Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.cassandra.io.sstable; import java.io.Closeable; import java.io.File; import java.io.IOException; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; import java.util.Map; import java.util.SortedSet; import java.util.concurrent.TimeUnit; import java.util.stream.Collectors; import com.datastax.driver.core.ProtocolVersion; import com.datastax.driver.core.TypeCodec; import org.apache.cassandra.cql3.statements.schema.CreateTableStatement; import org.apache.cassandra.cql3.statements.schema.CreateTypeStatement; import org.apache.cassandra.schema.TableMetadata; import org.apache.cassandra.config.DatabaseDescriptor; import org.apache.cassandra.cql3.ColumnSpecification; import org.apache.cassandra.cql3.QueryOptions; import org.apache.cassandra.cql3.QueryProcessor; import org.apache.cassandra.cql3.UpdateParameters; import org.apache.cassandra.cql3.functions.UDHelper; import org.apache.cassandra.cql3.statements.ModificationStatement; import org.apache.cassandra.cql3.statements.UpdateStatement; import org.apache.cassandra.db.Clustering; import org.apache.cassandra.db.SystemKeyspace; import org.apache.cassandra.db.marshal.UserType; import org.apache.cassandra.dht.IPartitioner; import org.apache.cassandra.dht.Murmur3Partitioner; import org.apache.cassandra.exceptions.InvalidRequestException; import org.apache.cassandra.exceptions.SyntaxException; import org.apache.cassandra.io.sstable.format.SSTableFormat; import org.apache.cassandra.schema.Functions; import org.apache.cassandra.schema.KeyspaceMetadata; import org.apache.cassandra.schema.KeyspaceParams; import org.apache.cassandra.schema.Schema; import org.apache.cassandra.schema.SchemaConstants; import org.apache.cassandra.schema.SchemaKeyspace; import org.apache.cassandra.schema.TableMetadataRef; import org.apache.cassandra.schema.Tables; import org.apache.cassandra.schema.Types; import org.apache.cassandra.schema.Views; import org.apache.cassandra.service.ClientState; import org.apache.cassandra.utils.ByteBufferUtil; /** * Utility to write SSTables. * <p> * Typical usage looks like: * <pre> * String type = CREATE TYPE myKs.myType (a int, b int)"; * String schema = "CREATE TABLE myKs.myTable (" * + " k int PRIMARY KEY," * + " v1 text," * + " v2 int," * + " v3 myType," * + ")"; * String insert = "INSERT INTO myKs.myTable (k, v1, v2, v3) VALUES (?, ?, ?, ?)"; * * // Creates a new writer. You need to provide at least the directory where to write the created sstable, * // the schema for the sstable to write and a (prepared) insert statement to use. If you do not use the * // default partitioner (Murmur3Partitioner), you will also need to provide the partitioner in use, see * // CQLSSTableWriter.Builder for more details on the available options. * CQLSSTableWriter writer = CQLSSTableWriter.builder() * .inDirectory("path/to/directory") * .withType(type) * .forTable(schema) * .using(insert).build(); * * UserType myType = writer.getUDType("myType"); * // Adds a nember of rows to the resulting sstable * writer.addRow(0, "test1", 24, myType.newValue().setInt("a", 10).setInt("b", 20)); * writer.addRow(1, "test2", null, null); * writer.addRow(2, "test3", 42, myType.newValue().setInt("a", 30).setInt("b", 40)); * * // Close the writer, finalizing the sstable * writer.close(); * </pre> * * Please note that {@code CQLSSTableWriter} is <b>not</b> thread-safe (multiple threads cannot access the * same instance). It is however safe to use multiple instances in parallel (even if those instance write * sstables for the same table). */ public class CQLSSTableWriter implements Closeable { public static final ByteBuffer UNSET_VALUE = ByteBufferUtil.UNSET_BYTE_BUFFER; static { DatabaseDescriptor.clientInitialization(false); // Partitioner is not set in client mode. if (DatabaseDescriptor.getPartitioner() == null) DatabaseDescriptor.setPartitionerUnsafe(Murmur3Partitioner.instance); } private final AbstractSSTableSimpleWriter writer; private final UpdateStatement insert; private final List<ColumnSpecification> boundNames; private final List<TypeCodec> typeCodecs; private CQLSSTableWriter(AbstractSSTableSimpleWriter writer, UpdateStatement insert, List<ColumnSpecification> boundNames) { this.writer = writer; this.insert = insert; this.boundNames = boundNames; this.typeCodecs = boundNames.stream().map(bn -> UDHelper.codecFor(UDHelper.driverType(bn.type))) .collect(Collectors.toList()); } /** * Returns a new builder for a CQLSSTableWriter. * * @return the new builder. */ public static Builder builder() { return new Builder(); } /** * Adds a new row to the writer. * <p> * This is a shortcut for {@code addRow(Arrays.asList(values))}. * * @param values the row values (corresponding to the bind variables of the * insertion statement used when creating by this writer). * @return this writer. */ public CQLSSTableWriter