Summary:
Here are the major changes to the Merge Interface. It has been expanded
to handle cases where the MergeOperator is not associative. It does so by stacking
up merge operations while scanning through the key history (i.e.: during Get() or
Compaction), until a valid Put/Delete/end-of-history is encountered; it then
applies all of the merge operations in the correct sequence starting with the
base/sentinel value.
I have also introduced an "AssociativeMerge" function which allows the user to
take advantage of associative merge operations (such as in the case of counters).
The implementation will always attempt to merge the operations/operands themselves
together when they are encountered, and will resort to the "stacking" method if
and only if the "associative-merge" fails.
This implementation is conjectured to allow MergeOperator to handle the general
case, while still providing the user with the ability to take advantage of certain
efficiencies in their own merge-operator / data-structure.
NOTE: This is a preliminary diff. This must still go through a lot of review,
revision, and testing. Feedback welcome!
Test Plan:
-This is a preliminary diff. I have only just begun testing/debugging it.
-I will be testing this with the existing MergeOperator use-cases and unit-tests
(counters, string-append, and redis-lists)
-I will be "desk-checking" and walking through the code with the help gdb.
-I will find a way of stress-testing the new interface / implementation using
db_bench, db_test, merge_test, and/or db_stress.
-I will ensure that my tests cover all cases: Get-Memtable,
Get-Immutable-Memtable, Get-from-Disk, Iterator-Range-Scan, Flush-Memtable-to-L0,
Compaction-L0-L1, Compaction-Ln-L(n+1), Put/Delete found, Put/Delete not-found,
end-of-history, end-of-file, etc.
-A lot of feedback from the reviewers.
Reviewers: haobo, dhruba, zshao, emayanke
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11499
Summary:
With the Makefile now updated to correctly update all .o files, this
should fix the issues recompiling stringappend_test. This should also fix the
"segmentation-fault" that we were getting earlier. Now, stringappend_test should
be clean, and I have added it back to the unit-tests. Also made some minor updates
to the tests themselves.
Test Plan:
1. make clean; make stringappend_test -j 32 (will test it by itself)
2. make clean; make all check -j 32 (to run all unit tests)
3. make clean; make release (test in release mode)
4. valgrind ./stringappend_test (valgrind tests)
Reviewers: haobo, jpaton, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11505
Summary:
I'm concerned about a random seg-fault that sometimes occurs when
running stringappend_test. I will investigate further. First, I am removing
stringappend_test from the regular release tests, and making some clean-ups
to the code.
Test Plan:
1. make stringappend_test
2. ./stringappend_test
Reviewers: haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D11313
Summary:
Implemented the StringAppendOperator class (subclass of MergeOperator).
Found in utilities/merge_operators/string_append/stringappend.{h,cc}
It is a rocksdb Merge Operator that supports string/list concatenation
with a configurable delimiter.
The tests are found in .../stringappend_test.cc. It implements a
map : key -> (list of strings), with core operations Append(list_key,val)
and Get(list_key).
Test Plan:
1. Navigate to your rocksdb repository
2. Execute: make stringappend_test (to compile)
3. Execute: ./stringappend_test (to run the tests)
4. Execute: make all check (to test the ENTIRE rocksdb codebase / regression)
Reviewers: haobo, dhruba, zshao
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10737
Deon Nicholas