Pass parsed user key to prefix extractor in V2 compaction

Previously, the prefix extractor was being supplied with the RocksDB
key instead of a parsed user key. This makes correct interpretation
by calling application fragile or impossible.
Update HISTORY.md
Merge pull request #230 from cockroachdb/spencerkimball/send-user-keys-to-v2-filter

Pass parsed user key to prefix extractor in V2 compaction
attempt to fix auto_roll_logger_test

Summary:
auto_roll_logger_test fails from time to time. I wasn't able to repro
the issue but by looking at the code, it seems like the initial ctime_
value can be set to the boundary of the second so it may still have a
chance to get rolled when interval is set to 1 second.

```
util/auto_roll_logger_test.cc:120: failed: 118 > 708
==19470== Syscall param msync(start) points to unaddressable byte(s)
==19470==    at 0x4E46CE0: __msync_nocancel (in
/usr/local/fbcode/gcc-4.8.1-glibc-2.17/lib/libpthread-2.17.so)
==19470==    by 0x584EFB: access_mem (Ginit.c:137)
==19470==    by 0x5834E3: _ULx86_64_access_reg (libunwind_i.h:162)
==19470==    by 0x585601: apply_reg_state (Gparser.c:742)
==19470==    by 0x5866BE: _ULx86_64_dwarf_find_save_locs (Gparser.c:883)
==19470==    by 0x584550: _ULx86_64_dwarf_step (Gstep.c:34)
==19470==    by 0x583653: _ULx86_64_step (Gstep.c:71)
==19470==    by 0x583FD2: _ULx86_64_tdep_trace (Gtrace.c:217)
==19470==    by 0x5831C3: backtrace (backtrace.c:69)

Test Plan: ./auto_roll_logger_test

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21951
Fix valgrind error in c_test
Adding Cuckoo Table SST option to db_bench

Summary: Adding flags to use cuckoo table SST in db_bench.cc

Test Plan: Ran benchmark with fillseq and readrandom

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21729
Bump up version

Summary: Bump up version after we've cut 3.4

Test Plan: N/A

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb, dhruba, igor

Differential Revision: https://reviews.facebook.net/D22047
Update release note of 3.4

Summary: N/A

Test Plan: N/A

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb, igor

Differential Revision: https://reviews.facebook.net/D22053
WriteBatchWithIndex: a wrapper of WriteBatch, with a searchable index

Summary:
Add WriteBatchWithIndex so that a user can query data out of a WriteBatch, to support MongoDB's read-its-own-write.

WriteBatchWithIndex uses a skiplist to store the binary index. The index stores the offset of the entry in the write batch. When searching for a key, the key for the entry is read by read the entry from the write batch from the offset.

Define a new iterator class for querying data out of WriteBatchWithIndex. A user can create an iterator of the write batch for one column family, seek to a key and keep calling Next() to see next entries.

I will add more unit tests if people are OK about this API.

Test Plan:
make all check
Add unit tests.

Reviewers: yhchiang, igor, MarkCallaghan, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb, xjin

Differential Revision: https://reviews.facebook.net/D21381
Adding Column Family support in db_bench.

Summary:
Adding num_column_families flag. Adding support for column families in DoWrite and ReadRandom methods.
[Igor, please let me know if this approach sounds good. I shall add it to other methods too.]

Test Plan: Ran fillseq on 1M keys and 10 Column families and ran readrandom.

Reviewers: sdong, yhchiang, igor, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21387
Removing BitStream* functions

Summary: I was checking some functions in coding.h and coding.cc when I noticed these unused functions. Let's remove them.

Test Plan: compiles

Reviewers: sdong, ljin, yhchiang, dhruba

Reviewed By: dhruba

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22077
Remove BitStream* tests
Add CuckooHash table format to table_reader_bench

Summary: Make table_reader_bench cover all the three table formats.

Test Plan: Run it using three options

Reviewers: radheshyamb, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22137
Optimize storage parameters for spatialDB

Summary: We need to start compression at level 1, while OptimizeForLevelComapaction() only sets up rocksdb to start compressing at level 2. I also adjusted some other things.

Test Plan: compiles

Reviewers: yinwang

Reviewed By: yinwang

Differential Revision: https://reviews.facebook.net/D22203
Revert the unintended change that DestroyDB() doesn't clean up info logs.

Summary: A previous change triggered a change by mistake: DestroyDB() will keep info logs under DB directory. Revert the unintended change.

