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Refactor storage delta in storage v2

Browse Source 
Reviewers: mtomic, teon.banek

Reviewed By: mtomic

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D2171
This commit is contained in:
Matej Ferencevic 2019-07-03 14:45:43 +02:00
parent db72ef05f8
commit 0833a74fd8
4 changed files with 141 additions and 79 deletions
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95
src/storage/v2/delta.hpp
View File

@ -15,41 +15,104 @@ struct Delta {
SET_PROPERTY,
};
Delta(Action action, uint64_t key, const PropertyValue &value,
std::atomic<uint64_t> *timestamp, uint64_t command_id)
: action(action),
key(key),
value(value),
struct DeleteObjectTag {};
struct RecreateObjectTag {};
struct AddLabelTag {};
struct RemoveLabelTag {};
struct SetPropertyTag {};
Delta(DeleteObjectTag, std::atomic<uint64_t> *timestamp, uint64_t command_id)
: action(Action::DELETE_OBJECT),
timestamp(timestamp),
command_id(command_id) {}
Delta(RecreateObjectTag, std::atomic<uint64_t> *timestamp,
uint64_t command_id)
: action(Action::RECREATE_OBJECT),
timestamp(timestamp),
command_id(command_id) {}
Delta(AddLabelTag, uint64_t label, std::atomic<uint64_t> *timestamp,
uint64_t command_id)
: action(Action::ADD_LABEL),
timestamp(timestamp),
command_id(command_id),
prev(nullptr),
next(nullptr) {}
label(label) {}
Delta(RemoveLabelTag, uint64_t label, std::atomic<uint64_t> *timestamp,
uint64_t command_id)
: action(Action::REMOVE_LABEL),
timestamp(timestamp),
command_id(command_id),
label(label) {}
Delta(SetPropertyTag, uint64_t key, const PropertyValue &value,
std::atomic<uint64_t> *timestamp, uint64_t command_id)
: action(Action::SET_PROPERTY),
timestamp(timestamp),
command_id(command_id),
property({key, value}) {}
Delta(Delta &&other) noexcept
: action(other.action),
key(other.key),
value(std::move(other.value)),
timestamp(other.timestamp),
command_id(other.command_id),
prev(other.prev),
next(other.next.load()) {}
next(other.next.load()) {
switch (other.action) {
case Action::DELETE_OBJECT:
case Action::RECREATE_OBJECT:
break;
case Action::ADD_LABEL:
case Action::REMOVE_LABEL:
label = other.label;
break;
case Action::SET_PROPERTY:
property.key = other.property.key;
new (&property.value) PropertyValue(std::move(other.property.value));
break;
}
// reset the action of other
other.DestroyValue();
other.action = Action::DELETE_OBJECT;
}
Delta(const Delta &) = delete;
Delta &operator=(const Delta &) = delete;
Delta &operator=(Delta &&other) = delete;
~Delta() {}
~Delta() { DestroyValue(); }
Action action;
uint64_t key; // Used as the label id or the property id.
PropertyValue value; // Used as the property value (only for SET_PROPERTY).
// TODO: optimize with in-place copy
std::atomic<uint64_t> *timestamp;
uint64_t command_id;
Delta *prev;
std::atomic<Delta *> next;
Delta *prev{nullptr};
std::atomic<Delta *> next{nullptr};
union {
uint64_t label;
struct {
uint64_t key;
storage::PropertyValue value;
} property;
};
private:
void DestroyValue() {
switch (action) {
case Action::DELETE_OBJECT:
case Action::RECREATE_OBJECT:
case Action::ADD_LABEL:
case Action::REMOVE_LABEL:
break;
case Action::SET_PROPERTY:
property.value.~PropertyValue();
break;
}
}
};
} // namespace storage

