Implement class name caching and optimized equality check.

library/DFProcess-linux-SHM.cpp

@@ -383,7 +383,7 @@ void SHMProcess::readSTLVector(const uint32_t address, t_vecTriplet & triplet)
 }
 
 
-string SHMProcess::readClassName (uint32_t vptr)
+string SHMProcess::doReadClassName (uint32_t vptr)
 {
     if(!d->locked) throw Error::MemoryAccessDenied(vptr);
 

library/DFProcess-linux-wine.cpp

@@ -73,7 +73,7 @@ namespace {
             size_t readSTLString (uint32_t offset, char * buffer, size_t bufcapacity);
             size_t writeSTLString(const uint32_t address, const std::string writeString);
             // get class name of an object with rtti/type info
-            std::string readClassName(uint32_t vptr);
+            std::string doReadClassName(uint32_t vptr);
     };
 }
 
@@ -168,7 +168,7 @@ const string WineProcess::readSTLString (uint32_t offset)
     return stl.readSTLString(offset);
 }
 
-string WineProcess::readClassName (uint32_t vptr)
+string WineProcess::doReadClassName (uint32_t vptr)
 {
     return stl.readClassName(vptr);
 }

library/DFProcess-linux.cpp

@@ -73,7 +73,7 @@ namespace {
             size_t writeSTLString(const uint32_t address, const std::string writeString);
             size_t copySTLString(const uint32_t address, const uint32_t target);
             // get class name of an object with rtti/type info
-            std::string readClassName(uint32_t vptr);
+            std::string doReadClassName(uint32_t vptr);
     };
 }
 
@@ -217,7 +217,7 @@ size_t NormalProcess::copySTLString (uint32_t offset, uint32_t target)
     return header._M_length;
 }
 
-string NormalProcess::readClassName (uint32_t vptr)
+string NormalProcess::doReadClassName (uint32_t vptr)
 {
     int typeinfo = Process::readDWord(vptr - 0x4);
     int typestring = Process::readDWord(typeinfo + 0x4);

library/DFProcess-windows-SHM.cpp

@@ -394,7 +394,7 @@ void SHMProcess::readSTLVector(const uint32_t address, t_vecTriplet & triplet)
     read(address + d->vector_start, sizeof(triplet), (uint8_t *) &triplet);
 }
 
-string SHMProcess::readClassName (uint32_t vptr)
+string SHMProcess::doReadClassName (uint32_t vptr)
 {
     int rtti = Process::readDWord(vptr - 0x4);
     int typeinfo = Process::readDWord(rtti + 0xC);

library/DFProcess-windows.cpp

@@ -89,7 +89,7 @@ namespace
             size_t readSTLString (uint32_t offset, char * buffer, size_t bufcapacity);
             size_t writeSTLString(const uint32_t address, const std::string writeString);
             // get class name of an object with rtti/type info
-            std::string readClassName(uint32_t vptr);
+            std::string doReadClassName(uint32_t vptr);
 
             const std::string readCString (uint32_t offset);
 
@@ -590,7 +590,7 @@ size_t NormalProcess::writeSTLString (uint32_t address, string str)
     return stl.writeSTLString(address, str);
 }
 
-string NormalProcess::readClassName (uint32_t vptr)
+string NormalProcess::doReadClassName (uint32_t vptr)
 {
     return stl.readClassName(vptr);
 }

library/include/dfhack/DFProcess.h

@@ -30,6 +30,7 @@ distribution.
 #include "DFPragma.h"
 #include "DFExport.h"
 #include <iostream>
+#include <map>
 
 namespace DFHack
 {
@@ -93,12 +94,16 @@ namespace DFHack
         uint32_t end;
         uint32_t alloc_end;
     };
+
     /**
      * Allows low-level access to the memory of an OS process. OS processes can be enumerated by \ref ProcessEnumerator
      * \ingroup grp_context
      */
     class DFHACK_EXPORT Process
     {
+        protected:
+            std::map<uint32_t, std::string> classNameCache;
+
         public:
             /// this is the single most important destructor ever. ~px
             virtual ~Process(){};
@@ -178,7 +183,14 @@ namespace DFHack
             /// read a STL vector
             virtual void readSTLVector(const uint32_t address, t_vecTriplet & triplet) = 0;
             /// get class name of an object with rtti/type info
-            virtual std::string readClassName(uint32_t vptr) = 0;
+            virtual std::string doReadClassName(uint32_t vptr) = 0;
+
+            std::string readClassName(uint32_t vptr) {
+                std::map<uint32_t, std::string>::iterator it = classNameCache.find(vptr);
+                if (it != classNameCache.end())
+                    return it->second;
+                return classNameCache[vptr] = doReadClassName(vptr);
+            }
 
             /// read a null-terminated C string
             virtual const std::string readCString (uint32_t offset) = 0;
@@ -211,5 +223,20 @@ namespace DFHack
             virtual bool SetAndWait (uint32_t state) = 0;
     };
 
+    class DFHACK_EXPORT ClassNameCheck {
+        std::string name;
+        uint32_t vptr;
+    public:
+        ClassNameCheck() : vptr(0) {}
+        ClassNameCheck(std::string _name) : name(_name), vptr(0) {}
+        ClassNameCheck &operator= (const ClassNameCheck &b) {
+            name = b.name; vptr = b.vptr; return *this;
+        }
+        bool operator() (Process *p, uint32_t ptr) {
+            if (vptr == 0 && p->readClassName(ptr) == name)
+                vptr = ptr;
+            return (vptr && vptr == ptr);
+        }
+    };
 }
 #endif

library/modules/Items.cpp

@@ -419,7 +419,7 @@ class Items::Private
         std::map<uint32_t, ItemDesc *> descVTable;
         uint32_t refVectorOffset;
         uint32_t refIDOffset;
-        uint32_t ownerRefVTable;
+        ClassNameCheck isOwnerRefClass;
 };
 
 Items::Items(DFContextShared * d_)
@@ -427,7 +427,8 @@ Items::Items(DFContextShared * d_)
     d = new Private;
     d->d = d_;
     d->owner = d_->p;
-    d->ownerRefVTable = d->refVectorOffset = d->refIDOffset = 0;
+    d->refVectorOffset = d->refIDOffset = 0;
+    d->isOwnerRefClass = ClassNameCheck("general_ref_unit_itemownerst");
 }
 
 bool Items::Start()
@@ -508,16 +509,7 @@ int32_t Items::getItemOwnerID(const DFHack::dfh_item &item)
         uint32_t curRef = p_refs[i];
         uint32_t vtbl = d->owner->readDWord(curRef);
 
-        if (!d->ownerRefVTable)
-        {
-            std::string className = d->owner->readClassName(vtbl);
-            if (className == "general_ref_unit_itemownerst")
-                d->ownerRefVTable = vtbl;
-            else
-                continue;
-        }
-        else if (d->ownerRefVTable != vtbl)
-            continue;
+        if (!d->isOwnerRefClass(d->owner, vtbl)) continue;
 
         return d->owner->readDWord(curRef + d->refIDOffset);
     }

library/private/SHMProcess.h

@@ -74,7 +74,7 @@ namespace DFHack
 
         void readSTLVector(const uint32_t address, t_vecTriplet & triplet);
         // get class name of an object with rtti/type info
-        std::string readClassName(uint32_t vptr);
+        std::string doReadClassName(uint32_t vptr);
 
         const std::string readCString (uint32_t offset);