Summary:
react-native-windows builds treat a lot of c++ compiler warnings as errors. Including ones that cause value truncation when assigning `size_t` values to an `int`.
This fixes the compiler warning, by using `size_t` as the type for `i`, which matches `size`. I then modified the loop to avoid the value underflow that occurs when decrementing an unsigned zero value.
## Changelog
[Internal] [Changed] - Fix compiler warnings around mixing int and size_t usage in unsafe ways
Pull Request resolved: https://github.com/facebook/react-native/pull/34889
Test Plan: This code change was made in react-native-windows when integrating latest react-native changes. -- our fabric implementation was able to run through this code without any issues.
Reviewed By: mdvacca
Differential Revision: D40158306
Pulled By: rozele
fbshipit-source-id: b6858cb953635b37fd63a88ed1a372eb3dc394f7
Summary:
A follow up to D38708718 (https://github.com/facebook/react-native/commit/403fea25f65a38f4b4d8e0edcf89741b29e62059) review, this factors feature flags for Fabric core code into a separate file, `CoreFeatures`.
Keeping them together is arguably better for maintenance and makes code easier to reason about.
Changelog: [Internal]
Reviewed By: sammy-SC
Differential Revision: D40007784
fbshipit-source-id: 1885d5d6200575c6015f063d8b05813b18b47ffb
Summary:
Previously, ViewPropsMapBuffer conversions were hardcoded deep in Android infrastructrue. I've generalized this into a different mechanism to allow any Props struct to support MapBuffer props.
There are still some things that need to be cleaned up and this should be treated as experimental. One thing we likely want to do is remove the hardcoded IDs (fine for codegen'd code; less so for handwritten) and use compile-time-hashed IDs instead with human-readable string names.
Changelog: [Internal]
Reviewed By: mdvacca
Differential Revision: D38708719
fbshipit-source-id: 64603dee7f21828be31346c555d99862dab304ea
Summary:
Instead of having a special flag just for View MapBuffer props, we now use one flag to indicate that MapBuffer should be used for all props; each XShadowNode must set a special trait indicating if that ShadowNode supports MapBuffer props.
Changelog: [Internal]
Reviewed By: mdvacca
Differential Revision: D38708718
fbshipit-source-id: b398ec62a0db9c0ff23c0007c5503cf2838c4173
Summary:
changelog: [internal]
Add more clang tidy rules to prevent common class of bugs.
Reviewed By: javache
Differential Revision: D39245194
fbshipit-source-id: 5521c5c4653d7005b96ebba494e810ba5075afbc
Summary:
Improve errors thrown when prop conversion fails by adding the property being converted. Removes the specialization of convertRawProp for std::optional since we can handle that in a fromRawValue specialization instead.
To make this work, we need to remove noexcept from a number of calls. This noexcept behaviour was making these exceptions effectively uncatcheable. The original motivation of D23787492 (https://github.com/facebook/react-native/commit/57dd48b2464ac04b860f2f69cb4f131990fe4dbd) is correct, as we cannot reliably pass on exceptions to JS and assume that the state will be recoverable, so instead we log an error and carry on with the default value available. We should improve how the error gets reported to the user, as it will currently be hidden in logcat.
Changelog: [Internal]
Differential Revision: D39052812
fbshipit-source-id: 9692633930555e64a3769116fc484a19e534aa3f
Summary:
Improve errors thrown when prop conversion fails by adding the property being converted. Removes the specialization of convertRawProp for std::optional since we can handle that in a fromRawValue specialization instead.
To make this work, we need to remove noexcept from a number of calls. This noexcept behaviour was making these exceptions effectively uncatcheable. The original motivation of D23787492 (https://github.com/facebook/react-native/commit/57dd48b2464ac04b860f2f69cb4f131990fe4dbd) is correct, as we cannot reliably pass on exceptions to JS and assume that the state will be recoverable, so instead we log an error and carry on with the default value available. We should improve how the error gets reported to the user, as it will currently be hidden in logcat.
