public Store(string path)
{
var families = new ColumnFamilies();
try
{
foreach (var family in RocksDb.ListColumnFamilies(Options.Default, Path.GetFullPath(path)))
{
families.Add(new ColumnFamilies.Descriptor(family, new ColumnFamilyOptions()));
}
}
catch { }
db = RocksDb.Open(Options.Default, Path.GetFullPath(path), families);
ColumnFamilyHandle defaultFamily = db.GetDefaultColumnFamily();
byte[] value = db.Get(SYS_Version, defaultFamily, Options.ReadDefault);
if (value != null && Version.TryParse(Encoding.ASCII.GetString(value), out Version version) && version >= Version.Parse("3.0.0"))
{
return;
}
if (value != null)
{
// Clean all families only if the version are different
Parallel.For(0, byte.MaxValue + 1, (x) => db.DropColumnFamily(x.ToString()));
_families.Clear();
}
// Update version
db.Put(SYS_Version, Encoding.ASCII.GetBytes(Assembly.GetExecutingAssembly().GetName().Version.ToString()), defaultFamily, Options.WriteDefault);
}
internal static RocksDbSharp.RocksDb GetDatabase(string databasePath, SliceTransform prefixTransform)
{
var columnFamilies = new ColumnFamilies();
if (File.Exists(databasePath) || Directory.Exists(databasePath))
{
var currentColumnFamilies = RocksDbSharp.RocksDb.ListColumnFamilies(new DbOptions(), databasePath);
foreach (var columnFamily in currentColumnFamilies.ToHashSet())
{
columnFamilies.Add(columnFamily,
new ColumnFamilyOptions()
.SetPrefixExtractor(prefixTransform)
.SetBlockBasedTableFactory(new BlockBasedTableOptions()
.SetWholeKeyFiltering(true)
.SetIndexType(BlockBasedTableIndexType.Binary)));
}
}
return(RocksDbSharp.RocksDb.Open(new DbOptions()
.SetCreateIfMissing()
.SetCreateMissingColumnFamilies()
.IncreaseParallelism(10),
databasePath,
columnFamilies));
}
private static ColumnFamilies GetColumnFamilies(T[] keys)
{
var result = new ColumnFamilies();
foreach (var key in keys)
{
result.Add(key.ToString(), new ColumnFamilyOptions());
}
return(result);
}
private static ColumnFamilies GetColumnFamilies(IDbConfig dbConfig, string name, T[] keys)
{
var result = new ColumnFamilies();
var blockCacheSize = ReadConfig <ulong>(dbConfig, nameof(dbConfig.BlockCacheSize), name);
foreach (var key in keys)
{
var columnFamilyOptions = new ColumnFamilyOptions();
columnFamilyOptions.OptimizeForPointLookup(blockCacheSize);
columnFamilyOptions.SetBlockBasedTableFactory(new BlockBasedTableOptions().SetFilterPolicy(BloomFilterPolicy.Create()));
result.Add(key.ToString(), columnFamilyOptions);
}
return(result);
}
public DataContext(string path = "ether.db")
{
_lastTxIdDictionary = new Dictionary <string, long>();
var options = new DbOptions()
.SetCreateIfMissing(true)
.SetCreateMissingColumnFamilies(true);
// Create column families
IEnumerable <string> cols = null;
ColumnFamilies columnFamilies = new ColumnFamilies();
try
{
cols = RocksDb.ListColumnFamilies(options, path);
foreach (var col in cols)
{
columnFamilies.Add(col, new ColumnFamilyOptions());
}
}
catch (Exception e)
{
// Database not exist nothing todo
}
finally
{
_db = RocksDb.Open(options, path, columnFamilies);
// Load column families to the dictionary
_columnFamiliesDictionary = new Dictionary <string, ColumnFamilyHandle>();
if (cols != null)
{
foreach (var col in cols)
{
_columnFamiliesDictionary.Add(col, _db.GetColumnFamily(col));
}
foreach (var col in cols)
{
// Load latest transaction Ids
if (!col.Contains(':') && col != "default")
{
var lastTxIdstr = _db.Get("lastTxId", GetColFamily(col + ":lastid"));
_lastTxIdDictionary.Add(col,
string.IsNullOrEmpty(lastTxIdstr) ? 0 : long.Parse(lastTxIdstr));
}
}
}
}
}
static ColumnFamilies GetColumnFamilies(string path)
{
