Class SstFileWriter

Namespace

RocksDbNet

Assembly

RocksDb.Net.dll

Writes key-value pairs in sorted order to a standalone SST file that can later be ingested into a database via IngestExternalFile(IReadOnlyList<string>, IngestExternalFileOptions). Keys must be added in ascending order.

public sealed class SstFileWriter : RocksDbHandle, IDisposable

Inheritance

object

RocksDbHandle

SstFileWriter

Implements

IDisposable

Inherited Members

RocksDbHandle.Handle

RocksDbHandle.Owned

RocksDbHandle.IsDisposed

RocksDbHandle.ThrowIfDisposed()

RocksDbHandle.Dispose()

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Properties

FileSize

Returns the size of the written file in bytes (available after Finish()).

public ulong FileSize { get; }

Property Value

ulong

Methods

Create(DbOptions)

Creates a new SstFileWriter using default environment options and the provided database options (for comparator / compression settings).

public static SstFileWriter Create(DbOptions options)

Parameters

options DbOptions

Returns

SstFileWriter

Remarks

The writer keeps a reference to options for its own lifetime, because RocksDb keeps the comparator and the env out of them by raw pointer and reads both on every write. That stops them being collected under a live writer; disposing them yourself while it is open is still your mistake to avoid.

Create(EnvOptions, DbOptions)

Creates a new SstFileWriter with explicit environment options, for control over how the file is written: direct or memory mapped I/O, preallocation, sync behaviour and rate limiting.

public static SstFileWriter Create(EnvOptions envOptions, DbOptions options)

Parameters

envOptions EnvOptions

options DbOptions

Returns

SstFileWriter

Remarks

envOptions is read here and not retained: RocksDb copies what it needs out of it, so the caller may dispose it once the writer exists. options is different — the writer keeps a reference to it, because RocksDb keeps the comparator and the env out of it by raw pointer and reads both on every write. Do not dispose those while the writer is open.

Delete(ReadOnlySpan<byte>)

Writes a deletion record for key.

public void Delete(ReadOnlySpan<byte> key)

Parameters

key ReadOnlySpan<byte>

DisposeHandle()

Releases the native handle. Called during disposal.

protected override void DisposeHandle()

Remarks

Protected rather than public: it destroys the native object without marking this instance disposed or clearing the handle, so calling it from outside and then disposing normally would free the same pointer twice. It was the most Dispose-looking member on the type. Callers want Dispose().

Finish()

Finalizes and closes the SST file. Must be called before ingestion.

public void Finish()

Merge(ReadOnlySpan<byte>, ReadOnlySpan<byte>)

Writes a merge operand. Keys must be added in ascending order.

public void Merge(ReadOnlySpan<byte> key, ReadOnlySpan<byte> value)

Parameters

key ReadOnlySpan<byte>

value ReadOnlySpan<byte>

Open(string)

Opens filePath for writing. Call before any Put/Merge/Delete.

public void Open(string filePath)

Parameters

filePath string

Put(ReadOnlySpan<byte>, ReadOnlySpan<byte>)

Writes a key-value pair. Keys must be added in ascending order.

public void Put(ReadOnlySpan<byte> key, ReadOnlySpan<byte> value)

Parameters

key ReadOnlySpan<byte>

value ReadOnlySpan<byte>