Pool file handles to prevent "too many open files" errors #161
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jeskesen
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Oct 3, 2025
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LGTM. with a couple of comments/questions
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| time_az_ms, frame_write_times_az = run_acquire_zarr_test(data, az_path, t_chunk_size, xy_chunk_size) | ||
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| """ |
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Is this a commented block of code meant to be removed?
| #include <string> | ||
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| namespace zarr { | ||
| class FileHandle |
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I had to look at this for a bit before figuring out what its function is (wrapping the platform-specific file handles into a class C++ can work with). Perhaps a comment to that effect?
So, why go through all that effort when std::filesystem exists?
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Because I need to use the platform-specific functions to get finer control and better performance. For example, #156 is not possible using the standard library.
jeskesen
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Oct 3, 2025
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Introduces a
FileHandlePoolclass (similar toThreadPoolandS3ConnectionPoolto manage file handle allocation and prevent exhausting OS limits during concurrent file I/O. This PR actually increases in some cases the number of open files that acquire-zarr may have at a time, due to the old scheme being limited by a fixed, more or less arbitrary, constant.Changes
FileHandleandFileHandlePoolclasses to manage file handle lifecyclegetrlimit(RLIMIT_NOFILE)on POSIX,_getmaxstdio()on Windows)FileSinkconstructor,ArrayBaseconstructors, and the variousmake_file_sinkoverloads require astd::shared_ptr<FileHandlePool>. These changes are BREAKING but internal.