From 4778a2c4add21e0696877c884ba4fd88c52cedf6 Mon Sep 17 00:00:00 2001
From: Dwight <dmerriman@gmail.com>
Date: Wed, 31 Mar 2010 15:08:40 -0400
Subject: [PATCH] mmf abstraction 2

---
 db/database.h              |  4 ++--
 db/db.cpp                  |  4 ++--
 db/pdfile.cpp              |  5 +++--
 db/pdfile.h                | 16 ++++++++--------
 dbtests/namespacetests.cpp |  2 +-
 5 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/db/database.h b/db/database.h
index 868af0bab26..f6160e9a90e 100644
--- a/db/database.h
+++ b/db/database.h
@@ -137,8 +137,8 @@ namespace mongo {
                 int minSize = 0;
                 if ( n != 0 && files[ n - 1 ] )
                     minSize = files[ n - 1 ]->getHeader()->fileLength;
-                if ( sizeNeeded + MDFHeader::headerSize() > minSize )
-                    minSize = sizeNeeded + MDFHeader::headerSize();
+                if ( sizeNeeded + DataFileHeader::headerSize() > minSize )
+                    minSize = sizeNeeded + DataFileHeader::headerSize();
                 try {
                     p->open( fullNameString.c_str(), minSize, preallocateOnly );
                 }
diff --git a/db/db.cpp b/db/db.cpp
index 218dd608d5f..981fdf7433b 100644
--- a/db/db.cpp
+++ b/db/db.cpp
@@ -316,7 +316,7 @@ namespace mongo {
     bool shouldRepairDatabases = 0;
     bool forceRepair = 0;
     
-    bool doDBUpgrade( const string& dbName , string errmsg , MDFHeader * h ){
+    bool doDBUpgrade( const string& dbName , string errmsg , DataFileHeader * h ){
         static DBDirectClient db;
         
         if ( h->version == 4 && h->versionMinor == 4 ){
@@ -361,7 +361,7 @@ namespace mongo {
             log(1) << "\t" << dbName << endl;
             Client::Context ctx( dbName );
             MongoDataFile *p = cc().database()->getFile( 0 );
-            MDFHeader *h = p->getHeader();
+            DataFileHeader *h = p->getHeader();
             if ( !h->currentVersion() || forceRepair ) {
                 log() << "****" << endl;
                 log() << "****" << endl;
diff --git a/db/pdfile.cpp b/db/pdfile.cpp
index 51f179fc902..897b748e191 100644
--- a/db/pdfile.cpp
+++ b/db/pdfile.cpp
@@ -199,7 +199,7 @@ namespace mongo {
             }
         } else {
             while ( size > 0 ) {
-                int max = MongoDataFile::maxSize() - MDFHeader::headerSize();
+                int max = MongoDataFile::maxSize() - DataFileHeader::headerSize();
                 int desiredExtentSize = (int) (size > max ? max : size);
                 Extent *e = database->allocExtent( ns, desiredExtentSize, newCapped );
                 size -= e->length;
@@ -325,7 +325,8 @@ namespace mongo {
             return;
         }
         
-        header = (MDFHeader *) mmf.map(filename, size);
+        _p = mmf.map(filename, size);
+        header = (DataFileHeader *) _p.at(0);
         if( sizeof(char *) == 4 ) 
             uassert( 10084 , "can't map file memory - mongo requires 64 bit build for larger datasets", header);
         else
diff --git a/db/pdfile.h b/db/pdfile.h
index 85dc191f167..c5d91452aa2 100644
--- a/db/pdfile.h
+++ b/db/pdfile.h
@@ -34,7 +34,7 @@
 
 namespace mongo {
 
-    class MDFHeader;
+    class DataFileHeader;
     class Extent;
     class Record;
     class Cursor;
@@ -56,7 +56,6 @@ namespace mongo {
 
     /*---------------------------------------------------------------------*/
 
-    class MDFHeader;
     class MongoDataFile {
         friend class DataFileMgr;
         friend class BasicCursor;
@@ -70,7 +69,7 @@ namespace mongo {
         */
         Extent* createExtent(const char *ns, int approxSize, bool capped = false, int loops = 0);
 
-        MDFHeader *getHeader() {
+        DataFileHeader *getHeader() {
             return header;
         }
 
@@ -84,8 +83,10 @@ namespace mongo {
         Extent* _getExtent(DiskLoc loc);
         Record* recordAt(DiskLoc dl);
 
-        MemoryMappedFile mmf;
-        MDFHeader *header;
+        typedef MemoryMappedFile MMF;
+        MMF mmf;
+        MMF::Pointer _p;
+        DataFileHeader *header;
         int fileNo;
     };
 
@@ -254,8 +255,7 @@ namespace mongo {
           ----------------------
     */
 
-    /* data file header */
-    class MDFHeader {
+    class DataFileHeader {
     public:
         int version;
         int versionMinor;
@@ -267,7 +267,7 @@ namespace mongo {
         char data[4];
 
         static int headerSize() {
-            return sizeof(MDFHeader) - 4;
+            return sizeof(DataFileHeader) - 4;
         }
 
         bool currentVersion() const {
diff --git a/dbtests/namespacetests.cpp b/dbtests/namespacetests.cpp
index 205c5d24223..0a0e52b6e0c 100644
--- a/dbtests/namespacetests.cpp
+++ b/dbtests/namespacetests.cpp
@@ -741,7 +741,7 @@ namespace NamespaceTests {
         //        private:
         //            virtual string spec() const {
         //                // NOTE 256 added to size in _userCreateNS()
-        //                long long big = MongoDataFile::maxSize() - MDFHeader::headerSize();
+        //                long long big = MongoDataFile::maxSize() - DataFileHeader::headerSize();
         //                stringstream ss;
         //                ss << "{\"capped\":true,\"size\":" << big << "}";
         //                return ss.str();