if (RocksDb.TryListColumnFamilies(new DbOptions(), path, out var names))
{
var columnFamilyOptions = new ColumnFamilyOptions();
var families = new ColumnFamilies();
foreach (var name in names)
{
families.Add(name, columnFamilyOptions);
}
return(families);
}
return(new ColumnFamilies());
}
private RocksDbStore(string fileName)
{
AppDomain.CurrentDomain.ProcessExit += (s, e) => Shutdown();
logger.Message("RocksDBStore: " + fileName);
this.fileName = fileName.Replace("\\", "/");
var path = Path.GetDirectoryName(fileName);
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
//TODO check options
var options = new DbOptions()
.SetCreateIfMissing(true)
.SetCreateMissingColumnFamilies(true);
var columnFamilies = new ColumnFamilies
{
{ "default", new ColumnFamilyOptions().OptimizeForPointLookup(256) },
//{ "test", new ColumnFamilyOptions()
// //.SetWriteBufferSize(writeBufferSize)
// //.SetMaxWriteBufferNumber(maxWriteBufferNumber)
// //.SetMinWriteBufferNumberToMerge(minWriteBufferNumberToMerge)
// .SetMemtableHugePageSize(2 * 1024 * 1024)
// .SetPrefixExtractor(SliceTransform.CreateFixedPrefix((ulong)8))
// .SetBlockBasedTableFactory(bbto)
//},
};
try
{
var partitionList = RocksDb.ListColumnFamilies(options, path);
foreach (var partition in partitionList)
{
columnFamilies.Add(partition, new ColumnFamilyOptions());
}
}
catch
{
logger.Warning("Inital start, no partitions created yet!");
}
logger.Message("Opening database at: " + path);
_db = RocksDb.Open(options, path, columnFamilies);
}
/// <summary>
/// Open <see cref="RocksDb"/> from path in configuration.
/// </summary>
/// <param name="path">The path of <see cref="RocksDb"/> to load.</param>
/// <returns>A <see cref="RocksDb"/> instance.</returns>
public RocksDb Load(string path)
{
var columnFamilies = new ColumnFamilies();
foreach (var columnFamily in RocksDb.ListColumnFamilies(
_options,
path))
{
if (columnFamily is null)
{
continue;
}
columnFamilies.Add(columnFamily, new ColumnFamilyOptions());
}
return(RocksDb.Open(_options, path, columnFamilies !));
}
public static RocksDbWrapper Create(IRocksDbOptionsProvider optionsProvider, string path, IEnumerable <string> partitionsList)
{
Preconditions.CheckNonWhiteSpace(path, nameof(path));
Preconditions.CheckNotNull(optionsProvider, nameof(optionsProvider));
DbOptions dbOptions = Preconditions.CheckNotNull(optionsProvider.GetDbOptions());
IEnumerable <string> existingColumnFamilies = ListColumnFamilies(dbOptions, path);
IEnumerable <string> columnFamiliesList = existingColumnFamilies.Union(Preconditions.CheckNotNull(partitionsList, nameof(partitionsList)), StringComparer.OrdinalIgnoreCase).ToList();
var columnFamilies = new ColumnFamilies();
foreach (string columnFamilyName in columnFamiliesList)
{
columnFamilies.Add(columnFamilyName, optionsProvider.GetColumnFamilyOptions());
}
RocksDb db = RocksDb.Open(dbOptions, path, columnFamilies);
var rocksDbWrapper = new RocksDbWrapper(dbOptions, db, path);
return(rocksDbWrapper);
}
private RocksDbStore(string fileName, Logger logger)
{
AppDomain.CurrentDomain.ProcessExit += (s, e) => Shutdown();
this.logger = logger;
logger.Message("RocksDBStore: " + fileName);
this.fileName = fileName.Replace("\\", "/");
var path = Path.GetDirectoryName(fileName);
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
//TODO check options
var options = new DbOptions()
.SetCreateIfMissing(true)
.SetCreateMissingColumnFamilies(true);
var columnFamilies = new ColumnFamilies
{
{ "default", new ColumnFamilyOptions().OptimizeForPointLookup(256) },
};
try
{
var partitionList = RocksDb.ListColumnFamilies(options, path);
foreach (var partition in partitionList)
