Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

* add write batch iterator and append interface
Signed-off-by: Little-Wallace <bupt2013211450@gmail.com>

Adding more perf context counters.
Signed-off-by: Yi Wu <yiwu@pingcap.com>

Signed-off-by: Jay Lee <BusyJayLee@gmail.com>

update rocksdb to include tikv/rocksdb#185 for master
Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

update rocksdb to include tikv/rocksdb#184 for master
Signed-off-by: ti-srebot <ti-srebot@pingcap.com>
Signed-off-by: Yi Wu <yiwu@pingcap.com>

### Summary
Integration with rockset/rocksdb-cloud to add CloudEnv features for operating with cloud services like AWS S3 as a datastore.
- Created a sub-crate `librocksdb_cloud_sys` which contains the `rocksdb-cloud` sub-module containing code for managing cloud interactions, extracted from rockset/rocksdb-cloud and currently residing in [tikv/rocksdb~6.4.cloud](https://github.com/tikv/rocksdb/tree/6.4.cloud)
- Made necessary changes to [tikv/rocksdb~6.4.tikv](https://github.com/tikv/rocksdb/tree/6.4.tikv) that is housed in the sub-module `rocksdb` within the parent crate.
- Wrote CMakeLists.txt for use in the build process of `rocksdb_cloud` as a static library, usable for C-ABI based FFI calls. Added the above code to the build process of parent crate `librocksdb_sys` along with C-ABI binding code within `crocksdb`
- Created 'cloud.rs' and added `new_aws_env()` method to Env type of `rocksdb.rs` that merely makes a call to the `CloudEnv::NewAwsEnv()` via FFI for use as library features upstream. A test for the same was also added here.
- Used feature based conditional compile macros to all cloud interaction code.
- Made requisite changes to CI config for handling AWS SDK compilation.
- Added a sequence of steps to update submodule within Makefile

Solves #514

## Checkpoints

- [x] Added rocksdb-cloud as submodule in crate `librocksdb_cloud_sys`.
- [x] Write CMakeLists.txt to build only `cloud` code.
- [x] Generate C-bindings to interface with `NewAwsEnv` and `CloudEnvOptions`
- [x] Create `Env::new_aws_env` as an interface in rust
Signed-off-by: Devdutt Shenoi <devdutt@outlook.in>

Signed-off-by: glorv <glorvs@163.com>

Signed-off-by: tabokie <xy.tao@outlook.com>

Jemallocator has not been active for several months. We published our
own fork, which upgraded jemalloc to 5.2.1.
Signed-off-by: Jay Lee <BusyJayLee@gmail.com>

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

* RocksDB may print large log lines up to 64k. The default 1k buffer for `logv` is too small and truncates rocksdb log. When we detect log line is too long, we allocate a large enough buffer on heap and try again.
* When log level is not specified, defaults to header level.

* use shared_ptr for rate limiter
Signed-off-by: Ryan Leung <rleungx@gmail.com>

* support change rate limiter dynamically
Signed-off-by: Ryan Leung <rleungx@gmail.com>

Signed-off-by: Yi Wu <yiwu@pingcap.com>

Signed-off-by: sre-bot <sre-bot@pingcap.com>

Signed-off-by: qupeng <qupeng@pingcap.com>

Signed-off-by: Connor1996 <zbk602423539@gmail.com>

* add titan customized stats
Signed-off-by: Connor <zbk602423539@gmail.com>

Signed-off-by: Neil Shen <overvenus@gmail.com>

remove Valist and make logger return the log string instead of ```snprinf``` by client.
Signed-off-by: Wangweizhen <hawking.rei@gmail.com>

- Export encryption perf context api
- Fix travis
- Default nightly toolchain
Signed-off-by: TXXT <hunterlxt@live.com>

* add run sst dump
Signed-off-by: Connor <zbk602423539@gmail.com>

Signed-off-by: Wangweizhen <hawking.rei@gmail.com>

UCP https://github.com/tikv/tikv/issues/6496

Fix this error from clippy.

```
this public function dereferences a raw pointer but is not marked `unsafe`
help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#not_unsafe_ptr_arg_deref

```

rocksdb: Fix wrong key being read on ingested file with global seqno and delta encoding (facebook#6669) (#469)

#463 forget to expose `static_libcpp` feature to top level Cargo.toml. Fixing it.
Signed-off-by: Yi Wu <yiwu@pingcap.com>