Valentin Shergin 091edd2ef7 Fabric: Clear separation between commmit and tryCommit
Summary: Previously we had a single `commit` function that accepts an argument that enables auto-retry mechanism. As Spencer pointed out, that wasn't so useful and clear. So, I split the method into two with more expressive names.

Reviewed By: sahrens

Differential Revision: D13681594

fbshipit-source-id: 529f729d597206e9a0ac940f005a1569a9bef707
2019-01-16 20:22:40 -08:00

90 lines
2.6 KiB
C++

// Copyright (c) Facebook, Inc. and its affiliates.
// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.
#pragma once
#include <folly/SharedMutex.h>
#include <memory>
#include <shared_mutex>
#include <react/components/root/RootShadowNode.h>
#include <react/core/LayoutConstraints.h>
#include <react/core/ReactPrimitives.h>
#include <react/core/ShadowNode.h>
#include <react/mounting/ShadowViewMutation.h>
#include <react/uimanager/ShadowTreeDelegate.h>
namespace facebook {
namespace react {
using ShadowTreeCommitTransaction = std::function<UnsharedRootShadowNode(
const SharedRootShadowNode &oldRootShadowNode)>;
/*
* Represents the shadow tree and its lifecycle.
*/
class ShadowTree final {
public:
/*
* Creates a new shadow tree instance.
*/
ShadowTree(
SurfaceId surfaceId,
const LayoutConstraints &layoutConstraints,
const LayoutContext &layoutContext);
~ShadowTree();
/*
* Returns the `SurfaceId` associated with the shadow tree.
*/
SurfaceId getSurfaceId() const;
/*
* Performs commit calling `transaction` function with a `oldRootShadowNode`
* and expecting a `newRootShadowNode` as a return value.
* The `transaction` function can abort commit returning `nullptr`.
* If a `revision` pointer is not null, the method will store there a
* contiguous revision number of the successfully performed transaction.
* Returns `true` if the operation finished successfully.
*/
bool tryCommit(
ShadowTreeCommitTransaction transaction,
int *revision = nullptr) const;
/*
* Calls `tryCommit` in a loop until it finishes successfully.
*/
void commit(ShadowTreeCommitTransaction transaction, int *revision = nullptr)
const;
#pragma mark - Delegate
/*
* Sets and gets the delegate.
* The delegate is stored as a raw pointer, so the owner must null
* the pointer before being destroyed.
*/
void setDelegate(ShadowTreeDelegate const *delegate);
ShadowTreeDelegate const *getDelegate() const;
private:
UnsharedRootShadowNode cloneRootShadowNode(
const SharedRootShadowNode &oldRootShadowNode,
const LayoutConstraints &layoutConstraints,
const LayoutContext &layoutContext) const;
void emitLayoutEvents(const ShadowViewMutationList &mutations) const;
const SurfaceId surfaceId_;
mutable folly::SharedMutex commitMutex_;
mutable SharedRootShadowNode rootShadowNode_; // Protected by `commitMutex_`.
mutable int revision_{1}; // Protected by `commitMutex_`.
ShadowTreeDelegate const *delegate_;
};
} // namespace react
} // namespace facebook