Hi John, I ' m an Java developer for 20 years and relative new to python. But I would like to help for a better effort. How and where could I start and help?
Thanks and regards Friedhelm -----Ursprüngliche Nachricht----- Von: Hdf-forum [mailto:[email protected]] Im Auftrag von [email protected] Gesendet: Mittwoch, 20. Dezember 2017 15:03 An: [email protected] Betreff: Hdf-forum Digest, Vol 102, Issue 25 Send Hdf-forum mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Hdf-forum digest..." Today's Topics: 1. Re: h5serv, Tablet, compound (John Readey) 2. Re: Errors when install HDF5 (??) 3. [RFC] [PATCH] Windows Unicode Filename support (Christian Seiler) ---------------------------------------------------------------------- Message: 1 Date: Tue, 19 Dec 2017 22:25:11 +0000 From: John Readey <[email protected]> To: HDF Users Discussion List <[email protected]> Subject: Re: [Hdf-forum] h5serv, Tablet, compound Message-ID: <[email protected]> Content-Type: text/plain; charset="utf-8" Hi Freidhelm, I?d love to have pytables and pandas integrated with HDF Server, but that would take some work. A lot of effort went into h5pyd and it?s working pretty well as a h5py drop in. So, I think the best approach would be to first refactor pytables to use h5py. This is what Andy Scopatz proposed earlier: https://www.hdfgroup.org/2015/09/python-hdf5-a-vision/. Unfortunately, not much progress has been made in this effort. Anyway, once we have pytables on h5py, it would be easy to have pytables use h5py or h5pyd depending on if the file is a local posix file, or a HDF Server-based content. And from there, pandas support should come for free as well. For the question about production environments ? the project is relatively new, so please exercise reasonable precautions ? Backup any data you put into h5serv, follow best practices for security, don?t use for nuclear power plant control systems ( , etc. Cheers, John On 12/8/17, 5:45 AM, "Hdf-forum on behalf of ISCaD GmbH" <[email protected] on behalf of [email protected]> wrote: Hi, I begin use of h5serv and have to question. 1. I would like to use pytables or pandas, is this possible with h5pyd or must I use compound datatype and when....has anybody an example? 2. Is the reference with docker for production like environments safe ? Thanks Friedhelm _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5 ------------------------------ Message: 2 Date: Wed, 20 Dec 2017 21:46:45 +0800 From: ?? <[email protected]> To: HDF Users Discussion List <[email protected]> Subject: Re: [Hdf-forum] Errors when install HDF5 Message-ID: <[email protected]> Content-Type: text/plain; charset="gb2312" Hello, Barbara, Thank you sooooo much for your reply, I am sorry to reply you late. I have installed by running ?yum install hdf5 hdf5-devel?. Although I don?t know which version I have installed, and the program I need runs well. I just focus the program so I ignore the error I have meet. By the way, thank you for your concern. Have a nice day. Jie Jiang > ? 2017?12?7????12:06??? <[email protected]> ??? > > <config.log> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.hdfgroup.org/pipermail/hdf-forum_lists.hdfgroup.org/attachment s/20171220/dfc8c13a/attachment-0001.html> ------------------------------ Message: 3 Date: Wed, 20 Dec 2017 14:05:10 +0100 From: Christian Seiler <[email protected]> To: [email protected] Subject: [Hdf-forum] [RFC] [PATCH] Windows Unicode Filename support Message-ID: <[email protected]> Content-Type: text/plain; charset="utf-8"; Format="flowed" Dear all, Preface ======= I'd like to contribute a patch to HDF5, and this appears to be the appropriate place to send it to. If I am mistaken, I'd appreciate a pointer where to go instead. (It would be great if the website could have some prominent information about how to contribute to HDF5. Also, I couldn't find it, does HDF5 have a version control repository, such as Git or SVN?) Problem description =================== Windows has two different representations of filenames: 8-bit fixed-width "ANSI" and 16-bit "Unicode" (effectively UTF-16). The 8-bit representation depends on the locale settings of the computer; the lower 128 values correspond to ASCII, while the upper 128 values depend on the locale settings of the computer; in Germany, for example, code page 1252 is typically used. (Very similar, but not identical to ISO-8859-1.) When using standardized C / POSIX functions as HDF5 does (open, fopen, etc.), which accept 8-bit strings, they will always assume the local 8-bit encoding. The problem is that the local 8-bit will never be able to encode all possible filenames that the operating system supports, as a fixed 8-bit encoding will never be able to encode all Unicode characters. Furthermore, in some languages there are so many characters that any fixed 8-bit encoding will never be able to represent all of them. This in turn means that on Windows systems it is possible to have HDF5 fail to open a file if the file name (or the directory that contains it) contains characters that are not representable in the local 8-bit encoding of the system. For example, on a typical US Windows installation it is not possible to use HDF5 to store files with names that contain e.g. Japanese characters, even though the operating system itself does support these. To actually access all possible files Microsoft offers alternatives to the standard functions that accept UTF-16 filenames in form of wchar_t strings. There is _wopen() instead of open(), and _wfopen() instead of fopen(). (For reference: other operating systems, such as Linux and Mac OS X, always represent filenames as 8-bit strings; the operating system often does not care about the precise encoding and leaves it up to the software itself (though in practice this most