addRow(Object... values) throws InvalidRequestException, IOException { return addRow(Arrays.asList(values)); } /** * Adds a new row to the writer. * <p> * Each provided value type should correspond to the types of the CQL column * the value is for. The correspondance between java type and CQL type is the * same one than the one documented at * www.datastax.com/drivers/java/2.0/apidocs/com/datastax/driver/core/DataType.Name.html#asJavaClass(). * <p> * If you prefer providing the values directly as binary, use * {@link #rawAddRow} instead. * * @param values the row values (corresponding to the bind variables of the * insertion statement used when creating by this writer). * @return this writer. */ public CQLSSTableWriter addRow(List<Object> values) throws InvalidRequestException, IOException { int size = Math.min(values.size(), boundNames.size()); List<ByteBuffer> rawValues = new ArrayList<>(size); for (int i = 0; i < size; i++) { Object value = values.get(i); rawValues.add(serialize(value, typeCodecs.get(i))); } return rawAddRow(rawValues); } /** * Adds a new row to the writer. * <p> * This is equivalent to the other addRow methods, but takes a map whose * keys are the names of the columns to add instead of taking a list of the * values in the order of the insert statement used during construction of * this write. * <p> * Please note that the column names in the map keys must be in lowercase unless * the declared column name is a * <a href="http://cassandra.apache.org/doc/cql3/CQL.html#identifiers">case-sensitive quoted identifier</a> * (in which case the map key must use the exact case of the column). * * @param values a map of colum name to column values representing the new * row to add. Note that if a column is not part of the map, it's value will * be {@code null}. If the map contains keys that does not correspond to one * of the column of the insert statement used when creating this writer, the * the corresponding value is ignored. * @return this writer. */ public CQLSSTableWriter addRow(Map<String, Object> values) throws InvalidRequestException, IOException { int size = boundNames.size(); List<ByteBuffer> rawValues = new ArrayList<>(size); for (int i = 0; i < size; i++) { ColumnSpecification spec = boundNames.get(i); Object value = values.get(spec.name.toString()); rawValues.add(serialize(value, typeCodecs.get(i))); } return rawAddRow(rawValues); } /** * Adds a new row to the writer given already serialized values. * * @param values the row values (corresponding to the bind variables of the * insertion statement used when creating by this writer) as binary. * @return this writer. */ public CQLSSTableWriter rawAddRow(ByteBuffer... values) throws InvalidRequestException, IOException { return rawAddRow(Arrays.asList(values)); } /** * Adds a new row to the writer given already serialized values. * <p> * This is a shortcut for {@code rawAddRow(Arrays.asList(values))}. * * @param values the row values (corresponding to the bind variables of the * insertion statement used when creating by this writer) as binary. * @return this writer. */ public CQLSSTableWriter rawAddRow(List<ByteBuffer> values) throws InvalidRequestException, IOException { if (values.size() != boundNames.size()) throw new InvalidRequestException( String.format("Invalid number of arguments, expecting %d values but got %d", boundNames.size(), values.size())); QueryOptions options = QueryOptions.forInternalCalls(null, values); List<ByteBuffer> keys = insert.buildPartitionKeyNames(options); SortedSet<Clustering> clusterings = insert.createClustering(options); long now = System.currentTimeMillis(); // Note that we asks indexes to not validate values (the last 'false' arg below) because that triggers a 'Keyspace.open' // and that forces a lot of initialization that we don't want. UpdateParameters params = new UpdateParameters(insert.metadata, insert.updatedColumns(), options, insert.getTimestamp(TimeUnit.MILLISECONDS.toMicros(now), options), (int) TimeUnit.MILLISECONDS.toSeconds(now), insert.getTimeToLive(options), Collections.emptyMap()); try { for (ByteBuffer key : keys) { for (Clustering clustering : clusterings) insert.addUpdateForKey(writer.getUpdateFor(key), clustering, params); } return this; } catch (SSTableSimpleUnsortedWriter.SyncException e) { // If we use a BufferedWriter and had a problem writing to disk, the IOException has been // wrapped in a SyncException (see BufferedWriter below). We want to extract that IOE. throw (IOException) e.getCause(); } } /** * Adds a new row to the writer given already serialized values. * <p> * This is equivalent to the other rawAddRow methods, but takes a map whose * keys are the names of the columns to add instead of taking a list of the * values in the order of the insert statement used during construction of * this write. * * @param values a map of colum name to column values representing the