22655a398b
Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e |
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| .circleci | ||
| .github/workflows | ||
| buckifier | ||
| build_tools | ||
| cache | ||
| cmake | ||
| coverage | ||
| db | ||
| db_stress_tool | ||
| docs | ||
| env | ||
| examples | ||
| file | ||
| hdfs | ||
| include/rocksdb | ||
| java | ||
| logging | ||
| memory | ||
| memtable | ||
| monitoring | ||
| options | ||
| port | ||
| table | ||
| test_util | ||
| third-party | ||
| tools | ||
| trace_replay | ||
| util | ||
| utilities | ||
| .clang-format | ||
| .gitignore | ||
| .lgtm.yml | ||
| .travis.yml | ||
| .watchmanconfig | ||
| appveyor.yml | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| DEFAULT_OPTIONS_HISTORY.md | ||
| defs.bzl | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
| INSTALL.md | ||
| issue_template.md | ||
| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
| src.mk | ||
| TARGETS | ||
| thirdparty.inc | ||
| USERS.md | ||
| Vagrantfile | ||
| WINDOWS_PORT.md | ||
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key-value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it especially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples
See the github wiki for more explanation.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/ and https://rocksdb.slack.com/
License
RocksDB is dual-licensed under both the GPLv2 (found in the COPYING file in the root directory) and Apache 2.0 License (found in the LICENSE.Apache file in the root directory). You may select, at your option, one of the above-listed licenses.