Summary:
There's no technological impediment to allowing the Bloom
filter bits/key to be non-integer (fractional/decimal) values, and it
provides finer control over the memory vs. accuracy trade-off. This is
especially handy in using the format_version=5 Bloom filter in place
of the old one, because bits_per_key=9.55 provides the same accuracy as
the old bits_per_key=10.
This change not only requires refining the logic for choosing the best
num_probes for a given bits/key setting, it revealed a flaw in that logic.
As bits/key gets higher, the best num_probes for a cache-local Bloom
filter is closer to bpk / 2 than to bpk * 0.69, the best choice for a
standard Bloom filter. For example, at 16 bits per key, the best
num_probes is 9 (FP rate = 0.0843%) not 11 (FP rate = 0.0884%).
This change fixes and refines that logic (for the format_version=5
Bloom filter only, just in case) based on empirical tests to find
accuracy inflection points between each num_probes.
Although bits_per_key is now specified as a double, the new Bloom
filter converts/rounds this to "millibits / key" for predictable/precise
internal computations. Just in case of unforeseen compatibility
issues, we round to the nearest whole number bits / key for the
legacy Bloom filter, so as not to unlock new behaviors for it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6092
Test Plan: unit tests included
Differential Revision: D18711313
Pulled By: pdillinger
fbshipit-source-id: 1aa73295f152a995328cb846ef9157ae8a05522a
Summary:
This PR comments out the rest of the unused arguments which allow us to turn on the -Wunused-parameter flag. This is the second part of a codemod relating to https://github.com/facebook/rocksdb/pull/3557.
Closes https://github.com/facebook/rocksdb/pull/3662
Differential Revision: D7426121
Pulled By: Dayvedde
fbshipit-source-id: 223994923b42bd4953eb016a0129e47560f7e352
Summary:
I have manually audited the entire RocksJava code base.
Sorry for the large pull-request, I have broken it down into many small atomic commits though.
My initial intention was to fix the warnings that appear when running RocksJava on Java 8 with `-Xcheck:jni`, for example when running `make jtest` you would see many errors similar to:
```
WARNING in native method: JNI call made without checking exceptions when required to from CallObjectMethod
WARNING in native method: JNI call made without checking exceptions when required to from CallVoidMethod
WARNING in native method: JNI call made without checking exceptions when required to from CallStaticVoidMethod
...
```
A few of those warnings still remain, however they seem to come directly from the JVM and are not directly related to RocksJava; I am in contact with the OpenJDK hostpot-dev mailing list about these - http://mail.openjdk.java.net/pipermail/hotspot-dev/2017-February/025981.html.
As a result of fixing these, I realised we were not r
Closes https://github.com/facebook/rocksdb/pull/1890
Differential Revision: D4591758
Pulled By: siying
fbshipit-source-id: 7f7fdf4
Previous to this commit Filters passed as parameters to the
BlockTableConfig are disposed before they should be disposed.
Further Smart pointer usage was corrected.
Java holds now the smart pointer to the FilterPolicy correctly
and cares about freeing underlying c++ structures.
Summary:
1. Move disOwnNativeHandle() function from RocksDB to RocksObject
to allow other RocksObject to use disOwnNativeHandle() when its
ownership of native handle has been transferred.
2. RocksObject now has an abstract implementation of dispose(),
which does the following two things. First, it checks whether
both isOwningNativeHandle() and isInitialized() return true.
If so, it will call the protected abstract function dispose0(),
which all the subclasses of RocksObject should implement. Second,
it sets nativeHandle_ = 0. This redesign ensure all subclasses
of RocksObject have the same dispose behavior.
3. All subclasses of RocksObject now should implement dispose0()
instead of dispose(), and dispose0() will be called only when
isInitialized() returns true.
Test Plan:
make rocksdbjava
make jtest
Reviewers: dhruba, sdong, ankgup87, rsumbaly, swapnilghike, zzbennett, haobo
Reviewed By: haobo
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D18801
