLeaf = 0x02; virtual void read(off_t offset, size_t count, blockstore::Data *result) = 0;
struct NodeHeader { virtual void write(off_t offset, size_t count, const blockstore::Data &data) = 0;
unsigned char magicNumber;
};
void flush(); virtual uint64_t numBytesInThisNode() = 0;
static std::unique_ptr<DataNode> load(std::unique_ptr<blockstore::Block> block); static std::unique_ptr<DataNode> load(std::unique_ptr<blockstore::Block> block);
static std::unique_ptr<DataInnerNode> initializeNewInnerNode(std::unique_ptr<blockstore::Block> block);
static std::unique_ptr<DataLeafNode> initializeNewLeafNode(std::unique_ptr<blockstore::Block> block);
protected: protected:
DataNode(std::unique_ptr<blockstore::Block> block); DataNode(DataNodeView block);
std::unique_ptr<blockstore::Block> _block;
DataNodeView _node;
}; };
} }
} }
#endif #endif

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@ -0,0 +1,93 @@
#pragma once
#ifndef BLOBSTORE_IMPLEMENTATIONS_ONBLOCKS_IMPL_DATANODEVIEW_H_
#define BLOBSTORE_IMPLEMENTATIONS_ONBLOCKS_IMPL_DATANODEVIEW_H_
#include "blockstore/interface/Block.h"
#include "blobstore/implementations/onblocks/BlobStoreOnBlocks.h"
#include "fspp/utils/macros.h"
#include <memory>
namespace blobstore {
namespace onblocks {
class DataNodeView {
public:
DataNodeView(std::unique_ptr<blockstore::Block> block): _block(std::move(block)) {}
virtual ~DataNodeView() {}
DataNodeView(DataNodeView &&rhs) = default;
//Total size of the header
static constexpr unsigned int HEADERSIZE_BYTES = 8;
//Where in the header is the magic number
static constexpr unsigned int MAGICNUMBER_OFFSET_BYTES = 0;
//Where in the header is the size field (for inner nodes: number of children, for leafs: content data size)
static constexpr unsigned int SIZE_OFFSET_BYTES = 4;
//How big is one blob in total (header + data)
static constexpr unsigned int BLOCKSIZE_BYTES = BlobStoreOnBlocks::BLOCKSIZE;
//How much space is there for data
static constexpr unsigned int DATASIZE_BYTES = BLOCKSIZE_BYTES - HEADERSIZE_BYTES;
static constexpr unsigned char magicNumberNodeWithChildren = 0x01;
static constexpr unsigned char magicNumberLeaf = 0x02;
static constexpr unsigned char magicNumberRootWithChildren = 0x03;
static constexpr unsigned char magicNumberRootLeaf = 0x04;
const uint8_t *MagicNumber() const {
return GetOffset<MAGICNUMBER_OFFSET_BYTES, uint8_t>();
}
uint8_t *MagicNumber() {
return const_cast<uint8_t*>(const_cast<const DataNodeView*>(this)->MagicNumber());
}
const uint32_t *Size() const {
return GetOffset<SIZE_OFFSET_BYTES, uint32_t>();
}
uint32_t *Size() {
return const_cast<uint32_t*>(const_cast<const DataNodeView*>(this)->Size());
}
template<typename Entry>
const Entry *DataBegin() const {
return GetOffset<HEADERSIZE_BYTES, Entry>();
}
template<typename Entry>
Entry *DataBegin() {
return const_cast<Entry*>(const_cast<const DataNodeView*>(this)->DataBegin<Entry>());
}
template<typename Entry>
const Entry *DataEnd() const {
constexpr unsigned int NUM_ENTRIES = DATASIZE_BYTES / sizeof(Entry);
return DataBegin<Entry>() + NUM_ENTRIES;
}
template<typename Entry>
Entry *DataEnd() {
return const_cast<Entry*>(const_cast<const DataNodeView*>(this)->DataEnd<Entry>());
}
protected:
template<int offset, class Type>
const Type *GetOffset() const {
return (Type*)(((const int8_t*)_block->data())+offset);
}
private:
DISALLOW_COPY_AND_ASSIGN(DataNodeView);
std::unique_ptr<blockstore::Block> _block;
};
}
}
#endif

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@ -24,27 +24,12 @@ public:
#define EXPECT_IS_PTR_TYPE(Type, ptr) EXPECT_NE(nullptr, dynamic_cast<Type*>(ptr)) << "Given pointer cannot be cast to the given type" #define EXPECT_IS_PTR_TYPE(Type, ptr) EXPECT_NE(nullptr, dynamic_cast<Type*>(ptr)) << "Given pointer cannot be cast to the given type"
TEST_F(DataNodeTest, InitializeNewLeafNodeCreatesLeafNodeObject) {
auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
Key key = block.key;
auto leafNode = DataNode::initializeNewLeafNode(std::move(block.block));
EXPECT_IS_PTR_TYPE(DataLeafNode, leafNode.get());
}
TEST_F(DataNodeTest, InitializeNewInnerNodeCreatesInnerNodeObject) {
auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
Key key = block.key;
auto innerNode = DataNode::initializeNewInnerNode(std::move(block.block));
EXPECT_IS_PTR_TYPE(DataInnerNode, innerNode.get());
}
TEST_F(DataNodeTest, LeafNodeIsRecognizedAfterStoreAndLoad) { TEST_F(DataNodeTest, LeafNodeIsRecognizedAfterStoreAndLoad) {
auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE); auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
Key key = block.key; Key key = block.key;
auto node = DataNode::initializeNewLeafNode(std::move(block.block)); {
node->flush(); DataLeafNode(std::move(block.block)).InitializeNewLeafNode();
}
auto loaded_node = DataNode::load(blockStore->load(key)); auto loaded_node = DataNode::load(blockStore->load(key));
@ -54,8 +39,9 @@ TEST_F(DataNodeTest, LeafNodeIsRecognizedAfterStoreAndLoad) {
TEST_F(DataNodeTest, InnerNodeIsRecognizedAfterStoreAndLoad) { TEST_F(DataNodeTest, InnerNodeIsRecognizedAfterStoreAndLoad) {
auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE); auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
Key key = block.key; Key key = block.key;
auto node = DataNode::initializeNewInnerNode(std::move(block.block)); {
node->flush(); DataInnerNode(std::move(block.block)).InitializeNewInnerNode();
}
auto loaded_node = DataNode::load(blockStore->load(key)); auto loaded_node = DataNode::load(blockStore->load(key));
@ -65,10 +51,13 @@ TEST_F(DataNodeTest, InnerNodeIsRecognizedAfterStoreAndLoad) {
TEST_F(DataNodeTest, DataNodeCrashesOnLoadIfMagicNumberIsWrong) { TEST_F(DataNodeTest, DataNodeCrashesOnLoadIfMagicNumberIsWrong) {
auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE); auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
Key key = block.key; Key key = block.key;
DataNode::NodeHeader* header = (DataNode::NodeHeader*)block.block->data(); {
header->magicNumber = 0xFF; // this is an invalid magic number DataNodeView view(std::move(block.block));
*view.MagicNumber() = 0xFF; // this is an invalid magic number
}
auto loaded_block = blockStore->load(key);
EXPECT_ANY_THROW( EXPECT_ANY_THROW(
DataNode::load(std::move(block.block)) DataNode::load(std::move(loaded_block))
); );
} }