Changelog: [Internal]
Reviewed By: philIip
Differential Revision: D38938632
fbshipit-source-id: 1dc9a544ca679463a8aad5cc632bd918f42b15d1
Summary:
Improve errors thrown when prop conversion fails by adding the property being converted. Removes the specialization of `convertRawProp` for `std::optional` since we can handle that in a `fromRawValue` specialization instead.
To make this work, we need to remove `noexcept` from a number of calls. This noexcept behaviour was making these exceptions effectively uncatcheable. The original motivation of D23787492 (https://github.com/facebook/react-native/commit/57dd48b2464ac04b860f2f69cb4f131990fe4dbd) is correct, as we cannot reliably pass on exceptions to JS and assume that the state will be recoverable, so instead we log an error and carry on with the default value available. We should improve how the error gets reported to the user, as it will currently be hidden in logcat.
Changelog: [Internal]
Reviewed By: JoshuaGross
Differential Revision: D37055069
fbshipit-source-id: 8ce121a9b187f068d3ab790c6fae66d53e6338d2
Summary:
Currently the PropSetter parser parses all border{TopLeft,TopRight,...}Radius props except for `borderRadius`.
This is the fix.
Changelog: [Internal]
Reviewed By: NickGerleman
Differential Revision: D38678226
fbshipit-source-id: 8c5d67a652c2b327aa50a997e8e886630fe139c0
Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/34403
This change mirrors D38457812 (https://github.com/facebook/react-native/commit/063c2b4668b279ccbca639f98f7a0a5c4d7c5690) which added -Wpedantic to ReactCommon targets, but for the Android build used by OSS. This should ensure contributors see the same warnings locally as the internal build would produce.
Changelog:
[Android][Changed] - Enable -Wpedantic in OSS Android Targets
Reviewed By: cortinico
Differential Revision: D38632454
fbshipit-source-id: 19a036ee3f902eb9d47c568aef448af9d8562358
Summary:
Folly's molly target combines a number of targets that are supposed to be useable on mobile. Since we're trying to move away from folly, we should instead list explicitly which parts of folly we're using so we can remove them over time, and track which targets no longer have any folly dependencies.
Changelog: [Internal]
Reviewed By: NickGerleman
Differential Revision: D38352060
fbshipit-source-id: 09d0d84793692f97f4d49390c99c38b23441df54
Summary:
React Native is compiled downstream with MSVC, meaning the introduction of code depending on language extensions specific to gcc/clang may cause breakage.
We can enable `-Wpedantic` to flag any behavior not officially supported by the specified C++ standard. This will includes rules beyond what MSVC has trouble with, but seems to not have too many "noisy warnings".
This change enables -Wpedantic in BUCK targets within ReactCommon.
This makes the OSS C++ build for Android/iOS slightly more permissive than the internal build, A followup is to add the changes to OSS build logic as well, to avoid contributors seeing more errors upon internal submission. (checking with cortinico on how to do this for Android).
react-native-windows uses a higher warning level than `-Wall`, which is an additional cause of compilation failures, but is not addressed as part of this change.
Changelog:
[Internal][Changed] - Enable -Wpedantic for targets inside ReactCommon
Reviewed By: rshest
Differential Revision: D38457812
fbshipit-source-id: 014da1ac0b7ad8f78154e6e447ed58def6bd0d47
Summary:
Changelog:
[Android][Fixed] - Fix regression when setting shadow node properties.
Also simplified the corresponding macros to avoid using lambdas altogether, as they are not required.
Note that this **does not** modify any constexpr-related semantics of the existing code, as the main constexpr macro, `CONSTEXPR_RAW_PROPS_KEY_HASH` evaluation result is still contstexpr value, and the other ones already involved non-const parts (see my comments).
Reviewed By: NickGerleman
Differential Revision: D38356411
fbshipit-source-id: 22c330d3425c8aed36693f4652f1b257d2dc96be
Summary:
Fix macro errors for Windows. Current syntax breaks the build of the React Common project on Windows because the ({...}) syntax is not supported; must be replaced with lambda expressions.
