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/*
* Copyright (C) 2012-2016 DataStax Inc.
*
* This software can be used solely with DataStax Enterprise. Please consult the license at
* http://www.datastax.com/terms/datastax-dse-driver-license-terms
*/
package com.datastax.driver.dse.graph;
import com.datastax.driver.core.ConsistencyLevel;
import com.datastax.driver.core.QueryOptions;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Statement;
import com.datastax.driver.dse.DseSession;
import com.google.common.base.Function;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import static com.google.common.base.Preconditions.checkNotNull;
/**
* An executable graph query.
*/
public abstract class GraphStatement {
private volatile String graphLanguage;
private volatile String graphSource;
private volatile String graphName;
private volatile boolean systemQuery;
private volatile ConsistencyLevel graphReadConsistencyLevel;
private volatile ConsistencyLevel graphWriteConsistencyLevel;
private volatile Boolean idempotent;
private volatile Function transformResultFunction = GraphResultSet.ROW_TO_DEFAULTGRAPHNODE;
private final Map graphInternalOptions = new ConcurrentHashMap();
/**
* Returns the graph language to use with this statement.
*
* @return the graph language to use with this statement.
* @see #setGraphLanguage(String)
*/
public String getGraphLanguage() {
return graphLanguage;
}
/**
* Sets the graph language to use with this statement.
*
* This property is not required; if it is not set, the default {@link GraphOptions#getGraphLanguage()} will be
* used when executing the statement.
*
* @param graphLanguage the Graph language to use with this statement.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setGraphLanguage(String graphLanguage) {
checkNotNull(graphLanguage, "graphLanguage cannot be null");
this.graphLanguage = graphLanguage;
return this;
}
/**
* Returns the graph traversal source name to use with this statement.
*
* @return the graph traversal source name to use with this statement.
* @see #setGraphSource(String)
*/
public String getGraphSource() {
return graphSource;
}
/**
* Sets the graph traversal source name to use with this statement.
*
* This property is not required; if it is not set, the default {@link GraphOptions#getGraphSource()} will be
* used when executing the statement.
*
* @param graphSource the graph traversal source name to use with this statement.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setGraphSource(String graphSource) {
checkNotNull(graphSource, "graphSource cannot be null");
this.graphSource = graphSource;
return this;
}
/**
* Returns the graph name to use with this statement.
*
* @return the graph name to use with this statement.
* @see #getGraphName()
*/
public String getGraphName() {
return graphName;
}
/**
* Sets the graph name to use with this statement.
*
* This property is not required; if it is not set, the default {@link GraphOptions#getGraphName()} (which may
* itself be unset) will be used when executing the statement.
*
* If a default name is set on the global options, but this statement is a system query that you explicitly want to
* run without a graph name, use {@link #setSystemQuery()}.
*
* If {@link #setSystemQuery()} was called on this statement previously, setting a graph name forces the statement
* to be a non-system query again.
*
* @param graphName the graph name to use with this statement.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setGraphName(String graphName) {
checkNotNull(graphName, "graphName cannot be null");
this.graphName = graphName;
this.systemQuery = false;
return this;
}
/**
* Forces this statement to use no graph name, even if a default graph name was defined with
* {@link GraphOptions#setGraphName(String)}.
*
* If a graph name was previously defined on this statement, it will be reset.
*
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setSystemQuery() {
this.systemQuery = true;
this.graphName = null;
return this;
}
/**
* Returns whether this statement is marked as a system query.
*
* @return whether this statement is marked as a system query.
*/
public boolean isSystemQuery() {
return this.systemQuery;
}
/**
* Returns the read consistency level to use with this statement.
*
* @return the read consistency level configured with this statement.
*/
public ConsistencyLevel getGraphReadConsistencyLevel() {
return this.graphReadConsistencyLevel;
}
/**
* Sets the read consistency level to use for this statement.
*
* This setting will override the consistency level set with {@link GraphStatement#setConsistencyLevel(ConsistencyLevel)}
* only for the READ part of the graph query.
*
* Please see {@link GraphStatement#setConsistencyLevel(ConsistencyLevel)} for more information.
*
* @param consistencyLevel the consistency level to set.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setGraphReadConsistencyLevel(ConsistencyLevel consistencyLevel) {
checkNotNull(consistencyLevel, "graphReadConsistencyLevel cannot be null");
this.graphReadConsistencyLevel = consistencyLevel;
return this;
}
/**
* Sets whether this statement is idempotent.
*
* @param idempotent the new value.
* @return this {@code Statement} object.
* @see Statement#isIdempotent()
*/
public GraphStatement setIdempotent(boolean idempotent) {
this.idempotent = idempotent;
return this;
}
/**
* Whether this statement is idempotent, i.e. whether it can be applied multiple times
* without changing the result beyond the initial application.
*
* @return whether this statement is idempotent, or {@code null} if it uses the default
* {@link QueryOptions#getDefaultIdempotence()}.
* @see Statement#setIdempotent(boolean)
*/
public Boolean isIdempotent() {
return idempotent;
}
/**
* Returns the write consistency level to use with this statement.
*
* @return the write consistency level configured with this statement.
*/
public ConsistencyLevel getGraphWriteConsistencyLevel() {
return this.graphWriteConsistencyLevel;
}
/**
* Sets the write consistency level to use for this statement.
*
* This setting will override the consistency level set with {@link GraphStatement#setConsistencyLevel(ConsistencyLevel)}
* only for the write part of the graph query.
*
* Please see {@link GraphStatement#setConsistencyLevel(ConsistencyLevel)} for more information.