new * row to add. Note that if a column is not part of the map, it's value will * be {@code null}. If the map contains keys that does not correspond to one * of the column of the insert statement used when creating this writer, the * the corresponding value is ignored. * @return this writer. */ public CQLSSTableWriter rawAddRow(Map<String, ByteBuffer> values) throws InvalidRequestException, IOException { int size = Math.min(values.size(), boundNames.size()); List<ByteBuffer> rawValues = new ArrayList<>(size); for (int i = 0; i < size; i++) { ColumnSpecification spec = boundNames.get(i); rawValues.add(values.get(spec.name.toString())); } return rawAddRow(rawValues); } /** * Returns the User Defined type, used in this SSTable Writer, that can * be used to create UDTValue instances. * * @param dataType name of the User Defined type * @return user defined type */ public com.datastax.driver.core.UserType getUDType(String dataType) { KeyspaceMetadata ksm = Schema.instance.getKeyspaceMetadata(insert.keyspace()); UserType userType = ksm.types.getNullable(ByteBufferUtil.bytes(dataType)); return (com.datastax.driver.core.UserType) UDHelper.driverType(userType); } /** * Close this writer. * <p> * This method should be called, otherwise the produced sstables are not * guaranteed to be complete (and won't be in practice). */ public void close() throws IOException { writer.close(); } private ByteBuffer serialize(Object value, TypeCodec codec) { if (value == null || value == UNSET_VALUE) return (ByteBuffer) value; return codec.serialize(value, ProtocolVersion.NEWEST_SUPPORTED); } /** * A Builder for a CQLSSTableWriter object. */ public static class Builder { private File directory; protected SSTableFormat.Type formatType = null; private CreateTableStatement.Raw schemaStatement; private final List<CreateTypeStatement.Raw> typeStatements; private ModificationStatement.Parsed insertStatement; private IPartitioner partitioner; private boolean sorted = false; private long bufferSizeInMB = 128; protected Builder() { this.typeStatements = new ArrayList<>(); } /** * The directory where to write the sstables. * <p> * This is a mandatory option. * * @param directory the directory to use, which should exists and be writable. * @return this builder. * * @throws IllegalArgumentException if {@code directory} doesn't exist or is not writable. */ public Builder inDirectory(String directory) { return inDirectory(new File(directory)); } /** * The directory where to write the sstables (mandatory option). * <p> * This is a mandatory option. * * @param directory the directory to use, which should exists and be writable. * @return this builder. * * @throws IllegalArgumentException if {@code directory} doesn't exist or is not writable. */ public Builder inDirectory(File directory) { if (!directory.exists()) throw new IllegalArgumentException(directory + " doesn't exists"); if (!directory.canWrite()) throw new IllegalArgumentException(directory + " exists but is not writable"); this.directory = directory; return this; } public Builder withType(String typeDefinition) throws SyntaxException { typeStatements.add( QueryProcessor.parseStatement(typeDefinition, CreateTypeStatement.Raw.class, "CREATE TYPE")); return this; } /** * The schema (CREATE TABLE statement) for the table for which sstable are to be created. * <p> * Please note that the provided CREATE TABLE statement <b>must</b> use a fully-qualified * table name, one that include the keyspace name. * <p> * This is a mandatory option. * * @param schema the schema of the table for which sstables are to be created. * @return this builder. * * @throws IllegalArgumentException if {@code schema} is not a valid CREATE TABLE statement * or does not have a fully-qualified table name. */ public Builder forTable(String schema) { this.schemaStatement = QueryProcessor.parseStatement(schema, CreateTableStatement.Raw.class, "CREATE TABLE"); return this; } /** * The partitioner to use. * <p> * By default, {@code Murmur3Partitioner} will be used. If this is not the partitioner used * by the cluster for which the SSTables are created, you need to use this method to * provide the correct partitioner. * * @param partitioner the partitioner to use. * @return this builder. */ public Builder withPartitioner(IPartitioner partitioner) { this.partitioner = partitioner; return this; } /** * The INSERT or UPDATE statement defining the order of the values to add for a given CQL row. * <p> * Please note that the provided INSERT statement <b>must</b> use a fully-qualified * table name, one that include the keyspace name. Moreover, said statement must use * bind variables since these variables will be bound to values by the resulting writer. * <p> * This is a mandatory option. * * @param insert an insertion statement that defines the order * of column values to use. * @return this builder. * * @throws