/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.bigdata.rdf.sail.webapp;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
import java.util.UUID;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import org.openrdf.model.Graph;
import org.openrdf.model.Resource;
import org.openrdf.model.Statement;
import org.openrdf.model.URI;
import org.openrdf.model.Value;
import org.openrdf.model.impl.LinkedHashModel;
import org.openrdf.repository.RepositoryResult;
import org.openrdf.rio.RDFFormat;
import org.openrdf.rio.RDFWriter;
import org.openrdf.rio.RDFWriterRegistry;
import com.bigdata.bop.BOp;
import com.bigdata.bop.BOpUtility;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.PipelineOp;
import com.bigdata.bop.engine.AbstractRunningQuery;
import com.bigdata.bop.engine.BOpStats;
import com.bigdata.bop.engine.IRunningQuery;
import com.bigdata.bop.engine.QueryEngine;
import com.bigdata.bop.engine.QueryLog;
import com.bigdata.bop.engine.StaticAnalysisStat;
import com.bigdata.bop.engine.StaticAnalysisStats;
import com.bigdata.bop.fed.QueryEngineFactory;
import com.bigdata.journal.IIndexManager;
import com.bigdata.journal.ITransactionService;
import com.bigdata.journal.ITx;
import com.bigdata.journal.TimestampUtility;
import com.bigdata.mdi.PartitionLocator;
import com.bigdata.rdf.sail.BigdataSail;
import com.bigdata.rdf.sail.BigdataSailQuery;
import com.bigdata.rdf.sail.BigdataSailRepositoryConnection;
import com.bigdata.rdf.sail.sparql.Bigdata2ASTSPARQLParser;
import com.bigdata.rdf.sail.sparql.ast.SimpleNode;
import com.bigdata.rdf.sail.webapp.BigdataRDFContext.AbstractQueryTask;
import com.bigdata.rdf.sail.webapp.BigdataRDFContext.RunningQuery;
import com.bigdata.rdf.sail.webapp.BigdataRDFContext.UpdateTask;
import com.bigdata.rdf.sail.webapp.client.ConnectOptions;
import com.bigdata.rdf.sail.webapp.client.EncodeDecodeValue;
import com.bigdata.rdf.sparql.ast.ASTBase.Annotations;
import com.bigdata.rdf.sparql.ast.ASTContainer;
import com.bigdata.rdf.sparql.ast.QueryRoot;
import com.bigdata.rdf.sparql.ast.explainhints.ExplainHints;
import com.bigdata.rdf.sparql.ast.explainhints.IExplainHint;
import com.bigdata.rdf.store.AbstractTripleStore;
import com.bigdata.relation.accesspath.AccessPath;
import com.bigdata.service.IBigdataFederation;
import com.bigdata.service.IDataService;
import com.bigdata.service.ndx.ClientIndexView;
import com.bigdata.util.InnerCause;
/**
* SPARQL Query (GET/POST) and SPARQL UPDATE handler (POST).
*
* @author martyncutcher
* @author thompsonbry
*/
public class QueryServlet extends BigdataRDFServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
static private final transient Logger log = Logger.getLogger(QueryServlet.class);
/**
* The name of the parameter/attribute that contains the SPARQL query.
* <p>
* Note: This can be either a URL query parameter or a servlet request
* attribute. The latter is used to support chaining of a linked data GET as
* a SPARQL DESCRIBE query.
*/
static final transient String ATTR_QUERY = "query";
/**
* The name of the parameter/attribute that contains boolean flag to
* suppress incremental truth maintenance.
* <p>
* Note: This can be either a URL query parameter or a servlet request
* attribute. The latter is used to support chaining of a linked data GET as
* a SPARQL DESCRIBE query.
*/
static final transient String ATTR_TRUTH_MAINTENANCE = "suppressTruthMaintenance";
/**
* The name of the parameter/attribute that contains boolean flag to include
* inferred statements while evaluating queries or returning statements.
*
* @see BLZG-1207 (getStatements() ingores includeInferred)
*/
static final transient String INCLUDE_INFERRED = "includeInferred";
/**
* The name of the URL query parameter that contains the SPARQL UPDATE
* request.
*/
static final transient String ATTR_UPDATE = "update";
/**
* The name of the URL query parameter that indicates an ESTCARD request
* (fast range count).
*/
static final transient String ATTR_ESTCARD = "ESTCARD";
/**
* The name of the URL query parameter that indicates an HASSTMT request
* (test for the existence of one or more statements matching a triple
* pattern).
*/
static final transient String ATTR_HASSTMT = "HASSTMT";
/**
* The name of the URL query parameter that indicates an GETSTMTS request
* (retrieve statements from a store)
*/
static final transient String ATTR_GETSTMTS = "GETSTMTS";
/**
* The name of the URL query parameter that indicates an request
* to return all contexts in the database.
*/
static final transient String ATTR_CONTEXTS = "CONTEXTS";
/**
* The name of the URL query parameter that indicates a shards report
* request (scale-out only).
*/
static final transient String ATTR_SHARDS = "SHARDS";
/**
* The name of the URL query parameter that indicates a request for a random
* {@link UUID}.
*/
static final transient String ATTR_UUID = "uuid";
/**
* The name of the URL query parameter which is any of:
* <dl>
* <dt>{@value ITx#UNISOLATED}</dt>
* <dd>A unisolated operation (iff the operation is a mutation - query is
* always against a read-only snapshot). See {@link ITx#UNISOLATED}.</dd>
* <dt>{@value ITx#READ_COMMITTED}</dt>
* <dd>A read-only operation with snapshot isolation semantics against the
* most recent commit point. See {@link ITx#READ_COMMITTED}</dd>
* <dt>timestamp</dt>
* <dd>The operation will be executed again the most recent committed state
* whose commit timestamp is less than or equal to <i>timestamp</i>.</dd>
* <dt>transaction</dt>
* <dd>The operation will be isolated by the transaction. The namespace MUST
* support isolatable indices. See
* {@link BigdataSail.Options#ISOLATABLE_INDICES}.</dd>
* </dl>
* <p>
* When not specified, the default for read-only operations is determined by
* {@link SparqlEndpointConfig#timestamp} and will generally be either
* {@link ITx#READ_COMMITTED} or a specific commit time that has been pinned
* by the server using {@link ConfigParams#READ_LOCK}. The default for
* mutation operations is {@link ITx#UNISOLATED} if the namespace does not
* support isolatable indices and a read/write transaction scoped to the
* operation otherwise.
