Package org.rocksdb

Class EnvOptions

  • All Implemented Interfaces:
    java.lang.AutoCloseable
    public class EnvOptions
extends RocksObject
    Options while opening a file to read/write

    • Constructor Detail

      • EnvOptions

        public EnvOptions()
        Construct with default Options

      • EnvOptions

        public EnvOptions​(DBOptions dbOptions)
        Construct from DBOptions.
        Parameters:
        dbOptions - the database options.

    • Method Detail

      • setUseMmapReads

        public EnvOptions setUseMmapReads​(boolean useMmapReads)
        Enable/Disable memory mapped reads. Default: false
        Parameters:
        useMmapReads - true to enable memory mapped reads, false to disable.
        Returns:
        the reference to these options.

      • useMmapReads

        public boolean useMmapReads()
        Determine if memory mapped reads are in-use.
        Returns:
        true if memory mapped reads are in-use, false otherwise.

      • setUseMmapWrites

        public EnvOptions setUseMmapWrites​(boolean useMmapWrites)
        Enable/Disable memory mapped Writes. Default: true
        Parameters:
        useMmapWrites - true to enable memory mapped writes, false to disable.
        Returns:
        the reference to these options.

      • useMmapWrites

        public boolean useMmapWrites()
        Determine if memory mapped writes are in-use.
        Returns:
        true if memory mapped writes are in-use, false otherwise.

      • setUseDirectReads

        public EnvOptions setUseDirectReads​(boolean useDirectReads)
        Enable/Disable direct reads, i.e. O_DIRECT. Default: false
        Parameters:
        useDirectReads - true to enable direct reads, false to disable.
        Returns:
        the reference to these options.

      • useDirectReads

        public boolean useDirectReads()
        Determine if direct reads are in-use.
        Returns:
        true if direct reads are in-use, false otherwise.

      • setUseDirectWrites

        public EnvOptions setUseDirectWrites​(boolean useDirectWrites)
        Enable/Disable direct writes, i.e. O_DIRECT. Default: false
        Parameters:
        useDirectWrites - true to enable direct writes, false to disable.
        Returns:
        the reference to these options.

      • useDirectWrites

        public boolean useDirectWrites()
        Determine if direct writes are in-use.
        Returns:
        true if direct writes are in-use, false otherwise.

      • setAllowFallocate

        public EnvOptions setAllowFallocate​(boolean allowFallocate)
        Enable/Disable fallocate calls. Default: true If false, fallocate() calls are bypassed.
        Parameters:
        allowFallocate - true to enable fallocate calls, false to disable.
        Returns:
        the reference to these options.

      • allowFallocate

        public boolean allowFallocate()
        Determine if fallocate calls are used.
        Returns:
        true if fallocate calls are used, false otherwise.

      • setSetFdCloexec

        public EnvOptions setSetFdCloexec​(boolean setFdCloexec)
        Enable/Disable the FD_CLOEXEC bit when opening file descriptors. Default: true
        Parameters:
        setFdCloexec - true to enable the FB_CLOEXEC bit, false to disable.
        Returns:
        the reference to these options.

      • setFdCloexec

        public boolean setFdCloexec()
        Determine i fthe FD_CLOEXEC bit is set when opening file descriptors.
        Returns:
        true if the FB_CLOEXEC bit is enabled, false otherwise.

      • setBytesPerSync

        public EnvOptions setBytesPerSync​(long bytesPerSync)
        Allows OS to incrementally sync files to disk while they are being written, in the background. Issue one request for every bytesPerSync written. Default: 0
        Parameters:
        bytesPerSync - 0 to disable, otherwise the number of bytes.
        Returns:
        the reference to these options.

      • bytesPerSync

        public long bytesPerSync()
        Get the number of incremental bytes per sync written in the background.
        Returns:
        0 if disabled, otherwise the number of bytes.

      • setFallocateWithKeepSize

        public EnvOptions setFallocateWithKeepSize​(boolean fallocateWithKeepSize)
        If true, we will preallocate the file with FALLOC_FL_KEEP_SIZE flag, which means that file size won't change as part of preallocation. If false, preallocation will also change the file size. This option will improve the performance in workloads where you sync the data on every write. By default, we set it to true for MANIFEST writes and false for WAL writes
        Parameters:
        fallocateWithKeepSize - true to preallocate, false otherwise.
        Returns:
        the reference to these options.

      • fallocateWithKeepSize

        public boolean fallocateWithKeepSize()
        Determine if file is preallocated.
        Returns:
        true if the file is preallocated, false otherwise.

      • setCompactionReadaheadSize

        public EnvOptions setCompactionReadaheadSize​(long compactionReadaheadSize)
        See DBOptions.setCompactionReadaheadSize(long).
        Parameters:
        compactionReadaheadSize - the compaction read-ahead size.
        Returns:
        the reference to these options.

      • setRandomAccessMaxBufferSize

        public EnvOptions setRandomAccessMaxBufferSize​(long randomAccessMaxBufferSize)
        See DBOptions.setRandomAccessMaxBufferSize(long).
        Parameters:
        randomAccessMaxBufferSize - the max buffer size for random access.
        Returns:
        the reference to these options.

      • setRateLimiter

        public EnvOptions setRateLimiter​(RateLimiter rateLimiter)
        Set the write rate limiter for flush and compaction.
        Parameters:
        rateLimiter - the rate limiter.
        Returns:
        the reference to these options.

      • rateLimiter

        public RateLimiter rateLimiter()
        Get the write rate limiter for flush and compaction.
        Returns:
        the rate limiter.