Make ExpressionContext a simple struct

RedBeard0531 · RedBeard0531 · commit b7e05118930c · 2013-08-09T13:38:27.000-04:00
At some point it should probably be renamed since it has nothing to do
with Expressions.
diff --git a/src/mongo/SConscript b/src/mongo/SConscript
@@ -341,7 +341,6 @@ env.StaticLibrary("coredb", [
         "db/pipeline/document_source_sort.cpp",
         "db/pipeline/document_source_unwind.cpp",
         "db/pipeline/expression.cpp",
-        "db/pipeline/expression_context.cpp",
         "db/pipeline/field_path.cpp",
         "db/pipeline/value.cpp",
         "db/projection.cpp",
diff --git a/src/mongo/db/commands/pipeline_command.cpp b/src/mongo/db/commands/pipeline_command.cpp
@@ -212,7 +212,7 @@ namespace mongo {
             string ns = parseNs(db, cmdObj);
 
             intrusive_ptr<ExpressionContext> pCtx =
-                ExpressionContext::create(&InterruptStatusMongod::status, NamespaceString(ns));
+                new ExpressionContext(InterruptStatusMongod::status, NamespaceString(ns));
 
             /* try to parse the command; if this fails, then we didn't run */
             intrusive_ptr<Pipeline> pPipeline = Pipeline::parseCommand(errmsg, cmdObj, pCtx);
@@ -227,7 +227,7 @@ namespace mongo {
 #if _DEBUG
             // This is outside of the if block to keep the object alive until the pipeline is finished.
             BSONObj parsed;
-            if (!pPipeline->isExplain() && !pCtx->getInShard()) {
+            if (!pPipeline->isExplain() && !pCtx->inShard) {
                 // Make sure all operations round-trip through Pipeline::toBson()
                 // correctly by reparsing every command on DEBUG builds. This is
                 // important because sharded aggregations rely on this ability.
@@ -281,7 +281,7 @@ namespace mongo {
                                   intrusive_ptr<Pipeline>& pPipeline,
                                   intrusive_ptr<ExpressionContext>& pCtx) {
             /* setup as if we're in the router */
-            pCtx->setInRouter(true);
+            pCtx->inRouter = true;
 
             /*
             Here, we'll split the pipeline in the same way we would for sharding,
@@ -315,8 +315,8 @@ namespace mongo {
             }
 
             /* on the shard servers, create the local pipeline */
-            intrusive_ptr<ExpressionContext> pShardCtx(
-                ExpressionContext::create(&InterruptStatusMongod::status, NamespaceString(ns)));
+            intrusive_ptr<ExpressionContext> pShardCtx =
+                new ExpressionContext(InterruptStatusMongod::status, NamespaceString(ns));
             intrusive_ptr<Pipeline> pShardPipeline(
                 Pipeline::parseCommand(errmsg, shardBson, pShardCtx));
             if (!pShardPipeline.get()) {
diff --git a/src/mongo/db/interrupt_status.h b/src/mongo/db/interrupt_status.h
@@ -16,8 +16,6 @@
 
 #pragma once
 
-#include "mongo/pch.h"
-
 namespace mongo {
 
     /**
@@ -38,7 +36,7 @@ namespace mongo {
 
            @throws a uassert if the process has received an interrupt (SIGINT)
          */
-        virtual void checkForInterrupt() = 0;
+        virtual void checkForInterrupt() const =0;
 
         /**
            Check for interrupt.
@@ -47,7 +45,7 @@ namespace mongo {
              "" if there hasn't been an interrupt.  These strings are static
              and don't need to be freed.
          */
-        virtual const char *checkForInterruptNoAssert() = 0;
+        virtual const char *checkForInterruptNoAssert() const =0;
 
     protected:
         /**
diff --git a/src/mongo/db/interrupt_status_mongod.cpp b/src/mongo/db/interrupt_status_mongod.cpp
@@ -23,16 +23,16 @@
 
 namespace mongo {
 
-    InterruptStatusMongod InterruptStatusMongod::status;
+    const InterruptStatusMongod InterruptStatusMongod::status;
 
     InterruptStatusMongod::InterruptStatusMongod() {
     }
 
-    void InterruptStatusMongod::checkForInterrupt() {
+    void InterruptStatusMongod::checkForInterrupt() const {
         killCurrentOp.checkForInterrupt();
     }
 