*
* @see TxServlet
* @see ITransactionService#newTx(long)
* @see BigdataRDFServlet#getTimestamp(HttpServletRequest)
* @see <a href="http://trac.bigdata.com/ticket/1156"> Support read/write
* transactions in the REST API</a>
*/
static final transient String ATTR_TIMESTAMP = "timestamp";
// /**
// * The name of the request attribute for the {@link AbstractQueryTask}.
// */
// static private final transient String ATTR_QUERY_TASK = "QueryTask";
public QueryServlet() {
}
@Override
protected void doPost(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
/*
* Note: HALoadBalancerServlet MUST be maintained if idempotent methods
* are added to doPost() in order to ensure that they are load balanced
* rather than always directed to the quorum leader.
*/
if (req.getParameter(ATTR_UPDATE) != null) {
// SPARQL 1.1 UPDATE.
doSparqlUpdate(req, resp);
} else if (RESTServlet.hasMimeType(req, MIME_SPARQL_UPDATE)) {
// SPARQL 1.1 UPDATE, see trac 711 for bug report motivating this case
doSparqlUpdate(req, resp);
} else if (req.getParameter(ATTR_UUID) != null) {
// UUID with caching defeated.
doUUID(req, resp);
} else if (req.getParameter(ATTR_ESTCARD) != null) {
// ESTCARD with caching defeated.
doEstCard(req, resp);
} else if (req.getParameter(ATTR_HASSTMT) != null) {
// HASSTMT with caching defeated.
doHasStmt(req, resp);
} else if (req.getParameter(ATTR_GETSTMTS) != null) {
// HASSTMT with caching defeated.
doGetStmts(req, resp);
} else if (req.getParameter(ATTR_CONTEXTS) != null) {
// CONTEXTS with caching defeated.
doContexts(req, resp);
} else {
// SPARQL Query.
doSparqlQuery(req, resp);
}
}
/**
* Handles query, ESTCARD, and SHARDS.
*/
@Override
protected void doGet(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (req.getParameter(ATTR_QUERY) != null) {
doSparqlQuery(req, resp);
} else if (req.getParameter(ATTR_UUID) != null) {
doUUID(req, resp);
} else if (req.getParameter(ATTR_ESTCARD) != null) {
doEstCard(req, resp);
} else if (req.getParameter(ATTR_HASSTMT) != null) {
doHasStmt(req, resp);
} else if (req.getParameter(ATTR_GETSTMTS) != null) {
doGetStmts(req, resp);
} else if (req.getParameter(ATTR_CONTEXTS) != null) {
doContexts(req, resp);
} else if (req.getParameter(ATTR_SHARDS) != null) {
doShardReport(req, resp);
} else {
doServiceDescription(req, resp);
return;
}
}
/**
* Generate and send a UUID as a <code>text/plain</code> response entity.
* This is intended for use by JavaScript clients that want to generate new
* URLs locally. JavaScript does not provide an easy means to generate
* UUIDs, so we've added one to the server.
*/
private void doUUID(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
buildAndCommitResponse(resp, HTTP_OK, MIME_TEXT_PLAIN, UUID.randomUUID()
.toString());
}
/**
* Generate a SPARQL 1.1 Service Description for the addressed triple store
* or quad store.
*
* @see https://sourceforge.net/apps/trac/bigdata/ticket/500
*/
private void doServiceDescription(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
/**
* Protect the entire operation with a transaction.
*
* @see <a href="http://trac.blazegraph.com/ticket/867"> NSS concurrency
* problem with list namespaces and create namespace </a>
*/
final long tx = getBigdataRDFContext().newTx(getTimestamp(req));
try {
final AbstractTripleStore tripleStore = getBigdataRDFContext()
.getTripleStore(getNamespace(req), tx);
if (tripleStore == null) {
/*
* There is no such triple/quad store instance.
*/
buildAndCommitNamespaceNotFoundResponse(req, resp);
return;
}
// The serviceURIs for this graph.
final String[] serviceURI = BigdataServlet.getServiceURIs(
getServletContext(), req);
/*
* TODO Resolve the SD class name and ctor via a configuration
* property for extensible descriptions.
*/
final Graph g = new LinkedHashModel();
{
final SD sd = new SD(g, tripleStore, serviceURI);
final SparqlEndpointConfig config = getBigdataRDFContext()
.getConfig();
sd.describeService(true/* describeStatistics */,
config.describeEachNamedGraph);
}
sendGraph(req, resp, g);
} catch (Throwable t) {
launderThrowable(t, resp, "");
} finally {
getBigdataRDFContext().abortTx(tx);
}
}
/**
* Handles SPARQL UPDATE.
*
* <pre>
* update OR update in body (see trac 711)
* using-graph-uri (0 or more)
* using-named-graph-uri (0 or more)
* </pre>
*
* @param req
* @param resp
* @throws IOException
*/
private void doSparqlUpdate(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (!isWritable(getServletContext(), req, resp)) {
// Service must be writable.
return;
}
// The SPARQL update
final String updateStr = getUpdateString(req);
final Map<String, Value> bindings = parseBindings(req, resp);
if (bindings == null) {
// There was an error in the bindings. The response was already
// committed.
return;
}
if (updateStr == null) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
"Required parameter not found: " + ATTR_UPDATE);
return;
}
try {
final String namespace = getNamespace(req);
final long timestamp = ITx.UNISOLATED;// getTimestamp(req);
/*
* Note: When GROUP_COMMIT (#566) is enabled the http output stream
* MUST NOT be closed from within the submitted task. Doing so would
* permit the client to conclude that the operation was finished before
* the group commit actually occurs. Instead, we leave it to the
* servlet container to close the http output stream only once the
* execution thread leaves this context. This provides the appropriate
* visibility guarantees.
*/
submitApiTask(
new SparqlUpdateTask(req, resp, namespace, timestamp, updateStr, bindings,
getBigdataRDFContext())).get();
} catch (Throwable t) {
launderThrowable(t, resp, "SPARQL-UPDATE: updateStr=" + updateStr);
}
}
static class SparqlUpdateTask extends AbstractRestApiTask<Void> {
private final String updateStr;
private final BigdataRDFContext context;
private final Map<String, Value> bindings;
/**
*
* @param namespace
* The namespace of the target KB instance.
* @param timestamp
* The timestamp used to obtain a mutable connection.
