org.apache.cassandra.config
Class Schema

java.lang.Object
  org.apache.cassandra.config.Schema

public class Schema
extends java.lang.Object

Field Summary

static Schema	instance
static int	NAME_LENGTH longest permissible KS or CF name.

Constructor Summary

Schema()
Initialize empty schema object

Method Summary

void	addSystemTable(KSMetaData systemTable) Add a new system table
void	clear() Clear all KS/CF metadata and reset version.
void	clearTableDefinition(KSMetaData ksm) Remove table definition from system
void	fixCFMaxId() This gets called after initialization to make sure that id generation happens properly.
Pair<java.lang.String,java.lang.String>	getCF(java.lang.Integer cfId)
CFMetaData	getCFMetaData(Descriptor descriptor)
CFMetaData	getCFMetaData(java.lang.Integer cfId) Get ColumnFamily metadata by its identifier
CFMetaData	getCFMetaData(java.lang.String tableName, java.lang.String cfName) Given a table name & column family name, get the column family meta data.
ColumnFamilyType	getColumnFamilyType(java.lang.String ksName, java.lang.String cfName) Get type of the ColumnFamily but it's keyspace/name
AbstractType<?>	getComparator(java.lang.String ksName, java.lang.String cfName) Get column comparator for ColumnFamily but it's keyspace/name
java.lang.Integer	getId(java.lang.String ksName, java.lang.String cfName) Lookup keyspace/ColumnFamily identifier
KSMetaData	getKSMetaData(java.lang.String table) Get metadata about table by its name
java.util.List<java.lang.String>	getNonSystemTables()
AbstractType<?>	getSubComparator(java.lang.String ksName, java.lang.String cfName) Get subComparator of the ColumnFamily
KSMetaData	getTableDefinition(java.lang.String table) Get metadata about table by its name
java.util.Collection<KSMetaData>	getTableDefinitions()
Table	getTableInstance(java.lang.String tableName) Get table instance by name
java.util.Map<java.lang.String,CFMetaData>	getTableMetaData(java.lang.String tableName) Get metadata about table inner ColumnFamilies
java.util.Set<java.lang.String>	getTables()
AbstractType<?>	getValueValidator(java.lang.String ksName, java.lang.String cfName, java.nio.ByteBuffer column) Get value validator for specific column
java.util.UUID	getVersion()
void	load(CFMetaData cfm) Load individual ColumnFamily Definition to the schema (to make ColumnFamily lookup faster)
Schema	load(java.util.Collection<KSMetaData> tableDefs) Load up non-system tables
Schema	load(KSMetaData keyspaceDef) Load specific keyspace into Schema
int	nextCFId()
void	purge(CFMetaData cfm) Used for ColumnFamily data eviction out from the schema
Table	removeTableInstance(java.lang.String tableName) Remove table from schema
void	setTableDefinition(KSMetaData ksm) Update (or insert) new table definition
void	storeTableInstance(Table table) Store given Table instance to the schema
void	updateVersion() Read schema from system table and calculate MD5 digest of every row, resulting digest will be converted into UUID which would act as content-based version of the schema.
void	updateVersionAndAnnounce()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

instance

public static final Schema instance

NAME_LENGTH

public static final int NAME_LENGTH

longest permissible KS or CF name. Our main concern is that filename not be more than 255 characters; the filename will contain both the KS and CF names. Since non-schema-name components only take up ~64 characters, we could allow longer names than this, but on Windows, the entire path should be not greater than 255 characters, so a lower limit here helps avoid problems. See CASSANDRA-4110.

See Also:

Constant Field Values

Constructor Detail

Schema

public Schema()

Initialize empty schema object

Method Detail

load

public Schema load(java.util.Collection<KSMetaData> tableDefs)

Load up non-system tables

Parameters:

tableDefs - The non-system table definitions

Returns:

self to support chaining calls

load

public Schema load(KSMetaData keyspaceDef)

Load specific keyspace into Schema

Parameters:

keyspaceDef - The keyspace to load up

Returns:

self to support chaining calls

getTableInstance

public Table getTableInstance(java.lang.String tableName)

Get table instance by name

Parameters:

tableName - The name of the table

Returns:

Table object or null if table was not found

storeTableInstance

public void storeTableInstance(Table table)

Store given Table instance to the schema

Parameters:

table - The Table instance to store

Throws:

java.lang.IllegalArgumentException - if Table is already stored

removeTableInstance

public Table removeTableInstance(java.lang.String tableName)

Remove table from schema

Parameters:

tableName - The name of the table to remove

Returns:

removed table instance or null if it wasn't found

clearTableDefinition

public void clearTableDefinition(KSMetaData ksm)

Remove table definition from system

Parameters:

ksm - The table definition to remove

getCFMetaData

public CFMetaData getCFMetaData(java.lang.String tableName,
                                java.lang.String cfName)

Given a table name & column family name, get the column family meta data. If the table name or column family name is not valid this function returns null.

