* 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>

Closes https://github.com/tikv/rust-rocksdb/issues/461Signed-off-by: David Wong <davidwg@calibra.com>

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

UCP [#6496](https://github.com/tikv/tikv/issues/6496)

add interface corresponds to the Logger interface 

Fix rust-rocksdb/master should point to rocksdb/6.4.tikv. Also update rocksdb with the change:
```
979a985cf 2020-03-25 yiwu@pingcap.com     Add counter in perf_context to time cipher time (#158)
```
Signed-off-by: Yi Wu <yiwu@pingcap.com>

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

Signed-off-by: Little-Wallace <bupt2013211450@gmail.com>

renew branch of multibatch-write. Optimize for large write batch block other thread.

Add `KeyManagedEncryptedEnv` API and related `EncryptionKeyManager` trait.
Signed-off-by: Yi Wu <yiwu@pingcap.com>

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

Signed-off-by: Little-Wallace <bupt2013211450@gmail.com>

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

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