*/
public SparqlUpdateTask(//
final HttpServletRequest req,//
final HttpServletResponse resp,//
final String namespace, //
final long timestamp,//
final String updateStr,//
final Map<String, Value> bindings,//
final BigdataRDFContext context//
) {
super(req, resp, namespace, timestamp);
this.updateStr = updateStr;
this.context = context;
this.bindings = bindings;
}
@Override
final public boolean isReadOnly() {
return false;
}
@Override
public Void call() throws Exception {
/*
* Parse the SPARQL UPDATE request before we obtain the connection
* object. This let's us overlap the parse of the next SPARQL UPDATE
* with the evaluation of the current one when those operations
* would otherwise be serialized (non-group commit mode).
*
* See BLZG-2039 SPARQL QUERY and SPARQL UPDATE should be parsed
* before obtaining the connection
*/
/*
* Setup the baseURI for this request. It will be set to the
* requestURI.
*/
final String baseURI = req.getRequestURL().toString();
/*
* Parse the query so we can figure out how it will need to
* be executed.
*
* Note: This goes through some pains to make sure that we
* parse the query exactly once in order to minimize the
* resources associated with the query parser.
*/
final ASTContainer astContainer = new Bigdata2ASTSPARQLParser()
.parseUpdate2(updateStr, baseURI);
if (log.isDebugEnabled())
log.debug(astContainer.toString());
BigdataSailRepositoryConnection conn = null;
boolean success = false;
try {
conn = getConnection();
{
/*
* Attempt to construct a task which we can use to evaluate
* the query.
*/
final UpdateTask updateTask = context.getUpdateTask(conn,
namespace, timestamp, baseURI, bindings, astContainer, req,
resp, resp.getOutputStream());
final FutureTask<Void> ft = new FutureTask<Void>(updateTask);
if (log.isTraceEnabled())
log.trace("Will run update: " + updateStr);
updateTask.updateFuture = ft;
/*
* Begin executing the query (asynchronous).
*
* Note: UPDATEs currently contend with QUERYs against the
* same thread pool.
*/
context.queryService.execute(ft);
// Wait for the Future.
ft.get();
success = true;
}
/**
* Note: The SPARQL UPDATE is already committed. This is done in
* the UpdateTask class when we execute the following code
*
* <pre>
* this.commitTime.set(update.execute2());
* </pre>
*/
// conn.commit();
return null;
} finally {
if (conn != null) {
if (!success)
conn.rollback();
conn.close();
}
}
}
@Override
public String toString() {
return getClass().getName() + "{namespace=" + getNamespace()
+ ",timestamp=" + getTimestamp() + ", updateStr=["
+ updateStr + "]}";
}
}
/**
* Run a SPARQL query.
*/
void doSparqlQuery(final HttpServletRequest req, final HttpServletResponse resp)
throws IOException {
if (!isReadable(getServletContext(), req, resp)) {
// HA Quorum in use, but quorum is not met.
return;
}
final String queryStr = getQueryString(req);
if (queryStr == null) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
"Not found: query");
return;
}
final Map<String, Value> bindings = parseBindings(req, resp);
if (bindings == null) {
// There was a problem with the bindings. An error response was
// already committed.
return;
}
// Note: The historical behavior was to always include inferences.
// @see BLZG-1207
final boolean includeInferred = getBooleanValue(req, INCLUDE_INFERRED,
true/* default */);
try {
final String namespace = getNamespace(req);
final long timestamp = getTimestamp(req);
submitApiTask(
new SparqlQueryTask(req, resp, namespace, timestamp, queryStr, includeInferred, bindings,
getBigdataRDFContext())).get();
} catch (Throwable t) {
launderThrowable(t, resp, "SPARQL-QUERY: queryStr=" + queryStr);
}
}
/**
* Helper task for the SPARQL QUERY.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
static class SparqlQueryTask extends AbstractRestApiTask<Void> {
private final String queryStr;
private final BigdataRDFContext context;
private final boolean includeInferred;
private final Map<String, Value> bindings;
public SparqlQueryTask(final HttpServletRequest req,
final HttpServletResponse resp, final String namespace,
final long timestamp, final String queryStr,
final boolean includeInferred, Map<String, Value> bindings,
final BigdataRDFContext context) {
super(req, resp, namespace, timestamp);
if (queryStr == null)
throw new IllegalArgumentException();
if (context == null)
throw new IllegalArgumentException();
this.queryStr = queryStr;
this.context = context;
this.includeInferred = includeInferred;
this.bindings = bindings;
}
@Override
final public boolean isReadOnly() {
return true;
}
@Override
public Void call() throws Exception {
/*
* Parse the query before obtaining the connection object.
*
* @see BLZG-2039 SPARQL QUERY and SPARQL UPDATE should be parsed
* before obtaining the connection
*/
// Setup the baseURI for this request.
final String baseURI = BigdataRDFContext.getBaseURI(req, resp);
// Parse the query.
final ASTContainer astContainer = new Bigdata2ASTSPARQLParser().parseQuery2(queryStr, baseURI);
BigdataSailRepositoryConnection conn = null;
try {
conn = getQueryConnection();
{
/*
* Setup task to execute the query. The task is executed on
* a thread pool. This bounds the possible concurrency of
* query execution (as opposed to queries accepted for
* eventual execution).
*
* Note: If the client closes the connection, then the
* response's InputStream will be closed and the task will
* terminate rather than running on in the background with a
* disconnected client.
*/
final OutputStream os = resp.getOutputStream();
/*
* Attempt to construct a task which we can use to evaluate
* the query.
*/
final AbstractQueryTask queryTask = context.getQueryTask(
conn, namespace, timestamp, queryStr, baseURI, astContainer, includeInferred, bindings,
null/* acceptOverride */, req, resp, os);
// /*
// * Test the cache.
// */
// {
//
// req.setAttribute(ATTR_QUERY_TASK, queryTask);
//
// doCache(req, resp);
//
// if (resp.isCommitted()) {
// // Answered by the cache.
// return;
// }
//
// }
final FutureTask<Void> ft = new FutureTask<Void>(queryTask);
if (log.isTraceEnabled())
log.trace("Will run query: " + queryStr);
/*
* Setup the response headers.
*/
resp.setStatus(HTTP_OK);
if (queryTask.explain) {
/*
* Send back an explanation of the query execution, not
* the query results.
*/
resp.setContentType(BigdataServlet.MIME_TEXT_HTML);
final Writer w = new OutputStreamWriter(os,
queryTask.charset);
try {
// Begin executing the query (asynchronous)
context.queryService.execute(ft);
// Send an explanation instead of the query results.
explainQuery(queryStr, queryTask, ft, w);
} finally {
w.flush();
w.close();
os.flush();
os.close();
}
} else {
/*
* Send back the query results.
