Safely create temporary files and directories #3378
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Thanks @eelstork ! This looks good |
eelstork
changed the title
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Adding a commit targeting safe creation of temporary files. In this case the approach used to create temporary directories cannot be reused:
The proposed solution consists in (safely) creating a temporary directory. This temporary directory is then used as a container for all temporary files. Optionally, this approach may be extended to the creation of temporary directories (meaning: safely create a temp directory, then use it as a container for all temp files and directories). |
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@ronghanghu this needs a little more work on my end, not compiling in VS. |
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@eelstork Thank you and don't worry. I'll take a look when it's ready :) |
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@ronghanghu ready for review. |
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@eelstork Thanks! I'll try to take a look tomorrow |
| *temp_filename = boost::filesystem::unique_path(model).string(); | ||
| } | ||
| static path temp_files_subpath; | ||
| static uint64_t next_temp_file = 0; |
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Better to move this two static variables into function MakeTempFilename (while keeping them static) so that they are only accessible in that function.
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@eelstork This should be ready. Let's fix the minor issue mentioned above and I'll merge. |
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Updated; looks good to me.
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Safely create temporary files and directories
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Thanks @eelstork ! |
With reference to #3324 I propose a modified implementation of
MakeTempDir.@futurely and @netheril96 suggested that the designated issue may be caused by a race condition.
Upon closer inspection, I find that:
unique_pathis specified to return a randomly generated path, which may or may not be unique. Boost implementations typically system level entropy sources to generate the path.mkdtempimplementations rely onmkdirto generate temporary directories. Race conditions are avoided by checking the return value ofmkdirinstead of checking whether a generated path already exists.mkdtempimplementations may use 5 or 6 bits of randomness.With this in mind the proposed solution is similar to how Python implements
mkdtemp(tempfile.py, line 322).