Summary:
The patch adds iterator support to the integrated BlobDB implementation.
Whenever a blob reference is encountered during iteration, the corresponding
blob is retrieved by calling `Version::GetBlob`, assuming the `expose_blob_index`
(formerly `allow_blob`) flag is *not* set. (Note: the flag is set by the old stacked
BlobDB implementation, which has its own blob file handling/blob retrieval logic.)
In addition, `DBIter` now uniformly returns `Status::NotSupported` with the error
message `"BlobDB does not support merge operator."` when encountering a
blob reference while performing a merge (instead of potentially returning a
message that implies the database should be opened using the stacked BlobDB's
`Open`.)
TODO: We can implement support for lazily retrieving the blob value (or in other
words, bypassing the retrieval of blob values based on key) by extending the `Iterator`
API with a new `PrepareValue` method (similarly to `InternalIterator`, which already
supports lazy values).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7731
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D25256293
Pulled By: ltamasi
fbshipit-source-id: c39cd782011495a526cdff99c16f5fca400c4811
Summary:
Previously, a `ReadOptions` object was stored in every `BlockBasedTableIterator`
and every `LevelIterator`. This redundancy consumes extra memory,
resulting in the `Arena` making more allocations, and iteration
observing worse cache performance.
This PR migrates callers of `NewInternalIterator()` and
`MakeInputIterator()` to provide a `ReadOptions` object guaranteed to
outlive the returned iterator. When the iterator's lifetime will be managed by the
user, this lifetime guarantee is achieved by storing the `ReadOptions`
value in `ArenaWrappedDBIter`. Then, sub-iterators of `NewInternalIterator()` and
`MakeInputIterator()` can hold a reference-to-const `ReadOptions`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7210
Test Plan:
- `make check` under ASAN and valgrind
- benchmark: on a DB with 2 L0 files and 3 L1+ levels, this PR reduced `Arena` allocation 4792 -> 4160 bytes.
Reviewed By: anand1976
Differential Revision: D22861323
Pulled By: ajkr
fbshipit-source-id: 54aebb3e89c872eeab0f5793b4b6e42878d093ce
Summary:
Preliminary support for iterator with user timestamp. Current implementation does not consider merge operator and reverse iterator. Auto compaction is also disabled in unit tests.
Create an iterator with timestamp.
```
...
read_opts.timestamp = &ts;
auto* iter = db->NewIterator(read_opts);
// target is key without timestamp.
for (iter->Seek(target); iter->Valid(); iter->Next()) {}
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {}
delete iter;
read_opts.timestamp = &ts1;
// lower_bound and upper_bound are without timestamp.
read_opts.iterate_lower_bound = &lower_bound;
read_opts.iterate_upper_bound = &upper_bound;
auto* iter1 = db->NewIterator(read_opts);
// Do Seek or SeekToFirst()
delete iter1;
```
Test plan (dev server)
```
$make check
```
Simple benchmarking (dev server)
1. The overhead introduced by this PR even when timestamp is disabled.
key size: 16 bytes
value size: 100 bytes
Entries: 1000000
Data reside in main memory, and try to stress iterator.
Repeated three times on master and this PR.
- Seek without next
```
./db_bench -db=/dev/shm/rocksdbtest-1000 -benchmarks=fillseq,seekrandom -enable_pipelined_write=false -disable_wal=true -format_version=3
```
master: 159047.0 ops/sec
this PR: 158922.3 ops/sec (2% drop in throughput)
- Seek and next 10 times
```
./db_bench -db=/dev/shm/rocksdbtest-1000 -benchmarks=fillseq,seekrandom -enable_pipelined_write=false -disable_wal=true -format_version=3 -seek_nexts=10
```
master: 109539.3 ops/sec
this PR: 107519.7 ops/sec (2% drop in throughput)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6255
Differential Revision: D19438227
Pulled By: riversand963
fbshipit-source-id: b66b4979486f8474619f4aa6bdd88598870b0746
Summary:
Cleanup some code without any real change in functionality.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6440
Differential Revision: D20015891
Pulled By: riversand963
fbshipit-source-id: 33e18754b0f002006a6d4805e9aaf84c0c8ad25a
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
Move definition and implementation for ArenaWrappedDBIter into its own .h/.cc files. Also, change inlining of functions to better comply with the Google C++ style guide.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5801
Test Plan: make check
Differential Revision: D17371012
Pulled By: anand1976
fbshipit-source-id: c1361abc2851575111e357a63d88be3b3d6cb341