*/
resp.setContentType(queryTask.mimeType);
if (queryTask.charset != null) {
// Note: Binary encodings do not specify charset.
resp.setCharacterEncoding(queryTask.charset.name());
}
if (isAttachment(queryTask.mimeType)) {
/*
* Mark this as an attachment (rather than inline).
* This is just a hint to the user agent. How the
* user agent handles this hint is up to it.
*/
resp.setHeader("Content-disposition",
"attachment; filename=query"
+ queryTask.queryId + "."
+ queryTask.fileExt);
}
if (TimestampUtility.isCommitTime(queryTask.timestamp)) {
/*
* A read against a commit time or a read-only tx.
* Such results SHOULD be cached because the data
* from which the response was constructed have
* snapshot isolation. (Note: It is possible that
* the commit point against which the query reads
* will be aged out of database and that the query
* would therefore fail if it were retried. This can
* happen with the RWStore or in scale-out.)
*
* Note: READ_COMMITTED requests SHOULD NOT be
* cached. Such requests will read against then
* current committed state of the database each time
* they are processed.
*
* Note: UNISOLATED queries SHOULD NOT be cached.
* Such operations will read on (and write on) the
* then current state of the unisolated indices on
* the database each time they are processed. The
* results of such operations could be different
* with each request.
*
* Note: Full read-write transaction requests SHOULD
* NOT be cached unless they are queries and the
* transaction scope is limited to the request
* (rather than running across multiple requests).
*/
resp.addHeader("Cache-Control", "public");
// to disable caching.
// r.addHeader("Cache-Control", "no-cache");
}
// Begin executing the query (asynchronous)
context.queryService.execute(ft);
// Wait for the Future.
ft.get();
}
}
return null;
} finally {
if (conn != null) {
conn.close();
}
}
}
} // SparqlQueryTask.
/**
* The SPARQL query.
*
* Note: This can be attached as a request attribute. That supports a
* linked data GET by turning it into a SPARQL DESCRIBE query.
* @throws IOException
*/
static private String getQueryString(final HttpServletRequest req)
throws IOException {
if (RESTServlet.hasMimeType(req, MIME_SPARQL_QUERY)) {
// return the body of the POST, see trac 711
return readFully(req.getReader());
}
return req.getParameter(ATTR_QUERY) != null ? req
.getParameter(ATTR_QUERY) : (String) req
.getAttribute(ATTR_QUERY);
}
static private String getUpdateString(final HttpServletRequest req)
throws IOException {
if (RESTServlet.hasMimeType(req, MIME_SPARQL_UPDATE)) {
// return the body of the POST, see trac 711
return readFully( req.getReader() );
}
return req.getParameter(ATTR_UPDATE);
}
/**
* Sends an explanation for the query rather than the query results. The
* query is still run, but the query statistics are reported instead of the
* query results.
*
* @param queryStr
* @param queryTask
* @param ft
* @param os
* @throws Exception
*
* TODO The complexity here is due to the lack of a tight
* coupling between the {@link RunningQuery}, the
* {@link BigdataSailQuery}, and the {@link IRunningQuery}. It
* was not possible to obtain that tight coupling with the 1.0.x
* releases of bigdata due to the integration with the Sail.
* This led to the practice of setting the query {@link UUID} so
* we could resolve it once the query was executing using
* {@link QueryEngine#getRunningQuery(UUID)}. This also required
* the spin loops in explainQuery() since we had to wait for the
* {@link IRunningQuery} to become available. This is also the
* reason why we can fail to report parts of the explanation for
* fast queries.
* <p>
* This issue could be revisited now. Probably the right way to
* do this is by defining our own evaluate() method on the
* {@link BigdataSailQuery} which would provide either an object
* to be monitored or an interface for a query listener. Either
* approach could be used to ensure that we always have the
* {@link IRunningQuery} for an {@link AbstractQueryTask} which
* was submitted for evaluation.
* <p>
* I have not moved on this issue because the RTO integration
* will change things again. Right now, we have one
* {@link IRunningQuery} per top-level submitted query (plus one
* for each named subquery). With the RTO integration, there
* could be more {@link IRunningQuery}s issued and we will also
* want to paint the statics which it uncovers in its rounds.
*/
static private void explainQuery(final String queryStr,
final AbstractQueryTask queryTask, final FutureTask<Void> ft,
final Writer w) throws Exception {
/*
* Spin until either we have the UUID of the IRunningQuery or the Future
* of the query is done.
*/
if(log.isDebugEnabled())
log.debug("Will build explanation");
UUID queryId2 = null;
IRunningQuery q = null;
while (!ft.isDone() && queryId2 == null) {
try {
// Wait a bit for queryId2 to be assigned.
ft.get(1/* timeout */, TimeUnit.MILLISECONDS);
} catch(TimeoutException ex) {
// Ignore.
}
if (queryTask.queryId2 != null) {
// Got it.
queryId2 = queryTask.queryId2;
break;
}
}
if (ft.isDone()) {
/*
* If the query is done, the check for an error before we build up
* the explanation document.
*/
ft.get();
/*
* No error and the Future is done. The UUID of the IRunningQuery
* MUST have been assigned. If we do not have it yet, then check
* once more. If it is not set then that is an error.
*/
if (queryTask.queryId2 != null) {
// Check once more.
queryId2 = queryTask.queryId2;
if (queryId2 == null) {
/*
* This should have been assigned unless the query failed
* during the setup.
*/
throw new AssertionError();
}
}
}
assert queryId2 != null;
/*
* Build the explanation.
*
* Note: The query may still be executing while we do this.
*
* Note: The document that we are building writes onto the http
* response. Therefore, the response MIGHT be committed anytime after we
* start producing this document.
*
* Note: If the query fails after this point, this method will wind up
* writing the stack trace into the response page.
*/
final HTMLBuilder doc = new HTMLBuilder(queryTask.charset.name(), w);
{
XMLBuilder.Node current = doc.root("html");
BigdataRDFContext.addHtmlHeader(current, charset);
current.node("h1", "Query");
final ASTContainer astContainer = queryTask.astContainer;
/*
* These things are available as soon as the parser runs, so we can
* paint them onto the page now.