{
columnFamilies.Add(partition, new ColumnFamilyOptions());
}
}
catch
{
logger.Warning("Inital start, no partitions created yet!");
}
logger.Message("Opening database at: " + path);
_db.Add(fileName, RocksDb.Open(options, path, columnFamilies));
}
private ColumnFamilies GetColumnFamilies(DbOptions options, string dbName)
{
var dbPath = Path.Combine(_path, dbName);
var columnFamilies = new ColumnFamilies();
List <string> listColumnFamilies;
try
{
listColumnFamilies = RocksDb.ListColumnFamilies(options, dbPath).ToList();
}
catch (RocksDbException)
{
listColumnFamilies = new List <string>();
}
foreach (string name in listColumnFamilies)
{
columnFamilies.Add(name, _options);
}
return(columnFamilies);
}
public static ColumnFamilyStorageRocksDbWrapper Create(string path, IEnumerable <string> partitionsList)
{
Preconditions.CheckNonWhiteSpace(path, nameof(path));
string dbPath = Path.Combine(path, DbFolderName);
string columnFamiliesFilePath = Path.Combine(path, ColumnFamiliesFileName);
var columnFamiliesProvider = new ColumnFamiliesProvider(columnFamiliesFilePath);
lock (ColumnFamiliesLock)
{
IEnumerable <string> existingColumnFamilies = columnFamiliesProvider.ListColumnFamilies();
IEnumerable <string> columnFamiliesList = existingColumnFamilies.Union(Preconditions.CheckNotNull(partitionsList, nameof(partitionsList)), StringComparer.OrdinalIgnoreCase).ToList();
var columnFamilies = new ColumnFamilies();
foreach (string columnFamilyName in columnFamiliesList)
{
columnFamilies.Add(columnFamilyName, new ColumnFamilyOptions());
}
columnFamiliesProvider.SetColumnFamilies(columnFamiliesList);
RocksDb db = RocksDb.Open(Options, dbPath, columnFamilies);
var rocksDbWrapper = new ColumnFamilyStorageRocksDbWrapper(db, columnFamiliesProvider);
return(rocksDbWrapper);
}
}
/// <summary>
/// Provides access to and/or creates a RocksDb persistent key-value store.
/// </summary>
/// <param name="storeDirectory">
/// The directory containing the key-value store.
/// </param>
/// <param name="defaultColumnKeyTracked">
/// Whether the default column should be key-tracked.
/// This will create two columns for the same data,
/// one with just keys and the other with key and value.
/// </param>
/// <param name="additionalColumns">
/// The names of any additional column families in the key-value store.
/// If no additional column families are provided, all entries will be stored
/// in the default column.
/// Column families are analogous to tables in relational databases.
/// </param>
/// <param name="additionalKeyTrackedColumns">
/// The names of any additional column families in the key-value store that
/// should also be key-tracked. This will create two columns for the same data,
/// one with just keys and the other with key and value.
/// Column families are analogous to tables in relational databases.
/// </param>
/// <param name="readOnly">
/// Whether the database should be opened read-only. This prevents modifications and
/// creating unnecessary metadata files related to write sessions.
/// </param>
/// <param name="dropMismatchingColumns">
/// If a store already exists at the given directory, whether any columns that mismatch the the columns that were passed into the constructor
/// should be dropped. This will cause data loss and can only be applied in read-write mode.
/// </param>
/// <param name="rotateLogs">
/// Have RocksDb rotate logs, useful for debugging performance issues. It will rotate logs every 12 hours,
/// up to a maximum of 60 logs (i.e. 30 days). When the maximum amount of logs is reached, the oldest logs
/// are overwritten in a circular fashion.
