parallel-hashmap VS chromium

Standard library maps/unordered_maps are themselves notoriously slow anyway. A sparse_hash_map from abseil or parallel-hashmaps[1] would be better.

[1] https://github.com/greg7mdp/parallel-hashmap

Cool! Looking forward to you trying my phmap - and please let me know if you have any question.

I do this as well in my phmap and gtl implementations. It makes the tables look worse in benchmarks like the above, but prevents really bad surprises occasionally.

Thanks a lot for the great benchmark, Martin. Glad you used different hash functions, because I do sacrifice some speed to make sure that the performance of my hash maps doesn't degrade drastically with poor hash functions. Happy to see that my phmap and gtl (the C++20 version) performed well.

I use https://github.com/greg7mdp/parallel-hashmap when I need better performance of maps and sets.

Then they should really try https://github.com/greg7mdp/parallel-hashmap, the current state of the art.

Unordered hash map shootout CMAP = https://github.com/tylov/STC KMAP = https://github.com/attractivechaos/klib PMAP = https://github.com/greg7mdp/parallel-hashmap FMAP = https://github.com/skarupke/flat_hash_map RMAP = https://github.com/martinus/robin-hood-hashing HMAP = https://github.com/Tessil/hopscotch-map TMAP = https://github.com/Tessil/robin-map UMAP = std::unordered_map Usage: shootout [n-million=40 key-bits=25] Random keys are in range [0, 2^25). Seed = 1656617916: T1: Insert/update random keys: KMAP: time: 1.949, size: 15064129, buckets: 33554432, sum: 165525449561381 CMAP: time: 1.649, size: 15064129, buckets: 22145833, sum: 165525449561381 PMAP: time: 2.434, size: 15064129, buckets: 33554431, sum: 165525449561381 FMAP: time: 2.112, size: 15064129, buckets: 33554432, sum: 165525449561381 RMAP: time: 1.708, size: 15064129, buckets: 33554431, sum: 165525449561381 HMAP: time: 2.054, size: 15064129, buckets: 33554432, sum: 165525449561381 TMAP: time: 1.645, size: 15064129, buckets: 33554432, sum: 165525449561381 UMAP: time: 6.313, size: 15064129, buckets: 31160981, sum: 165525449561381 T2: Insert sequential keys, then remove them in same order: KMAP: time: 1.173, size: 0, buckets: 33554432, erased 20000000 CMAP: time: 1.651, size: 0, buckets: 33218751, erased 20000000 PMAP: time: 3.840, size: 0, buckets: 33554431, erased 20000000 FMAP: time: 1.722, size: 0, buckets: 33554432, erased 20000000 RMAP: time: 2.359, size: 0, buckets: 33554431, erased 20000000 HMAP: time: 0.849, size: 0, buckets: 33554432, erased 20000000 TMAP: time: 0.660, size: 0, buckets: 33554432, erased 20000000 UMAP: time: 2.138, size: 0, buckets: 31160981, erased 20000000 T3: Remove random keys: KMAP: time: 1.973, size: 0, buckets: 33554432, erased 23367671 CMAP: time: 2.020, size: 0, buckets: 33218751, erased 23367671 PMAP: time: 2.940, size: 0, buckets: 33554431, erased 23367671 FMAP: time: 1.147, size: 0, buckets: 33554432, erased 23367671 RMAP: time: 1.941, size: 0, buckets: 33554431, erased 23367671 HMAP: time: 1.135, size: 0, buckets: 33554432, erased 23367671 TMAP: time: 1.064, size: 0, buckets: 33554432, erased 23367671 UMAP: time: 5.632, size: 0, buckets: 31160981, erased 23367671 T4: Iterate random keys: KMAP: time: 0.748, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 CMAP: time: 0.627, size: 23367671, buckets: 33218751, repeats: 8, sum: 4465059465719680 PMAP: time: 0.680, size: 23367671, buckets: 33554431, repeats: 8, sum: 4465059465719680 FMAP: time: 0.735, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 RMAP: time: 0.464, size: 23367671, buckets: 33554431, repeats: 8, sum: 4465059465719680 HMAP: time: 0.719, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 TMAP: time: 0.662, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 UMAP: time: 6.168, size: 23367671, buckets: 31160981, repeats: 8, sum: 4465059465719680 T5: Lookup random keys: KMAP: time: 0.943, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 CMAP: time: 0.863, size: 23367671, buckets: 33218751, lookups: 34235332, found: 29040438 PMAP: time: 1.635, size: 23367671, buckets: 33554431, lookups: 34235332, found: 29040438 FMAP: time: 0.969, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 RMAP: time: 1.705, size: 23367671, buckets: 33554431, lookups: 34235332, found: 29040438 HMAP: time: 0.712, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 TMAP: time: 0.584, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 UMAP: time: 1.974, size: 23367671, buckets: 31160981, lookups: 34235332, found: 29040438

std::unordered_map is notorious for being slow. Use a better implementation (I like the flat naps from here, which are the same as abseil’s). The question that needs to be asked too is if you need to use a map.