Resolves https://github.com/facebook/react-native/issues/34090
## Changelog
<!-- Help reviewers and the release process by writing your own changelog entry. For an example, see:
https://reactnative.dev/contributing/changelogs-in-pull-requests
-->
[General] [Fixed] - Fix macro errors for Windows.
lyahdav JoshuaGross
Pull Request resolved: https://github.com/facebook/react-native/pull/34299
Test Plan: Build on react-native-windows repo. Tested in RNW app.
Reviewed By: javache
Differential Revision: D38272966
Pulled By: NickGerleman
fbshipit-source-id: e76eac11cde173ef49465d01d793c593017f2ab7
Summary:
This diff fixes the bug T127619309 by exit early during calculateTransformedFrames if currentShadowNode cannot be casted
This is a bug that fired in fb4a but we didn't have a way to reproduce locally.
We are going to release this and enable feature flag with a MC
changelog: [internal] internal
Reviewed By: sammy-SC
Differential Revision: D38280674
fbshipit-source-id: 1c42c17678d8473564e4075a78d3c688efed1a23
Summary:
Calculation of TransformedFrames was a method introduced by D37994809 (https://github.com/facebook/react-native/commit/64528e5faa445907b8287b412c344f30c20fca61) to fix rendering of inverted flat lists.
We found that this operation is crashing in fb4a causing the UBN T127619309
This diff creates a feature flag to disable the calculation of TransformedFrames in Layoutable ShadowNodes. **The goal of this diff is to revert the behavior introduced by D37994809 (https://github.com/facebook/react-native/commit/64528e5faa445907b8287b412c344f30c20fca61)**
The featureFlag is disabled in fb4a and enabled in react AR (because ReactAr apps relies on the calculation of TransformedFrames and these apps are not affected)
The root cause of the bug will be fixed by D38280674 (which still requires more testing and investigation)
changelog: [internal] internal
Reviewed By: JoshuaGross
Differential Revision: D38286857
fbshipit-source-id: 721cd0554ae6a6b369b3f8dbb584160a270d0f18
Summary:
changelog: [internal]
Vertical and horizontal inversion was not taken into account in `computeRelativeLayoutMetrics`. To fix it, we precompute frames to include inversions.
Reviewed By: mdvacca
Differential Revision: D37994809
fbshipit-source-id: 043e6f19b6fa577f61fa3c739ce2d751ef973cc3
Summary:
Fix todo and inconsistency across codebase. It's better to have just one way to refer to these types.
Changelog: [Internal]
Reviewed By: philIip
Differential Revision: D37653146
fbshipit-source-id: e82f09caa6cd6eec5512b78f413708d9c04a7a83
Summary:
MSVC doesn't like Clang macros. Oops!
Constraints with this bit of code:
1. I'm trying to enforce constexpr in the most obvious, intuitive way possible. Macros are ugly but a "proper" solution would result in 10x as much code that is, totally subjectively, less readable to me.
2. This is evaluating at compile-time a hash of a string which is usually used in the `case` line of a switch statement.
For now I'm just hoping that MSVC will allow us to shadow `hash` which Xcode doesn't like. We might need to add a special pragma(s) for MSVC if it still doesn't like this.
Changelog: [Internal]
Reviewed By: lyahdav
Differential Revision: D37529949
fbshipit-source-id: 9aa605a9786bf5d194819ef8dade778875ae744e
Summary:
Perf numbers for this stack are given in terms of before-stack and after-stack, but the changes are split up for ease of review, and also to show that this migration CAN happen per-component and is 100% opt-in. Most existing C++ components do not /need/ to change at all.
# Problem Statement
During certain renders (select critical scenarios in specific products), UIManagerBinding::createNode time takes over 50% of JS thread CPU time. This could be higher or lower depending on the specific product and interaction, but overall createNode takes a lot of CPU time. The question is: can we improve this? What is the minimal overhead needed?
The vast, vast majority of time is taken up by prop parsing (specifically, converting JS values across the JSI into concrete values on the C++ props structs). Other methods like appendChild, etc, do not take up a significant amount of time; so we conclude that createNode is special, and the JSI itself, or calling into C++, is not the problem. Props parsing is the perf problem.
