java.lang.Object
- org.nuxeo.runtime.kv.AbstractKeyValueStoreProvider
- - org.nuxeo.ecm.core.storage.sql.kv.SQLKeyValueStore

All Implemented Interfaces:

KeyValueStore, KeyValueStoreProvider
```
public class SQLKeyValueStore
extends AbstractKeyValueStoreProvider
```
SQL implementation of a Key/Value Store Provider.
The following configuration properties are available:
- datasource: the datasource to use.
- table: the table to use. The default is the Store name.
If a namespace is specified, it is used as a table name suffix, otherwise of the store name.
This implementation uses a table with a KEY column (unique and not NULL), and for the value one of these three columns is used: LONG, STRING, BYTES. If possible LONG is used, then STRING, otherwise BYTES.
The TTL is stored as an expiration time (seconds since epoch) in its own column. Expiration is done by a thread running a cleanup DELETE query every 60 seconds.
Since:

10.10

Field Summary

Fields
Modifier and Type	Field	Description
`static String`	`BYTES_COL`	Bytes column, or NULL if the value is representable as a Long or String.
`protected Column`	`bytesCol`
`protected String`	`bytesColName`
`static String`	`DATASOURCE_PROP`	Datasource configuration property.
`protected String`	`dataSourceName`
`protected String`	`deleteAllSQL`
`protected String`	`deleteIfBytesSQL`
`protected String`	`deleteIfLongSQL`
`protected String`	`deleteIfStringSQL`
`protected String`	`deleteSQL`
`protected Dialect`	`dialect`
`protected String`	`existsSQL`
`protected String`	`expireSQL`
`protected String`	`getLongSQL`
`protected String`	`getMultiSQL`
`protected String`	`getSQL`
`protected String`	`insertLongSQL`
`protected String`	`insertSQL`
`static String`	`KEY_COL`	Key column, a short string.
`protected Column`	`keyCol`
`protected String`	`keyColName`
`protected String`	`keyStreamPrefixSQL`
`protected String`	`keyStreamSQL`
`protected JDBCLogger`	`logger`
`static String`	`LONG_COL`	Long column, or NULL if the value is not representable as a Long.
`protected Column`	`longCol`
`protected String`	`longColName`
`protected static int`	`MAX_RETRY`
`protected String`	`setTTLSQL`
`static String`	`STRING_COL`	String column, or NULL if the value is representable as a Long or not representable as a String.
`protected Column`	`stringCol`
`protected String`	`stringColName`
`protected TableImpl`	`table`
`static String`	`TABLE_PROP`	Table configuration property.
`protected String`	`tableName`
`static String`	`TTL_COL`	TTL column, holding expiration date in seconds since epoch, or NULL if there is no expiration.
`protected static int`	`TTL_EXPIRATION_FREQUENCY_MS`
`protected Column`	`ttlCol`
`protected String`	`ttlColName`
`protected Thread`	`ttlThread`
`protected String`	`updateLongSQL`
`protected String`	`updateReturningOracleSql`
`protected String`	`updateReturningPostgreSQLSql`
`protected String`	`updateReturningSQLServerSql`

Fields inherited from class org.nuxeo.runtime.kv.AbstractKeyValueStoreProvider
name, UTF_8_DECODERS