*
* @param consistencyLevel the consistency level to set.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setGraphWriteConsistencyLevel(ConsistencyLevel consistencyLevel) {
checkNotNull(consistencyLevel, "graphWriteConsistencyLevel cannot be null");
this.graphWriteConsistencyLevel = consistencyLevel;
return this;
}
/**
* Sets additional graph option. Those options are supposed to be used by advanced customers only. The different
* options settable here are referenced in the DSE documentation.
*
* @param optionKey the option's name.
* @param optionValue the option's value. The value is always a String and will be interpreted to the right type
* by the DSE server. To unset a value previously set you can put {@code null} as the option's value.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setGraphInternalOption(String optionKey, String optionValue) {
checkNotNull(optionKey, "option key cannot be null");
// Setting null as value means removing it from all payloads/maps.
if (optionValue == null) {
getGraphInternalOptions().remove(optionKey);
} else {
getGraphInternalOptions().put(optionKey, optionValue);
}
return this;
}
/**
* Returns the advanced option's value defined for the key in parameter.
*
* @param optionKey the name of the option.
* @return the value. If no value has previously been set for the specified option name, or if a value has been set
* then unset with {@code null} (see {@link GraphStatement#setGraphInternalOption}), this method
* returns {@code null}.
*/
public String getGraphInternalOption(String optionKey) {
return getGraphInternalOptions().get(optionKey);
}
Map getGraphInternalOptions() {
return graphInternalOptions;
}
/**
* Sets the consistency level to use for this statement.
*
* This setting will affect the general consistency when executing the graph query. However
* executing a graph query on the server side is going to involve the execution of CQL queries to the persistence
* engine that is Cassandra. Those queries can be both reads and writes and both will have a settable consistency
* level. Setting only this property will indicate to the server to use this consistency level for both reads and
* writes in Cassandra. Read or write consistency level can be set separately with respectively
* {@link GraphStatement#setGraphReadConsistencyLevel(ConsistencyLevel)} and
* {@link GraphStatement#setGraphWriteConsistencyLevel(ConsistencyLevel)} and will override the consistency set here.
*
* @param consistencyLevel the consistency level to set.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public abstract GraphStatement setConsistencyLevel(ConsistencyLevel consistencyLevel);
/**
* Returns the consistency level to use with this statement.
*
* This will return the consistency level used for reads and writes in Cassandra.
*
* Please see {@link GraphStatement#setConsistencyLevel(ConsistencyLevel)} for more information.
*
* @return the consistency level configured in this statement.
*/
public abstract ConsistencyLevel getConsistencyLevel();
/**
* Sets the default timestamp for this query (in microseconds since the epoch).
*
* The actual timestamp that will be used for this query is, in order of
* preference:
*
*
the timestamp specified through this method, if different from
* {@link Long#MIN_VALUE};
*
the timestamp returned by the {@link com.datastax.driver.core.TimestampGenerator} currently in use,
* if different from {@link Long#MIN_VALUE}.
*
* If none of these apply, no timestamp will be sent with the query and DseGraph
* will generate a server-side one.
*
* @param defaultTimestamp the default timestamp for this query (must be strictly
* positive).
* @return this {@link GraphStatement} instance (for method chaining).
* @see com.datastax.driver.dse.DseCluster.Builder#withTimestampGenerator(com.datastax.driver.core.TimestampGenerator)
*/
public abstract GraphStatement setDefaultTimestamp(long defaultTimestamp);
/**
* The default timestamp for this query.
*
* @return the default timestamp (in microseconds since the epoch).
*/
public abstract long getDefaultTimestamp();
/**
* Return the per-host socket read timeout that was set for this statement.
*
* @return the timeout. A negative value means that the timeout has not been set on this statement; the default
* {@link GraphOptions#getReadTimeoutMillis()} will be used.
*/
public abstract int getReadTimeoutMillis();
/**
* Overrides the default per-host read timeout ({@link GraphOptions#setReadTimeoutMillis(int)}) for this statement.
*
* If you don't call this method, the default {@link GraphOptions#getReadTimeoutMillis()} will be used.
*
* @param readTimeoutMillis the timeout to set. {@code 0} will disable the timeout for the query, negative values
* are not allowed.
* @return this {@link GraphOptions} instance (for method chaining).
*/
public abstract GraphStatement setReadTimeoutMillis(int readTimeoutMillis);
/**
* "Unwraps" the current graph statement, that is,
* returns an executable {@link Statement} object corresponding to this graph statement.
*
* This method is intended for internal use only, users wishing to execute graph statements
* should use {@link DseSession#executeGraph(GraphStatement)}.
*
* This method acts as a bridge between graph statements and
* regular {@link Statement}s.
*
* Implementations are free to cache the returned {@link Statement} if appropriate.
*
* @return an executable {@link Statement}.
*/
public abstract Statement unwrap();
/**
* Sets the function to transform a {@link com.datastax.driver.core.Row} to a {@link com.datastax.driver.dse.graph.GraphNode}.
*
* See {@link #getTransformResultFunction}.
*
* @param transformResultFunction the function to set.
* @return this {@link GraphStatement} instance (for method chaining).
*/
public GraphStatement setTransformResultFunction(Function transformResultFunction) {
this.transformResultFunction = transformResultFunction;
return this;
}
/**
* Allows users to input their own implementations of {@link com.datastax.driver.dse.graph.GraphNode}
* directly into the DSE Driver's workflow. This method must return a function that will
* take as a input a {@link Row} from the underlying Apache Cassandra driver, and return
* an object in the type {@link GraphNode}.
*
* @return the function that returns a {@link GraphNode} implementation.
*/
public Function getTransformResultFunction() {
return this.transformResultFunction;
}
}
