Encoding improvements
* New hash table implementation
--- Move away from 16-bit hashes since we need more than 64k buckets to hold 2M entries efficiently
--- Change to CityHash64, which is faster and stronger
--- Remove hardcoded max limit
* NAME_INDEX changed from contigouos int to monotonically increasing int
--- Opens up for future deduplication schemes that are better than number suffix dedup.
--- Saves some memory since we don't need to maintain a contiguous array
--- Typed up to cause compile errors when used as integer directly
* Avoid touching data repeatedly, normal path only does single hash of data
* New constructor that allows supplying string length up front
* Avoid dynamic allocations in string conversions >= 128 characters
* Avoid extra copying when splitting numbers
* More efficient IsPureAnsi check
* Only do one global lazy initialization call instead of multiple
* Switch to faster RW locks
* Switch from single lock to sharded hash map with separate locks
* Memory optimizations that reduces per entry overhead: 4 bytes slots, 2 byte headers and don't store null terminator
Improved API & documentation
* Document that IsValid() rarely makes sense
* Hide global state such as GetNames()
* Reduce amount of implementation details visible in header
* NameTypes.h size down by ~1/3 while adding documentation, stronger type safety and new APIs
Future possibilities
* Memory savings: Removing public NAME_INDEX and global FName array allows using the 32-bit FNameEntryId for arbitrary deduplication schemes. This can save both actual stored strings memory by deduplication and half the size of FName instances from 8B to 4B in shipping / test configs by removing the number part.
* Implementation can be tweaked further, for instance could persist 32-bit slot index hash inside slot to increase encoding performance in development / debug at the cost of memory.
Perf & mem results for internal project:
* Editor startup wall time: 12% speedup, 22.0s -> 19.5s
--- Warm disk and asset registry cache
--- Some gains from nametable serialization improvements
--- Some of these gains might be from orthogonal asset discovery optimizations
* Win64 Test Client memory usage with ~400k names: 30.3Mb -> 22.2Mb
#rb steve.robb, pj.kack
#jira UE-59973
[CL 5774657 by Johan Torp in Dev-Core branch]
* Removed code to invalidate makefiles when adding new source files. UBT should be reliable enough to make this determination itself nowadays, and ignored -invalidatemakefilesonly argument was causing modules to be recompiled.
* Fixed incorrect config section name when determining whether to allow hot reload from IDE. Now prevents hot reload from IDE when live coding is enabled.
* Added error message when trying to add a new class with Live Coding enabled.
* Added error messages when trying to start Live Coding after a hot reload has taken place.
* Added error messages when trying to hot reload with Live Coding enabled.
#jira UE-71253
#rb none
#ROBOMERGE-SOURCE: CL 5403464 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5403485 by ben marsh in Main branch]
#rb none
#jira UE-71399
#ROBOMERGE-SOURCE: CL 5365389 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5368509 by ben marsh in Main branch]
#rb none
#jira UE-71379
#ROBOMERGE-SOURCE: CL 5362145 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5368489 by ben marsh in Main branch]
#rb none
#jira UE-71269
#ROBOMERGE-SOURCE: CL 5361379 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5368488 by ben marsh in Main branch]
#rb none
#jira UE-71270
#ROBOMERGE-SOURCE: CL 5361279 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5368485 by ben marsh in Main branch]
#rb none
#jira UE-71359
#ROBOMERGE-SOURCE: CL 5361201 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5368484 by ben marsh in Main branch]
#rb none
#jira UE-71362
#ROBOMERGE-SOURCE: CL 5360814 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5368482 by ben marsh in Main branch]
#rb none
#jira UE-71274
#ROBOMERGE-SOURCE: CL 5353250 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5364960 by ben marsh in Main branch]
* Compile dropdown now just contains a checkbox for enabling live coding.
* Compile dropdown has a link to open the editor preferences window.
* Live coding can be enabled from the editor settings window.
* Option to show the console on startup is now folded into the startup mode.
* Options in the editor settings window are greyed out unless live coding is enabled.
#rb none
#jira
#ROBOMERGE-SOURCE: CL 5352692 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5364901 by ben marsh in Main branch]
#rb none
#jira UE-71126
#ROBOMERGE-SOURCE: CL 5350227 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5364819 by ben marsh in Main branch]
#rb none
#jira UE-71077
#ROBOMERGE-SOURCE: CL 5343160 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5343162 by ben marsh in Main branch]
#rb none
#jira
#rnx
#ROBOMERGE-SOURCE: CL 5341380 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5341387 by ben marsh in Main branch]
#rb none
#jira
#ROBOMERGE-SOURCE: CL 5340479 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5340483 by ben marsh in Main branch]
#rb none
#jira
#rnx
#ROBOMERGE-SOURCE: CL 5312346 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5316165 by ben marsh in Main branch]
#rb none
#jira
#rnx
#ROBOMERGE-SOURCE: CL 5312269 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5316164 by ben marsh in Main branch]
#rb none
#rnx
#jira
#ROBOMERGE-SOURCE: CL 5312261 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5316163 by ben marsh in Main branch]
#rb none
#jira
#rnx
#ROBOMERGE-SOURCE: CL 5307349 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5314652 by ben marsh in Main branch]
#rb none
#jira
#ROBOMERGE-SOURCE: CL 5307320 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5314647 by ben marsh in Main branch]
Allows fast iteration of C++ changes without restarting the application. To use, select the "Live Coding (Experimental)" mode from the drop down menu next to the editor's compile button, or type "LiveCoding" into the console for a monolithic build. Press Ctrl+Alt+F11 to find changes and compile.
Changes vs standalone Live++ version:
* UBT is used to execute builds. This allows standard UE4 adaptive unity mode, allows us to reuse object files when we do regular builds, supports using any build executor allowed by UBT (XGE, SNDBS, etc..).
* Adding new source files is supported.
* Custom visualizer for FNames is supported via a weakly linked symbol in a static library (Engine/Extras/NatvisHelpers).
* Settings are exposed in the editor's project settings dialog.
* Standalone application has been rewritten as a Slate app ("LiveCodingConsole"). There is an additional option to start the program as hidden, where it will not be visible until Ctrl+Alt+F11 is hit. Similarly, closing the window will hide it instead of closing the application.
* Does not require a standalone licensed version of Live++.
Known issues:
* Does not currently support class layout changes / object reinstancing
#rb none
[FYI] Marc.Audy, Stefan.Boberg, Nick.Penwarden
#jira
#ROBOMERGE-SOURCE: CL 5304722 in //UE4/Release-4.22/...
#ROBOMERGE-BOT: RELEASE (Release-4.22 -> Main)
[CL 5309051 by ben marsh in Main branch]