Constructor Summary

Constructors
Constructor Description

SQLKeyValueStore()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`long`	`addAndGet(String key, long delta)`	Atomically adds the delta to the value associated to the key, interpreted as a long represented as a string.
`protected long`	`addAndGetGeneric(String key, long delta)`
`protected Column`	`addColumn(String columnName, ColumnType type)`
`protected void`	`checkColumns(Connection connection)`	Checks that columns have expected JDBC types.
`void`	`clear()`	Clears the content of this Key/Value store provider.
`void`	`close()`	Closes this Key/Value store provider.
`boolean`	`compareAndSet(String key, byte[] expected, byte[] value, long ttl)`	Atomically sets the value associated to the key to the given value, with the given TTL, if the current value is the expected value.
`protected boolean`	`compareAndSet(String key, Object expected, Object value, long ttl)`
`boolean`	`compareAndSet(String key, String expected, String value, long ttl)`	Atomically sets the value associated to the key to the given value, with the given TTL, if the current value is the expected value.
`protected void`	`createTable(Connection connection)`
`protected String`	`escapeLike(String prefix)`
`protected void`	`expireTTLOnce()`
`protected void`	`expireTTLThread()`	Runs in a thread to do TTL expiration.
`byte[]`	`get(String key)`	Retrieves the value associated to the key.
`Map<String,byte[]>`	`get(Collection<String> keys)`	Retrieves the key/value map associated with the keys.
`protected Connection`	`getConnection()`
`protected String`	`getDatabaseSchemaName(Connection connection)`
`Long`	`getLong(String key)`	Retrieves the value associated to the key.
`Map<String,Long>`	`getLongs(Collection<String> keys)`	Retrieves the key/value map associated with the keys.
`protected Object`	`getObject(String key)`
`protected void`	`getObjects(Collection<String> keys, BiConsumer<String,Object> consumer)`
`String`	`getString(String key)`	Retrieves the value associated to the key.
`Map<String,String>`	`getStrings(Collection<String> keys)`	Retrieves the key/value map associated with the keys.
`protected void`	`getTable(Connection connection, String tbl)`
`protected Long`	`getTTLValue(long ttl)`
`void`	`initialize(KeyValueStoreDescriptor descriptor)`	Initializes this Key/Value store provider.
`Stream<String>`	`keyStream()`	Returns a `Stream` of the keys contained in this Key/Value store provider.
`Stream<String>`	`keyStream(String prefix)`	Returns a `Stream` of the keys with the given prefix contained in this Key/Value store provider.
`protected Stream<String>`	`keyStream(Connection connection, String prefix)`
`protected String`	`nParams(int n)`
`protected void`	`prepareSQL()`
`void`	`put(String key, byte[] bytes)`	Sets the value associated to the key.
`void`	`put(String key, byte[] bytes, long ttl)`	Sets the value associated to the key, and a TTL.
`void`	`put(String key, Long value)`	Sets the value associated to the key.
`void`	`put(String key, Long value, long ttl)`	Sets the value associated to the key.
`protected void`	`put(String key, Object value, long ttl)`
`void`	`put(String key, String string)`	Sets the value associated to the key.
`void`	`put(String key, String string, long ttl)`	Sets the value associated to the key, and a TTL.
`protected void`	`setToPreparedStatement(String sql, PreparedStatement ps, List<Column> columns, List<? extends Serializable> values)`
`protected void`	`setToPreparedStatement(String sql, PreparedStatement ps, Column column, Serializable value)`
`protected void`	`setToPreparedStatement(String sql, PreparedStatement ps, Column column1, Serializable value1, Column column2, Serializable value2)`
`protected void`	`setToPreparedStatement(String sql, PreparedStatement ps, Column column1, Serializable value1, Column column2, Serializable value2, Column column3, Serializable value3)`
`boolean`	`setTTL(String key, long ttl)`	Sets the TTL for an existing key.
`protected void`	`sleepBeforeRetry()`
`protected void`	`startTTLThread()`
`protected void`	`stopTTLThread()`
`protected boolean`	`tableExists(Connection connection)`
`protected byte[]`	`toBytes(Object value)`
`protected Long`	`toLong(Object value)`
`protected Object`	`toStorage(Object value)`	Canonicalizes value for the database: use a String or a Long if possible.
`String`	`toString()`
`protected String`	`toString(Object value)`
`protected Long`	`ttlToStorage(long ttl)`

Methods inherited from class org.nuxeo.runtime.kv.AbstractKeyValueStoreProvider
bytesToLong, bytesToString, compareAndSet, compareAndSet, longToBytes, stringToBytes

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DATASOURCE_PROP
```
public static final String DATASOURCE_PROP
```
    Datasource configuration property.
    
    See Also:
    
    Constant Field Values
  - TABLE_PROP
```
public static final String TABLE_PROP
```
    Table configuration property. Default is the store name. The namespace is also used for disambiguation.
    
