dur optimizations to not journal too much

1 files changed, 35 insertions, 2 deletions

diff --git a/db/dur.h b/db/dur.h
index 4b897621cb2..04786818678 100644
--- a/db/dur.h
+++ b/db/dur.h
@@ -11,12 +11,16 @@ namespace mongo {
 

 #if !defined(_DURABLE)

         inline void startup() { }

-        inline void* writingPtr(void *x, size_t len) { return x; }

+        inline void* writingPtr(void *x, unsigned len) { return x; }

         inline DiskLoc& writingDiskLoc(DiskLoc& d) { return d; }

         inline int& writingInt(int& d) { return d; }

         template <typename T> inline T* writing(T *x) { return x; }

         inline void assertReading(void *p) { }

         template <typename T> inline T* writingNoLog(T *x) { return x; }

+        void* writingAtOffset(void *buf, unsigned ofs, unsigned len) { return buf; }

+        template <typename T>

+        inline T* alreadyDeclared(T *x) { return x; }

+        inline void declareWriteIntent(void *, unsigned) { }

 #else

 

         /** call during startup so durability module can initialize 

@@ -33,7 +37,22 @@ namespace mongo {
             verify that your length is correct though.

         */

 

-        void* writingPtr(void *x, size_t len);

+        /** declare intent to write to x for up to len 

+            @return pointer where to write.  this is modified when testIntent is true.

+        */

+        void* writingPtr(void *x, unsigned len);

+

+        /** declare write intent; should already be in the write view to work correctly when testIntent is true. 

+            if you aren't, use writingPtr() instead.

+        */

+        void declareWriteIntent(void *x, unsigned len); 

+

+        /** declare intent to write

+            @param ofs offset within buf at which we will write

+            @param len the length at ofs we will write

+            @return new buffer pointer.  this is modified when testIntent is true.

+        */

+        void* writingAtOffset(void *buf, unsigned ofs, unsigned len);

 

         inline DiskLoc& writingDiskLoc(DiskLoc& d) {

             return *((DiskLoc*) writingPtr(&d, sizeof(d)));

@@ -43,6 +62,19 @@ namespace mongo {
             return *((int*) writingPtr(&d, sizeof(d)));

         }

 

+        /** "assume i've already indicated write intent, let me write"

+        */

+        template <typename T>

+        inline

+        T* alreadyDeclared(T *x) { 

+#if defined(_TESTINTENT)

+            return (T*) MongoMMF::switchToPrivateView(x);

+#else

+            return x; 

+#endif

+        }

+

+        /** declare intent to write to x for sizeof(*x) */

         template <typename T> 

         inline 

         T* writing(T *x) { 

@@ -67,6 +99,7 @@ namespace mongo {
 

     } // namespace dur

 

+    /** declare that we are modifying a diskloc and this is a datafile write. */

     inline DiskLoc& DiskLoc::writing() const { return dur::writingDiskLoc(*const_cast< DiskLoc * >( this )); }

 

 }