// shardkey.cpp
/**
* Copyright (C) 2008 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*/
#include "pch.h"
#include "chunk.h"
#include "../db/jsobj.h"
#include "mongo/db/json.h"
#include "../util/startup_test.h"
#include "../util/timer.h"
namespace mongo {
ShardKeyPattern::ShardKeyPattern( BSONObj p ) : pattern( p.getOwned() ) {
pattern.getFieldNames(patternfields);
BSONObjBuilder min;
BSONObjBuilder max;
BSONObjIterator it(p);
while (it.more()) {
BSONElement e (it.next());
min.appendMinKey(e.fieldName());
max.appendMaxKey(e.fieldName());
}
gMin = min.obj();
gMax = max.obj();
}
bool ShardKeyPattern::hasShardKey( const BSONObj& obj ) const {
/* this is written s.t. if obj has lots of fields, if the shard key fields are early,
it is fast. so a bit more work to try to be semi-fast.
*/
for(set::const_iterator it = patternfields.begin(); it != patternfields.end(); ++it) {
BSONElement e = obj.getFieldDotted(it->c_str());
if(e.eoo() || e.type() == Array || (e.type() == Object && e.embeddedObject().firstElementFieldName()[0] == '$')) {
// cant use getGtLtOp here as it returns Equality for unknown $ops and we want to reject them
return false;
}
}
return true;
}
bool ShardKeyPattern::isPrefixOf( const BSONObj& otherPattern ) const {
return pattern.isPrefixOf( otherPattern );
}
bool ShardKeyPattern::isUniqueIndexCompatible( const BSONObj& uniqueIndexPattern ) const {
if ( ! uniqueIndexPattern.isEmpty() &&
str::equals( uniqueIndexPattern.firstElementFieldName(), "_id" ) ){
return true;
}
return pattern.isFieldNamePrefixOf( uniqueIndexPattern );
}
bool ShardKeyPattern::isSpecial() const {
BSONForEach(e, pattern) {
int fieldVal = e.numberInt();
if ( fieldVal != 1 && fieldVal != -1 ){
return true;
}
}
return false;
}
string ShardKeyPattern::toString() const {
return pattern.toString();
}
BSONObj ShardKeyPattern::moveToFront(const BSONObj& obj) const {
vector keysToMove;
keysToMove.push_back("_id");
BSONForEach(e, pattern) {
if (strchr(e.fieldName(), '.') == NULL && strcmp(e.fieldName(), "_id") != 0)
keysToMove.push_back(e.fieldName());
}
if (keysToMove.size() == 1) {
return obj;
}
else {
BufBuilder buf (obj.objsize());
buf.appendNum((unsigned)0); // refcount
buf.appendNum(obj.objsize());
vector > copies;
pair toCopy ((const char*)NULL, 0); // C++ NULL isn't a pointer type yet
BSONForEach(e, obj) {
bool moveToFront = false;
for (vector::const_iterator it(keysToMove.begin()), end(keysToMove.end()); it!=end; ++it) {
if (strcmp(e.fieldName(), *it) == 0) {
moveToFront = true;
break;
}
}
if (moveToFront) {
buf.appendBuf(e.fieldName()-1, e.size());
if (toCopy.first) {
copies.push_back(toCopy);
toCopy.first = NULL;
}
}
else {
if (!toCopy.first) {
toCopy.first = e.fieldName()-1;
toCopy.second = e.size();
}
else {
toCopy.second += e.size();
}
}
}
for (vector >::const_iterator it(copies.begin()), end(copies.end()); it!=end; ++it) {
buf.appendBuf(it->first, it->second);
}
if (toCopy.first) {
buf.appendBuf(toCopy.first, toCopy.second);
}
buf.appendChar('\0');
BSONObj out ((BSONObj::Holder*)buf.buf());
buf.decouple();
return out;
}
}
/* things to test for compound :
\ middle (deprecating?)