    See Also:
    
    Constant Field Values
  - KEY_COL
```
public static final String KEY_COL
```
    Key column, a short string.
    
    See Also:
    
    Constant Field Values
  - LONG_COL
```
public static final String LONG_COL
```
    Long column, or NULL if the value is not representable as a Long.
    
    See Also:
    
    Constant Field Values
  - STRING_COL
```
public static final String STRING_COL
```
    String column, or NULL if the value is representable as a Long or not representable as a String.
    
    See Also:
    
    Constant Field Values
  - BYTES_COL
```
public static final String BYTES_COL
```
    Bytes column, or NULL if the value is representable as a Long or String.
    
    See Also:
    
    Constant Field Values
  - TTL_COL
```
public static final String TTL_COL
```
    TTL column, holding expiration date in seconds since epoch, or NULL if there is no expiration.
    
    See Also:
    
    Constant Field Values
  - TTL_EXPIRATION_FREQUENCY_MS
```
protected static final int TTL_EXPIRATION_FREQUENCY_MS
```
    See Also:
    
    Constant Field Values
  - MAX_RETRY
```
protected static final int MAX_RETRY
```
    See Also:
    
    Constant Field Values
  - logger
```
protected JDBCLogger logger
```
  - dataSourceName
```
protected String dataSourceName
```
  - dialect
```
protected Dialect dialect
```
  - table
```
protected TableImpl table
```
  - keyCol
```
protected Column keyCol
```
  - longCol
```
protected Column longCol
```
  - stringCol
```
protected Column stringCol
```
  - bytesCol
```
protected Column bytesCol
```
  - ttlCol
```
protected Column ttlCol
```
  - tableName
```
protected String tableName
```
  - keyColName
```
protected String keyColName
```
  - longColName
```
protected String longColName
```
  - stringColName
```
protected String stringColName
```
  - bytesColName
```
protected String bytesColName
```
  - ttlColName
```
protected String ttlColName
```
  - ttlThread
```
protected Thread ttlThread
```
  - getSQL
```
protected String getSQL
```
  - getMultiSQL
```
protected String getMultiSQL
```
  - getLongSQL
```
protected String getLongSQL
```
  - deleteAllSQL
```
protected String deleteAllSQL
```
  - deleteSQL
```
protected String deleteSQL
```
  - deleteIfLongSQL
```
protected String deleteIfLongSQL
```
  - deleteIfStringSQL
```
protected String deleteIfStringSQL
```
  - deleteIfBytesSQL
```
protected String deleteIfBytesSQL
```
  - expireSQL
```
protected String expireSQL
```
  - keyStreamSQL
```
protected String keyStreamSQL
```
  - keyStreamPrefixSQL
```
protected String keyStreamPrefixSQL
```
  - setTTLSQL
```
protected String setTTLSQL
```
  - existsSQL
```
protected String existsSQL
```
  - insertSQL
```
protected String insertSQL
```
  - insertLongSQL
```
protected String insertLongSQL
```
  - updateLongSQL
```
protected String updateLongSQL
```
  - updateReturningPostgreSQLSql
```
protected String updateReturningPostgreSQLSql
```
  - updateReturningOracleSql
```
protected String updateReturningOracleSql
```
  - updateReturningSQLServerSql
```
protected String updateReturningSQLServerSql
```
- Constructor Detail
  - SQLKeyValueStore
```
public SQLKeyValueStore()
```
- Method Detail
  - initialize
```
public void initialize(KeyValueStoreDescriptor descriptor)
```
    Description copied from interface: KeyValueStoreProvider
    
    Initializes this Key/Value store provider.
    
