MongoDB client submitted by Yen Pai

build.xml

@@ -28,6 +28,11 @@
 		<antcall target="dbcompile"/>
 	</target>
 
+   	<target name="dbcompile-mongodb" depends="compile">
+		<property name="db.dir" value="db/mongodb"/>
+		<antcall target="dbcompile"/>
+	</target>
+
 	<target name="compile">
         <mkdir dir="${classes.dir}"/>
         <javac srcdir="${src.dir}" destdir="${classes.dir}" excludes="com/yahoo/ycsb/db/**" deprecation="on">

db/mongodb/lib/README

+This directory should contain jars for building and running MongoDB

db/mongodb/src/com/yahoo/ycsb/db/MongoDbClient.java

+/**
+ * MongoDB client binding for YCSB.
+ *
+ * Submitted by Yen Pai on 5/11/2010.
+ *
+ * https://gist.github.com/000a66b8db2caf42467b#file_mongo_db.java
+ *
+ */
+
+package com.yahoo.ycsb.db;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Properties;
+import java.util.Set;
+import java.util.Vector;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.mongodb.BasicDBObject;
+import com.mongodb.DBAddress;
+import com.mongodb.DBCollection;
+import com.mongodb.DBCursor;
+import com.mongodb.DBObject;
+import com.mongodb.Mongo;
+import com.mongodb.DB.WriteConcern;
+import com.yahoo.ycsb.DB;
+import com.yahoo.ycsb.DBException;
+
+/**
+* MongoDB client for YCSB framework.
+*
+* Properties to set:
+*
+* mongodb.url=mongodb://localhost:27017
+* mongodb.database=ycsb
+*
+* @author ypai
+*
+*/
+public class MongoDbClient extends DB {
+
+    private static final Logger logger = LoggerFactory.getLogger(MongoDbClient.class);
+
+    private Mongo mongo;
+    private WriteConcern writeConcern;
+    private String database;
+
+    /**
+* Initialize any state for this DB. Called once per DB instance; there is
+* one DB instance per client thread.
+*/
+    public void init() throws DBException {
+        // initialize MongoDb driver
+        Properties props = getProperties();
+        String url = props.getProperty("mongodb.url");
+        database = props.getProperty("mongodb.database");
+        String writeConcernType = props.getProperty("mongodb.writeConcern");
+
+        if ("none".equals(writeConcernType)) {
+            writeConcern = WriteConcern.NONE;
+        } else if ("strict".equals(writeConcernType)) {
+            writeConcern = WriteConcern.STRICT;
+        } else if ("normal".equals(writeConcernType)) {
+            writeConcern = WriteConcern.NORMAL;
+        }
+
+        try {
+            // strip out prefix since Java driver doesn't currently support
+            // standard
+            // connection format URL yet
+            // http://www.mongodb.org/display/DOCS/Connections
+            if (url.startsWith("mongodb://")) {
+                url = url.substring(10);
+            }
+
+            mongo = new Mongo(new DBAddress(url));
+        } catch (Exception e1) {
+            logger.error(
+                    "Could not initialize MongoDB connection pool for Loader: "
+                            + e1, e1);
+            return;
+        }
+
+    }
+
+    @Override
+    /**
+* Delete a record from the database.
+*
+* @param table The name of the table
+* @param key The record key of the record to delete.
+* @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
+*/
+    public int delete(String table, String key) {
+        try {
+            com.mongodb.DB db = mongo.getDB(database);
+            DBCollection collection = db.getCollection(table);
+            DBObject q = new BasicDBObject().append("_id", key);
+            if (writeConcern.equals(WriteConcern.STRICT)) {
+                q.put("$atomic", true);
+            }
+            collection.remove(q);
+
+            // see if record was deleted
+            DBObject errors = db.getLastError();
+
+            return (Long) errors.get("n") == 1 ? 0 : 1;
+        } catch (Exception e) {
+            logger.error(e + "", e);
+            return 1;
+        }
+
+    }
+
+    @Override
+    /**
+* Insert a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
+* record key.
+*
+* @param table The name of the table
+* @param key The record key of the record to insert.
+* @param values A HashMap of field/value pairs to insert in the record
+* @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
+*/
+    public int insert(String table, String key, HashMap<String, String> values) {
+        try {
+            com.mongodb.DB db = mongo.getDB(database);
+            DBCollection collection = db.getCollection(table);
+            DBObject r = new BasicDBObject().append("_id", key);
+            r.putAll(values);
+
+            collection.setWriteConcern(writeConcern);
+
+            collection.insert(r);
+
+            // determine if record was inserted
+            DBObject errors = db.getLastError();
+            return (Long) errors.get("n") == 1 ? 0 : 1;
+        } catch (Exception e) {
+            logger.error(e + "", e);
+            return 1;
+        }
+
+    }
+
+    @Override
+    @SuppressWarnings ("unchecked")
+    /**
+* Read a record from the database. Each field/value pair from the result will be stored in a HashMap.
+*
+* @param table The name of the table
+* @param key The record key of the record to read.
