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https://issues.apache.org/jira/browse/GEODE-8756?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17251944#comment-17251944
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ASF subversion and git services commented on GEODE-8756:
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Commit 4f504e4c4b229d883002d6dfb0a5512277ebfb69 in geode-native's branch
refs/heads/develop from Mario Salazar de Torres
[ https://gitbox.apache.org/repos/asf?p=geode-native.git;h=4f504e4 ]
GEODE-8756: Fix CacheableString::objectSize (#703)
- objectSize was not taking into account null-terminator character,
which as of C++11, as stated in § 21.4.7.1, should be included at
the end of the same string character sequence.
- Also, in those cases in which SSO applied, the returned size was
higher than the actual one.
- A parametrized UT was added to check objectSize is returning the
right size. Note that no fixed sizes are part of such test, given
that each std::string implementation could have a different SSO
size.
* Revision 2
- Added a new class called size_tracking_allocator, which is a custom
allocator used to track the size STL objects.
- Changed testing approach so it does not replicate internal logic, and
instead it instantiates a basic_string<char> with the new custom
allocator so heap size is tracked this way.
> CacheableString objectSize is not correct
> -----------------------------------------
>
> Key: GEODE-8756
> URL: https://issues.apache.org/jira/browse/GEODE-8756
> Project: Geode
> Issue Type: Sub-task
> Components: native client
> Affects Versions: 1.11.0, 1.12.0, 1.13.0, 1.13.1
> Reporter: Mario Salazar de Torres
> Assignee: Mario Salazar de Torres
> Priority: Major
> Labels: pull-request-available
>
> CacheableString objectSize function is returning an incorrect value.
> This class is based upon STL's string implementation, and most of the
> compilers implementations apply what's called SSO.
> What SSO basically does is if the string occupies less than a certain amount,
> no extra memory would be allocated in the heap, and the character-sequence
> would be stored in the object itself. This is typically achieved by using
> union semantics.
> Right now if SSO applies, objectSize calculates the size of std::string as
> sizeof(std::string) + m_str.capacity(), which is more than it actually
> occupies.
> On the other hand starting C++11 STL's strings needs to allocate an extra
> character
> to keep the null-terminator in the same buffer as the actual string. This is
> specified in section § 21.4.7.1 within the C++11 standard.
> Because of this objectSize should take the null-terminator into account,
> which was not the case.
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