-    const char *InterruptStatusMongod::checkForInterruptNoAssert() {
+    const char *InterruptStatusMongod::checkForInterruptNoAssert() const {
         return killCurrentOp.checkForInterruptNoAssert();
     }
 
diff --git a/src/mongo/db/interrupt_status_mongod.h b/src/mongo/db/interrupt_status_mongod.h
@@ -16,7 +16,6 @@
 
 #pragma once
 
-#include "mongo/pch.h"
 #include "mongo/db/interrupt_status.h"
 
 namespace mongo {
@@ -26,13 +25,13 @@ namespace mongo {
         boost::noncopyable {
     public:
         // virtuals from InterruptStatus
-        virtual void checkForInterrupt();
-        virtual const char *checkForInterruptNoAssert();
+        virtual void checkForInterrupt() const;
+        virtual const char *checkForInterruptNoAssert() const;
 
         /*
           Static singleton instance.
          */
-        static InterruptStatusMongod status;
+        static const InterruptStatusMongod status;
 
     private:
         InterruptStatusMongod();
diff --git a/src/mongo/db/pipeline/document_source_geo_near.cpp b/src/mongo/db/pipeline/document_source_geo_near.cpp
@@ -101,7 +101,7 @@ namespace mongo {
 
         BSONObjBuilder geoNear; // not building a subField
 
-        geoNear.append("geoNear", pExpCtx->getNs().coll()); // not in toBson
+        geoNear.append("geoNear", pExpCtx->ns.coll()); // not in toBson
 
         if (coordsIsArray) {
             geoNear.appendArray("near", coords);
@@ -131,7 +131,7 @@ namespace mongo {
         massert(16603, "Already ran geoNearCommand",
                 !resultsIterator);
 
-        bool ok = _mongod->directClient()->runCommand(pExpCtx->getNs().db().toString(),
+        bool ok = _mongod->directClient()->runCommand(pExpCtx->ns.db().toString(),
                                                       buildGeoNearCmd(),
                                                       cmdOutput);
         uassert(16604, "geoNear command failed: " + cmdOutput.toString(),
diff --git a/src/mongo/db/pipeline/document_source_group.cpp b/src/mongo/db/pipeline/document_source_group.cpp
@@ -80,15 +80,15 @@ namespace mongo {
                 _firstPartOfNextGroup = _sorterIterator->next();
             }
 
-            return makeDocument(_currentId, _currentAccumulators, pExpCtx->getInShard());
+            return makeDocument(_currentId, _currentAccumulators, pExpCtx->inShard);
 
         } else {
             if (groups.empty())
                 return boost::none;
 
             Document out = makeDocument(groupsIterator->first,
                                         groupsIterator->second,
-                                        pExpCtx->getInShard());
+                                        pExpCtx->inShard);
 
             if (++groupsIterator == groups.end())
                 dispose();
@@ -158,7 +158,7 @@ namespace mongo {
         , populated(false)
         , _doingMerge(false)
         , _spilled(false)
-        , _extSortAllowed(pExpCtx->getExtSortAllowed() && !pExpCtx->getInRouter())
+        , _extSortAllowed(pExpCtx->extSortAllowed && !pExpCtx->inRouter)
         , _maxMemoryUsageBytes(100*1024*1024)
     {}
 
@@ -391,7 +391,7 @@ namespace mongo {
             DEV {
                 // In debug mode, spill every time we have a duplicate id to stress merge logic.
                 if (!inserted // is a dup
-                        && !pExpCtx->getInRouter() // can't spill to disk in router
+                        && !pExpCtx->inRouter // can't spill to disk in router
                         && !_extSortAllowed // don't change behavior when testing external sort
                         && sortedFiles.size() < 20 // don't open too many FDs
                         ) {
diff --git a/src/mongo/db/pipeline/document_source_merge_cursors.cpp b/src/mongo/db/pipeline/document_source_merge_cursors.cpp
@@ -90,7 +90,7 @@ namespace mongo {
             // open each cursor and send message asking for a batch
             for (CursorIds::const_iterator it = _cursorIds.begin(); it !=_cursorIds.end(); ++it) {
                 _cursors.push_back(boost::make_shared<CursorAndConnection>(
-                            it->first, pExpCtx->getNs(), it->second));
+                            it->first, pExpCtx->ns, it->second));
                 verify(_cursors.back()->connection->lazySupported());
                 _cursors.back()->cursor.initLazy(); // shouldn't block
             }
diff --git a/src/mongo/db/pipeline/document_source_out.cpp b/src/mongo/db/pipeline/document_source_out.cpp
@@ -138,13 +138,13 @@ namespace mongo {
                                      << typeName(pBsonElement->type()),
                 pBsonElement->type() == String);
         
