first cut at "fast count"r0.0.6_rc1

9 files changed, 125 insertions, 13 deletions

diff --git a/db/btree.cpp b/db/btree.cpp
index c4a36e2e0ea..d7f0c1e7c02 100644
--- a/db/btree.cpp
+++ b/db/btree.cpp
@@ -847,13 +847,6 @@ void BtreeCursor::checkUnused() {
 		cout << "btree unused skipped:" << u << endl;
 }
 
-/*DiskLoc BtreeCursor::currLoc() {
-	assert( !bucket.isNull() );
-	_KeyNode& kn = bucket.btree()->k(keyOfs);
-	assert( kn.isUsed() );
-	return kn.recordLoc;
-}*/
-
 bool BtreeCursor::advance() { 
 	if( bucket.isNull() )
 		return false;
diff --git a/db/db.vcproj b/db/db.vcproj
index 446dda2e6a9..60d4da0b402 100644
--- a/db/db.vcproj
+++ b/db/db.vcproj
@@ -199,6 +199,10 @@
 				>

 			</File>

 			<File

+				RelativePath=".\json.cpp"

+				>

+			</File>

+			<File

 				RelativePath="..\grid\message.cpp"

 				>

 			</File>

@@ -281,6 +285,10 @@
 				>

 			</File>

 			<File

+				RelativePath=".\json.h"

+				>

+			</File>

+			<File

 				RelativePath="..\util\lruishmap.h"

 				>

 			</File>

diff --git a/db/jsobj.h b/db/jsobj.h
index cc7e570307a..50cc3a55fd6 100644
--- a/db/jsobj.h
+++ b/db/jsobj.h
@@ -330,6 +330,13 @@ public:
 		b.append(fieldName);
 		b.append(n);
 	}
+	void appendOID(const char *fieldName) { 
+		b.append((char) jstOID);
+		b.append(fieldName);
+		b.append((long long) 0);
+		b.append((unsigned) 0);
+	}
+
 	void appendDate(const char *fieldName, unsigned long long dt) { 
 		b.append((char) Date);
 		b.append(fieldName);
@@ -342,6 +349,7 @@ public:
 		b.append(str);
 	}
 
+	/* JSObj will free the buffer when it is finished. */
 	JSObj doneAndDecouple() { 
 		int l;
 		return JSObj(decouple(l), true);
diff --git a/db/json.cpp b/db/json.cpp
new file mode 100644
index 00000000000..6c875ab95d4
--- /dev/null
+++ b/db/json.cpp
@@ -0,0 +1,46 @@
+// json.cpp
+
+#include "stdafx.h"
+#include "json.h"
+#include "../util/builder.h"
+
+/* partial implementation for now */
+
+void skipWhite(const char *&p) { 
+	while( *p == ' ' || *p == '\r' || *p == '\n' || *p == '\t' )
+		p++;
+}
+
+void value(JSObjBuilder& b, const char *&p, string& id) { 
+	if( strncmp(p, "ObjId()", 7) == 0 ) {
+		p += 7;
+		b.appendOID(id.c_str());
+	}
+}
+
+void _fromjson(JSObjBuilder& b, const char *&p) { 
+	while( 1 ) { 
+		skipWhite(p);
+		if( *p == 0 )
+			break;
+		if( *p == '{' ) { _fromjson(b,++p); continue; }
+		if( *p == '}' ) { ++p; break; }
+		if( *p == '_' || isalpha(*p) ) { 
+			string id;
+			while( *p == '_' || isalpha(*p) || isdigit(*p)  ) { 
+				id += *p++;
+			}
+			skipWhite(p);
+			assert( *p == ':' ); p++;
+			skipWhite(p);
+			value(b, p, id);
+			continue;
+		}
+	}
+}
+
+JSObj fromjson(const char *str) { 
+	JSObjBuilder b;
+	_fromjson(b,str);
+	return b.doneAndDecouple();
+}
diff --git a/db/json.h b/db/json.h
new file mode 100644
index 00000000000..febee18940e
--- /dev/null
+++ b/db/json.h
@@ -0,0 +1,8 @@
+// json.h
+
+#pragma once
+
+#include "../stdafx.h"
+#include "jsobj.h"
+
+JSObj fromjson(const char *str);
diff --git a/db/makefile b/db/makefile
index 76d8cbfdb2f..f8ea9ab2f4b 100644
--- a/db/makefile
+++ b/db/makefile
@@ -8,7 +8,7 @@ LIBS= $(LIB_DEPS)  $(LIB_BOOST) -lstdc++
 
 JVM_LIBS = -L/opt/java/lib/
 
-OBJS=../stdafx.o ../util/sock.o ../grid/message.o ../util/mmap.o pdfile.o query.o jsobj.o introspect.o btree.o clientcursor.o ../util/util.o javajs.o tests.o
+OBJS=../stdafx.o ../util/sock.o ../grid/message.o ../util/mmap.o pdfile.o query.o jsobj.o introspect.o btree.o clientcursor.o ../util/util.o javajs.o tests.o json.o
 
 # ../grid/protorecv.o ../grid/protosend.o
 
diff --git a/db/namespace.h b/db/namespace.h
index e8e056ed958..0854a666ed6 100644
--- a/db/namespace.h
+++ b/db/namespace.h
@@ -73,11 +73,12 @@ public:
 
 extern int bucketSizes[];
 
