DatabaseTarget - Enable OptimizeBufferReuse by default

[snakefoot]

Waiting for NLog ver. 4.5

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This change is 

[304NotModified]

NLog.UnitTests.Targets.Wrappers.BufferingTargetWrapperTests.BufferingTargetWrapperAsyncTest1 [FAIL]
Assert.Equal() Failure
Expected: 19
Actual: 18
Stack Trace:
at NLog.UnitTests.Targets.Wrappers.BufferingTargetWrapperTests.BufferingTargetWrapperAsyncTest1 () [0x001e6] in <50fe24b3f1d14d7092cf9b8d5f6ecaaa>:0
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00038] in <8f2c484307284b51944a1a13a14c0266>:0
1922 total, 1 failed, 21 skipped, took 50.686 seconds

Seems a fail from a recent change. Is that possible?

[304NotModified]

Reviewed 1 of 2 files at r1.
Review status: 1 of 2 files reviewed at latest revision, 2 unresolved discussions, some commit checks failed.

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src/NLog/Targets/DatabaseTarget.cs, line 93 at r1 (raw file):

            this.ConnectionStringsSettings = ConfigurationManager.ConnectionStrings;
            this.CommandType = CommandType.Text;
            this.OptimizeBufferReuse = GetType() == typeof(DatabaseTarget);

what's the use of this? Not enabling in subclasses?

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src/NLog/Targets/DatabaseTarget.cs, line 662 at r1 (raw file):

                    this.EnsureConnectionOpen(cs);

                    using (var command = this.activeConnection.CreateCommand())

behavior change?

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Comments from Reviewable

[snakefoot]

Seems a fail from a recent change. Is that possible?

Looks more like a bad unit test. There is no guarantee that the write-events will complete before the flush-event as MyAsyncTarget is using ThreadPool.QueueUserWorkItem.

So the the flushHit-event can be triggered before everything is written, thus causing the problem with expecting 19 but only 18 written.

Maybe MyAsyncTarget should apply the newly created AsyncOperationCounter :). Like it has been done in AsyncTargetWrapperTests.cs

[codecov-io]

Codecov Report

Merging #1908 into master will increase coverage by <1%.
The diff coverage is 74%.

@@           Coverage Diff           @@
##           master   #1908    +/-   ##
=======================================
+ Coverage      81%     81%   +<1%     
=======================================
  Files         285     285            
  Lines       19436   19441     +5     
  Branches     2263    2263            
=======================================
+ Hits        15823   15837    +14     
- Misses       3060    3066     +6     
+ Partials      553     538    -15

[304NotModified]

Reviewed 1 of 2 files at r1.
Review status: all files reviewed at latest revision, 2 unresolved discussions.

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Comments from Reviewable

[snakefoot]

@304NotModified Updated documentation: https://github.com/NLog/NLog/wiki/Database-target