libnetwork/resolvconf: some cleaning up and optimisations#44234
Merged
thaJeztah merged 8 commits intomoby:masterfrom Apr 26, 2023
Merged
libnetwork/resolvconf: some cleaning up and optimisations#44234thaJeztah merged 8 commits intomoby:masterfrom
thaJeztah merged 8 commits intomoby:masterfrom
Conversation
thaJeztah
changed the title
thaJeztah
force-pushed
the
resolvconf_refactor_step1
branch
2 times, most recently
from
d3c060b to
191d532
Compare
thaJeztah
force-pushed
the
resolvconf_refactor_step1
branch
2 times, most recently
from
6ba5b9b to
eb74235
Compare
thaJeztah
force-pushed
the
resolvconf_refactor_step1
branch
from
eb74235 to
78f765e
Compare
thaJeztah
force-pushed
the
resolvconf_refactor_step1
branch
from
78f765e to
6140f52
Compare
tianon
approved these changes
Dec 22, 2022
thaJeztah
force-pushed
the
resolvconf_refactor_step1
branch
from
6140f52 to
f53639d
Compare
Member
Author
|
@corhere ptal 🤗 |
corhere
approved these changes
Jan 11, 2023
Comment on lines
+9
to
14
| func hashData(data []byte) []byte { | ||
| f := sha256.Sum256(data) | ||
| out := make([]byte, 2*sha256.Size) | ||
| hex.Encode(out, f[:]) | ||
| return append([]byte("sha256:"), out...) | ||
| } |
Contributor
There was a problem hiding this comment.
It can be done with even fewer allocs:
Suggested change
| func hashData(data []byte) []byte { | |
| f := sha256.Sum256(data) | |
| out := make([]byte, 2*sha256.Size) | |
| hex.Encode(out, f[:]) | |
| return append([]byte("sha256:"), out...) | |
| } | |
| const hashPrefix = "sha256:" | |
| func hashData(data []byte) []byte { | |
| out := make([]byte, len(hashPrefix)+hex.EncodedLen(sha256.Size)) | |
| copy(out, hashPrefix) | |
| f := sha256.Sum256(data) | |
| hex.Encode(out[len(hashPrefix):], f[:]) | |
| return out | |
| } |
The code seemed overly complicated, requiring a reader to be constructed,
where in all cases, the data was already available in a variable. This patch
simplifies the utility to not require a reader, which also makes it a bit
more performant:
go install golang.org/x/perf/cmd/benchstat@latest
GO111MODULE=off go test -run='^$' -bench=. -count=20 > old.txt
GO111MODULE=off go test -run='^$' -bench=. -count=20 > new.txt
benchstat old.txt new.txt
name old time/op new time/op delta
HashData-10 201ns ± 1% 128ns ± 1% -36.16% (p=0.000 n=18+20)
name old alloc/op new alloc/op delta
HashData-10 416B ± 0% 208B ± 0% -50.00% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
HashData-10 6.00 ± 0% 3.00 ± 0% -50.00% (p=0.000 n=20+20)
A small change was made in `Build()`, which previously returned the resolv.conf
data, even if the function failed to write it. In the new variation, `nil` is
consistently returned on failures.
Note that in various places, the hash is not even used, so we may be able to
simplify things more after this.
Signed-off-by: Sebastiaan van Stijn <[email protected]>
After my last change, I noticed that the hash is used as a []byte in most
cases (other than tests). This patch updates the type to use a []byte, which
(although unlikely very important) also improves performance:
Compared to the previous version:
benchstat new.txt new2.txt
name old time/op new time/op delta
HashData-10 128ns ± 1% 116ns ± 1% -9.77% (p=0.000 n=20+20)
name old alloc/op new alloc/op delta
HashData-10 208B ± 0% 88B ± 0% -57.69% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
HashData-10 3.00 ± 0% 2.00 ± 0% -33.33% (p=0.000 n=20+20)
And compared to the original version:
benchstat old.txt new2.txt
name old time/op new time/op delta
HashData-10 201ns ± 1% 116ns ± 1% -42.39% (p=0.000 n=18+20)
name old alloc/op new alloc/op delta
HashData-10 416B ± 0% 88B ± 0% -78.85% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
HashData-10 6.00 ± 0% 2.00 ± 0% -66.67% (p=0.000 n=20+20)
Signed-off-by: Sebastiaan van Stijn <[email protected]>
The test was assuming that the "source" file was always "/etc/resolv.conf", but the `Get()` function uses `Path()` to find the location of resolv.conf, which may be different. While at it, also changed some `t.Fatalf()` to `t.Errorf()`, and renamed some variables for clarity. Signed-off-by: Sebastiaan van Stijn <[email protected]>
Use t.TempDir() for convenience, and change some t.Fatal's to Errors, so that all tests can run instead of failing early. Signed-off-by: Sebastiaan van Stijn <[email protected]>
Looks like the intent is to exclude windows (which wouldn't have /etc/resolv.conf nor systemd), but most tests would run fine elsewhere. This allows running the tests on macOS for local testing. Signed-off-by: Sebastiaan van Stijn <[email protected]>
Signed-off-by: Sebastiaan van Stijn <[email protected]>
- Verify the content to be equal, not "contains"; this output should be predictable. - Also verify the content returned by the function to match. Signed-off-by: Sebastiaan van Stijn <[email protected]>
Signed-off-by: Sebastiaan van Stijn <[email protected]>
thaJeztah
force-pushed
the
resolvconf_refactor_step1
branch
from
f53639d to
56fbbde
Compare
Member
Author
|
Forgot about this one; did a rebase to get a fresh run of CI, and will merge when it completes (I might do a follow up with that last bit of optimisation from #44234 (comment)) |
thaJeztah
added
status/4-merge
kind/refactor
Member
Author
|
Some Windows failures are unrelated (may be an issue with Docker Hub; there was a similar issue earlier today); |
Member
Author
|
confirmed that those failures are unrelated; see #45415. bringing this one in 👍 |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
See individual commits for details
- A picture of a cute animal (not mandatory but encouraged)