-        NamespaceString outputNs(pExpCtx->getNs().db().toString() + '.' + pBsonElement->str());
+        NamespaceString outputNs(pExpCtx->ns.db().toString() + '.' + pBsonElement->str());
         return new DocumentSourceOut(outputNs, pExpCtx);
     }
 
     void DocumentSourceOut::sourceToBson(BSONObjBuilder *pBuilder, bool explain) const {
         massert(17000, "$out shouldn't have different db than input",
-                _outputNs.db() == pExpCtx->getNs().db());
+                _outputNs.db() == pExpCtx->ns.db());
 
         pBuilder->append("$out", _outputNs.coll());
     }
diff --git a/src/mongo/db/pipeline/document_source_sort.cpp b/src/mongo/db/pipeline/document_source_sort.cpp
@@ -184,7 +184,7 @@ namespace mongo {
             opts.limit = limitSrc->getLimit();
 
         opts.maxMemoryUsageBytes = 100*1024*1024;
-        opts.extSortAllowed = pExpCtx->getExtSortAllowed() && !pExpCtx->getInRouter();
+        opts.extSortAllowed = pExpCtx->extSortAllowed && !pExpCtx->inRouter;
 
         scoped_ptr<MySorter> sorter (MySorter::make(opts, Comparator(*this)));
 
diff --git a/src/mongo/db/pipeline/expression_context.cpp b/src/mongo/db/pipeline/expression_context.cpp
diff --git a/src/mongo/db/pipeline/expression_context.h b/src/mongo/db/pipeline/expression_context.h
@@ -16,46 +16,33 @@
 
 #pragma once
 
-#include "mongo/pch.h"
-
-#include "mongo/util/intrusive_counter.h"
+#include "mongo/db/interrupt_status.h"
 #include "mongo/db/namespace_string.h"
+#include "mongo/util/intrusive_counter.h"
 
 namespace mongo {
 
-    class InterruptStatus;
-
-    class ExpressionContext : public IntrusiveCounterUnsigned {
+    struct ExpressionContext : public IntrusiveCounterUnsigned {
     public:
-        void setInShard(bool b) { inShard = b; }
-        void setInRouter(bool b) { inRouter = b; }
-        void setExtSortAllowed(bool b) { extSortAllowed = b; }
-        void setNs(NamespaceString ns) { _ns = ns; }
-
-        bool getInShard() const { return inShard; }
-        bool getInRouter() const { return inRouter; }
-        bool getExtSortAllowed() const { return extSortAllowed; }
-        const NamespaceString& getNs() const { return _ns; }
-
-        /**
-           Used by a pipeline to check for interrupts so that killOp() works.
-
-           @throws if the operation has been interrupted
+        ExpressionContext(const InterruptStatus& status, const NamespaceString& ns)
+            : inShard(false)
+            , inRouter(false)
+            , extSortAllowed(false)
+            , interruptStatus(status)
+            , ns(ns)
+        {}
+        /** Used by a pipeline to check for interrupts so that killOp() works.
+         *  @throws if the operation has been interrupted
          */
-        void checkForInterrupt();
-
-        ExpressionContext* clone();
-
-        static ExpressionContext *create(InterruptStatus *pStatus, const NamespaceString& ns);
-
-    private:
-        ExpressionContext(InterruptStatus *pStatus, const NamespaceString& ns);
+        void checkForInterrupt() {
+            // The check could be expensive, at least in relative terms.
+            RARELY interruptStatus.checkForInterrupt();
+        }
         
         bool inShard;
         bool inRouter;
         bool extSortAllowed;
-        unsigned intCheckCounter; // interrupt check counter
-        InterruptStatus *const pStatus;
-        NamespaceString _ns;
+        const InterruptStatus& interruptStatus;
+        NamespaceString ns;
     };
 }
diff --git a/src/mongo/db/pipeline/pipeline.cpp b/src/mongo/db/pipeline/pipeline.cpp
@@ -125,7 +125,7 @@ namespace mongo {
 
             /* if the request came from the router, we're in a shard */
             if (!strcmp(pFieldName, fromRouterName)) {
-                pCtx->setInShard(cmdElement.Bool());
+                pCtx->inShard = cmdElement.Bool();
                 continue;
             }
 
@@ -140,7 +140,7 @@ namespace mongo {
                         str::stream() << "allowDiskUsage must be a bool, not a "
                                       << typeName(cmdElement.type()),
                         cmdElement.type() == Bool);
-                pCtx->setExtSortAllowed(cmdElement.Bool());
+                pCtx->extSortAllowed = cmdElement.Bool();
                 continue;
             }
 