*
* Note: The code is written defensively even though all of this
* information should be available
*/
{
final String queryString = astContainer.getQueryString();
if (queryString != null) {
current.node("h2", "SPARQL");
current.node("pre", queryString);
}
final SimpleNode parseTree = ((SimpleNode) astContainer
.getParseTree());
if (parseTree != null) {
current.node("h2", "Parse Tree");
current.node("pre", parseTree.dump(""));
}
final QueryRoot originalAST = astContainer.getOriginalAST();
if (originalAST != null) {
current.node("h2", "Original AST");
current.node("pre", originalAST.toString());
}
}
/*
* Spin until we get the IRunningQuery reference or the query is
* done, in which case we won't get it.
*/
if (queryId2 != null) {
if(log.isDebugEnabled())
log.debug("Resolving IRunningQuery: queryId2=" + queryId2);
final IIndexManager indexManager = BigdataServlet
.getIndexManager(queryTask.req.getServletContext());
final QueryEngine queryEngine = QueryEngineFactory.getInstance()
.getQueryController(indexManager);
while (!ft.isDone() && q == null) {
try {
// Wait a bit for the IRunningQuery to *start*.
ft.get(1/* timeout */, TimeUnit.MILLISECONDS);
} catch(TimeoutException ex) {
// Ignore.
}
// Resolve the IRunningQuery.
try {
q = queryEngine.getRunningQuery(queryId2);
} catch (RuntimeException ex) {
if (InnerCause.isInnerCause(ex, InterruptedException.class)) {
// Ignore. Query terminated normally, but we don't have
// it.
} else {
// Ignore. Query has error, but we will get err from
// Future.
}
}
}
if (q != null)
if(log.isDebugEnabled())
log.debug("Resolved IRunningQuery: query=" + q);
}
/*
* Once the IRunningQuery is available, we know that the query has
* been optimized and can paint the final (optimized) AST and the
* query plan onto the page.
*
* Note: The code is written defensively even though all of this
* information should be available
*/
if (q != null) {
current.node("h2", "Static Analysis Statistics");
{
final StaticAnalysisStats saStats = q.getStaticAnalysisStats();
if (saStats==null) {
current.node("p",
"Static Analysis Statistics are not available.");
} else {
current = current.node("table");
// table header
current = current.node("tr");
current.node("th").text("object").close();
current.node("th").text("category").close();
current.node("th").text("elapsed [ms]").close();
current.node("th").text("elapsed [us]").close();
current.node("th").text("numCalls").close();
current = current.close(); // tr
{
// parser stats
final StaticAnalysisStat pStat = saStats.getParserStat();
if (pStat != null) {
current = current.node("tr");
current.node("td").text(pStat.getStatName()).close();
current.node("td").text("Parser").close();
current.node("td").text(String.valueOf(pStat.getElapsed() / 1000000)).close();
current.node("td").text(String.valueOf(pStat.getElapsed() / 1000)).close();
current.node("td").text(String.valueOf(pStat.getNrCalls())).close();
current = current.close(); // tr
}
}
{
// batch resolve Value => IV stats
final StaticAnalysisStat rStat = saStats.getResolveValuesStat();
if (rStat != null) {
current = current.node("tr");
current.node("td").text(rStat.getStatName()).close();
current.node("td").text("Resolve Values").close();
current.node("td").text(String.valueOf(rStat.getElapsed() / 1000000)).close();
current.node("td").text(String.valueOf(rStat.getElapsed() / 1000)).close();
current.node("td").text(String.valueOf(rStat.getNrCalls())).close();
current = current.close(); // tr
}
}
{
final StaticAnalysisStat lStat = saStats.getOptimizerLoopStat();
if (lStat != null) {
current = current.node("tr");
current.node("td").text(lStat.getStatName()).close();
current.node("td").text("Optimizers (all)").close();
current.node("td").text(String.valueOf(lStat.getElapsed() / 1000000)).close();
current.node("td").text(String.valueOf(lStat.getElapsed() / 1000)).close();
current.node("td").text(String.valueOf(lStat.getNrCalls())).close();
current = current.close(); // tr
}
}
{
final Collection<StaticAnalysisStat> optimizerStats = saStats.getOptimizerStats();
for (StaticAnalysisStat oStat : optimizerStats) {
current = current.node("tr");
current.node("td").text(oStat.getStatName()).close();
current.node("td").text("Optimizer").close();
current.node("td").text(String.valueOf(oStat.getElapsed() / 1000000)).close();
current.node("td").text(String.valueOf(oStat.getElapsed() / 1000)).close();
current.node("td").text(String.valueOf(oStat.getNrCalls())).close();
current = current.close(); // tr
}
}
{
final StaticAnalysisStat rStat = saStats.getRangeCountStat();
if (rStat != null) {
current = current.node("tr");
current.node("td").text(rStat.getStatName()).close();
current.node("td").text("Range Count").close();
current.node("td").text(String.valueOf(rStat.getElapsed() / 1000000)).close();
current.node("td").text(String.valueOf(rStat.getElapsed() / 1000)).close();
current.node("td").text(String.valueOf(rStat.getNrCalls())).close();
current = current.close(); // tr
}
}
current = current.close(); // table
}
}
final QueryRoot optimizedAST = astContainer.getOptimizedAST();
final IBindingSet[] bs = astContainer.getOptimizedASTBindingSets();
if (optimizedAST != null) {
current.node("h2", "Optimized AST");
current.node("pre", optimizedAST.toString(0, bs));
}
{
// render explain hints, if at least one is present
final Iterator<BOp> it =
ExplainHints.explainHintAnnotatedBOpIterator(optimizedAST);
if (it.hasNext()) {
// header
current.node("h2", "Explain Hints");
current = current.node("table");
// table header
current = current.node("tr");
current.node("th").text("#").close();
current.node("th").text("type").close();
current.node("th").text("severity").close();
current.node("th").text("AST node").close();
current.node("th").text("description").close();
current = current.close(); // tr
int ctr = 0;
while (it.hasNext()) { // no effect if !hasExplainHints
final BOp bop = it.next();
final ExplainHints explainHints =
(ExplainHints)bop.getProperty(Annotations.EXPLAIN_HINTS);
for (IExplainHint hint : explainHints) {
current = current.node("tr");
current.node("td").text(String.valueOf(ctr++)).close();
if (hint.getHelpLink()!=null) {
current.node("td").node("a").
attr("href", hint.getHelpLink()).
text(hint.getExplainHintType()).close().close();
} else {
current.node("td").text(hint.getExplainHintType()).close();
}
current.node("td").text(hint.getExplainHintSeverity().toString()).close();
current.node("td").text(hint.getExplainHintNode().toString()).close();
current.node("td").text(hint.getExplainHintDescription()).close();
current = current.close(); // tr
}
}
// closing code
current = current.close(); // table
}
}
final PipelineOp queryPlan = astContainer.getQueryPlan();
if (queryPlan != null) {
current.node("h2", "Query Plan");
current.node("pre", BOpUtility.toString(queryPlan));
}
}
try {
/*
* Wait for the Future. If the query fails, then note the
* exception but do NOT rethrow it. The exception will get
* painted into the page.
