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// 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 <http://www.gnu.org/licenses/>.
*/
#include "pch.h"
#include "chunk.h"
#include "../db/jsobj.h"
#include "../util/unittest.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();
}
int ShardKeyPattern::compare( const BSONObj& lObject , const BSONObj& rObject ) const {
BSONObj L = extractKey(lObject);
uassert( 10198 , "left object doesn't have full shard key", L.nFields() == (int)patternfields.size());
BSONObj R = extractKey(rObject);
uassert( 10199 , "right object doesn't have full shard key", R.nFields() == (int)patternfields.size());
return L.woCompare(R);
}
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<string>::const_iterator it = patternfields.begin(); it != patternfields.end(); ++it) {
if(obj.getFieldDotted(it->c_str()).eoo())
return false;
}
return true;
}
bool ShardKeyPattern::isPrefixOf( const BSONObj& otherPattern ) const {
BSONObjIterator a( pattern );
BSONObjIterator b( otherPattern );
while ( a.more() && b.more() ) {
BSONElement x = a.next();
BSONElement y = b.next();
if ( strcmp( x.fieldName() , y.fieldName() ) )
return false;
}
return ! a.more();
}
string ShardKeyPattern::toString() const {
return pattern.toString();
}
BSONObj ShardKeyPattern::moveToFront(const BSONObj& obj) const {
vector<const char*> keysToMove;
keysToMove.push_back("_id");
BSONForEach(e, pattern) {
if (strchr(e.fieldName(), '.') == NULL)
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<pair<const char*, size_t> > copies;
pair<const char*, size_t> toCopy ((const char*)NULL, 0); // C++ NULL isn't a pointer type yet
BSONForEach(e, obj) {
bool moveToFront = false;
for (vector<const char*>::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<pair<const char*, size_t> >::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 UnitTest {
public:
void testIsPrefixOf() {
{
ShardKeyPattern k( BSON( "x" << 1 ) );
assert( ! k.isPrefixOf( BSON( "a" << 1 ) ) );
assert( k.isPrefixOf( BSON( "x" << 1 ) ) );
assert( k.isPrefixOf( BSON( "x" << 1 << "a" << 1 ) ) );
assert( ! k.isPrefixOf( BSON( "a" << 1 << "x" << 1 ) ) );
}
{
ShardKeyPattern k( BSON( "x" << 1 << "y" << 1 ) );
assert( ! k.isPrefixOf( BSON( "x" << 1 ) ) );
assert( ! k.isPrefixOf( BSON( "x" << 1 << "z" << 1 ) ) );
assert( k.isPrefixOf( BSON( "x" << 1 << "y" << 1 ) ) );
assert( k.isPrefixOf( BSON( "x" << 1 << "y" << 1 << "z" << 1 ) ) );
}
}
void hasshardkeytest() {
BSONObj x = fromjson("{ zid : \"abcdefg\", num: 1.0, name: \"eliot\" }");
ShardKeyPattern k( BSON( "num" << 1 ) );
assert( k.hasShardKey(x) );
assert( !k.hasShardKey( fromjson("{foo:'a'}") ) );
// try compound key
{
ShardKeyPattern k( fromjson("{a:1,b:-1,c:1}") );
assert( k.hasShardKey( fromjson("{foo:'a',a:'b',c:'z',b:9,k:99}") ) );
assert( !k.hasShardKey( fromjson("{foo:'a',a:'b',c:'z',bb:9,k:99}") ) );
assert( !k.hasShardKey( fromjson("{k:99}") ) );
}
}
void extractkeytest() {
ShardKeyPattern k( fromjson("{a:1,'sub.b':-1,'sub.c':1}") );
BSONObj x = fromjson("{a:1,'sub.b':2,'sub.c':3}");
assert( k.extractKey( fromjson("{a:1,sub:{b:2,c:3}}") ).woEqual(x) );
assert( k.extractKey( fromjson("{sub:{b:2,c:3},a:1}") ).woEqual(x) );
}
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));
assert(ret.woEqual(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));
assert(ret.woEqual(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));
assert(ret.woEqual(BSON("a" << 1 << "b" << 1 << "z" << 1 << "y" << 1 << "Z" << 1 << "Y" << 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 );
assert( k.compare( min , max ) < 0 );
assert( k.compare( min , k1 ) < 0 );
assert( k.compare( max , min ) > 0 );
assert( k.compare( min , min ) == 0 );
hasshardkeytest();
assert( k.hasShardKey( k1 ) );
assert( ! k.hasShardKey( BSON( "key2" << 1 ) ) );
BSONObj a = k1;
BSONObj b = BSON( "key" << 999 );
assert( k.compare(a,b) < 0 );
testIsPrefixOf();
// add middle multitype tests
moveToFrontTest();
if (0) { // toggle to run benchmark
moveToFrontBenchmark(0);
moveToFrontBenchmark(10);
moveToFrontBenchmark(100);
}
log(1) << "shardKeyTest passed" << endl;
}
} shardKeyTest;
} // namespace mongo
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