Summary:
This patch adds direct IO capability to RocksDB Env.
The direct IO capability is required for persistent cache since NVM is best
accessed as 4K direct IO. SSDs can leverage direct IO for reading.
Direct IO requires the offset and size be sector size aligned, and memory to
be kernel page aligned. Since neither RocksDB/Persistent read cache data
layout is aligned to sector size, the code can accommodate reading unaligned IO size
(or unaligned memory) at the cost of an alloc/copy.
The write code path expects the size and memory to be aligned.
Test Plan: Run RocksDB unit tests
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57393
Summary:
Persistent read cache relies on the accuracy of the GetUniqueIdFromFile
to generate a unique key for a given block of data. Currently we don't have an
implementation for Mac.
This patch adds an implementation.
Test Plan: Run unit tests
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D58413
Summary:
Added a new abstraction to cache page to RocksDB designed for the read
cache use.
RocksDB current block cache is more of an object cache. For the persistent read cache
project, what we need is a page cache equivalent. This changes adds a cache
abstraction to RocksDB to cache pages called PersistentCache. PersistentCache can cache
uncompressed pages or raw pages (content as in filesystem). The user can
choose to operate PersistentCache either in COMPRESSED or UNCOMPRESSED mode.
Blame Rev:
Test Plan: Run unit tests
Reviewers: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55707
in 64-bit.
Currently, a signed off_t type is being used for the following
interfaces for both offset and the length in bytes:
* `Allocate`
* `RangeSync`
On Linux `off_t` is automatically either 32 or 64-bit depending on
the platform. On Windows it is always a 32-bit signed long which
limits file access and in particular space pre-allocation
to effectively 2 Gb.
Proposal is to replace off_t with uint64_t as a portable type
always access files with 64-bit interfaces.
May need to modify posix code but lack resources to test it.
Summary: include/posix/io_posix.h is not a public API. Although include/posix/ is not a public header directory, it is confusing to put non-public headers to under include/. Move it to util/ to be clearer.
Test Plan: Run all tests
Reviewers: rven, IslamAbdelRahman, anthony, kradhakrishnan, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D49611
Summary: include/posix/io_posix.h should not depend on ROCKSDB_FALLOCATE_PRESENT. Remove it.
Test Plan: Build it with both of ROCKSDB_FALLOCATE_PRESENT defined and not defined.
Reviewers: rven, yhchiang, anthony, kradhakrishnan, IslamAbdelRahman, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D49563
Summary: Mac build breaks as include/posix/io_posix.h doesn't include errno. Move the exact function declaration to io_posix.cc
Test Plan: Run all test. Will run on Mac
Reviewers: rven, anthony, yhchiang, IslamAbdelRahman, igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D49551
Summary: IO Posix depends on too many .h files. Move most of them to .cc files.
Test Plan: make all
Reviewers: anthony, rven, IslamAbdelRahman, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D49479
Summary: This patch splits the posix storage backend into Env and
the actual *File implementations. The motivation is to allow other Envs
to use posix as a library. This enables a storage backend different from
posix to split its secondary storage between a normal file system
partition managed by posix, and it own media.
Test Plan: No new functionality is added to posix Env or the library,
thus the current tests should suffice.