    Specified by:
    
    initialize in interface KeyValueStoreProvider
    
    Overrides:
    
    initialize in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    descriptor - the store provider descriptor
  - close
```
public void close()
```
    Description copied from interface: KeyValueStoreProvider
    
    Closes this Key/Value store provider.
  - getTable
```
protected void getTable(Connection connection,
                        String tbl)
                 throws SQLException
```
    Throws:
    
    SQLException
  - addColumn
```
protected Column addColumn(String columnName,
                           ColumnType type)
```
  - prepareSQL
```
protected void prepareSQL()
```
  - startTTLThread
```
protected void startTTLThread()
```
  - stopTTLThread
```
protected void stopTTLThread()
```
  - expireTTLThread
```
protected void expireTTLThread()
```
    Runs in a thread to do TTL expiration.
  - escapeLike
```
protected String escapeLike(String prefix)
```
  - toStorage
```
protected Object toStorage(Object value)
```
    Canonicalizes value for the database: use a String or a Long if possible.
  - toBytes
```
protected byte[] toBytes(Object value)
```
  - toString
```
protected String toString(Object value)
```
  - toLong
```
protected Long toLong(Object value)
               throws NumberFormatException
```
    Throws:
    
    NumberFormatException
  - getConnection
```
protected Connection getConnection()
                            throws SQLException
```
    Throws:
    
    SQLException
  - setToPreparedStatement
```
protected void setToPreparedStatement(String sql,
                                      PreparedStatement ps,
                                      Column column,
                                      Serializable value)
                               throws SQLException
```
    Throws:
    
    SQLException
  - setToPreparedStatement
```
protected void setToPreparedStatement(String sql,
                                      PreparedStatement ps,
                                      Column column1,
                                      Serializable value1,
                                      Column column2,
                                      Serializable value2)
                               throws SQLException
```
    Throws:
    
    SQLException
  - setToPreparedStatement
```
protected void setToPreparedStatement(String sql,
                                      PreparedStatement ps,
                                      Column column1,
                                      Serializable value1,
                                      Column column2,
                                      Serializable value2,
                                      Column column3,
                                      Serializable value3)
                               throws SQLException
```
    Throws:
    
    SQLException
  - setToPreparedStatement
```
protected void setToPreparedStatement(String sql,
                                      PreparedStatement ps,
                                      List<Column> columns,
                                      List<? extends Serializable> values)
                               throws SQLException
```
    Throws:
    
    SQLException
  - tableExists
```
protected boolean tableExists(Connection connection)
                       throws SQLException
```
    Throws:
    
    SQLException
  - createTable
```
protected void createTable(Connection connection)
                    throws SQLException
```
    Throws:
    
    SQLException
  - checkColumns
```
protected void checkColumns(Connection connection)
                     throws SQLException
```
    Checks that columns have expected JDBC types.
    
    Throws:
    
    SQLException
  - getDatabaseSchemaName
```
protected String getDatabaseSchemaName(Connection connection)
                                throws SQLException
```
    Throws:
    
    SQLException
  - expireTTLOnce
```
protected void expireTTLOnce()
```
  - clear
```
public void clear()
```
    Description copied from interface: KeyValueStoreProvider
    
    Clears the content of this Key/Value store provider.
  - keyStream
```
public Stream<String> keyStream()
```
    Description copied from interface: KeyValueStoreProvider
    
    Returns a Stream of the keys contained in this Key/Value store provider.
    This operation may be slow and should only be used for management or debug purposes.
    
    Returns:
    
    the stream of keys
  - keyStream
```
public Stream<String> keyStream(String prefix)
```
    Description copied from interface: KeyValueStoreProvider
    
    Returns a Stream of the keys with the given prefix contained in this Key/Value store provider.
    This operation may be slow and should only be used for management or debug purposes.
    
    Returns:
    
    the stream of keys
  - keyStream
```
protected Stream<String> keyStream(Connection connection,
                                   String prefix)
                            throws SQLException
```
    Throws:
    
    SQLException
  - get
```
public byte[] get(String key)
```
    Description copied from interface: KeyValueStore
    
    Retrieves the value associated to the key.
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the value, or null if there is no value
  - getString
```
public String getString(String key)
```
    Description copied from interface: KeyValueStore
    
    Retrieves the value associated to the key.
    
    Specified by:
    
    getString in interface KeyValueStore
    
    Overrides:
    
    getString in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the value, or null if there is no value
  - getLong
```
public Long getLong(String key)
             throws NumberFormatException
```
    Description copied from interface: KeyValueStore
    
    Retrieves the value associated to the key.
    