*/
ft.get();
/*
* Note: An InterruptedException here is NOT caught. It means
* that this Thread was interrupted rather than the Query.
*/
} catch (ExecutionException ex) {
// Some error.
final Throwable cause = ex.getCause();
// Format the stack trace.
final StringWriter sw = new StringWriter();
cause.printStackTrace(new PrintWriter(sw));
final String s = sw.getBuffer().toString();
// And write it into the page.
current.node("pre").text(s).close();
// Fall through and paint the query stats table(s).
}
current.node("h2", "Query Evaluation Statistics");
if (q == null) {
/*
* This can happen if we fail to get the IRunningQuery reference
* before the query terminates. E.g., if the query runs too
* quickly there is a data race and the reference may not be
* available anymore.
*/
current.node("p",
"Statistics are not available (query already terminated).");
} else {
// An array of the declared child queries.
final IRunningQuery[] children = ((AbstractRunningQuery) q)
.getChildren();
final long elapsedMillis = q.getElapsed();
final BOpStats stats = q.getStats().get(
q.getQuery().getId());
final String solutionsOut = stats == null ? NA : Long
.toString(stats.unitsOut.get());
final String chunksOut = stats == null ? NA : Long
.toString(stats.chunksOut.get());
current.node("p")//
.text("solutions=" + solutionsOut)//
.text(", chunks=" + chunksOut)//
.text(", subqueries=" + children.length)//
.text(", elapsed=" + elapsedMillis + "ms")//
.text(q.isCancelled()?", CANCELLED.":".")
.close();
/*
* Format query statistics as a table.
*
* Note: This is writing on the Writer so it goes directly into
* the HTML document we are building for the client.
*/
final boolean clusterStats = q.getFederation() != null;
// no mutation for query.
final boolean mutationStats = false;
QueryLog.getTableXHTML(queryStr, q, children, w,
false/* summaryOnly */, 0/* maxBopLength */,
clusterStats,
queryTask.explainDetails/* detailedStats */,
mutationStats);
}
doc.closeAll(current);
}
}
/**
* Estimate the cardinality of an access path (fast range count).
*
* @param req
* @param resp
*
* @see <a href="http://trac.bigdata.com/ticket/1127"> Extend ESTCARD method
* for exact range counts </a>
*/
private void doEstCard(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (!isReadable(getServletContext(), req, resp)) {
// HA Quorum in use, but quorum is not met.
return;
}
final boolean exact = getBooleanValue(req, "exact", false/* default */);
final Resource s;
final URI p;
final Value o;
final Resource[] c;
try {
s = EncodeDecodeValue.decodeResource(req.getParameter("s"));
p = EncodeDecodeValue.decodeURI(req.getParameter("p"));
o = EncodeDecodeValue.decodeValue(req.getParameter("o"));
c = decodeContexts(req, "c");
// c = EncodeDecodeValue.decodeContexts(req.getParameterValues("c"));
} catch (IllegalArgumentException ex) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
ex.getLocalizedMessage());
return;
}
if (log.isInfoEnabled())
log.info("ESTCARD: access path: (exact=" + exact + ", s=" + s + ", p="
+ p + ", o=" + o + ", c=" + Arrays.toString(c) + ")");
try {
submitApiTask(
new EstCardTask(req, resp, getNamespace(req),
getTimestamp(req), //
exact,//
s, p, o, c)).get();
} catch (Throwable t) {
launderThrowable(t, resp,
"ESTCARD: access path: (exact=" + exact + ", s=" + s + ", p="
+ p + ", o=" + o + ", c=" + Arrays.toString(c) + ")");
}
}
/**
* Helper task for the ESTCARD query.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
private static class EstCardTask extends AbstractRestApiTask<Void> {
private final boolean exact;
private final Resource s;
private final URI p;
private final Value o;
private final Resource[] c;
public EstCardTask(final HttpServletRequest req,
final HttpServletResponse resp, final String namespace,
final long timestamp, final boolean exact,
final Resource s, final URI p,
final Value o, final Resource[] c) {
super(req, resp, namespace, timestamp);
this.exact = exact;
this.s = s;
this.p = p;
this.o = o;
this.c = c;
}
@Override
public boolean isReadOnly() {
return true;
}
@Override
public Void call() throws Exception {
final long begin = System.currentTimeMillis();
BigdataSailRepositoryConnection conn = null;
try {
conn = getQueryConnection();
// Range count all statements matching that access path.
long rangeCount = 0;
if (c != null && c.length > 0) {
for (Resource r : c) {
rangeCount += conn.getTripleStore().getAccessPath(s, p, o, r)
.rangeCount(exact);
}
} else {
rangeCount += conn.getTripleStore()
.getAccessPath(s, p, o, (Resource) null)
.rangeCount(exact);
}
final long elapsed = System.currentTimeMillis() - begin;
buildAndCommitRangeCountResponse(resp, rangeCount, elapsed);
return null;
} finally {
if (conn != null) {
conn.close();
}
}
}
} // ESTCARD task.
/**
* Return <code>true</code> iff at least one matching statement exists in the
* namespace.
*
* @param req
* @param resp
*
* @see <a href="http://trac.bigdata.com/ticket/1109"> hasStatements can
* overestimate and ignores includeInferred (REST API) </a>
*/
private void doHasStmt(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (!isReadable(getServletContext(), req, resp)) {
// HA Quorum in use, but quorum is not met.