@@ -418,7 +418,7 @@ namespace mongo {
             pBuilder->append(explainName, explain);
         }
 
-        if (pCtx->getExtSortAllowed()) {
+        if (pCtx->extSortAllowed) {
             pBuilder->append("allowDiskUsage", true);
         }
 
@@ -452,7 +452,7 @@ namespace mongo {
           the result documents for explain.
         */
         if (explain) {
-            if (!pCtx->getInRouter())
+            if (!pCtx->inRouter)
                 writeExplainShard(result);
             else {
                 writeExplainMongos(result);
@@ -536,7 +536,7 @@ namespace mongo {
     }
 
     bool Pipeline::canRunInMongos() const {
-        if (pCtx->getExtSortAllowed())
+        if (pCtx->extSortAllowed)
             return false;
 
         if (dynamic_cast<DocumentSourceNeedsMongod*>(sources.back().get()))
diff --git a/src/mongo/dbtests/documentsourcetests.cpp b/src/mongo/dbtests/documentsourcetests.cpp
diff --git a/src/mongo/s/commands_public.cpp b/src/mongo/s/commands_public.cpp
diff --git a/src/mongo/s/interrupt_status_mongos.cpp b/src/mongo/s/interrupt_status_mongos.cpp
diff --git a/src/mongo/s/interrupt_status_mongos.h b/src/mongo/s/interrupt_status_mongos.h

Original file line number	Diff line number	Diff line change
`@@ -23,16 +23,16 @@`
`23`	`23`
`24`	`24`	`namespace mongo {`
`25`	`25`
`26`		`- InterruptStatusMongod InterruptStatusMongod::status;`
	`26`	`+ const InterruptStatusMongod InterruptStatusMongod::status;`
`27`	`27`
`28`	`28`	`InterruptStatusMongod::InterruptStatusMongod() {`
`29`	`29`	`}`
`30`	`30`
`31`		`- void InterruptStatusMongod::checkForInterrupt() {`
	`31`	`+ void InterruptStatusMongod::checkForInterrupt() const {`
`32`	`32`	`killCurrentOp.checkForInterrupt();`
`33`	`33`	`}`
`34`	`34`
`35`		`- const char *InterruptStatusMongod::checkForInterruptNoAssert() {`
	`35`	`+ const char *InterruptStatusMongod::checkForInterruptNoAssert() const {`
`36`	`36`	`return killCurrentOp.checkForInterruptNoAssert();`
`37`	`37`	`}`
`38`	`38`
Original file line number	Diff line number	Diff line change
`@@ -90,7 +90,7 @@ namespace mongo {`
`90`	`90`	`// open each cursor and send message asking for a batch`
`91`	`91`	`for (CursorIds::const_iterator it = _cursorIds.begin(); it !=_cursorIds.end(); ++it) {`
`92`	`92`	`_cursors.push_back(boost::make_shared<CursorAndConnection>(`
`93`		`- it->first, pExpCtx->getNs(), it->second));`
	`93`	`+ it->first, pExpCtx->ns, it->second));`
`94`	`94`	`verify(_cursors.back()->connection->lazySupported());`
`95`	`95`	`_cursors.back()->cursor.initLazy(); // shouldn't block`
`96`	`96`	`}`
Original file line number	Diff line number	Diff line change
`@@ -138,13 +138,13 @@ namespace mongo {`
`138`	`138`	`<< typeName(pBsonElement->type()),`
`139`	`139`	`pBsonElement->type() == String);`
`140`	`140`
`141`		`- NamespaceString outputNs(pExpCtx->getNs().db().toString() + '.' + pBsonElement->str());`
	`141`	`+ NamespaceString outputNs(pExpCtx->ns.db().toString() + '.' + pBsonElement->str());`
`142`	`142`	`return new DocumentSourceOut(outputNs, pExpCtx);`
`143`	`143`	`}`
`144`	`144`
`145`	`145`	`void DocumentSourceOut::sourceToBson(BSONObjBuilder *pBuilder, bool explain) const {`
`146`	`146`	`massert(17000, "$out shouldn't have different db than input",`
`147`		`- _outputNs.db() == pExpCtx->getNs().db());`
	`147`	`+ _outputNs.db() == pExpCtx->ns.db());`
`148`	`148`
`149`	`149`	`pBuilder->append("$out", _outputNs.coll());`
`150`	`150`	`}`