- fix compile error with env_test; static casts added

Summary: Copy improvements from fbcode's version of EnvHdfs to our open-source version. Some very important bug fixes in there.

Test Plan: compiles

Reviewers: dhruba, haobo, sdong

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18711

Summary:
* Now each Log related function has a variant that takes an additional
  argument indicating its log level, which is one of the following:
 - DEBUG, INFO, WARN, ERROR, FATAL.

* To ensure backward-compatibility, old version Log functions are kept
  unchanged.

* Logger now has a member variable indicating its log level.  Any incoming
  Log request which log level is lower than Logger's log level will not
  be output.

* The output of the newer version Log will be prefixed by its log level.

Test Plan:
Add a LogType test in auto_roll_logger_test.cc

 = Sample log output =
    2014/02/11-00:03:07.683895 7feded179840 [DEBUG] this is the message to be written to the log file!!
    2014/02/11-00:03:07.683898 7feded179840 [INFO] this is the message to be written to the log file!!
    2014/02/11-00:03:07.683900 7feded179840 [WARN] this is the message to be written to the log file!!
    2014/02/11-00:03:07.683903 7feded179840 [ERROR] this is the message to be written to the log file!!
    2014/02/11-00:03:07.683906 7feded179840 [FATAL] this is the message to be written to the log file!!

Reviewers: dhruba, xjin, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16071

Summary:
@dhruba, I'm not sure where we need to sync the directory. I implemented the function in Env() and added the dir sync just after we close the newly created file in the builder.

Should I also add FsyncDir() to new files that get created by a compaction?

Test Plan: Confirmed that FsyncDir is returning Status::OK()

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D14751

Summary:
Add appropriate LICENSE and Copyright message.

Test Plan:
make check

Reviewers:

CC:

Task ID: #

Blame Rev:

Summary: virtual NewRandomRWFile is not implemented on EnvHdfs, causing build failure.

Test Plan: make clean; make all check

Reviewers: dhruba, haobo, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13383

Summary: Migrate names of properties from 'leveldb' prefix to 'rocksdb' prefix.

Test Plan: make check

Reviewers: emayanke, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13311

Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.

Test Plan: compile rocksdb

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13287

Summary: Replace include/leveldb with include/rocksdb.

Test Plan:
make clean; make check
make clean; make release

Differential Revision: https://reviews.facebook.net/D12489

Summary:
This patch allows an application to specify whether to use bufferedio,
reads-via-mmaps and writes-via-mmaps per database. Earlier, there
was a global static variable that was used to configure this functionality.

The default setting remains the same (and is backward compatible):
 1. use bufferedio
 2. do not use mmaps for reads
 3. use mmap for writes
 4. use readaheads for reads needed for compaction

I also added a parameter to db_bench to be able to explicitly specify
whether to do readaheads for compactions or not.

Test Plan: make check

Reviewers: sheki, heyongqiang, MarkCallaghan

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9429

Summary:
scripted NULL to nullptr in
* include/leveldb/
* db/
* table/
* util/

Test Plan: make all check

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9003

Summary:
Replace manual memory management with std::unique_ptr in a
number of places; not exhaustive, but this fixes a few leaks with file
handles as well as clarifies semantics of the ownership of file handles
with log classes.

Test Plan: db_stress, make check

Reviewers: dhruba

Reviewed By: dhruba

CC: zshao, leveldb, heyongqiang

Differential Revision: https://reviews.facebook.net/D8043

Summary:
Create a directory "archive" in the DB directory.
During DeleteObsolteFiles move the WAL files (*.log) to the Archive directory,
instead of deleting.

Test Plan: Created a DB using DB_Bench. Reopened it. Checked if files move.

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6975

Summary:
Scripted and removed all trailing spaces and converted all tabs to
spaces.

Also fixed other lint errors.
All lint errors from this point of time should be taken seriously.

Test Plan: make all check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7059

Summary:
Clean up compiler warnings generated by -Wall option.
make clean all OPT=-Wall

This is a pre-requisite before making a new release.

Test Plan: compile and run unit tests

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5019

Make Leveldb save data into HDFS files. You have to set USE_HDFS in your environment variable to compile leveldb with HDFS support.

Test Plan: Run benchmark.

Differential Revision: https://reviews.facebook.net/D3549