public static boolean ignoredSchemaRow(Row row) {
try {
return systemKeyspaceNames.contains(ByteBufferUtil.string(row.key.key));
} catch (CharacterCodingException e) {
throw new RuntimeException(e);
}
}
public class Schema {
private static final Logger logger = LoggerFactory.getLogger(Schema.class);
public static final Schema instance = new Schema();
/**
* 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.
*/
public static final int NAME_LENGTH = 48;
/* metadata map for faster table lookup */
private final Map<String, KSMetaData> tables = new NonBlockingHashMap<String, KSMetaData>();
/* Table objects, one per keyspace. Only one instance should ever exist for any given keyspace. */
private final Map<String, Table> tableInstances = new NonBlockingHashMap<String, Table>();
/* metadata map for faster ColumnFamily lookup */
private final BiMap<Pair<String, String>, UUID> cfIdMap = HashBiMap.create();
// mapping from old ColumnFamily Id (Integer) to a new version which is UUID
private final BiMap<Integer, UUID> oldCfIdMap = HashBiMap.create();
private volatile UUID version;
// 59adb24e-f3cd-3e02-97f0-5b395827453f
public static final UUID emptyVersion;
public static final ImmutableSet<String> systemKeyspaceNames =
ImmutableSet.of(Table.SYSTEM_KS, Tracing.TRACE_KS);
static {
try {
emptyVersion = UUID.nameUUIDFromBytes(MessageDigest.getInstance("MD5").digest());
} catch (NoSuchAlgorithmException e) {
throw new AssertionError();
}
}
/** Initialize empty schema object */
public Schema() {}
/**
* Load up non-system tables
*
* @param tableDefs The non-system table definitions
* @return self to support chaining calls
*/
public Schema load(Collection<KSMetaData> tableDefs) {
for (KSMetaData def : tableDefs) load(def);
return this;
}
/**
* Load specific keyspace into Schema
*
* @param keyspaceDef The keyspace to load up
* @return self to support chaining calls
*/
public Schema load(KSMetaData keyspaceDef) {
for (CFMetaData cfm : keyspaceDef.cfMetaData().values()) load(cfm);
setTableDefinition(keyspaceDef);
return this;
}
/**
* Get table instance by name
*
* @param tableName The name of the table
* @return Table object or null if table was not found
*/
public Table getTableInstance(String tableName) {
return tableInstances.get(tableName);
}
/**
* Store given Table instance to the schema
*
* @param table The Table instance to store
* @throws IllegalArgumentException if Table is already stored
*/
public void storeTableInstance(Table table) {
if (tableInstances.containsKey(table.name))
throw new IllegalArgumentException(
String.format("Table %s was already initialized.", table.name));
tableInstances.put(table.name, table);
}
/**
* Remove table from schema
*
* @param tableName The name of the table to remove
* @return removed table instance or null if it wasn't found
*/
public Table removeTableInstance(String tableName) {
return tableInstances.remove(tableName);
}
/**
* Remove table definition from system
*
* @param ksm The table definition to remove
*/
public void clearTableDefinition(KSMetaData ksm) {
tables.remove(ksm.name);
}
/**
* 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.
*
* @param tableName The table name
* @param cfName The ColumnFamily name
* @return ColumnFamily Metadata object or null if it wasn't found
*/
public CFMetaData getCFMetaData(String tableName, String cfName) {
assert tableName != null;
KSMetaData ksm = tables.get(tableName);
return (ksm == null) ? null : ksm.cfMetaData().get(cfName);
}
/**
* Get ColumnFamily metadata by its identifier
*
* @param cfId The ColumnFamily identifier
* @return metadata about ColumnFamily
*/
public CFMetaData getCFMetaData(UUID cfId) {
Pair<String, String> cf = getCF(cfId);
return (cf == null) ? null : getCFMetaData(cf.left, cf.right);
}
public CFMetaData getCFMetaData(Descriptor descriptor) {
return getCFMetaData(descriptor.ksname, descriptor.cfname);
}
/**
* Get type of the ColumnFamily but it's keyspace/name
*
* @param ksName The keyspace name
* @param cfName The ColumnFamily name
* @return The type of the ColumnFamily
*/
public ColumnFamilyType getColumnFamilyType(String ksName, String cfName) {
assert ksName != null && cfName != null;
CFMetaData cfMetaData = getCFMetaData(ksName, cfName);
return (cfMetaData == null) ? null : cfMetaData.cfType;
}
/**
* Get column comparator for ColumnFamily but it's keyspace/name
*
* @param ksName The keyspace name
* @param cfName The ColumnFamily name
* @return The comparator of the ColumnFamily
*/
public AbstractType<?> getComparator(String ksName, String cfName) {
assert ksName != null;
CFMetaData cfmd = getCFMetaData(ksName, cfName);
if (cfmd == null)
throw new IllegalArgumentException(
"Unknown ColumnFamily " + cfName + " in keyspace " + ksName);
return cfmd.comparator;
}
/**
* Get subComparator of the ColumnFamily
*
* @param ksName The keyspace name
* @param cfName The ColumnFamily name
* @return The subComparator of the ColumnFamily
*/
public AbstractType<?> getSubComparator(String ksName, String cfName) {
assert ksName != null;
return getCFMetaData(ksName, cfName).subcolumnComparator;
