storage: fix up docstring comments #1
Closed
Conversation
This file contains 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
In order to make actually reading the interfaces easier (as well as making godoc actually useful), we need to comment the interface methods themselves rather than the whole interface. Signed-off-by: Aleksa Sarai <[email protected]>
|
Looks good, merging. |
|
Uhh d4ee4f6 isn't a merge, you took my commit then stripped my |
|
Doh. That's what I get for using git merge instead of the web UI. Alright if I rewrite the history to try to restore it? |
|
Oh, wait, those are two commits. 6a6198a should be exactly what was proposed. |
|
Ah, my apologies. The short message was the same so I didn't think to go through the history (since there wasn't a merge commit). Sorry about that. :P |
|
No worries. I'll try to use the web UI to do those in the future. |
|
I actually don't like the Web UI either, but personally I always make sure to use |
|
Ah, so that's what I missed. Thanks for the tip! |
kolyshkin
added a commit
to kolyshkin/storage
that referenced
this pull request
May 16, 2020
This subtle bug keeps lurking in because error checking for `Mkdir()` and `MkdirAll()` is slightly different wrt `EEXIST`/`IsExist`: - for `Mkdir()`, `IsExist` error should (usually) be ignored (unless you want to make sure directory was not there before) as it means "the destination directory was already there"; - for `MkdirAll()`, `IsExist` error should NEVER be ignored. This commit removes ignoring the IsExist error, as it should not be ignored. For more details, a quote from my opencontainers/runc#162 (July 2015): -quote- TL;DR: check for IsExist(err) after a failed MkdirAll() is both redundant and wrong -- so two reasons to remove it. Quoting MkdirAll documentation: MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error. If path is already a directory, MkdirAll does nothing and returns nil. This means two things: If a directory to be created already exists, no error is returned. If the error returned is IsExist (EEXIST), it means there exists a non-directory with the same name as MkdirAll need to use for directory. Example: we want to MkdirAll("a/b"), but file "a" (or "a/b") already exists, so MkdirAll fails. The above is a theory, based on quoted documentation and my UNIX knowledge. In practice, though, current MkdirAll implementation [1] returns ENOTDIR in most of cases described in containers#2, with the exception when there is a race between MkdirAll and someone else creating the last component of MkdirAll argument as a file. In this very case MkdirAll() will indeed return EEXIST. Because of containers#1, IsExist check after MkdirAll is not needed. Because of containers#2 and containers#3, ignoring IsExist error is just plain wrong, as directory we require is not created. It's cleaner to report the error now. Note this error is all over the tree, I guess due to copy-paste, or trying to follow the same usage pattern as for Mkdir(), or some not quite correct examples on the Internet. [1] https://github.com/golang/go/blob/f9ed2f75/src/os/path.go -end-quote- Signed-off-by: Kir Kolyshkin <[email protected]>
kolyshkin
added a commit
to kolyshkin/storage
that referenced
this pull request
May 18, 2020
This subtle bug keeps lurking in because error checking for `Mkdir()` and `MkdirAll()` is slightly different wrt `EEXIST`/`IsExist`: - for `Mkdir()`, `IsExist` error should (usually) be ignored (unless you want to make sure directory was not there before) as it means "the destination directory was already there"; - for `MkdirAll()`, `IsExist` error should NEVER be ignored. This commit removes ignoring the IsExist error, as it should not be ignored. For more details, a quote from my opencontainers/runc#162 (July 2015): -quote- TL;DR: check for IsExist(err) after a failed MkdirAll() is both redundant and wrong -- so two reasons to remove it. Quoting MkdirAll documentation: MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error. If path is already a directory, MkdirAll does nothing and returns nil. This means two things: If a directory to be created already exists, no error is returned. If the error returned is IsExist (EEXIST), it means there exists a non-directory with the same name as MkdirAll need to use for directory. Example: we want to MkdirAll("a/b"), but file "a" (or "a/b") already exists, so MkdirAll fails. The above is a theory, based on quoted documentation and my UNIX knowledge. In practice, though, current MkdirAll implementation [1] returns ENOTDIR in most of cases described in containers#2, with the exception when there is a race between MkdirAll and someone else creating the last component of MkdirAll argument as a file. In this very case MkdirAll() will indeed return EEXIST. Because of containers#1, IsExist check after MkdirAll is not needed. Because of containers#2 and containers#3, ignoring IsExist error is just plain wrong, as directory we require is not created. It's cleaner to report the error now. Note this error is all over the tree, I guess due to copy-paste, or trying to follow the same usage pattern as for Mkdir(), or some not quite correct examples on the Internet. [1] https://github.com/golang/go/blob/f9ed2f75/src/os/path.go -end-quote- Signed-off-by: Kir Kolyshkin <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
In order to make actually reading the interfaces easier (as well as
making godoc actually useful), we need to comment the interface methods
themselves rather than the whole interface.
Signed-off-by: Aleksa Sarai [email protected]