Can we improve it? (Spoiler: yes)
# How does props parsing work today?
Today, props parsing works as follows:
1. The ConcreteComponentDescriptor will construct a RawPropsParser (one per component /type/, per application: so one for View, one for Image, one for Text... etc)
2. Once per component type per application, ConcreteComponentDescriptor will call "prepare" on the RawPropsParser with an empty, default-constructed ConcreteProps struct. This ConcreteProps struct will cause RawProps.at(field) for every single field.
3. Based on the RawProps::at calls in part 2, RawPropsParser constructs a Map from props string names (width, height, position, etc) to a position within a "value index" array.
4. The above is what happens before any actual props are parsed; and the RawPropsParser is now ready to parse actual Props.
5. When props are actually being parsed from a JSI dictionary, we now have two phases:
1. The RawPropsParser `preparse`s the RawProps, by iterating over the JSI map and filling in two additional data structures: a linear list of RawValues, and a mapping from the ValueIndex array (`keyIndexToValueIndex_`; see step 3) to a value's position in the values list (`value_` in RawPropsParser/RawProps);
2. The ConcretePropT constructor is called, which is the same as in step 2/3, which calls `fieldValue = rawProps.at("fieldName")` repeatedly.
3. For each `at` call, the RawProps will look up a prop name in the Map constructed in step 3, and either return an empty value, or map the key name to the `keyIndexToValueIndex_` array, which maps to a value in `values_`, which is then returned and further parsed.
So, a few things that become clear with the current architecture:
1. Complexity is a property of the number of /possible/ props that /can/ be parsed, not what is actually used in product code. This violates the "only pay for what you use" principal. If you have `<View opacity={0.5} />`, the ViewProps constructor will request ~170 properties, not 1!
2. There's a lot of pre-parsing which isn't free
3. The levels of indirection aren't free, and make cache misses more likely and pipelining is more challenging
4. The levels of indirection also require more memory - minor, but not free
# How can we improve it?
The goal is to improve props parsing with minimal or zero impact on backwards-compability. We should be able to migrate over components when it's clear there's a performance issue, without requiring everything gets migrated over at once. This both (1) helps us prove out the new architecture, (2) derisks the project, (3) gives us time, internally and externally, to perfect the APIs and gradually migrate everything over before deleting the old infrastructure code entirely.
Thus, the goal is to do something that introduces a zero-cost abstraction. This isn't entirely possible in practice, and in fact this method slightly regresses components that do not use the new architecture /at all/, while dramatically improving migrated components and causing the impact of the /old/ architecture to be minimal.
# Solution
1. We still keep the existing system in place entirely.
2. After Props are constructed (see ConcreteComponentDescriptor changes) we iterate over all the /values/ set from JS, and call PropsT::setProp. Incidentally, this allows us to easily reuse the same prop for multiple values for "free", which was expensive in the old system.
3. It's worth noting that this makes a Props struct "less immutable" than it was before, and essentially now we have a "builder pattern" for Props. (If we really wanted to, we could still require a single constructor for Props, and then actually use an intermediate PropsBuilder to accumulate values - but I don't think this overhead would be worth for the conceptual "immutability" win, and instead a "Construct/Set/Seal" model works fine, and we still have all the same guarantees of immutability after the parsing phase)
# Implementation Details
# How to properly construct a single Prop value
Minor detail: parsing a single prop is a 3-step process. We imagine two scenarios: (1) Creating a new ShadowNode/Props A from nothing/void, so the previous Props value is just the default constructor. (2) Cloning a ShadowNode A->B and therefore Props A must be copied to Props B before parsing.
We will denote this as a clone from A->B, where A may or may not be a previous node or a default-constructed Props node; and imagine in particular that we're setting the "opacity" value for PropsB.
