61f1baaedf
Summary: Scan and Dump commands in ldb use iterator. We need to also print timestamp for ttl databases for debugging. For this I create a TtlIterator class pointer in these functions and assign it the value of Iterator pointer which actually points to t TtlIterator object, and access the new function ValueWithTS which can return TS also. Buckets feature for dump command: gives a count of different key-values in the specified time-range distributed across the time-range partitioned according to bucket-size. start_time and end_time are specified in unixtimestamp and bucket in seconds on the user-commandline Have commented out 3 ines from ldb_test.py so that the test does not break right now. It breaks because timestamp is also printed now and I have to look at wildcards in python to compare properly. Test Plan: python tools/ldb_test.py Reviewers: vamsi, dhruba, haobo, sheki Reviewed By: vamsi CC: leveldb Differential Revision: https://reviews.facebook.net/D11403
rocksdb: A persistent key-value store for flash storage
Authors: The Facebook Database Engineering Team
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 an Log-Stuctured-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.
The core of this code has been derived from open-source leveldb.
The code under this directory implements a system for maintaining a
persistent key/value store.
See doc/index.html for more explanation.
See doc/impl.html for a brief overview of the implementation.
The public interface is in include/*.h. 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.
Guide to header files:
include/db.h
Main interface to the DB: Start here
include/options.h
Control over the behavior of an entire database, and also
control over the behavior of individual reads and writes.
include/comparator.h
Abstraction for user-specified comparison function. If you want
just bytewise comparison of keys, you can use the default comparator,
but clients can write their own comparator implementations if they
want custom ordering (e.g. to handle different character
encodings, etc.)
include/iterator.h
Interface for iterating over data. You can get an iterator
from a DB object.
include/write_batch.h
Interface for atomically applying multiple updates to a database.
include/slice.h
A simple module for maintaining a pointer and a length into some
other byte array.
include/status.h
Status is returned from many of the public interfaces and is used
to report success and various kinds of errors.
include/env.h
Abstraction of the OS environment. A posix implementation of
this interface is in util/env_posix.cc
include/table.h
include/table_builder.h
Lower-level modules that most clients probably won't use directly