}
/**
* Get value validator for specific column
*
* @param ksName The keyspace name
* @param cfName The ColumnFamily name
* @param column The name of the column
* @return value validator specific to the column or default (per-cf) one
*/
public AbstractType<?> getValueValidator(String ksName, String cfName, ByteBuffer column) {
return getCFMetaData(ksName, cfName).getValueValidator(column);
}
/**
* Get metadata about table by its name
*
* @param table The name of the table
* @return The table metadata or null if it wasn't found
*/
public KSMetaData getKSMetaData(String table) {
assert table != null;
return tables.get(table);
}
/** @return collection of the non-system tables */
public List<String> getNonSystemTables() {
return ImmutableList.copyOf(Sets.difference(tables.keySet(), systemKeyspaceNames));
}
/**
* Get metadata about table by its name
*
* @param table The name of the table
* @return The table metadata or null if it wasn't found
*/
public KSMetaData getTableDefinition(String table) {
return getKSMetaData(table);
}
/**
* Get metadata about table inner ColumnFamilies
*
* @param tableName The name of the table
* @return metadata about ColumnFamilies the belong to the given table
*/
public Map<String, CFMetaData> getTableMetaData(String tableName) {
assert tableName != null;
KSMetaData ksm = tables.get(tableName);
assert ksm != null;
return ksm.cfMetaData();
}
/** @return collection of the all table names registered in the system (system and non-system) */
public Set<String> getTables() {
return tables.keySet();
}
/**
* @return collection of the metadata about all tables registered in the system (system and
* non-system)
*/
public Collection<KSMetaData> getTableDefinitions() {
return tables.values();
}
/**
* Update (or insert) new table definition
*
* @param ksm The metadata about table
*/
public void setTableDefinition(KSMetaData ksm) {
assert ksm != null;
tables.put(ksm.name, ksm);
}
/* ColumnFamily query/control methods */
public void addOldCfIdMapping(Integer oldId, UUID newId) {
if (oldId == null) return;
oldCfIdMap.put(oldId, newId);
}
public UUID convertOldCfId(Integer oldCfId) throws UnknownColumnFamilyException {
UUID cfId = oldCfIdMap.get(oldCfId);
if (cfId == null)
throw new UnknownColumnFamilyException(
"ColumnFamily identified by old " + oldCfId + " was not found.", null);
return cfId;
}
public Integer convertNewCfId(UUID newCfId) {
return oldCfIdMap.containsValue(newCfId) ? oldCfIdMap.inverse().get(newCfId) : null;
}
/**
* @param cfId The identifier of the ColumnFamily to lookup
* @return The (ksname,cfname) pair for the given id, or null if it has been dropped.
*/
public Pair<String, String> getCF(UUID cfId) {
return cfIdMap.inverse().get(cfId);
}
/**
* Lookup keyspace/ColumnFamily identifier
*
* @param ksName The keyspace name
* @param cfName The ColumnFamily name
* @return The id for the given (ksname,cfname) pair, or null if it has been dropped.
*/
public UUID getId(String ksName, String cfName) {
return cfIdMap.get(Pair.create(ksName, cfName));
}
/**
* Load individual ColumnFamily Definition to the schema (to make ColumnFamily lookup faster)
*
* @param cfm The ColumnFamily definition to load
*/
public void load(CFMetaData cfm) {
Pair<String, String> key = Pair.create(cfm.ksName, cfm.cfName);
if (cfIdMap.containsKey(key))
throw new RuntimeException(
String.format(
"Attempting to load already loaded column family %s.%s", cfm.ksName, cfm.cfName));
logger.debug("Adding {} to cfIdMap", cfm);
cfIdMap.put(key, cfm.cfId);
}
/**
* Used for ColumnFamily data eviction out from the schema
*
* @param cfm The ColumnFamily Definition to evict
*/
public void purge(CFMetaData cfm) {
cfIdMap.remove(Pair.create(cfm.ksName, cfm.cfName));
}
/* Version control */
/** @return current schema version */
public UUID getVersion() {
return version;
}
/**
* 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.
*/
public void updateVersion() {
try {
MessageDigest versionDigest = MessageDigest.getInstance("MD5");
for (Row row : SystemTable.serializedSchema()) {
if (invalidSchemaRow(row) || ignoredSchemaRow(row)) continue;
row.cf.updateDigest(versionDigest);
}
version = UUID.nameUUIDFromBytes(versionDigest.digest());
SystemTable.updateSchemaVersion(version);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/*
* Like updateVersion, but also announces via gossip
*/
public void updateVersionAndAnnounce() {
updateVersion();
MigrationManager.passiveAnnounce(version);
}
/** Clear all KS/CF metadata and reset version. */
public synchronized void clear() {
for (String table : getNonSystemTables()) {
KSMetaData ksm = getTableDefinition(table);
for (CFMetaData cfm : ksm.cfMetaData().values()) purge(cfm);
clearTableDefinition(ksm);
}
updateVersionAndAnnounce();
}
public static boolean invalidSchemaRow(Row row) {
return row.cf == null || (row.cf.isMarkedForDelete() && row.cf.isEmpty());
}
public static boolean ignoredSchemaRow(Row row) {
try {
return systemKeyspaceNames.contains(ByteBufferUtil.string(row.key.key));
} catch (CharacterCodingException e) {
throw new RuntimeException(e);
}
}
}