We must first (1) copy a value over from the previous version of the Props struct, so B.opacity = A.opacity; (2) Determine if opacity has been set from JS. If so, and there is a value, B.opacity = parse(JSValue). (3) If JS has passed in a value for the prop, BUT the value is `null`, it means that JS is resetting or deleting the prop, so we must set it BACK to the default. In this case we set PropsB.opacity = DefaultConstructedProps.opacity.
We must take care in general to ensure that the correct behavior is achieved here, which should help to explain some of the code below.
## String comparisons vs hash comparisons
In the previous system, a RawPropsKey is three `const char*` strings, concatenated together repeatedly /at runtime/. In practice, the ONLY reason we have the prefix, name, suffix Key structure is for the templated prop parsing in ViewProps and YogaStyableProps - that's it. It's not used anywhere else. Further, the key {"margin", "Left", "Width"} is identical to the key {"marginLeftWidth", null, null} and we don't do anything fancy with matching prefixes before comparing the whole string, or similar. Before comparison, keys are concatenated into a single string and then we use `strcmp`. The performance of this isn't terrible, but it's nonzero overhead.
I think we can do better and it's sufficient to compare hashed string values; even better, we can construct most of these /at compile time/ using constexpr, and using `switch` statements guarantee no hash collisions within a single Props struct (it's possible there's a collision between Props.cpp and ViewProps.cpp, for example, since they're different switch statements). We may eventually want to be more robust against has collisions; I personally don't find the risk to be too great, hash collisions with these keys are exceedingly unlikely (or maybe I just like to live dangerously). Thus, at runtime, each setProp requires computing a single hash for the value coming from JS, and then int comparisons with a bunch of pre-compiled values.
If we want to be really paranoid, we could be robust to hash collisions by doing `switch COMPILED_HASH("opacity"): if (strcmp(strFromJs, "opacity") == 0)`. I'm happy to do this if there's enough concern.
## Macros
Yuck! I'm using lots of C preprocessor macros. In general I found this way, way easier in reducing code and (essentially) doing codegen for me vs templated code for the switch cases and hashing prop names at compile-time. Maybe there's a better way.
Changelog: [Added][Fabric] New API for efficient props construction
Reviewed By: javache
Differential Revision: D37050215
fbshipit-source-id: d2dcd351a93b9715cfeb5197eb0d6f9194ec6eb9
Summary:
This target is not a good idea for a number of reasons:
1. It groups up multiple targets which breaks the dependency graph
2. It does not handle dependency remapping correctly
3. It has no mirror into fbcode
We should warn people this is a bad idea
Reviewed By: alexmalyshev
Differential Revision: D36519357
fbshipit-source-id: d60ca3237c7710118732578fecd1b2fc8903321b
Summary:
This diff cleans up several Android Makefiles which we're not using anymore
as they've been replaced by CMake files.
There are still 3 Makefiles left, which I'm aiming to remove in the near future.
Changelog:
[Internal] [Changed] - Remove unused Makefiles from React Native core
Reviewed By: javache
Differential Revision: D36660902
fbshipit-source-id: 8afffac74d493616b0f9414567821cd69f4ef803
Summary:
Cherry picking https://github.com/facebook/react-native/pull/33707 to main branch
This change is extending the changes made by alespergl to reduce the file paths and command lengths of ndk build commands
Essentially we are shortening the length of the source files by using relative paths instead of absolute paths as enumerated by the wildcard expression
This commit is extending the fix by including all the new modules introduced into RN for the new architecture, including the generated modules.
We are also reverting the ndk bump as ndk23 is crashing frequently when building RN with new arch. The reduced file paths lengths ensures the ndk bump is not required for relatively short application paths.
Fix building RN with new architecture on Windows boxes by using relative paths for C++ sources
## Changelog
Fix building RN with new architecture on Windows boxes by using relative paths for C++ sources
[CATEGORY] [TYPE] - Message
Pull Request resolved: https://github.com/facebook/react-native/pull/33784
Test Plan: Verified building on windows box
Reviewed By: javache
Differential Revision: D36241928
Pulled By: cortinico
fbshipit-source-id: 1ce428a271724cbd3b00a24fe03e7d69253f169b
Summary:
Minimal set of changes to intercept events in external modules. Current intended use-case is for Reanimated to handle events for the Animated properties.