///
/// Every time the RocksDb instance is open, the current log file is truncated, which means that if you
/// open the DB more than once in a 12 hour period, you will only have partial information.
/// </param>
public RocksDbStore(
string storeDirectory,
bool defaultColumnKeyTracked = false,
IEnumerable <string> additionalColumns = null,
IEnumerable <string> additionalKeyTrackedColumns = null,
bool readOnly = false,
bool dropMismatchingColumns = false,
bool rotateLogs = false)
{
m_storeDirectory = storeDirectory;
m_defaults.DbOptions = new DbOptions()
.SetCreateIfMissing(true)
.SetCreateMissingColumnFamilies(true)
// The background compaction threads run in low priority, so they should not hamper the rest of
// the system. The number of cores in the system is what we want here according to official docs,
// and we are setting this to the number of logical processors, which may be higher.
.SetMaxBackgroundCompactions(Environment.ProcessorCount)
.SetMaxBackgroundFlushes(1)
.IncreaseParallelism(Environment.ProcessorCount / 2)
// Ensure we have performance statistics for profiling
.EnableStatistics();
// A small comment on things tested that did not work:
// * SetAllowMmapReads(true) and SetAllowMmapWrites(true) produce a dramatic performance drop
// * SetUseDirectReads(true) disables the OS cache, and although that's good for random point lookups,
// it produces a dramatic performance drop otherwise.
m_defaults.WriteOptions = new WriteOptions()
// Disable the write ahead log to reduce disk IO. The write ahead log
// is used to recover the store on crashes, so a crash will lose some writes.
// Writes will be made in-memory only until the write buffer size
// is reached and then they will be flushed to storage files.
.DisableWal(1)
// This option is off by default, but just making sure that the C# wrapper
// doesn't change anything. The idea is that the DB won't wait for fsync to
// return before acknowledging the write as successful. This affects
// correctness, because a write may be ACKd before it is actually on disk,
// but it is much faster.
.SetSync(false);
var blockBasedTableOptions = new BlockBasedTableOptions()
// Use a bloom filter to help reduce read amplification on point lookups. 10 bits per key yields a
// ~1% false positive rate as per the RocksDB documentation. This builds one filter per SST, which
// means its optimized for not having a key.
.SetFilterPolicy(BloomFilterPolicy.Create(10, false))
// Use a hash index in SST files to speed up point lookup.
.SetIndexType(BlockBasedTableIndexType.HashSearch)
// Whether to use the whole key or a prefix of it (obtained through the prefix extractor below).
// Since the prefix extractor is a no-op, better performance is achieved by turning this off (i.e.
// setting it to true).
.SetWholeKeyFiltering(true);
m_defaults.ColumnFamilyOptions = new ColumnFamilyOptions()
.SetBlockBasedTableFactory(blockBasedTableOptions)
.SetPrefixExtractor(SliceTransform.CreateNoOp());
if (rotateLogs)
{
// Maximum number of information log files
m_defaults.DbOptions.SetKeepLogFileNum(60);
// Do not rotate information logs based on file size
m_defaults.DbOptions.SetMaxLogFileSize(0);
// How long before we rotate the current information log file
m_defaults.DbOptions.SetLogFileTimeToRoll((ulong)TimeSpan.FromHours(12).Seconds);
}
m_columns = new Dictionary <string, ColumnFamilyInfo>();
additionalColumns = additionalColumns ?? CollectionUtilities.EmptyArray <string>();
additionalKeyTrackedColumns = additionalKeyTrackedColumns ?? CollectionUtilities.EmptyArray <string>();
// The columns that exist in the store on disk may not be in sync with the columns being passed into the constructor
HashSet <string> existingColumns;
try
{