*/
class ShardKeyUnitTest : public StartupTest {
public:
void hasshardkeytest() {
BSONObj x = fromjson("{ zid : \"abcdefg\", num: 1.0, name: \"eliot\" }");
ShardKeyPattern k( BSON( "num" << 1 ) );
verify( k.hasShardKey(x) );
verify( !k.hasShardKey( fromjson("{foo:'a'}") ) );
verify( !k.hasShardKey( fromjson("{x: {$gt: 1}}") ) );
// try compound key
{
ShardKeyPattern k( fromjson("{a:1,b:-1,c:1}") );
verify( k.hasShardKey( fromjson("{foo:'a',a:'b',c:'z',b:9,k:99}") ) );
verify( !k.hasShardKey( fromjson("{foo:'a',a:'b',c:'z',bb:9,k:99}") ) );
verify( !k.hasShardKey( fromjson("{k:99}") ) );
}
// try dotted key
{
ShardKeyPattern k( fromjson("{'a.b':1}") );
verify( k.hasShardKey( fromjson("{a:{b:1,c:1},d:1}") ) );
verify( k.hasShardKey( fromjson("{'a.b':1}") ) );
verify( !k.hasShardKey( fromjson("{'a.c':1}") ) );
verify( !k.hasShardKey( fromjson("{a:{c:1},d:1}") ) );
verify( !k.hasShardKey( fromjson("{a:1}") ) );
verify( !k.hasShardKey( fromjson("{b:1}") ) );
}
}
void extractkeytest() {
ShardKeyPattern k( fromjson("{a:1,'sub.b':-1,'sub.c':1}") );
BSONObj x = fromjson("{a:1,'sub.b':2,'sub.c':3}");
verify( k.extractKey( fromjson("{a:1,sub:{b:2,c:3}}") ).binaryEqual(x) );
verify( k.extractKey( fromjson("{sub:{b:2,c:3},a:1}") ).binaryEqual(x) );
}
void isSpecialTest() {
ShardKeyPattern k1( BSON( "a" << 1) );
verify( ! k1.isSpecial() );
ShardKeyPattern k2( BSON( "a" << -1 << "b" << 1 ) );
verify( ! k2.isSpecial() );
ShardKeyPattern k3( BSON( "a" << "hashed") );
verify( k3.isSpecial() );
ShardKeyPattern k4( BSON( "a" << 1 << "b" << "hashed") );
verify( k4.isSpecial() );
}
void moveToFrontTest() {
ShardKeyPattern sk (BSON("a" << 1 << "b" << 1));
BSONObj ret;
ret = sk.moveToFront(BSON("z" << 1 << "_id" << 1 << "y" << 1 << "a" << 1 << "x" << 1 << "b" << 1 << "w" << 1));
verify(ret.binaryEqual(BSON("_id" << 1 << "a" << 1 << "b" << 1 << "z" << 1 << "y" << 1 << "x" << 1 << "w" << 1)));
ret = sk.moveToFront(BSON("_id" << 1 << "a" << 1 << "b" << 1 << "z" << 1 << "y" << 1 << "x" << 1 << "w" << 1));
verify(ret.binaryEqual(BSON("_id" << 1 << "a" << 1 << "b" << 1 << "z" << 1 << "y" << 1 << "x" << 1 << "w" << 1)));
ret = sk.moveToFront(BSON("z" << 1 << "y" << 1 << "a" << 1 << "b" << 1 << "Z" << 1 << "Y" << 1));
verify(ret.binaryEqual(BSON("a" << 1 << "b" << 1 << "z" << 1 << "y" << 1 << "Z" << 1 << "Y" << 1)));
}
void uniqueIndexCompatibleTest() {
ShardKeyPattern k1( BSON( "a" << 1 ) );
verify( k1.isUniqueIndexCompatible( BSON( "_id" << 1 ) ) );
verify( k1.isUniqueIndexCompatible( BSON( "a" << 1 << "b" << 1 ) ) );
verify( k1.isUniqueIndexCompatible( BSON( "a" << -1 ) ) );
verify( ! k1.isUniqueIndexCompatible( BSON( "b" << 1 ) ) );
ShardKeyPattern k2( BSON( "a" << "hashed") );
verify( k2.isUniqueIndexCompatible( BSON( "a" << 1 ) ) );
verify( ! k2.isUniqueIndexCompatible( BSON( "b" << 1 ) ) );
}
void moveToFrontBenchmark(int numFields) {
BSONObjBuilder bb;
bb.append("_id", 1);
for (int i=0; i < numFields; i++)
bb.append(BSONObjBuilder::numStr(i), 1);
bb.append("key", 1);
BSONObj o = bb.obj();
ShardKeyPattern sk (BSON("key" << 1));
Timer t;
const int iterations = 100*1000;
for (int i=0; i< iterations; i++) {
sk.moveToFront(o);
}
const double secs = t.micros() / 1000000.0;
const double ops_per_sec = iterations / secs;
cout << "moveToFront (" << numFields << " fields) secs: " << secs << " ops_per_sec: " << ops_per_sec << endl;
}
void run() {
extractkeytest();
ShardKeyPattern k( BSON( "key" << 1 ) );
BSONObj min = k.globalMin();
// cout << min.jsonString(TenGen) << endl;
BSONObj max = k.globalMax();
BSONObj k1 = BSON( "key" << 5 );
verify( min < max );
verify( min < k.extractKey( k1 ) );
verify( max > min );
hasshardkeytest();
verify( k.hasShardKey( k1 ) );
verify( ! k.hasShardKey( BSON( "key2" << 1 ) ) );
BSONObj a = k1;
BSONObj b = BSON( "key" << 999 );
verify( k.extractKey( a ) < k.extractKey( b ) );
isSpecialTest();
// add middle multitype tests
moveToFrontTest();
uniqueIndexCompatibleTest();
if (0) { // toggle to run benchmark
moveToFrontBenchmark(0);
moveToFrontBenchmark(10);
moveToFrontBenchmark(100);
}
LOG(1) << "shardKeyTest passed" << endl;
}
} shardKeyTest;
} // namespace mongo