Changelog: [Added] Add listeners to allow intercepting events in C++ core.
Reviewed By: cipolleschi
Differential Revision: D35312534
fbshipit-source-id: ec924b57fd0c0dabf7be7b886dbef23bf3170d6c
Summary:
Now that the PFH node has been renamed this updates the pfh label.
Produced via `xbgs -l -e '"pfh:ReactNative_CommonInfrastructurePlaceholde"' | xargs sed -i 's/"pfh:ReactNative_CommonInfrastructurePlaceholde"/"pfh:ReactNative_CommonInfrastructurePlaceholder"/'`
Reviewed By: jkeljo
Differential Revision: D35374087
fbshipit-source-id: 61590f69de5a69ec3b8a0478f6dd43409de3c70b
Summary:
While it would be better to be able to do all of the ownership metadata at the Buck macro level, that proved to be more work than expected.
This diff adds the corresponding pfh label to all targets in `xplat/js/react-native-github` that have a Supermodule label. Once the migration is complete the Supermodules labels will be able to be removed.
Reviewed By: cortinico
Differential Revision: D35221544
fbshipit-source-id: d87d5e266dfb5e6ee087251dc34dff5db299bbaf
Summary:
Adding more context for event dispatching process in systrace.
Changelog: [Internal]
Reviewed By: philIip
Differential Revision: D35208257
fbshipit-source-id: 4a70e15a0074d4a53a895066e6fa1e60a6ebda0d
Summary:
Changes in https://github.com/facebook/react-native/compare/7cece3423...189c2c895 broke build for Windows because of a conversion from size_t to int. Adds a static cast to int to fix the error and restore windows build
Error Message
```
##[error]node_modules\react-native\ReactCommon\react\renderer\core\RawPropsParser.cpp(100,42): Error C2220: the following warning is treated as an error
3>D:\a\_work\1\s\node_modules\react-native\ReactCommon\react\renderer\core\RawPropsParser.cpp(100,42): error C2220: the following warning is treated as an error [D:\a\_work\1\s\vnext\Microsoft.ReactNative\Microsoft.ReactNative.vcxproj]
##[warning]node_modules\react-native\ReactCommon\react\renderer\core\RawPropsParser.cpp(100,42): **Warning C4267: '=': conversion from 'size_t' to 'int', possible loss of data**
3>D:\a\_work\1\s\node_modules\react-native\ReactCommon\react\renderer\core\RawPropsParser.cpp(100,42): warning C4267: '=': conversion from 'size_t' to 'int', possible loss of data [D:\a\_work\1\s\vnext\Microsoft.ReactNative\Microsoft.ReactNative.vcxproj]
```
## Changelog
[General] [Fixed] - Restore Windows build with RawPropsParser.cpp
Pull Request resolved: https://github.com/facebook/react-native/pull/33432
Test Plan: Tested locally and changes pass in the react-native-windows pipeline, change is being merged into the main branch of react-native-windows.
Reviewed By: philIip
Differential Revision: D34907928
Pulled By: javache
fbshipit-source-id: 8b76cbef0b637f2d607a8aefd2998322c3245713
Summary:
This Diff moves from specifying a list of files to use file(GLOB) with
CONFIGURE_DEPENDS on several CMakefiles.
I've updates those where we use globbing also inside buck.
Changelog:
[Internal] [Changed] - Setup Globbing with CONFIGURE_DEPENDS inside CMake files
Reviewed By: ShikaSD
Differential Revision: D34826311
fbshipit-source-id: 8fc654626c897cdc4cdd79c699ce19f1e5e1212f
Summary:
Rearranges folly_futures configuration into a static library only required for `hermes-inspector` + `folly_runtime` which merges `folly_json` and mutex-related implementations `folly_futures` was used for. As `hermes-executor-debug` is removed by `vmCleanup` configurations later, it allows to shave additional 300KB from the release APK size.
