1. 15 Apr, 2020 8 commits
    • Kirill Smelkov's avatar
      lib/zodb: Add patch to ZODB.Connection to support callback on connection DB view change · 959ae2d0
      Kirill Smelkov authored
      Wendelin.core 2 will need to hook into when client ZODB.Connection
      changes its database view and readjust WCFS-level client connection
      ZODB.Connection can change its view on either connection reopen, or even
      without reopen on start of new transaction.
      This patch implements ZODB.Connection.onResyncCallback for ZODB5 only.
      ZODB4 and ZODB3 support is TODO.
    • Kirill Smelkov's avatar
      lib/zodb: Add zconn_at draft (ZODB5 only) · 3bd82127
      Kirill Smelkov authored
      For wendelin.core v2 we need a way to know at which particular database
      state application-level ZODB connection is viewing the database. Knowing
      that state, WCFS client library will interact with WCFS filesystem server
      and, in simple terms, request the server to provide data as of that
      particular database state.
      Contrary to ZODB/go[1] ZODB/py does not provide the functionality to
      obtain DB state of connection view, so we have to build it ourselves.
      Let us call the function that for a client ZODB connection returns
      database state corresponding to its database view as zconn_at.
      It is relatively easy to implement zconn_at for ZODB5, since ZODB5
      adopted MVCC uniformly and this patch does just that. However even with
      ZODB5 currently all released ZODB5 versions have race in
      Connection.open() vs invalidations[2], and so the first ZODB5 release
      with which zconn_at implemented here will work reliable should be
      upcoming ZODB 5.5.2
      It is TODO to implement zconn_at for ZODB4 and ZODB3, which organize
      things differently.
      Please note what would happen if zconn_at gives, even a bit, incorrect
      answer: wcfs client will ask wcfs server to provide array data as of
      different database state compared to current on-client ZODB connection.
      This will result in that data accessed via ZBigArray will _not_
      correspond to all other data accessed via regular ZODB mechanism.
      It is, in other words, would be a data corruptions.
      [1] https://godoc.org/lab.nexedi.com/kirr/neo/go/zodb#Connection
      [2] https://github.com/zopefoundation/ZODB/issues/290
    • Kirill Smelkov's avatar
      lib/zodb: Add zmajor - way to know under which ZODB 3, 4 or 5 we are running · 8c0b7471
      Kirill Smelkov authored
      This will be needed in the following patches to know how to inject
      zconn_at or zconn resync functionality into particular ZODB version.
    • Kirill Smelkov's avatar
      bigfile/zodb: Cosmetics · c671aaea
      Kirill Smelkov authored
      - mention in comments that _ZBigFileH not only proxies changes from
        virtmem -> ZODB, but also the other way: virtmem <- ZODB.
      - refresh comments, fix typo.
    • Kirill Smelkov's avatar
      bigfile/file.h: Cosmetics · 927458f6
      Kirill Smelkov authored
      - Provide brief top-level overview + refresh loadblk/storeblk/release comments.
      - Add `typedef struct bigfile_ops bigfile_ops` that we usually add for all structs.
    • Kirill Smelkov's avatar
      bigfile/virtmem: vma_page_addr: Kill wrong XXX · 34ed82c6
      Kirill Smelkov authored
      It is valid to compare a Page and a VMA only if they belong to the same
    • Kirill Smelkov's avatar
      bigfile/virtmem: Factor-out checking whether `page->fpgoffset` is in file-range covered by `vma` · d53a480f
      Kirill Smelkov authored
      -> into vma_page_infilerange().
      We will soon need to use this functionality from several places.
    • Kirill Smelkov's avatar
      bigfile/virtmem: fileh_mmap: Refactor a bit · 516f4625
      Kirill Smelkov authored
      Start preparing vma early, not after the call to mem_valloc.
      This codeflow will be more convenient when we add mmap-through-wcfs codepath.
  2. 14 Apr, 2020 4 commits
  3. 01 Apr, 2020 2 commits
  4. 18 Dec, 2019 8 commits
    • Kirill Smelkov's avatar
      bigfile/py: Move data structures to public .h file · 907bd9d4
      Kirill Smelkov authored
      This is needed so that e.g. a Python class implemented in C or Cython
      (cdef class) could inherit from PyBigFile.