+* @param fields The list of fields to read, or null for all of them
+* @param result A HashMap of field/value pairs for the result
+* @return Zero on success, a non-zero error code on error or "not found".
+*/
+    public int read(String table, String key, Set<String> fields,
+            HashMap<String, String> result) {
+        try {
+            com.mongodb.DB db = mongo.getDB(database);
+            DBCollection collection = db.getCollection(table);
+            DBObject q = new BasicDBObject().append("_id", key);
+            DBObject fieldsToReturn = new BasicDBObject();
+            boolean returnAllFields = fields == null;
+
+            DBObject queryResult = null;
+            if (!returnAllFields) {
+                Iterator<String> iter = fields.iterator();
+                while (iter.hasNext()) {
+                    fieldsToReturn.put(iter.next(), 1);
+                }
+                queryResult = collection.findOne(q, fieldsToReturn);
+            } else {
+                queryResult = collection.findOne(q);
+            }
+
+            if (queryResult != null) {
+	       //toMap() returns a Map, but result.putAll() expects a Map<String,String>. Hence, the suppress warnings.
+                result.putAll(queryResult.toMap());
+            }
+            return queryResult != null ? 0 : 1;
+        } catch (Exception e) {
+            logger.error(e + "", e);
+            return 1;
+        }
+
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    /**
+* Perform a range scan for a set of records in the database. Each field/value pair from the result will be stored in a HashMap.
+*
+* @param table The name of the table
+* @param startkey The record key of the first record to read.
+* @param recordcount The number of records to read
+* @param fields The list of fields to read, or null for all of them
+* @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one record
+* @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
+*/
+    public int scan(String table, String startkey, int recordcount,
+            Set<String> fields, Vector<HashMap<String, String>> result) {
+        try {
+            com.mongodb.DB db = mongo.getDB(database);
+            DBCollection collection = db.getCollection(table);
+            // { "_id":{"$gte":startKey, "$lte":{"appId":key+"\uFFFF"}} }
+            DBObject scanRange = new BasicDBObject().append("$gte", startkey);
+            DBObject q = new BasicDBObject().append("_id", scanRange);
+            DBCursor cursor = collection.find(q).limit(recordcount);
+            while (cursor.hasNext()) {
+	       //toMap() returns a Map, but result.add() expects a Map<String,String>. Hence, the suppress warnings.
+                result.add((HashMap<String, String>) cursor.next().toMap());
+            }
+            return 0;
+        } catch (Exception e) {
+            logger.error(e + "", e);
+            return 1;
+        }
+
+    }
+
+    @Override
+    /**
+* Update a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
+* record key, overwriting any existing values with the same field name.
+*
+* @param table The name of the table
+* @param key The record key of the record to write.
+* @param values A HashMap of field/value pairs to update in the record
+* @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
+*/
+    public int update(String table, String key, HashMap<String, String> values) {
+        try {
+            com.mongodb.DB db = mongo.getDB(database);
+            DBCollection collection = db.getCollection(table);
+            DBObject q = new BasicDBObject().append("_id", key);
+            DBObject u = new BasicDBObject();
+            DBObject fieldsToSet = new BasicDBObject();
+            Iterator<String> keys = values.keySet().iterator();
+            String tmpKey = null, tmpVal = null;
+            while (keys.hasNext()) {
+                tmpKey = keys.next();
+                tmpVal = values.get(tmpKey);
+                fieldsToSet.put(tmpKey, tmpVal);
+
+            }
+            u.put("$set", fieldsToSet);
+
+            collection.setWriteConcern(writeConcern);
+
+            collection.update(q, u);
+
+            // determine if record was inserted
+            DBObject errors = db.getLastError();
+
+            return (Long) errors.get("n") == 1 ? 0 : 1;
+        } catch (Exception e) {
+            logger.error(e + "", e);
+            return 1;
+        }
+
+    }
+}
+
+

src/com/yahoo/ycsb/CommandLine.java

@@ -326,9 +326,17 @@ public class CommandLine
 		  int ret=db.scan(table,tokens[1],Integer.parseInt(tokens[2]),fields,results);
 		  System.out.println("Return code: "+ret);
 		  int record=0;
+		  if (results.size()==0)
+		  {
+		     System.out.println("0 records");
+		  }
+		  else
+		  {
+		     System.out.println("--------------------------------");
+		  }
 		  for (HashMap<String,String> result : results)
 		  {
-		     System.out.println("Record"+(record++));
+		     System.out.println("Record "+(record++));
 		     for (Map.Entry<String,String> ent : result.entrySet())
 		     {
 			System.out.println(ent.getKey()+"="+ent.getValue());