    Specified by:
    
    getLong in interface KeyValueStore
    
    Overrides:
    
    getLong in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the value, or null if there is no value
    
    Throws:
    
    NumberFormatException - if the value cannot be returned as a Long
  - get
```
public Map<String,byte[]> get(Collection<String> keys)
```
    Description copied from interface: KeyValueStore
    
    Retrieves the key/value map associated with the keys.
    
    Specified by:
    
    get in interface KeyValueStore
    
    Overrides:
    
    get in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    keys - the keys
    
    Returns:
    
    the key/value map
  - getStrings
```
public Map<String,String> getStrings(Collection<String> keys)
```
    Description copied from interface: KeyValueStore
    
    Retrieves the key/value map associated with the keys.
    
    Specified by:
    
    getStrings in interface KeyValueStore
    
    Overrides:
    
    getStrings in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    keys - the keys
    
    Returns:
    
    the key/value map
  - getLongs
```
public Map<String,Long> getLongs(Collection<String> keys)
                                throws NumberFormatException
```
    Description copied from interface: KeyValueStore
    
    Retrieves the key/value map associated with the keys.
    
    Specified by:
    
    getLongs in interface KeyValueStore
    
    Overrides:
    
    getLongs in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    keys - the keys
    
    Returns:
    
    the key/value map
    
    Throws:
    
    NumberFormatException - if one of the values cannot be returned as a Long
  - getObject
```
protected Object getObject(String key)
```
  - getObjects
```
protected void getObjects(Collection<String> keys,
                          BiConsumer<String,Object> consumer)
```
  - nParams
```
protected String nParams(int n)
```
  - ttlToStorage
```
protected Long ttlToStorage(long ttl)
```
  - getTTLValue
```
protected Long getTTLValue(long ttl)
```
  - put
```
public void put(String key,
                byte[] bytes)
```
    Description copied from interface: KeyValueStore
    
    Sets the value associated to the key.
    
    Specified by:
    
    put in interface KeyValueStore
    
    Overrides:
    
    put in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    bytes - the value, which may be null
  - put
```
public void put(String key,
                byte[] bytes,
                long ttl)
```
    Description copied from interface: KeyValueStore
    
    Sets the value associated to the key, and a TTL.
    
    Parameters:
    
    key - the key
    
    bytes - the value, which may be null
    
    ttl - the TTL, in seconds (0 for infinite)
  - put
```
public void put(String key,
                String string)
```
    Description copied from interface: KeyValueStore
    
    Sets the value associated to the key.
    
    Specified by:
    
    put in interface KeyValueStore
    
    Overrides:
    
    put in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    string - the value, which may be null
  - put
```
public void put(String key,
                String string,
                long ttl)
```
    Description copied from interface: KeyValueStore
    
    Sets the value associated to the key, and a TTL.
    
    Specified by:
    
    put in interface KeyValueStore
    
    Overrides:
    
    put in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    string - the value, which may be null
    
    ttl - the TTL, in seconds (0 for infinite)
  - put
```
public void put(String key,
                Long value)
```
    Description copied from interface: KeyValueStore
    
    Sets the value associated to the key.
    
    Specified by:
    
    put in interface KeyValueStore
    
    Overrides:
    
    put in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    value - the value, which may be null
  - put
```
public void put(String key,
                Long value,
                long ttl)
```
    Description copied from interface: KeyValueStore
    
    Sets the value associated to the key.
    
    Specified by:
    
    put in interface KeyValueStore
    
    Overrides:
    
    put in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    value - the value, which may be null
    
    ttl - the TTL, in seconds (0 for infinite)
  - put
```
protected void put(String key,
                   Object value,
                   long ttl)
```
  - setTTL
```
public boolean setTTL(String key,
                      long ttl)
```
    Description copied from interface: KeyValueStore
    
    Sets the TTL for an existing key.
    