return;
}
final boolean includeInferred = getBooleanValue(req, INCLUDE_INFERRED,
true/* default */);
final Resource s;
final URI p;
final Value o;
final Resource[] c;
try {
s = EncodeDecodeValue.decodeResource(req.getParameter("s"));
p = EncodeDecodeValue.decodeURI(req.getParameter("p"));
o = EncodeDecodeValue.decodeValue(req.getParameter("o"));
c = decodeContexts(req, "c");
// c = EncodeDecodeValue.decodeContexts(req.getParameterValues("c"));
} catch (IllegalArgumentException ex) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
ex.getLocalizedMessage());
return;
}
if (log.isInfoEnabled())
log.info("HASSTMT: access path: (includeInferred=" + includeInferred
+ ", s=" + s + ", p=" + p + ", o=" + o + ", c="
+ Arrays.toString(c) + ")");
try {
submitApiTask(
new HasStmtTask(req, resp, getNamespace(req), getTimestamp(req), //
includeInferred,//
s, p, o, c)).get();
} catch (Throwable t) {
launderThrowable(t, resp, "HASSTMT: access path: (includeInferred="
+ includeInferred + ", s=" + s + ", p=" + p + ", o=" + o
+ ", c=" + Arrays.toString(c) + ")");
}
}
/**
* Helper task for the HASSTMT query.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan
* Thompson</a>
*/
private static class HasStmtTask extends AbstractRestApiTask<Void> {
private final boolean includeInferred;
private final Resource s;
private final URI p;
private final Value o;
private final Resource[] c;
public HasStmtTask(final HttpServletRequest req,
final HttpServletResponse resp, final String namespace,
final long timestamp, final boolean includeInferred,
final Resource s, final URI p, final Value o, final Resource[] c) {
super(req, resp, namespace, timestamp);
this.includeInferred = includeInferred;
this.s = s;
this.p = p;
this.o = o;
this.c = c;
}
@Override
public boolean isReadOnly() {
return true;
}
@Override
public Void call() throws Exception {
final long begin = System.currentTimeMillis();
BigdataSailRepositoryConnection conn = null;
try {
conn = getQueryConnection();
// Note: We have to align Sail semantics for Resource... with the
// REST API.
final boolean found = conn.hasStatement(s, p, o, includeInferred,
c == null ? new Resource[0] : c);
final long elapsed = System.currentTimeMillis() - begin;
buildAndCommitBooleanResponse(resp, found, elapsed);
return null;
} finally {
if (conn != null) {
conn.close();
}
}
}
} // HASSTMT task.
/**
* Return statements.
*
*/
private void doGetStmts(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (!isReadable(getServletContext(), req, resp)) {
// HA Quorum in use, but quorum is not met.
return;
}
// Note: The historical behavior was to always include inferrences.
// @see BLZG-1207
final boolean includeInferred = getBooleanValue(req, INCLUDE_INFERRED,
true/* default */);
final Resource s;
final URI p;
final Value o;
final Resource[] c;
final Enumeration<String> mimeTypes;
try {
s = EncodeDecodeValue.decodeResource(req.getParameter("s"));
p = EncodeDecodeValue.decodeURI(req.getParameter("p"));
o = EncodeDecodeValue.decodeValue(req.getParameter("o"));
c = decodeContexts(req, "c");
mimeTypes = req.getHeaders(ConnectOptions.ACCEPT_HEADER);
} catch (IllegalArgumentException ex) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
ex.getLocalizedMessage());
return;
}
if (log.isInfoEnabled())
log.info("GETSTMTS: access path: (includeInferred=" + includeInferred
+ ", s=" + s + ", p=" + p + ", o=" + o + ", c="
+ Arrays.toString(c) + ")");
try {
submitApiTask(
new GetStmtsTask(req, resp, getNamespace(req), getTimestamp(req), //
includeInferred,//
s, p, o, c, mimeTypes)).get();
} catch (Throwable t) {
launderThrowable(t, resp, "GETSTMTS: access path: (includeInferred="
+ includeInferred + ", s=" + s + ", p=" + p + ", o=" + o
+ ", c=" + Arrays.toString(c) + ")");
}
}
/**
* Helper task for the GETSTMTS query.
*
*/
private static class GetStmtsTask extends AbstractRestApiTask<Void> {
private final Enumeration<String> mimeTypes;
private final boolean includeInferred;
private final Resource s;
private final URI p;
private final Value o;
private final Resource[] c;
public GetStmtsTask(final HttpServletRequest req,
final HttpServletResponse resp, final String namespace,
final long timestamp, final boolean includeInferred,
final Resource s, final URI p, final Value o, final Resource[] c, Enumeration<String> mimeTypes) {
super(req, resp, namespace, timestamp);
this.includeInferred = includeInferred;
this.s = s;
this.p = p;
this.o = o;
this.c = c;
this.mimeTypes = mimeTypes;
}
@Override
public boolean isReadOnly() {
return true;
}
@Override
public Void call() throws Exception {
BigdataSailRepositoryConnection conn = null;
try {
conn = getQueryConnection();
String mimeType = null;
RDFFormat format = null;
if (mimeTypes!=null) {
mimeTypesLoop:
while(mimeTypes.hasMoreElements()) {
for (String mt:mimeTypes.nextElement().split(",")) {
mt = mt.trim();
RDFFormat fmt = RDFWriterRegistry.getInstance()
.getFileFormatForMIMEType(mt);
if (conn.getTripleStore().isQuads() && (mt.equals(RDFFormat.NQUADS.getDefaultMIMEType()) || mt.equals(RDFFormat.TURTLE.getDefaultMIMEType())) || !conn.getTripleStore().isQuads() && fmt != null) {
mimeType = mt;
format = fmt;
break mimeTypesLoop;
}
}
}
}
if (format==null) {
if(conn.getTripleStore().isQuads()){
mimeType = RDFFormat.NQUADS.getDefaultMIMEType();
} else {
mimeType = RDFFormat.NTRIPLES.getDefaultMIMEType();
}
format = RDFWriterRegistry.getInstance()
.getFileFormatForMIMEType(mimeType);
}
resp.setContentType(mimeType);
final OutputStream os = resp.getOutputStream();
final RDFWriter w = RDFWriterRegistry.getInstance().get(format)
.getWriter(os);
RepositoryResult<Statement> stmts = null;
try {
w.startRDF();
stmts = conn.getStatements(s, p, o, includeInferred, c);
while(stmts.hasNext()){
w.handleStatement(stmts.next());
}
w.endRDF();
} finally {
if (stmts != null) {
stmts.close();
}
os.flush();
os.close();
}
return null;
} finally {
if (conn != null) {
conn.close();
}
}
}
} // GETSTMTS task.
/**
* Report on the contexts in use in the quads database.
*/
private void doContexts(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (!isReadable(getServletContext(), req, resp)) {
// HA Quorum in use, but quorum is not met.
return;
}
try {
submitApiTask(
new RestApiGetContextsTask(req, resp, getNamespace(req),
getTimestamp(req))).get();
} catch (Throwable t) {
launderThrowable(t, resp, "GET-CONTEXTS");
}
}
/**
* Private API reports the shards against which the access path would
* read.