IllegalArgumentException if {@code insertStatement} is not a valid insertion * statement, does not have a fully-qualified table name or have no bind variables. */ public Builder using(String insert) { this.insertStatement = QueryProcessor.parseStatement(insert, ModificationStatement.Parsed.class, "INSERT/UPDATE"); return this; } /** * The size of the buffer to use. * <p> * This defines how much data will be buffered before being written as * a new SSTable. This correspond roughly to the data size that will have the created * sstable. * <p> * The default is 128MB, which should be reasonable for a 1GB heap. If you experience * OOM while using the writer, you should lower this value. * * @param size the size to use in MB. * @return this builder. */ public Builder withBufferSizeInMB(int size) { this.bufferSizeInMB = size; return this; } /** * Creates a CQLSSTableWriter that expects sorted inputs. * <p> * If this option is used, the resulting writer will expect rows to be * added in SSTable sorted order (and an exception will be thrown if that * is not the case during insertion). The SSTable sorted order means that * rows are added such that their partition key respect the partitioner * order. * <p> * You should thus only use this option is you know that you can provide * the rows in order, which is rarely the case. If you can provide the * rows in order however, using this sorted might be more efficient. * <p> * Note that if used, some option like withBufferSizeInMB will be ignored. * * @return this builder. */ public Builder sorted() { this.sorted = true; return this; } @SuppressWarnings("resource") public CQLSSTableWriter build() { if (directory == null) throw new IllegalStateException( "No ouptut directory specified, you should provide a directory with inDirectory()"); if (schemaStatement == null) throw new IllegalStateException( "Missing schema, you should provide the schema for the SSTable to create with forTable()"); if (insertStatement == null) throw new IllegalStateException( "No insert statement specified, you should provide an insert statement through using()"); synchronized (CQLSSTableWriter.class) { if (Schema.instance.getKeyspaceMetadata(SchemaConstants.SCHEMA_KEYSPACE_NAME) == null) Schema.instance.load(SchemaKeyspace.metadata()); if (Schema.instance.getKeyspaceMetadata(SchemaConstants.SYSTEM_KEYSPACE_NAME) == null) Schema.instance.load(SystemKeyspace.metadata()); String keyspaceName = schemaStatement.keyspace(); if (Schema.instance.getKeyspaceMetadata(keyspaceName) == null) { Schema.instance.load(KeyspaceMetadata.create(keyspaceName, KeyspaceParams.simple(1), Tables.none(), Views.none(), Types.none(), Functions.none())); } KeyspaceMetadata ksm = Schema.instance.getKeyspaceMetadata(keyspaceName); TableMetadata tableMetadata = ksm.tables.getNullable(schemaStatement.table()); if (tableMetadata == null) { Types types = createTypes(keyspaceName); tableMetadata = createTable(types); Schema.instance.load(ksm.withSwapped(ksm.tables.with(tableMetadata)).withSwapped(types)); } UpdateStatement preparedInsert = prepareInsert(); TableMetadataRef ref = TableMetadataRef.forOfflineTools(tableMetadata); AbstractSSTableSimpleWriter writer = sorted ? new SSTableSimpleWriter(directory, ref, preparedInsert.updatedColumns()) : new SSTableSimpleUnsortedWriter(directory, ref, preparedInsert.updatedColumns(), bufferSizeInMB); if (formatType != null) writer.setSSTableFormatType(formatType); return new CQLSSTableWriter(writer, preparedInsert, preparedInsert.getBindVariables()); } } private Types createTypes(String keyspace) { Types.RawBuilder builder = Types.rawBuilder(keyspace); for (CreateTypeStatement.Raw st : typeStatements) st.addToRawBuilder(builder); return builder.build(); } /** * Creates the table according to schema statement * * @param types types this table should be created with */ private TableMetadata createTable(Types types) { ClientState state = ClientState.forInternalCalls(); CreateTableStatement statement = schemaStatement.prepare(state); statement.validate(ClientState.forInternalCalls()); TableMetadata.Builder builder = statement.builder(types); if (partitioner != null) builder.partitioner(partitioner); return builder.build(); } /** * Prepares insert statement for writing data to SSTable * * @return prepared Insert statement and it's bound names */ private UpdateStatement prepareInsert() { ClientState state = ClientState.forInternalCalls(); UpdateStatement insert = (UpdateStatement) insertStatement.prepare(state); insert.validate(state); if (insert.hasConditions()) throw new IllegalArgumentException("Conditional statements are not supported"); if (insert.isCounter()) throw new IllegalArgumentException("Counter update statements are not supported"); if (insert.getBindVariables().isEmpty()) throw new IllegalArgumentException("Provided insert statement has no bind variables"); return insert; } } }