18
src/storage/v2/mvcc.hpp
View File

@ -64,12 +64,12 @@ inline bool PrepareForWrite(Transaction *transaction, Vertex *vertex) {
return false;
}
/// This function creates a delta in the transaction and returns a pointer to
/// the created delta. It doesn't perform any linking of the delta and is
/// primarily used to create the first delta for an object.
inline Delta *CreateDelta(Transaction *transaction, Delta::Action action,
uint64_t key) {
return &transaction->deltas.emplace_back(action, key, PropertyValue(),
/// This function creates a `DELETE_OBJECT` delta in the transaction and returns
/// a pointer to the created delta. It doesn't perform any linking of the delta
/// and is primarily used to create the first delta for an object (that must be
/// a `DELETE_OBJECT` delta).
inline Delta *CreateDeleteObjectDelta(Transaction *transaction) {
return &transaction->deltas.emplace_back(Delta::DeleteObjectTag(),
&transaction->commit_timestamp,
transaction->command_id);
}
@ -77,10 +77,10 @@ inline Delta *CreateDelta(Transaction *transaction, Delta::Action action,
/// This function creates a delta in the transaction for the Vertex object and
/// links the delta into the Vertex's delta list. It also adds the Vertex to the
/// transaction's modified vertices list.
template <class... Args>
inline void CreateAndLinkDelta(Transaction *transaction, Vertex *vertex,
Delta::Action action, uint64_t key,
const PropertyValue &value = PropertyValue()) {
auto delta = &transaction->deltas.emplace_back(action, key, value,
Args &&... args) {
auto delta = &transaction->deltas.emplace_back(std::forward<Args>(args)...,
&transaction->commit_timestamp,
transaction->command_id);

19
src/storage/v2/storage.hpp
View File

@ -81,7 +81,7 @@ class Storage final {
VertexAccessor CreateVertex() {
auto gid = storage_->vertex_id_.fetch_add(1, std::memory_order_acq_rel);
auto acc = storage_->vertices_.access();
auto delta = CreateDelta(transaction_, Delta::Action::DELETE_OBJECT, 0);
auto delta = CreateDeleteObjectDelta(transaction_);
auto [it, inserted] =
acc.insert(Vertex{storage::Gid::FromUint(gid), delta});
CHECK(inserted) << "The vertex must be inserted here!";
@ -128,7 +128,7 @@ class Storage final {
switch (current->action) {
case Delta::Action::REMOVE_LABEL: {
auto it = std::find(vertex->labels.begin(), vertex->labels.end(),
current->key);
current->label);
CHECK(it != vertex->labels.end()) << "Invalid database state!";
std::swap(*it, *vertex->labels.rbegin());
vertex->labels.pop_back();
@ -136,23 +136,24 @@ class Storage final {
}
case Delta::Action::ADD_LABEL: {
auto it = std::find(vertex->labels.begin(), vertex->labels.end(),
current->key);
current->label);
CHECK(it == vertex->labels.end()) << "Invalid database state!";
vertex->labels.push_back(current->key);
vertex->labels.push_back(current->label);
break;
}
case Delta::Action::SET_PROPERTY: {
auto it = vertex->properties.find(current->key);
auto it = vertex->properties.find(current->property.key);
if (it != vertex->properties.end()) {
if (current->value.IsNull()) {
if (current->property.value.IsNull()) {
// remove the property
vertex->properties.erase(it);
} else {
// set the value
it->second = current->value;
it->second = current->property.value;
}
} else if (!current->value.IsNull()) {
vertex->properties.emplace(current->key, current->value);
} else if (!current->property.value.IsNull()) {
vertex->properties.emplace(current->property.key,
current->property.value);
}
break;
}