existingColumns = new HashSet <string>(RocksDb.ListColumnFamilies(m_defaults.DbOptions, m_storeDirectory));
}
catch (RocksDbException)
{
// If there is no existing store, an exception will be thrown, ignore it
existingColumns = new HashSet <string>();
}
// In read-only mode, open all existing columns in the store without attempting to validate it against the expected column families
if (readOnly)
{
var columnFamilies = new ColumnFamilies();
foreach (var name in existingColumns)
{
columnFamilies.Add(name, m_defaults.ColumnFamilyOptions);
}
m_store = RocksDb.OpenReadOnly(m_defaults.DbOptions, m_storeDirectory, columnFamilies, errIfLogFileExists: false);
}
else
{
// For read-write mode, column families may be added, so set up column families schema
var columnsSchema = new HashSet <string>(additionalColumns);
// Default column
columnsSchema.Add(ColumnFamilies.DefaultName);
// For key-tracked column familiies, create two columns:
// 1: Normal column of { key : value }
// 2: Key-tracking column of { key : empty-value }
if (defaultColumnKeyTracked)
{
// To be robust to the RocksDB-selected default column name changing,
// just name the default column's key-tracking column KeyColumnSuffix
columnsSchema.Add(KeyColumnSuffix);
}
foreach (var name in additionalKeyTrackedColumns)
{
columnsSchema.Add(name);
columnsSchema.Add(name + KeyColumnSuffix);
}
// Figure out which columns are not part of the schema
var outsideSchemaColumns = new List <string>(existingColumns.Except(columnsSchema));
// RocksDB requires all columns in the store to be opened in read-write mode, so merge existing columns
// with the columns schema that was passed into the constructor
existingColumns.UnionWith(columnsSchema);
var columnFamilies = new ColumnFamilies();
foreach (var name in existingColumns)
{
columnFamilies.Add(name, m_defaults.ColumnFamilyOptions);
}
m_store = RocksDb.Open(m_defaults.DbOptions, m_storeDirectory, columnFamilies);
// Provide an opportunity to update the store to the new column family schema
if (dropMismatchingColumns)
{
foreach (var name in outsideSchemaColumns)
{
m_store.DropColumnFamily(name);
existingColumns.Remove(name);
}
}
}
var userFacingColumns = existingColumns.Where(name => !name.EndsWith(KeyColumnSuffix));
foreach (var name in userFacingColumns)
{
var isKeyTracked = existingColumns.Contains(name + KeyColumnSuffix);
m_columns.Add(name, new ColumnFamilyInfo()
{
Handle = m_store.GetColumnFamily(name),
UseKeyTracking = isKeyTracked,
KeyHandle = isKeyTracked ? m_store.GetColumnFamily(name + KeyColumnSuffix) : null,
});
}
m_columns.TryGetValue(ColumnFamilies.DefaultName, out m_defaultColumnFamilyInfo);
}
/// <summary>
/// Provides access to and/or creates a RocksDb persistent key-value store.
/// </summary>
public RocksDbStore(RocksDbStoreArguments arguments)
{
m_storeDirectory = arguments.StoreDirectory;
m_openBulkLoad = arguments.OpenBulkLoad;
m_defaults.DbOptions = new DbOptions()
.SetCreateIfMissing(true)
.SetCreateMissingColumnFamilies(true)
// The background compaction threads run in low priority, so they should not hamper the rest of
// the system. The number of cores in the system is what we want here according to official docs,
// and we are setting this to the number of logical processors, which may be higher.
// See: https://github.com/facebook/rocksdb/wiki/RocksDB-Tuning-Guide#parallelism-options
#if !PLATFORM_OSX
.SetMaxBackgroundCompactions(Environment.ProcessorCount)
.SetMaxBackgroundFlushes(1)
#else
// The memtable uses significant chunks of available system memory on macOS, we increase the number
// of background flushing threads (low priority) and set the DB write buffer size. This allows for
// up to 128 MB in memtables across all column families before we flush to disk.