      Don't put _bigfile.h into separate include/ directory, and keep it along
      main .c file, similarly to how pygolang is organized.
    • Kirill Smelkov's avatar
      bigfile/py: Provide package-level documentation · 3684d164
      Kirill Smelkov authored
      Provide package-level documentation that gives brief overview of what
      this package does. Split internal notes into separate comment.
    • Kirill Smelkov's avatar
      bigfile/py: Stop using Plan9 C extensions · bf44905b
      Kirill Smelkov authored
      Starting from 5755a6b3 (Basic setup.py / Makefile to build/install/sdist
      stuff + bigfile.so skeleton) and 35eb95c2 (bigfile: Python wrapper
      around virtual memory subsystem) we were using Plan9 C extensions[1] for
      simple inheritance. Those extensions are supported by GCC with
      -fplan9-extensions option. However that option is supported only for C,
      while for C++ it does not work at all with error produced by the compiler
      on Plan9 syntax.
      Soon we'll need to add another extension - written in C++ - to
      wendelin.core . This extension will be providing client side of WCFS and
      integrating that with virtmem. In that extension we'll need to use
      _bigfile data structures - in particular we'll need to use PyBigFile and
      extend it with another `cdef class` children written in Cython/C++.
      This patch prepares for that: first stop using Plan9 C extensions in
      _bigfile py module data structures and adapt the code correspondingly.
      In the next patch we'll move those data structures into an .h file.
      We don't drop -fplan9-extensions from setup.py, because Plan9-style
      inheritance continues to be used internally by virtmem - e.g. in
      ram_shmfs.c and friends.
      A bit pity to drop that good stuff, but given that we'll need to use C++
      for WCFS client for other good stuff provided by pygolang[2], it is a
      reasonable compromise.
      [1] http://9p.io/sys/doc/comp.html  "Extensions" section
      [2] https://pypi.org/project/pygolang
    • Kirill Smelkov's avatar
      bigfile/zodb: Factor-out LivePersistent into -> lib/zodb · c02776e9
      Kirill Smelkov authored
      It was from long-ago marked as "XXX move to common place".
    • Kirill Smelkov's avatar
      bigfile/zodb: FIXME invalidations are not working correctly on blocks topology change · 8c32c9f6
      Kirill Smelkov authored
      I noticed this while working on WCFS: if file blocks topology change,
      the invalidation process is not working correctly. It is also not
      correct with respect to live cache pressure.
      Add FIXME in the code and test for live cache pressure.
    • Kirill Smelkov's avatar
      bigfile/zodb: Explain why we always mark ZBlk object changed if block data change · d27ade8e
      Kirill Smelkov authored
      For ZBlk0 this is trivial, but for ZBlk1 it may seem that we could avoid
      changing ZBlk object itself and mark only pointed-to ZData object as
      changed. However that would be not correct to do if we consider
      Noticed while working on WCFS.
    • Kirill Smelkov's avatar
      *: Add package-level documentation to ZODB-related packages · d5e0d2f9
      Kirill Smelkov authored
      Add package-level documentation to
        - bigfile/file_zodb.py,
        - bigarray/array_zodb.py, and
        - lib/zodb.py
      The most interesting read is file_zodb.py .
      Slightly improve documenation for functions in a couple of places.
      Improving documentation was long overdue and it is improved only slightly by this commit.
    • Kirill Smelkov's avatar
      tests: Keep ZEO test database on /tmp/ · 70c998c1
      Kirill Smelkov authored
      We already keep FileStorage test database on /tmp/ and NEO itself (via
      neo.tests.functional.NEOCluster) also keeps test data on tmpfs. However
      test database for ZEO was created in current directory and was wearing
      out SSD unnecessarily.
      FIXME zeo_forker currently does not provide API to keep all server files
      in particular place. This way server conf and log are still emitted in
      current directory, but at least we move data.fs away. Since conf and log
      are uniquely named, e.g. server-<ΧΧΧ>.conf and tmpYYY.log, and it was
      only that Data.fs was named non-uniquely, by moving Data.fs into unique
      per-server place, this also helps with-ZEO tests to execute correctly in
      parallel with `tox -p`.
