Linus Groh a82c56f9f7 LibJS: Speed up IndexedPropertyIterator by computing non-empty indices
This provides a huge speed-up for objects with large numbers as property
keys in some situation. Previously we would simply iterate from 0-<max>
and check if there's a non-empty value at each index - now we're being
smarter and compute a list of non-empty indices upfront, by checking
each value in the packed elements vector and appending the sparse
elements hashmap keys (for GenericIndexedPropertyStorage).

Consider this example, an object with a single own property, which is a
number increasing by a factor of 10 each iteration:

    for (let i = 0; i < 10; ++i) {
        const o = {[10 ** i]: "foo"};
        const start = Date.now();
        Object.getOwnPropertyNames(o);  // <-- IndexedPropertyIterator
        const end = Date.now();
        console.log(`${10 ** i} -> ${(end - start) / 1000}s`);
    }

Before this change:

    1 -> 0.0000s
    10 -> 0.0000s
    100 -> 0.0000s
    1000 -> 0.0000s
    10000 -> 0.0005s
    100000 -> 0.0039s
    1000000 -> 0.0295s
    10000000 -> 0.2489s
    100000000 -> 2.4758s
    1000000000 -> 25.5669s

After this change:

    1 -> 0.0000s
    10 -> 0.0000s
    100 -> 0.0000s
    1000 -> 0.0000s
    10000 -> 0.0000s
    100000 -> 0.0000s
    1000000 -> 0.0000s
    10000000 -> 0.0000s
    100000000 -> 0.0000s
    1000000000 -> 0.0000s

Fixes #3805.
2020-10-20 08:51:41 +02:00
2020-10-19 11:29:55 +02:00
2020-10-17 23:20:31 +02:00
2020-10-12 19:53:25 +02:00
2020-10-13 13:53:17 +02:00
2020-07-30 17:07:40 +02:00
2020-09-19 17:16:57 +02:00

SerenityOS

Graphical Unix-like operating system for x86 computers.

Travis CI status

About

SerenityOS is a love letter to '90s user interfaces with a custom Unix-like core. It flatters with sincerity by stealing beautiful ideas from various other systems.

Roughly speaking, the goal is a marriage between the aesthetic of late-1990s productivity software and the power-user accessibility of late-2000s *nix. This is a system by us, for us, based on the things we like.

I (Andreas) regularly post raw hacking sessions and demos on my YouTube channel.

Sometimes I write about the system on my github.io blog.

I'm also on Patreon and GitHub Sponsors if you would like to show some support that way.

Screenshot

Screenshot as of 8ea4375

Kernel features

  • x86 (32-bit) kernel with pre-emptive multi-threading
  • Hardware protections (SMEP, SMAP, UMIP, NX, WP, TSD, ...)
  • IPv4 stack with ARP, TCP, UDP and ICMP protocols
  • ext2 filesystem
  • POSIX signals
  • Purgeable memory
  • /proc filesystem
  • Pseudoterminals (with /dev/pts filesystem)
  • Filesystem notifications
  • CPU and memory profiling
  • SoundBlaster 16 driver
  • VMWare/QEMU mouse integration

System services

  • Launch/session daemon (SystemServer)
  • Compositing window server (WindowServer)
  • Text console manager (TTYServer)
  • DNS client (LookupServer)
  • Network protocols server (ProtocolServer)
  • Software-mixing sound daemon (AudioServer)
  • Desktop notifications (NotificationServer)
  • HTTP server (WebServer)
  • Telnet server (TelnetServer)
  • DHCP client (DHCPClient)

Libraries

  • C++ templates and containers (AK)
  • Event loop and utilities (LibCore)
  • 2D graphics library (LibGfx)
  • GUI toolkit (LibGUI)
  • Cross-process communication library (LibIPC)
  • HTML/CSS engine (LibWeb)
  • JavaScript engine (LibJS)
  • Markdown (LibMarkdown)
  • Audio (LibAudio)
  • PCI database (LibPCIDB)
  • Terminal emulation (LibVT)
  • Out-of-process network protocol I/O (LibProtocol)
  • Mathematical functions (LibM)
  • ELF file handling (LibELF)
  • POSIX threading (LibPthread)
  • Higher-level threading (LibThread)
  • Transport Layer Security (LibTLS)
  • HTTP and HTTPS (LibHTTP)

Userland features

  • Unix-like libc and userland
  • Shell with pipes and I/O redirection
  • On-line help system (both terminal and GUI variants)
  • Web browser (Browser)
  • C++ IDE (HackStudio)
  • IRC client
  • Desktop synthesizer (Piano)
  • Various desktop apps & games
  • Color themes

How do I read the documentation?

Man pages are browsable outside of SerenityOS under Base/usr/share/man.

When running SerenityOS you can use man for the terminal interface, or help for the GUI interface.

How do I build and run this?

See the SerenityOS build instructions

Before opening an issue

Please see the issue policy.

Communication hubs

The main hub is #serenityos on the Freenode IRC network.

We also have a project mailing list: serenityos-dev.

Author

Contributors

(And many more!) The people listed above have landed more than 100 commits in the project. :^)

License

SerenityOS is licensed under a 2-clause BSD license.

Description
No description provided
Readme BSD-2-Clause 280 MiB
Languages
C++ 66.2%
HTML 21.5%
JavaScript 10%
CMake 0.7%
Objective-C++ 0.5%
Other 1%