Parameters:

tableName - The table name

cfName - The ColumnFamily name

Returns:

ColumnFamily Metadata object or null if it wasn't found

getCFMetaData

public CFMetaData getCFMetaData(java.lang.Integer cfId)

Get ColumnFamily metadata by its identifier

Parameters:

cfId - The ColumnFamily identifier

Returns:

metadata about ColumnFamily

getCFMetaData

public CFMetaData getCFMetaData(Descriptor descriptor)

getColumnFamilyType

public ColumnFamilyType getColumnFamilyType(java.lang.String ksName,
                                            java.lang.String cfName)

Get type of the ColumnFamily but it's keyspace/name

Parameters:

ksName - The keyspace name

cfName - The ColumnFamily name

Returns:

The type of the ColumnFamily

getComparator

public AbstractType<?> getComparator(java.lang.String ksName,
                                     java.lang.String cfName)

Get column comparator for ColumnFamily but it's keyspace/name

Parameters:

ksName - The keyspace name

cfName - The ColumnFamily name

Returns:

The comparator of the ColumnFamily

getSubComparator

public AbstractType<?> getSubComparator(java.lang.String ksName,
                                        java.lang.String cfName)

Get subComparator of the ColumnFamily

Parameters:

ksName - The keyspace name

cfName - The ColumnFamily name

Returns:

The subComparator of the ColumnFamily

getValueValidator

public AbstractType<?> getValueValidator(java.lang.String ksName,
                                         java.lang.String cfName,
                                         java.nio.ByteBuffer column)

Get value validator for specific column

Parameters:

ksName - The keyspace name

cfName - The ColumnFamily name

column - The name of the column

Returns:

value validator specific to the column or default (per-cf) one

getKSMetaData

public KSMetaData getKSMetaData(java.lang.String table)

Get metadata about table by its name

Parameters:

table - The name of the table

Returns:

The table metadata or null if it wasn't found

getNonSystemTables

public java.util.List<java.lang.String> getNonSystemTables()

Returns:

collection of the non-system tables

getTableDefinition

public KSMetaData getTableDefinition(java.lang.String table)

Get metadata about table by its name

Parameters:

table - The name of the table

Returns:

The table metadata or null if it wasn't found

getTableMetaData

public java.util.Map<java.lang.String,CFMetaData> getTableMetaData(java.lang.String tableName)

Get metadata about table inner ColumnFamilies

Parameters:

tableName - The name of the table

Returns:

metadata about ColumnFamilies the belong to the given table

getTables

public java.util.Set<java.lang.String> getTables()

Returns:

collection of the all table names registered in the system (system and non-system)

getTableDefinitions

public java.util.Collection<KSMetaData> getTableDefinitions()

Returns:

collection of the metadata about all tables registered in the system (system and non-system)

setTableDefinition

public void setTableDefinition(KSMetaData ksm)

Update (or insert) new table definition

Parameters:

ksm - The metadata about table

addSystemTable

public void addSystemTable(KSMetaData systemTable)

Add a new system table

Parameters:

systemTable - The metadata describing new system table

getCF

public Pair<java.lang.String,java.lang.String> getCF(java.lang.Integer cfId)

Parameters:

cfId - The identifier of the ColumnFamily to lookup

Returns:

The (ksname,cfname) pair for the given id, or null if it has been dropped.

getId

public java.lang.Integer getId(java.lang.String ksName,
                               java.lang.String cfName)

Lookup keyspace/ColumnFamily identifier

Parameters:

ksName - The keyspace name

cfName - The ColumnFamily name

Returns:

The id for the given (ksname,cfname) pair, or null if it has been dropped.

load

public void load(CFMetaData cfm)

Load individual ColumnFamily Definition to the schema (to make ColumnFamily lookup faster)

Parameters:

cfm - The ColumnFamily definition to load

Throws:

ConfigurationException - if ColumnFamily was already loaded

purge

public void purge(CFMetaData cfm)

Used for ColumnFamily data eviction out from the schema

Parameters:

cfm - The ColumnFamily Definition to evict

fixCFMaxId

public void fixCFMaxId()

This gets called after initialization to make sure that id generation happens properly.

nextCFId

public int nextCFId()

Returns:

identifier for the new ColumnFamily (called primarily by CFMetaData constructor)

getVersion

public java.util.UUID getVersion()

Returns:

current schema version

updateVersion

public void updateVersion()

Read schema from system table and calculate MD5 digest of every row, resulting digest will be converted into UUID which would act as content-based version of the schema.

updateVersionAndAnnounce

public void updateVersionAndAnnounce()

clear

public void clear()

Clear all KS/CF metadata and reset version.