.SetMaxBackgroundCompactions(Environment.ProcessorCount / 4)
.SetMaxBackgroundFlushes(Environment.ProcessorCount / 4)
.SetDbWriteBufferSize(128 << 20)
#endif
.IncreaseParallelism(Environment.ProcessorCount / 2);
if (arguments.EnableStatistics)
{
m_defaults.DbOptions.EnableStatistics();
}
if (arguments.OpenBulkLoad)
{
m_defaults.DbOptions.PrepareForBulkLoad();
}
// Maximum number of information log files
if (arguments.RotateLogsNumFiles != null)
{
m_defaults.DbOptions.SetKeepLogFileNum(arguments.RotateLogsNumFiles.Value);
}
// Do not rotate information logs based on file size
if (arguments.RotateLogsMaxFileSizeBytes != null)
{
m_defaults.DbOptions.SetMaxLogFileSize(arguments.RotateLogsMaxFileSizeBytes.Value);
}
// How long before we rotate the current information log file
if (arguments.RotateLogsMaxAge != null)
{
m_defaults.DbOptions.SetLogFileTimeToRoll((ulong)arguments.RotateLogsMaxAge.Value.Seconds);
}
if (arguments.FastOpen)
{
// max_file_opening_threads is defaulted to 16, so no need to update here.
RocksDbSharp.Native.Instance.rocksdb_options_set_skip_stats_update_on_db_open(m_defaults.DbOptions.Handle, true);
}
if (arguments.DisableAutomaticCompactions)
{
m_defaults.DbOptions.SetDisableAutoCompactions(1);
}
// A small comment on things tested that did not work:
// * SetAllowMmapReads(true) and SetAllowMmapWrites(true) produce a dramatic performance drop
// * SetUseDirectReads(true) disables the OS cache, and although that's good for random point lookups,
// it produces a dramatic performance drop otherwise.
m_defaults.WriteOptions = new WriteOptions()
// Disable the write ahead log to reduce disk IO. The write ahead log
// is used to recover the store on crashes, so a crash will lose some writes.
// Writes will be made in-memory only until the write buffer size
// is reached and then they will be flushed to storage files.
.DisableWal(1)
// This option is off by default, but just making sure that the C# wrapper
// doesn't change anything. The idea is that the DB won't wait for fsync to
// return before acknowledging the write as successful. This affects
// correctness, because a write may be ACKd before it is actually on disk,
// but it is much faster.
.SetSync(false);
var blockBasedTableOptions = new BlockBasedTableOptions()
// Use a bloom filter to help reduce read amplification on point lookups. 10 bits per key yields a
// ~1% false positive rate as per the RocksDB documentation. This builds one filter per SST, which
// means its optimized for not having a key.
.SetFilterPolicy(BloomFilterPolicy.Create(10, false))
// Use a hash index in SST files to speed up point lookup.
.SetIndexType(BlockBasedTableIndexType.HashSearch)
// Whether to use the whole key or a prefix of it (obtained through the prefix extractor below).
// Since the prefix extractor is a no-op, better performance is achieved by turning this off (i.e.
// setting it to true).
.SetWholeKeyFiltering(true);
m_defaults.ColumnFamilyOptions = new ColumnFamilyOptions()
#if PLATFORM_OSX
// As advised by the official documentation, LZ4 is the preferred compression algorithm, our RocksDB
// dynamic library has been compiled to support this on macOS. Fallback to Snappy on other systems (default).