Test Plan: Add a unit test case to verify it.

Reviewers: ljin, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22209
Eliminate VersionSet memory leak

Summary:
ManifestDumpCommand::DoCommand was allocating a VersionSet and never
freeing it.

Test Plan: make

Reviewers: igor

Reviewed By: igor

Differential Revision: https://reviews.facebook.net/D22221
Improve Options sanitization and add MmapReadRequired() to TableFactory

Summary:
Currently, PlainTable must use mmap_reads.  When PlainTable is used but
allow_mmap_reads is not set, rocksdb will fail in flush.

This diff improve Options sanitization and add MmapReadRequired() to
TableFactory.

Test Plan:
export ROCKSDB_TESTS=PlainTableOptionsSanitizeTest
make db_test -j32
./db_test

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: you, leveldb

Differential Revision: https://reviews.facebook.net/D21939
Add missing implementaiton of SanitizeDBOptions in simple_table_db_test.cc

Summary:
Add missing implementaiton of SanitizeDBOptions in simple_table_db_test.cc

Test Plan:
make simple_table_db_test.cc
Fix the error of c_test.c

Summary:
Fix the error of c_test.c

Test Plan:
make c_test
./c_test
Implement Prepare method in CuckooTableReader

Summary:
- Implement Prepare method
- Rewrite performance tests in cuckoo_table_reader_test to write new file only if one doesn't already exist.
- Add performance tests for batch lookup along with prefetching.

Test Plan:
./cuckoo_table_reader_test --enable_perf
Results (We get better results if we used int64 comparator instead of string comparator (TBD in future diffs)):
With 100000000 items and hash table ratio 0.500000, number of hash functions used: 2.
Time taken per op is 0.208us (4.8 Mqps) with batch size of 0
With 100000000 items and hash table ratio 0.500000, number of hash functions used: 2.
Time taken per op is 0.182us (5.5 Mqps) with batch size of 10
With 100000000 items and hash table ratio 0.500000, number of hash functions used: 2.
Time taken per op is 0.161us (6.2 Mqps) with batch size of 25
With 100000000 items and hash table ratio 0.500000, number of hash functions used: 2.
Time taken per op is 0.161us (6.2 Mqps) with batch size of 50
With 100000000 items and hash table ratio 0.500000, number of hash functions used: 2.
Time taken per op is 0.163us (6.1 Mqps) with batch size of 100

With 100000000 items and hash table ratio 0.600000, number of hash functions used: 3.
Time taken per op is 0.252us (4.0 Mqps) with batch size of 0
With 100000000 items and hash table ratio 0.600000, number of hash functions used: 3.
Time taken per op is 0.192us (5.2 Mqps) with batch size of 10
With 100000000 items and hash table ratio 0.600000, number of hash functions used: 3.
Time taken per op is 0.195us (5.1 Mqps) with batch size of 25
With 100000000 items and hash table ratio 0.600000, number of hash functions used: 3.
Time taken per op is 0.191us (5.2 Mqps) with batch size of 50
With 100000000 items and hash table ratio 0.600000, number of hash functions used: 3.
Time taken per op is 0.194us (5.1 Mqps) with batch size of 100

With 100000000 items and hash table ratio 0.750000, number of hash functions used: 3.
Time taken per op is 0.228us (4.4 Mqps) with batch size of 0
With 100000000 items and hash table ratio 0.750000, number of hash functions used: 3.
Time taken per op is 0.185us (5.4 Mqps) with batch size of 10
With 100000000 items and hash table ratio 0.750000, number of hash functions used: 3.
Time taken per op is 0.186us (5.4 Mqps) with batch size of 25
With 100000000 items and hash table ratio 0.750000, number of hash functions used: 3.
Time taken per op is 0.189us (5.3 Mqps) with batch size of 50
With 100000000 items and hash table ratio 0.750000, number of hash functions used: 3.
Time taken per op is 0.188us (5.3 Mqps) with batch size of 100

With 100000000 items and hash table ratio 0.900000, number of hash functions used: 3.
Time taken per op is 0.325us (3.1 Mqps) with batch size of 0
With 100000000 items and hash table ratio 0.900000, number of hash functions used: 3.
Time taken per op is 0.196us (5.1 Mqps) with batch size of 10
With 100000000 items and hash table ratio 0.900000, number of hash functions used: 3.
Time taken per op is 0.199us (5.0 Mqps) with batch size of 25
With 100000000 items and hash table ratio 0.900000, number of hash functions used: 3.
Time taken per op is 0.196us (5.1 Mqps) with batch size of 50
With 100000000 items and hash table ratio 0.900000, number of hash functions used: 3.
Time taken per op is 0.209us (4.8 Mqps) with batch size of 100

Reviewers: sdong, yhchiang, igor, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22167