  5. 04 Dec, 2019 2 commits
  6. 29 Sep, 2019 1 commit
  7. 18 Sep, 2019 1 commit
  8. 15 Jul, 2019 1 commit
    • Kirill Smelkov's avatar
      bigfile/py: It is ok to have .fileh_open() as BigFile method · 7ee02038
      Kirill Smelkov authored
      There was an XXX of whether fileh_open should be a BigFile method or
      global function. However if it would be a global function it will need
      to anyway accept file parameter to indicate which file is opened, and
      that in turn suggests that it should be a file method. Remove XXX.
  9. 12 Jul, 2019 3 commits
    • Kirill Smelkov's avatar
      */tests: Use defer instead of finally · 2b457640
      Kirill Smelkov authored
      try/finally was used in a couple of places to save/restore default ZBlk
      format setting. Move the restore part close to save with the help of
    • Kirill Smelkov's avatar
      *: Use defer for dbclose & friends · 5c8340d2
      Kirill Smelkov authored
      For tests this makes sure that if one test fails, it won't make following
      tests fail just because the next test will fail trying to lock test database.
      For regular code (demo_zbigarray.py) this is also a good thing to do -
      to always close the database irregardless of whether an exception was
      raised before program reached end of main.
      Pygolang becomes regular - not test only - dependency. Being regular
      dependency is currently required only by demo_zbigarray.py, but it will
      be also used in upcoming wcfs, so adding pygolang into wendelin.core
      dependencies aligns with the plan.
      dbclose now uses defer almost everywhere - there are still few places in
      tests, where one test function is opening/closing test database multiple
      times - those were not (yet ?) converted.
    • Kirill Smelkov's avatar
      */tests: Use pytest.raises in modern way · b12e319e
      Kirill Smelkov authored
      Instead of
      	raises(Exception, 'code')
      	with raises(Exception):
      This removes lots of warnings, similar to below example:
      	  /home/kirr/src/wendelin/wendelin.core/bigfile/tests/test_basic.py:79: PytestDeprecationWarning: raises(..., 'code(as_a_string)') is deprecated, use the context manager form or use `exec()` directly
      	  See https://docs.pytest.org/en/latest/deprecations.html#raises-warns-exec
      	    raises(ROAttributeError, "f.blksize = 1") # RO attribute
  10. 11 Jul, 2019 3 commits
  11. 10 Jul, 2019 2 commits
  12. 09 Jul, 2019 2 commits
  13. 08 Jul, 2019 3 commits
    • Kirill Smelkov's avatar
      bigfile/test/test_ram: Don't forget to free allocated Page structs · e8eca379
      Kirill Smelkov authored
      test_ram is low-level test that tests RAM pages allocation/mmapping.
      As allocated pages are not integrated with virtmem (not added to any
      file mapping and RAM->lru_list) the Page structs have to be explicitly
      freed. Fixes e.g.
      	Direct leak of 80 byte(s) in 1 object(s) allocated from:
      	    #0 0x7ff29af46518 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
      	    #1 0x56131dc22289 in zalloc include/wendelin/utils.h:67
      	    #2 0x56131dc225d6 in ramh_alloc_page bigfile/tests/../ram.c:41
      	    #3 0x56131dc2a19e in main bigfile/tests/test_ram.c:130
      	    #4 0x7ff29ac9f09a in __libc_start_main ../csu/libc-start.c:308
    • Kirill Smelkov's avatar
      bigfile: RAM must be explicitly free'ed after close · f688a31d
      Kirill Smelkov authored
      Else on-heap allocated RAM object is leaked. Fixes e.g. the following
      error on ASAN:
      	Direct leak of 56 byte(s) in 1 object(s) allocated from:
      	    #0 0x7fc9ef390518 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
      	    #1 0x555ca792f309 in zalloc include/wendelin/utils.h:67
      	    #2 0x555ca7935f9a in ram_limited_new bigfile/tests/../../t/t_utils.c:35
      	    #3 0x555ca793a0ba in test_file_access_synthetic bigfile/tests/test_virtmem.c:292
      	    #4 0x555ca7967bc4 in main bigfile/tests/test_virtmem.c:1121
      	    #5 0x7fc9ef0e909a in __libc_start_main ../csu/libc-start.c:308
    • Kirill Smelkov's avatar
      bigfile/test: Don't forget to close opened RAM · f1931264
      Kirill Smelkov authored
      Only one place that was using ram_new was missing to call ram_close in
      the end.