88
src/storage/v2/vertex_accessor.hpp
View File

@ -57,8 +57,7 @@ class VertexAccessor final {
if (vertex_->deleted) return Result<bool>{false};
CreateAndLinkDelta(transaction_, vertex_, Delta::Action::RECREATE_OBJECT,
0);
CreateAndLinkDelta(transaction_, vertex_, Delta::RecreateObjectTag());
vertex_->deleted = true;
@ -77,8 +76,7 @@ class VertexAccessor final {
vertex_->labels.end())
return Result<bool>{false};
CreateAndLinkDelta(transaction_, vertex_, Delta::Action::REMOVE_LABEL,
label);
CreateAndLinkDelta(transaction_, vertex_, Delta::RemoveLabelTag(), label);
vertex_->labels.push_back(label);
return Result<bool>{true};
@ -95,7 +93,7 @@ class VertexAccessor final {
auto it = std::find(vertex_->labels.begin(), vertex_->labels.end(), label);
if (it == vertex_->labels.end()) return Result<bool>{false};
CreateAndLinkDelta(transaction_, vertex_, Delta::Action::ADD_LABEL, label);
CreateAndLinkDelta(transaction_, vertex_, Delta::AddLabelTag(), label);
std::swap(*it, *vertex_->labels.rbegin());
vertex_->labels.pop_back();
@ -117,14 +115,14 @@ class VertexAccessor final {
[&deleted, &has_label, label](const Delta &delta) {
switch (delta.action) {
case Delta::Action::REMOVE_LABEL: {
if (delta.key == label) {
if (delta.label == label) {
CHECK(has_label) << "Invalid database state!";
has_label = false;
}
break;
}
case Delta::Action::ADD_LABEL: {
if (delta.key == label) {
if (delta.label == label) {
CHECK(!has_label) << "Invalid database state!";
has_label = true;
}
@ -161,7 +159,7 @@ class VertexAccessor final {
switch (delta.action) {
case Delta::Action::REMOVE_LABEL: {
// Remove the label because we don't see the addition.
auto it = std::find(labels.begin(), labels.end(), delta.key);
auto it = std::find(labels.begin(), labels.end(), delta.label);
CHECK(it != labels.end()) << "Invalid database state!";
std::swap(*it, *labels.rbegin());
labels.pop_back();
@ -169,9 +167,9 @@ class VertexAccessor final {
}
case Delta::Action::ADD_LABEL: {
// Add the label because we don't see the removal.
auto it = std::find(labels.begin(), labels.end(), delta.key);
auto it = std::find(labels.begin(), labels.end(), delta.label);
CHECK(it == labels.end()) << "Invalid database state!";
labels.push_back(delta.key);
labels.push_back(delta.label);
break;
}
case Delta::Action::DELETE_OBJECT: {
@ -201,7 +199,7 @@ class VertexAccessor final {
auto it = vertex_->properties.find(property);
bool existed = it != vertex_->properties.end();
if (it != vertex_->properties.end()) {
CreateAndLinkDelta(transaction_, vertex_, Delta::Action::SET_PROPERTY,
CreateAndLinkDelta(transaction_, vertex_, Delta::SetPropertyTag(),
property, it->second);
if (value.IsNull()) {
// remove the property
@ -211,7 +209,7 @@ class VertexAccessor final {
it->second = value;
}
} else {
CreateAndLinkDelta(transaction_, vertex_, Delta::Action::SET_PROPERTY,
CreateAndLinkDelta(transaction_, vertex_, Delta::SetPropertyTag(),
property, PropertyValue());
if (!value.IsNull()) {
vertex_->properties.emplace(property, value);
@ -238,8 +236,8 @@ class VertexAccessor final {
[&deleted, &value, property](const Delta &delta) {
switch (delta.action) {
case Delta::Action::SET_PROPERTY: {
if (delta.key == property) {
value = delta.value;
if (delta.property.key == property) {
value = delta.property.value;
}
break;
}
@ -270,37 +268,37 @@ class VertexAccessor final {
properties = vertex_->properties;
delta = vertex_->delta;
}
ApplyDeltasForRead(transaction_, delta, view,
[&deleted, &properties](const Delta &delta) {
switch (delta.action) {
case Delta::Action::SET_PROPERTY: {
auto it = properties.find(delta.key);
if (it != properties.end()) {
if (delta.value.IsNull()) {
// remove the property
properties.erase(it);
} else {
// set the value
it->second = delta.value;
}
} else if (!delta.value.IsNull()) {
properties.emplace(delta.key, delta.value);
}
break;
}
case Delta::Action::DELETE_OBJECT: {
LOG(FATAL) << "Invalid accessor!";
break;
}
case Delta::Action::RECREATE_OBJECT: {
deleted = false;
break;
}
case Delta::Action::ADD_LABEL:
case Delta::Action::REMOVE_LABEL:
break;
}
});
ApplyDeltasForRead(
transaction_, delta, view, [&deleted, &properties](const Delta &delta) {
switch (delta.action) {
case Delta::Action::SET_PROPERTY: {
auto it = properties.find(delta.property.key);
if (it != properties.end()) {
if (delta.property.value.IsNull()) {
// remove the property
properties.erase(it);
} else {
// set the value
it->second = delta.property.value;
}
} else if (!delta.property.value.IsNull()) {
properties.emplace(delta.property.key, delta.property.value);
}
break;
}
case Delta::Action::DELETE_OBJECT: {
LOG(FATAL) << "Invalid accessor!";
break;
}
case Delta::Action::RECREATE_OBJECT: {
deleted = false;
break;
}
case Delta::Action::ADD_LABEL:
case Delta::Action::REMOVE_LABEL:
break;
}
});
if (deleted) {
return Result<std::unordered_map<uint64_t, PropertyValue>>{
Error::DELETED_OBJECT};