likely will be UTF-8 nowadays), which means that the standard 8-bit APIs can always be used to access any file on disk.) Example consequences of this problem: GUI application, user chooses a file from a "File Open" dialog, file name is converted appropriately and passed to HDF5, HDF5 cannot load the file (that the user chose in the same application) because the file (or a directory containing it) contains characters that can't be represented in the local code page. Rejected solutions ================== The most obvious solution would be to simply provide additional functions in HDF5 that also accept wchar_t filenames on Windows systems. However, HDF5 has a large number of methods that simply pass through file names (or maybe even manipulate them a bit) and this would lead to a huge duplication of existing code, which I don't believe is a good idea for the long-term maintenance of HDF5. An alternative suggestion (see e.g. [1]) would be to always assume on Windows systems that the filename supplied is encoded in UTF-8 (which, due to being variable-length, can represent all possible characters) and convert it to UTF-16 before passing it to the wide functions (_wopen, _wfopen) directly. This has the advantage that now all filenames can be represented. However this has the huge disadvantage that most software does not expect HDF5 to accept UTF-8-encoded file names, and if a program converts a string that it got from a "File Open" dialog into the local 8bit codepage (as many programs would do now), any character in the local code page beyond ASCII would cease to work (as UTF-8 encodes them differently). For example, since the German umlauts ?, ?, ? can be represented in the local codepage, file names with these characters can actually be opened on Windows systems with HDF5 at the moment (when using German locale settings, at least), and this change would break existing programs if it were to be added to HDF5 itself unconditionally. Proposed solution ================= I'd like to propose the following solution instead. It is based on the UTF-8 encoding idea, but keeps compatibility with existing software. - Default behavior: HDF5 behaves as it currently does and calls the standard "ANSI" open(), fopen(), etc. functions. It will hence continue to work with characters in the local code page. - Add a boolean to the file access property list that may be used to indicate that the file name is in UTF-8 on Windows systems (the boolean will be ignored on all other operating systems): H5Pset_windows_unicode_filenames(fapl, TRUE); - Update the filesystem drivers to check for this flag, and if it is set to actually do a conversion from UTF-8 to UTF-16 and then call the corresponding wide functions. The advantage is that current code doesn't break, but users who want to properly support Windows can actually do so, they just need to ensure they encode their filenames in UTF-8. The other main advantage is that the patch is not very invasive. I've attached (against 1.10.1) that implements this. The following is currently supported: - Property list flag accessors: H5Pset_windows_unicode_filenames(fapl, value); H5Pget_windows_unicode_filenames(fapl, &value); - SEC2/Windows driver - Core driver - stdio driver I've successfully tested this in the following constellation on a Windows 10 system with German locale (using MinGW-w64/gcc7.2.0 as the compiler, 64bit): - Flag not set, files with Umlauts, calling HDF5 with the file names encoded in the current codepage. (Compatibility check for existing software.) - Flag set, lots of different test cases (file names in pure ASCII, German Umlauts, Japanese characters, Hebrew characters, Arabic characters), calling HDF5 with the file names encoded in UTF-8 and the flag set in the FAPL before calling the HDF5 functions. I tested all three drivers (SEC2, Core, stdio) in both cases. I also tested that the patch doesn't break on Linux (Debian 9, gcc 7.2.0, 64bit x86) to ensure that the patches don't harm non-Windows platforms. What should work, but I haven't tested it: - The FAMILY driver, as that just passes through the FAPL to the underlying driver, and since UTF-8 is ASCII-compatible, any manipulation done in the driver should be safe as well. What I believe doesn't make sense to implement: - The direct I/O driver. It appears to contain some Windows code, but the CMake build system will never build it on Windows, so I left that out. If that is wrong and the direct I/O driver should work on Windows, I'll be happy to update the patch. What I didn't implement yet: - C++, Fortran and Java wrappers for the FAPL flag getters/setters - External File Lists (EFL) support (H5Defl.c) - HDF5 plugin libraries (H5PL.c) - Logging driver (H5FDlog.c) - Cache logging (H5Clog.c) Feedback is appreciated, and it would be fantastic if this could be included in a future version of HDF5. I would be willing to help out with the missing pieces. I do think that those can be added incrementally, and the current patch already improves the state of affairs on Windows quite a bit. For the avoidance of doubt: my employer agrees to license these changes under the same license that HDF5 1.10.1 is licensed under. Best regards, Christian References: [1] https://tschoonj.github.io/blog/2014/11/06/hdf5-on-windows-utf-8-filenames-s upport/ -------------- next part -------------- A non-text attachment was scrubbed... Name: windows_unicode_filenames.patch Type: text/x-patch Size: 25299 bytes Desc: not available URL: <http://lists.hdfgroup.org/pipermail/hdf-forum_lists.hdfgroup.org/attachment s/20171220/8dc6e569/attachment.bin> ------------------------------ Subject: Digest Footer _______________________________________________ Hdf-forum is for HDF software users discussion. 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