.SetCompression(CompressionTypeEnum.rocksdb_lz4_compression)
#endif
.SetBlockBasedTableFactory(blockBasedTableOptions)
.SetPrefixExtractor(SliceTransform.CreateNoOp());
m_columns = new Dictionary <string, ColumnFamilyInfo>();
// The columns that exist in the store on disk may not be in sync with the columns being passed into the constructor
HashSet <string> existingColumns;
try
{
existingColumns = new HashSet <string>(RocksDb.ListColumnFamilies(m_defaults.DbOptions, m_storeDirectory));
}
catch (RocksDbException)
{
// If there is no existing store, an exception will be thrown, ignore it
existingColumns = new HashSet <string>();
}
// In read-only mode, open all existing columns in the store without attempting to validate it against the expected column families
if (arguments.ReadOnly)
{
var columnFamilies = new ColumnFamilies();
foreach (var name in existingColumns)
{
columnFamilies.Add(name, m_defaults.ColumnFamilyOptions);
}
m_store = RocksDb.OpenReadOnly(m_defaults.DbOptions, m_storeDirectory, columnFamilies, errIfLogFileExists: false);
}
else
{
// For read-write mode, column families may be added, so set up column families schema
var additionalColumns = arguments.AdditionalColumns ?? CollectionUtilities.EmptyArray <string>();
var columnsSchema = new HashSet <string>(additionalColumns);
// Default column
columnsSchema.Add(ColumnFamilies.DefaultName);
// For key-tracked column familiies, create two columns:
// 1: Normal column of { key : value }
// 2: Key-tracking column of { key : empty-value }
if (arguments.DefaultColumnKeyTracked)
{
// To be robust to the RocksDB-selected default column name changing,
// just name the default column's key-tracking column KeyColumnSuffix
columnsSchema.Add(KeyColumnSuffix);
}
var additionalKeyTrackedColumns = arguments.AdditionalKeyTrackedColumns ?? CollectionUtilities.EmptyArray <string>();
foreach (var name in additionalKeyTrackedColumns)
{
columnsSchema.Add(name);
columnsSchema.Add(name + KeyColumnSuffix);
}
// Figure out which columns are not part of the schema
var outsideSchemaColumns = new List <string>(existingColumns.Except(columnsSchema));
// RocksDB requires all columns in the store to be opened in read-write mode, so merge existing columns
// with the columns schema that was passed into the constructor
existingColumns.UnionWith(columnsSchema);
var columnFamilies = new ColumnFamilies();
foreach (var name in existingColumns)
{
columnFamilies.Add(name, m_defaults.ColumnFamilyOptions);
}
m_store = RocksDb.Open(m_defaults.DbOptions, m_storeDirectory, columnFamilies);
// Provide an opportunity to update the store to the new column family schema
if (arguments.DropMismatchingColumns)
{
foreach (var name in outsideSchemaColumns)
{
m_store.DropColumnFamily(name);
existingColumns.Remove(name);
}
}
}
var userFacingColumns = existingColumns.Where(name => !name.EndsWith(KeyColumnSuffix));
foreach (var name in userFacingColumns)
{
var isKeyTracked = existingColumns.Contains(name + KeyColumnSuffix);
m_columns.Add(name, new ColumnFamilyInfo()
{
Handle = m_store.GetColumnFamily(name),
UseKeyTracking = isKeyTracked,
KeyHandle = isKeyTracked ? m_store.GetColumnFamily(name + KeyColumnSuffix) : null,
});
}
m_columns.TryGetValue(ColumnFamilies.DefaultName, out m_defaultColumnFamilyInfo);
}
/// <summary>
/// Provides access to and/or creates a RocksDb persistent key-value store.
/// </summary>
/// <param name="storeDirectory">
/// The directory containing the key-value store.
/// </param>
/// <param name="defaultColumnKeyTracked">
/// Whether the default column should be key-tracked.
/// This will create two columns for the same data,
/// one with just keys and the other with key and value.
/// </param>
/// <param name="additionalColumns">
/// The names of any additional column families in the key-value store.
/// If no additional column families are provided, all entries will be stored
/// in the default column.
/// Column families are analogous to tables in relational databases.
/// </param>
/// <param name="additionalKeyTrackedColumns">
/// The names of any additional column families in the key-value store that
/// should also be key-tracked. This will create two columns for the same data,
/// one with just keys and the other with key and value.
/// Column families are analogous to tables in relational databases.
/// </param>
/// <param name="readOnly">
/// Whether the database should be opened read-only. This prevents modifications and
/// creating unnecessary metadata files related to write sessions.
/// </param>
/// <param name="dropMismatchingColumns">
/// If a store already exists at the given directory, whether any columns that mismatch the the columns that were passed into the constructor
/// should be dropped. This will cause data loss and can only be applied in read-write mode.