A comparison against phmap would also be nice.

std::unordered_map is perfectly fine. You can do better with external libraries, like parallel hashmap, but these tend to be drop-in replacements

One of the unexpected use of shadow DOMs for me was a document generated for image resource URLs [1], because the HTML standard apparently specifies the exact DOM structure of the generated document except for the `` element [2].

[1] https://github.com/chromium/chromium/blob/f02ca73/third_part...

[2] https://html.spec.whatwg.org/multipage/document-lifecycle.ht...

Recently my favorite open source mouse gestures extension SmartUp Gestures was taken over by some shady entity (with github no longer being updated of course).

I opened Chrome ticket that they should ask to re-enable extension when ownership changes. They just closed the ticket replying with this link:

https://chromium.googlesource.com/chromium/src/+/main/extens...

:(

Hmm. It looks like files with the .lnk or .pif file extension can only be downloaded on a user gesture: https://chromium.googlesource.com/chromium/src/+/39841e54180...

So it can't be done silently. Although, I do wish the type was marked "DANGEROUS" a la dll files.

On Linux, Chromium uses setuid or user namespaces to restrict the access of sandboxed components and seccomp-bpf to reduce the kernel attack surface.

Check out the Chromium docs on this topic: https://chromium.googlesource.com/chromium/src/+/HEAD/docs/l...

You can also disable JIT in Firefox by setting javascript.options.baselinejit to false in about:config, although you won't get CET.

[1] https://github.com/chromium/chromium/blob/12c232c43ce7324d30...

Chromium targets iOS already: https://chromium.googlesource.com/chromium/src/+/main/docs/i...

For the sake of completeness, I've traced the evolution of the notice over time:

From 2008-07-26: "Going incognito doesn't affect the behavior of other people, servers, or software. Be wary of: / • Websites that collect or share information about you / • Internet service providers or employers that track the pages you visit / • Malicious software that tracks your keystrokes in exchange for free smileys / • Surveillance by secret agents / • People standing behind you" (https://chromium.googlesource.com/chromium/src/+/09911bf300f...)

From 2013-12-07: "Going incognito doesn't affect the behavior of other people, servers, software, or people standing behind you." (https://chromium.googlesource.com/chromium/src/+/c5e36c57178...)

From 2013-12-13: "However, you aren't invisible. Going incognito doesn't hide your browsing from your employer, your internet service provider, or the websites you visit." (https://chromium.googlesource.com/chromium/src/+/70821506825...)

From 2014-02-27: "However, you aren't invisible. Going incognito doesn't hide your browsing from your employer, your internet service provider, governments and other sophisticated attackers, or the websites you visit." (https://chromium.googlesource.com/chromium/src/+/ab54bd65701...)

From 2014-04-29: "Going incognito doesn't hide your browsing from your employer, your internet service provider, or the websites you visit." (https://chromium.googlesource.com/chromium/src/+/eb09a62ef40...)

From 2016-01-15: "However, you aren't invisible. Going incognito doesn’t hide your browsing from your employer, your internet service provider, or the websites you visit." (https://chromium.googlesource.com/chromium/src/+/b7dac1a6a79...)

From 2017-02-27: "Your activity might still be visible to: / • Websites you visit / • Your employer / • Your internet service provider" (https://chromium.googlesource.com/chromium/src/+/cfe102adddc...)

From 2017-03-29: "Your activity might still be visible to: / • Websites you visit / • Your employer or school / • Your internet service provider" (https://chromium.googlesource.com/chromium/src/+/7ca3ccf74e8...)

(Note that some of these were behind a feature flag for a few months.) Also, it looks like they've been intending to modify the new-tab page text for Incognito windows for some time, as part of the "Revamped Incognito NTP" project. You can view the modified text with 'chromium --enable-features=IncognitoNtpRevamp':

From 2021-08-13: "What Incognito doesn't do / Incognito does not make you invisible online: / • Sites know when you visit them / • Employers or schools can track browsing activity / • Internet service providers may monitor web traffic" (https://chromium.googlesource.com/chromium/src/+/e6ae57ba385...)

From 2022-01-25: "What Incognito doesn't do / Incognito does not make you invisible online: / • Sites and the services they use can see visits / • Employers or schools can track browsing activity / • Internet service providers can monitor web traffic" (https://chromium.googlesource.com/chromium/src/+/8b349f6c984...)

Blink can now be compiled for iOS, but without JIT or WASM:

https://chromium.googlesource.com/chromium/src/+/main/docs/i...

https://bugs.chromium.org/p/chromium/issues/detail?id=141170...

I think its weird that Vercel has this limit. There is no practical reason I can think of for having such a limit on URL characters that is so small. Chrome suggests a 2MB limit[0] for example. The platform itself doesn't have one, and Firefox I believe if memory serves (I can't find the source for this claim atm) is 1 MB effectively, and I don't think Safari is any lower than that either (and may well be more inline with Chrome on this, at 2 MB)

[0]: https://chromium.googlesource.com/chromium/src/+/master/docs...