Changelog: [Internal] - Rearrange folly build to reduce APK size
Reviewed By: cortinico
Differential Revision: D34342514
fbshipit-source-id: b646680343e6b9a7674019506b87b96f6007caf2
Summary:
This is the first round of CMake files to support the React Native build on Android.
They're supposed to eventually replace the various Android.mk files we have around in the codebase.
So far we're not actively using them. This is the first step towards migrating our
setup to use CMake
Changelog:
[Internal] [Changed] - First Round of CMake files for React Android
Reviewed By: ShikaSD
Differential Revision: D34762524
fbshipit-source-id: 6671e203a2c83b8874cefe796aa55aa987902a3b
Summary:
Changelog: [internal]
To avoid unnecessary string copy in event pipeline, use move semantics.
Event pipeline has ownership of event type. Passing it by reference ends up in a copy when `RawEvent` object is constructed. To avoid this, pass string by value through each layer and use move semantics to avoid extra copies.
Reviewed By: javache
Differential Revision: D34392608
fbshipit-source-id: c11d221be345665e165d9edbc360ba5a057e3890
Summary:
`size_` will always match `keys_.size()` so we don't have to keep track of it.
Changelog: [Internal]
Reviewed By: sammy-SC
Differential Revision: D34391445
fbshipit-source-id: f6c9316c989137425abfb7b3d72b571d08240f34
Summary:
With the `MapBuffer`-based props calculated from C++ props, there's no need to keep `rawProps` around for Android views.
This change makes sure that the `rawProps` field is only initialized under the feature flag that is responsible for enabling `MapBuffer` for prop diffing, potentially decreasing memory footprint and speeding up node initialization as JS props don't have to be converted to `folly::dynamic` anymore.
For layout animations, props rely on C++ values, so there's no need to update `rawProps` values either.
Changelog: [Internal][Android] - Do not init `rawProps` when mapbuffer serialization is used for ViewProps.
Reviewed By: mdvacca
Differential Revision: D33793044
fbshipit-source-id: 35873b10d3ca8b152b25344ef2c27aff9641846f
Summary:
Small performance improvement since we don't need to copy the char * into a string just for the sake of comparison.
Changelog: [Internal]
Reviewed By: sammy-SC
Differential Revision: D34351387
fbshipit-source-id: 10163164f6e95ab0737e8f865c37d8f0c3500662
Summary:
changelog: [internal]
You can read more about this rule on https://clang.llvm.org/extra/clang-tidy/checks/modernize-pass-by-value.html
# Isn't it wasteful to copy? Isn't reference more efficient?
This rule of thumb is no longer true since C++11 with move semantics. Let's look at some examples.
# Option one
```
class TextHolder
{
public:
TextBox(std::string const &text) : text_(text) {}
private:
std::string text_;
};
```
By using reference here, we prevent the caller from using rvalue to and avoiding copy. Regardless of what the caller passes in, copy always happens.
# Option two
```
class TextHolder
{
public:
TextBox(std::string const &text) : text_(text) {}
TextBox(std::string &&text) : text_(std::move(text)) {}
private:
std::string text_;
};
```
Here, we provide two constructors, one for const reference and one for rvalue reference. This gives the caller option to avoid copy. But now we have two constructors, which is not ideal.
# Option three (what we do in this diff)
```
class TextHolder
{
public:
TextBox(std::string text) : text_(std::move(text)) {}
private:
std::string text_;
};
```
Here, the caller has option to avoid copy and we only have single constructor.
Reviewed By: fkgozali, JoshuaGross
Differential Revision: D33276841
fbshipit-source-id: 619d5123d2e28937b22874650366629f24f20a63
Andrew Coates
Ruslan Shestopalyuk
Samuel Susla
Pieter De Baets
Shawn Shihang Wei
Ravi Shah
Joshua Gross
Nick Gerleman
Ruslan Shestopalyuk
Dark Knight
Chiara Mooney
David Vacca
Michael Lee (Engineering)
Nicola Corti
Anandraj Govindan
Chris Olszewski
Xin Chen
Tatiana Kapos
Andrei Shikov
Andres Suarez