    Parameters:
    
    key - the key
    
    ttl - the TTL, in seconds (0 for infinite)
    
    Returns:
    
    true if the TTL has been set, or false if the key does not exist
  - compareAndSet
```
public boolean compareAndSet(String key,
                             byte[] expected,
                             byte[] value,
                             long ttl)
```
    Description copied from interface: KeyValueStore
    
    Atomically sets the value associated to the key to the given value, with the given TTL, if the current value is the expected value.
    Note value comparison is done by value and not by reference.
    
    Parameters:
    
    key - the key
    
    expected - the expected value, which may be null
    
    value - the updated value, which may be null
    
    ttl - the TTL, in seconds (0 for infinite)
    
    Returns:
    
    true if the value was updated, or false if not (the expected value was not found)
  - compareAndSet
```
public boolean compareAndSet(String key,
                             String expected,
                             String value,
                             long ttl)
```
    Description copied from interface: KeyValueStore
    
    Atomically sets the value associated to the key to the given value, with the given TTL, if the current value is the expected value.
    Note value comparison is done by value and not by reference.
    
    Specified by:
    
    compareAndSet in interface KeyValueStore
    
    Overrides:
    
    compareAndSet in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    expected - the expected value, which may be null
    
    value - the updated value, which may be null
    
    ttl - the TTL, in seconds (0 for infinite)
    
    Returns:
    
    true if the value was updated, or false if not (the expected value was not found)
  - compareAndSet
```
protected boolean compareAndSet(String key,
                                Object expected,
                                Object value,
                                long ttl)
```
  - addAndGet
```
public long addAndGet(String key,
                      long delta)
               throws NumberFormatException
```
    Description copied from interface: KeyValueStore
    
    Atomically adds the delta to the value associated to the key, interpreted as a long represented as a string.
    If the value does not exist (if KeyValueStore.get(java.lang.String) would return null), it is interpreted as 0.
    
    Specified by:
    
    addAndGet in interface KeyValueStore
    
    Overrides:
    
    addAndGet in class AbstractKeyValueStoreProvider
    
    Parameters:
    
    key - the key
    
    delta - the delta to add
    
    Returns:
    
    the new value
    
    Throws:
    
    NumberFormatException - if the existing value cannot be interpreted as a long
  - sleepBeforeRetry
```
protected void sleepBeforeRetry()
```
  - addAndGetGeneric
```
protected long addAndGetGeneric(String key,
                                long delta)
                         throws NumberFormatException
```
    Throws:
    
    NumberFormatException
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class AbstractKeyValueStoreProvider

Class SQLKeyValueStore

Field Summary

Fields inherited from class org.nuxeo.runtime.kv.AbstractKeyValueStoreProvider

Constructor Summary

Method Summary

Methods inherited from class org.nuxeo.runtime.kv.AbstractKeyValueStoreProvider

Methods inherited from class java.lang.Object

Field Detail

DATASOURCE_PROP

TABLE_PROP

KEY_COL

LONG_COL

STRING_COL

BYTES_COL

TTL_COL

TTL_EXPIRATION_FREQUENCY_MS

MAX_RETRY

logger

dataSourceName

dialect

table

keyCol

longCol

stringCol

bytesCol

ttlCol

tableName

keyColName

longColName

stringColName

bytesColName

ttlColName

ttlThread

getSQL

getMultiSQL

getLongSQL

deleteAllSQL

deleteSQL

deleteIfLongSQL

deleteIfStringSQL

deleteIfBytesSQL

expireSQL

keyStreamSQL

keyStreamPrefixSQL

setTTLSQL

existsSQL

insertSQL

insertLongSQL

updateLongSQL

updateReturningPostgreSQLSql

updateReturningOracleSql

updateReturningSQLServerSql

Constructor Detail

SQLKeyValueStore

Method Detail

initialize

close

getTable

addColumn

prepareSQL

startTTLThread

stopTTLThread

expireTTLThread

escapeLike

toStorage

toBytes

toString

toLong

getConnection

setToPreparedStatement

setToPreparedStatement

setToPreparedStatement

setToPreparedStatement

tableExists

createTable

checkColumns

getDatabaseSchemaName

expireTTLOnce

clear

keyStream