var t = db.hashindex1;
t.drop()

//test non-single field hashed indexes don't get created (maybe change later)
var badspec = {a : "hashed" , b : 1};
t.ensureIndex( badspec );
assert.eq( t.getIndexes().length , 1 , "only _id index should be created");

//test unique index not created (maybe change later)
var goodspec = {a : "hashed"};
t.ensureIndex( goodspec , {"unique" : true});
assert.eq( t.getIndexes().length , 1 , "unique index got created.");

//now test that non-unique index does get created
t.ensureIndex(goodspec);
assert.eq( t.getIndexes().length , 2 , "hashed index didn't get created");

//test basic inserts
for(i=0; i < 10; i++ ){
	t.insert( {a:i } );
}
assert.eq( t.find().count() , 10 , "basic insert didn't work");
assert.eq( t.find().hint(goodspec).toArray().length , 10 , "basic insert didn't work");
assert.eq( t.find({a : 3}).hint({_id : 1}).toArray()[0]._id ,
		   t.find({a : 3}).hint(goodspec).toArray()[0]._id ,
		   "hashindex lookup didn't work" );


//make sure things with the same hash are not both returned
t.insert( {a: 3.1} );
assert.eq( t.find().count() , 11 , "additional insert didn't work");
assert.eq( t.find({a : 3.1}).hint(goodspec).toArray().length , 1);
assert.eq( t.find({a : 3}).hint(goodspec).toArray().length , 1);
//test right obj is found
assert.eq( t.find({a : 3.1}).hint(goodspec).toArray()[0].a , 3.1);

//test that hashed cursor is used when it should be
var cursorname = "BtreeCursor a_hashed";
assert.eq( t.find({a : 1}).explain().cursor ,
		cursorname ,
		"not using hashed cursor");

// SERVER-12222
//printjson( t.find({a : {$gte : 3 , $lte : 3}}).explain() )
//assert.eq( t.find({a : {$gte : 3 , $lte : 3}}).explain().cursor ,
//		cursorname ,
//		"not using hashed cursor");
assert.neq( t.find({c : 1}).explain().cursor ,
		cursorname ,
		"using irrelevant hashed cursor");

printjson( t.find({a : {$in : [1,2]}}).explain() )
// Hash index used with a $in set membership predicate.
assert.eq( t.find({a : {$in : [1,2]}}).explain()["cursor"],
           "BtreeCursor a_hashed",
           "not using hashed cursor");

// Hash index used with a singleton $and predicate conjunction.
assert.eq( t.find({$and : [{a : 1}]}).explain()["cursor"],
           "BtreeCursor a_hashed",
           "not using hashed cursor");

// Hash index used with a non singleton $and predicate conjunction.
assert.eq( t.find({$and : [{a : {$in : [1,2]}},{a : {$gt : 1}}]}).explain()["cursor"],
           "BtreeCursor a_hashed",
           "not using hashed cursor");

//test creation of index based on hash of _id index
var goodspec2 = {'_id' : "hashed"};
t.ensureIndex( goodspec2 );
assert.eq( t.getIndexes().length , 3 , "_id index didn't get created");

var newid = t.findOne()["_id"];
assert.eq( t.find( {_id : newid} ).hint( {_id : 1} ).toArray()[0]._id ,
		   t.find( {_id : newid} ).hint( goodspec2 ).toArray()[0]._id,
		   "using hashed index and different index returns different docs");


//test creation of sparse hashed index
var sparseindex = {b : "hashed"};
t.ensureIndex( sparseindex , {"sparse" : true});
assert.eq( t.getIndexes().length , 4 , "sparse index didn't get created");

//test sparse index has smaller total items on after inserts
for(i=0; i < 10; i++ ){
	t.insert( {b : i} );
}
var totalb = t.find().hint(sparseindex).toArray().length;
assert.eq( totalb , 10 , "sparse index has wrong total");

var total = t.find().hint({"_id" : 1}).toArray().length;
var totala = t.find().hint(goodspec).toArray().length;
assert.eq(total , totala , "non-sparse index has wrong total");
assert.lt(totalb , totala , "sparse index should have smaller total");