/// </param>
public RocksDbStore(
string storeDirectory,
bool defaultColumnKeyTracked = false,
IEnumerable <string> additionalColumns = null,
IEnumerable <string> additionalKeyTrackedColumns = null,
bool readOnly = false,
bool dropMismatchingColumns = false)
{
m_storeDirectory = storeDirectory;
m_defaults.DbOptions = new DbOptions()
.SetCreateIfMissing(true)
.SetCreateMissingColumnFamilies(true);
// Disable the write ahead log to reduce disk IO. The write ahead log
// is used to recover the store on crashes, so a crash will lose some writes.
// Writes will be made in-memory only until the write buffer size
// is reached and then they will be flushed to storage files.
m_defaults.WriteOptions = new WriteOptions().DisableWal(1);
m_defaults.ColumnFamilyOptions = new ColumnFamilyOptions();
m_columns = new Dictionary <string, ColumnFamilyInfo>();
additionalColumns = additionalColumns ?? CollectionUtilities.EmptyArray <string>();
additionalKeyTrackedColumns = additionalKeyTrackedColumns ?? CollectionUtilities.EmptyArray <string>();
// The columns that exist in the store on disk may not be in sync with the columns being passed into the constructor
HashSet <string> existingColumns;
try
{
existingColumns = new HashSet <string>(RocksDb.ListColumnFamilies(m_defaults.DbOptions, m_storeDirectory));
}
catch (RocksDbException)
{
// If there is no existing store, an exception will be thrown, ignore it
existingColumns = new HashSet <string>();
}
// In read-only mode, open all existing columns in the store without attempting to validate it against the expected column families
if (readOnly)
{
var columnFamilies = new ColumnFamilies();
foreach (var name in existingColumns)
{
columnFamilies.Add(name, m_defaults.ColumnFamilyOptions);
}
m_store = RocksDb.OpenReadOnly(m_defaults.DbOptions, m_storeDirectory, columnFamilies, errIfLogFileExists: false);
}
else
{
// For read-write mode, column families may be added, so set up column families schema
var columnsSchema = new HashSet <string>(additionalColumns);
// Default column
columnsSchema.Add(ColumnFamilies.DefaultName);
// For key-tracked column familiies, create two columns:
// 1: Normal column of { key : value }
// 2: Key-tracking column of { key : empty-value }
if (defaultColumnKeyTracked)
{
// To be robust to the RocksDB-selected default column name changing,
// just name the default column's key-tracking column KeyColumnSuffix
columnsSchema.Add(KeyColumnSuffix);
}
foreach (var name in additionalKeyTrackedColumns)
{
columnsSchema.Add(name);
columnsSchema.Add(name + KeyColumnSuffix);
}
// Figure out which columns are not part of the schema
var outsideSchemaColumns = new List <string>(existingColumns.Except(columnsSchema));
// RocksDB requires all columns in the store to be opened in read-write mode, so merge existing columns
// with the columns schema that was passed into the constructor
existingColumns.UnionWith(columnsSchema);
var columnFamilies = new ColumnFamilies();
foreach (var name in existingColumns)
{
columnFamilies.Add(name, m_defaults.ColumnFamilyOptions);
}
m_store = RocksDb.Open(m_defaults.DbOptions, m_storeDirectory, columnFamilies);
// Provide an opportunity to update the store to the new column family schema
if (dropMismatchingColumns)
{
foreach (var name in outsideSchemaColumns)
{
m_store.DropColumnFamily(name);
existingColumns.Remove(name);
}
}
}
var userFacingColumns = existingColumns.Where(name => !name.EndsWith(KeyColumnSuffix));
foreach (var name in userFacingColumns)
{
var isKeyTracked = existingColumns.Contains(name + KeyColumnSuffix);
m_columns.Add(name, new ColumnFamilyInfo()
{
Handle = m_store.GetColumnFamily(name),
UseKeyTracking = isKeyTracked,
KeyHandle = isKeyTracked ? m_store.GetColumnFamily(name + KeyColumnSuffix) : null,
});
}
m_columns.TryGetValue(ColumnFamilies.DefaultName, out m_defaultColumnFamilyInfo);
}