+/* this is the "header" for a collection that has all its details.  in the .ns file.
+*/
 class NamespaceDetails {
 public:
 	NamespaceDetails() { 
-		/* be sure to initialize new fields here, otherwise they will contain garbage by default.
-		*/
+		/* be sure to initialize new fields here -- doesn't default to zeroes the way we use it */
 		datasize = nrecords = 0;
 		lastExtentSize = 0;
 		nIndexes = 0;
diff --git a/db/pdfile.cpp b/db/pdfile.cpp
index 1ec6a11142d..28cd97f786c 100644
--- a/db/pdfile.cpp
+++ b/db/pdfile.cpp
@@ -576,7 +576,9 @@ auto_ptr<Cursor> DataFileMgr::findAll(const char *ns) {
 	return auto_ptr<Cursor>(new BasicCursor( e->firstRecord ));
 }
 
-/* get a table scan cursor, but can be forward or reverse direction */
+/* get a table scan cursor, but can be forward or reverse direction.
+   order.$natural - if set, > 0 means forward (asc), < 0 backward (desc).
+*/
 auto_ptr<Cursor> findTableScan(const char *ns, JSObj& order) {
 	Element el = order.findElement("$natural");
 	if( el.type() != Number || el.number() >= 0 )
@@ -919,7 +921,7 @@ DiskLoc DataFileMgr::insert(const char *ns, const void *buf, int len, bool god)
 		}
 		tableToIndex = nsdetails(tabletoidxns);
 		if( tableToIndex == 0 ) {
-			cout << "user warning: bad add index attempt, no such table(ns):" << tabletoidxns << endl;
+			cout << "user warning: ignoring add index, no such collection:" << tabletoidxns << endl;
 			return DiskLoc();
 		}
 		if( tableToIndex->nIndexes >= MaxIndexes ) { 
diff --git a/db/query.cpp b/db/query.cpp
index 3f76624dfb3..144c8d27f1a 100644
--- a/db/query.cpp
+++ b/db/query.cpp
@@ -10,6 +10,7 @@
 #include "btree.h"
 #include "../util/lruishmap.h"
 #include "javajs.h"
+#include "json.h"
 
 //ns->query->DiskLoc
 LRUishMap<JSObj,DiskLoc,5> lrutest(123);
@@ -29,6 +30,7 @@ JSObj emptyObj((char *) &emptyObject);
 
 int getGtLtOp(Element& e);
 void appendElementHandlingGtLt(JSObjBuilder& b, Element& e);
+int runCount(const char *ns, const JSObj& cmd, string& err);
 
 /* todo: _ cache query plans 
          _ use index on partial match with the query
@@ -552,9 +554,25 @@ inline bool _runCommands(const char *ns, JSObj& jsobj, stringstream& ss, BufBuil
 		}
 	}
 	else if( e.type() == String ) {
+		/* { count: "collectionname"[, query: <query>] } */
 		string us(ns, p-ns);
 
-		if( strcmp( e.fieldName(), "create") == 0 ) { 
+		if( strcmp( e.fieldName(), "count" ) == 0 ) { 
+			valid = true;
+			string ns = us + '.' + e.valuestr();
+			string err;
+			int n = runCount(ns.c_str(), jsobj, err);
+			int nn = n;
+			ok = true;
+			if( n < 0 ) { 
+				ok = false;
+				nn = 0;
+				if( !err.empty() )
+					anObjBuilder.append("errmsg", err.c_str());
+			}
+			anObjBuilder.append("n", (double) nn);
+		}
+		else if( strcmp( e.fieldName(), "create") == 0 ) { 
 			valid = true;
 			string ns = us + '.' + e.valuestr();
 			string err;
@@ -684,8 +702,36 @@ void killCursors(int n, long long *ids) {
 	cout << "killCursors: found " << k << " of " << n << endl;
 }
 
+// order.$natural sets natural order direction
 auto_ptr<Cursor> findTableScan(const char *ns, JSObj& order);
 
+JSObj id_obj = fromjson("{_id:ObjId()}");
+JSObj empty_obj = fromjson("{}");
+
+/* { count: "collectionname"[, query: <query>] } 
+   returns -1 on error.
+*/
+int runCount(const char *ns, const JSObj& cmd, string& err) { 
+	NamespaceDetails *d = nsdetails(ns);
+	if( d == 0 ) {
+		err = "ns does not exist";
+		return -1;
+	}
+
+	auto_ptr<Cursor> c = getIndexCursor(ns, id_obj, empty_obj);
+	if( c.get() == 0 ) {
+		cout << "TEMP: table scan" << endl;
+		c = findTableScan(ns, empty_obj);
+	}
+	else cout << "TEMP: indexed scan" << endl;
+	int count = 0;
+	if( c->ok() ) {
+		count++;
+		while( c->advance() ) count++;
+	}
+	return count;
+}
+
 QueryResult* runQuery(Message& message, const char *ns, int ntoskip, int _ntoreturn, JSObj jsobj, 
 					  auto_ptr< set<string> > filter, stringstream& ss) 
 {