*
* @param req
* @param resp
*/
private void doShardReport(final HttpServletRequest req,
final HttpServletResponse resp) throws IOException {
if (!isReadable(getServletContext(), req, resp)) {
// HA Quorum in use, but quorum is not met.
return;
}
if (!getBigdataRDFContext().isScaleOut()) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
"Not scale-out");
return;
}
final boolean doRangeCount = true;
final Resource s;
final URI p;
final Value o;
final Resource c;
try {
s = EncodeDecodeValue.decodeResource(req.getParameter("s"));
p = EncodeDecodeValue.decodeURI(req.getParameter("p"));
o = EncodeDecodeValue.decodeValue(req.getParameter("o"));
c = EncodeDecodeValue.decodeResource(req.getParameter("c"));
} catch (IllegalArgumentException ex) {
buildAndCommitResponse(resp, HTTP_BADREQUEST, MIME_TEXT_PLAIN,
ex.getLocalizedMessage());
return;
}
if (log.isInfoEnabled())
log.info("SHARDS: access path: (s=" + s + ", p=" + p + ", o="
+ o + ", c=" + c + ")");
try {
submitApiTask(
new ShardsTask(req, resp, getNamespace(req),
getTimestamp(req), s, p, o, c, doRangeCount)).get();
} catch (Throwable t) {
launderThrowable(t, resp, "SHARDS: access path: (s=" + s + ", p="
+ p + ", o=" + o + ", c=" + c + ")");
}
}
/**
* Task to report on the SHARDS used by a scale-out deployment.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
private static class ShardsTask extends AbstractRestApiTask<Void> {
private final Resource s;
private final URI p;
private final Value o;
private final Resource c;
private final boolean doRangeCount;
public ShardsTask(final HttpServletRequest req,
final HttpServletResponse resp, final String namespace,
final long timestamp, final Resource s, final URI p,
final Value o, final Resource c, final boolean doRangeCount) {
super(req, resp, namespace, timestamp);
this.s = s;
this.p = p;
this.o = o;
this.c = c;
this.doRangeCount = doRangeCount;
}
@Override
public boolean isReadOnly() {
return true;
}
@Override
public Void call() throws Exception {
final long begin = System.currentTimeMillis();
BigdataSailRepositoryConnection conn = null;
try {
conn = getQueryConnection();
final AccessPath<?> accessPath = (AccessPath<?>) conn
.getTripleStore()
.getAccessPath(s, p, o, c);
final ClientIndexView ndx = (ClientIndexView) accessPath
.getIndex();
final String charset = "utf-8";// TODO from request.
resp.setContentType(BigdataServlet.MIME_TEXT_HTML);
resp.setCharacterEncoding(charset);
final Writer w = resp.getWriter();
try {
final HTMLBuilder doc = new HTMLBuilder(charset, w);
XMLBuilder.Node current = doc.root("html");
BigdataRDFContext.addHtmlHeader(current, charset);
final IBigdataFederation<?> fed = (IBigdataFederation<?>)// getBigdataRDFContext()
getIndexManager();
final Iterator<PartitionLocator> itr = ndx.locatorScan(
timestamp, accessPath.getFromKey(),
accessPath.getToKey(), false/* reverseScan */);
int nlocators = 0;
// The distinct hosts on which the shards are located.
final Map<String,AtomicInteger> hosts = new TreeMap<String,AtomicInteger>();
// The host+locators in key order.
final StringBuilder sb = new StringBuilder();
while (itr.hasNext()) {
final PartitionLocator loc = itr.next();
final IDataService ds = fed.getDataService(loc
.getDataServiceUUID());
final String hostname = ds == null ? "N/A" : ds
.getHostname();
AtomicInteger nshards = hosts.get(hostname);
if (nshards == null) {
hosts.put(hostname,
nshards = new AtomicInteger());
}
nshards.incrementAndGet();
sb.append("\nhost=" + hostname);
sb.append(", locator=" + loc);
nlocators++;
} // while(itr.hasNext())
// elapsed locator scan time
final long begin2 = System.currentTimeMillis();
final long elapsed = begin2 - begin;
// fast range count (requires visiting shards)
final long rangeCount = doRangeCount ? accessPath
.rangeCount(false/* exact */) : -1;
// elapsed time for the fast range count
final long elapsed2 = System.currentTimeMillis()
- begin2;
current = current.node("H2", "summary");
{
current.node("p", "index="
+ ndx.getIndexMetadata().getName()
+ ", locators=" + nlocators + ", hosts="
+ hosts.size() + ", elapsed=" + elapsed
+ "ms");
if (doRangeCount) {
current.node("p", "rangeCount=" + rangeCount
+ ", elapsed=" + elapsed2 + "ms");
}
// current = current.close();
}
// host + locators in key order.
current.node("H2","shards").node("pre", sb.toString());
// hosts + #shards in host name order
{
sb.setLength(0); // clear buffer.
for (Map.Entry<String, AtomicInteger> e : hosts
.entrySet()) {
sb.append("\nhost=" + e.getKey());
sb.append(", #shards=" + e.getValue());
}
current.node("H2","hosts").node("pre", sb.toString());
}
doc.closeAll(current);
} finally {
w.flush();
w.close();
}
return null;
} finally {
if (conn != null) {
conn.close();
}
}
}
}
// /**
// * Test the SPARQL cache.
// */
// private void doCache(final HttpServletRequest req,
// final HttpServletResponse resp) throws IOException {
//
// // The query task.
// final AbstractQueryTask queryTask = (AbstractQueryTask) req
// .getAttribute(ATTR_QUERY_TASK);
//
// if (queryTask == null)
// return;
//
// final SparqlCache cache = getSparqlCache();
//
// if (cache == null)
// return;
//
// final CacheHit hit = cache.get(queryTask);
//
// if(hit == null)
// return;
//
// /*
// * Send the response.
// *
// * TODO If the cached response entity is the wrong content type (not
// * accepted by the Accept header), then de-serialize, convert, and
// * re-serialize. The cache could do that on its end or we could do it
// * here.
// *
// * Ideally the SparqlCache class can be reused outside of the NSS
// * context, e.g., for embedded applications which do not use the NSS at
// * all. This also supports a deeper integration into the query planner.
// * Both of which suggest that we should handle the conneg problems here.
// */
// resp.setStatus(HTTP_OK);
// resp.setContentType(hit.contentType);
// resp.setContentLength(hit.contentLength);
// resp.setDateHeader("Last-Modified", hit.lastModified);
// final OutputStream os = resp.getOutputStream();
// try {
// os.write(hit.data);
// os.flush();
// } finally {
// os.close();
// }
//
// }
}