Allow computing md5 hashes from hsStream derived classes

Sources/Plasma/PubUtilLib/plEncryption/plChecksum.cpp

@@ -91,6 +91,11 @@ plMD5Checksum::plMD5Checksum( const char *fileName )
     CalcFromFile( fileName );
 }
 
+plMD5Checksum::plMD5Checksum( hsStream* stream )
+{
+    CalcFromStream(stream);
+}
+
 void plMD5Checksum::Clear()
 {
     memset( fChecksum, 0, sizeof( fChecksum ) );
@@ -99,23 +104,30 @@ void plMD5Checksum::Clear()
 
 void    plMD5Checksum::CalcFromFile( const char *fileName )
 {
-    FILE *fp;
+    hsUNIXStream s;
     fValid = false;
     
-    if( fp = fopen(fileName, "rb" ) )
+    if( s.Open(fileName) )
+    {
+        CalcFromStream(&s);
+        s.Close();
+    }
+}
+
+void plMD5Checksum::CalcFromStream( hsStream* stream )
 {
+    UInt32 sPos = stream->GetPosition();
     unsigned loadLen = 1024 * 1024;
     Start();
 
     UInt8 *buf = TRACKED_NEW UInt8[loadLen];
     
-        while(int read = fread(buf, sizeof(UInt8), loadLen, fp))
+    while(int read = stream->Read(loadLen, buf))
         AddTo( read, buf );
     delete[] buf;
 
     Finish();
-        fclose(fp);
-    }
+    stream->SetPosition(sPos);
 }
 
 void    plMD5Checksum::Start( void )

Sources/Plasma/PubUtilLib/plEncryption/plChecksum.h

@@ -58,6 +58,8 @@ public:
     SumStorage GetChecksum() { return fSum; }
 };
 
+class hsStream;
+
 class plMD5Checksum 
 {
     protected:
@@ -74,11 +76,13 @@ class plMD5Checksum
         plMD5Checksum();
         plMD5Checksum( const plMD5Checksum &rhs );
         plMD5Checksum( const char *fileName );
+        plMD5Checksum( hsStream* stream );
 
         hsBool  IsValid( void ) const { return fValid; }
         void    Clear();
 
         void    CalcFromFile( const char *fileName );
+        void    CalcFromStream( hsStream* stream );
 
         void    Start( void );
         void    AddTo( UInt32 size, const UInt8 *buffer );