0a91bca5db
Summary: Without this change, someone on the machine on which I run "make check" could cause me to overwrite arbitrary files owned by me, via a symlink attack. Instead of using a predictable temporary directory and accepting to use a preexisting one, always create a new one using mkdtemp. If $TEST_IOCTL_FRIENDLY_TMPDIR is set and usable, attempt first to find a usable temporary directory therein. If not, or if unusable, then try /var/tmp and /tmp. If none of those is usable abort with a diagnostic. To do that, I added a new class. Its constructor finds a suitable directory or aborts, the sole member prints that directory's name, and the destructor unlinks what should be an empty directory. Note that while the code before this did not remove its temporary directory, there was only one per $UID. Now, there would be at least one per run or one per test, depending on implementation, so it is important to remove them. Test Plan: Run this on a fedora rawhide system, where /tmp is a tmpfs file system, and /var/tmp is ext4. # This gives a diagnostic that /dev/shm is not suitable # and ends up using /var/tmp. TEST_IOCTL_FRIENDLY_TMPDIR=/dev/shm ./env_test # Uses /var/tmp; same as when envvar not set. TEST_IOCTL_FRIENDLY_TMPDIR=/var/tmp ./env_test # Uses /tmp unless it's tmpfs, in which case it gives # a diagnostic and uses /var/tmp. TEST_IOCTL_FRIENDLY_TMPDIR=/tmp ./env_test Reviewers: ljin, rven, igor.sugak, yhchiang, sdong, igor Reviewed By: igor Subscribers: dhruba Differential Revision: https://reviews.facebook.net/D37287
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 specially 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/