0000572: add a method to Part module to read BRep data from string

git-svn-id: https://free-cad.svn.sourceforge.net/svnroot/free-cad/trunk@5410 e8eeb9e2-ec13-0410-a4a9-efa5cf37419d

src/Base/Stream.cpp

@@ -40,6 +40,7 @@
 #include "Stream.h"
 #include "Swap.h"
 #include "FileInfo.h"
+#include <CXX/Objects.hxx>
 
 using namespace Base;
 
@@ -533,6 +534,58 @@ IODeviceIStreambuf::seekpos(std::streambuf::pos_type pos,
     return seekoff(pos, std::ios_base::beg);
 }
 
+// ---------------------------------------------------------
+
+PyStreambuf::PyStreambuf(PyObject* o) : inp(o)
+{
+    setg (buffer+pbSize,
+          buffer+pbSize,
+          buffer+pbSize);
+}
+
+int PyStreambuf::underflow()
+{
+    if (gptr() < egptr()) {
+        return *gptr();
+    }
+
+    int numPutback;
+    numPutback = gptr() - eback();
+    if (numPutback > pbSize) {
+        numPutback = pbSize;
+    }
+
+    memcpy (buffer+(pbSize-numPutback), gptr()-numPutback, numPutback);
+
+    int num=0;
+    for (int i=0; i<bufSize; i++) {
+        char c;
+        Py::Tuple arg(1);
+        arg.setItem(0, Py::Int(1));
+        Py::Callable meth(Py::Object(inp).getAttr("read"));
+        try {
+            Py::Char res(meth.apply(arg));
+            c = static_cast<std::string>(res)[0];
+            num++;
+            buffer[pbSize+i] = c;
+            if (c == '\n')
+                break;
+        }
+        catch (Py::Exception& e) {
+            e.clear();
+            if (num == 0)
+                return EOF;
+            break;
+        }
+    }
+
+    setg (buffer+(pbSize-numPutback),
+          buffer+pbSize,
+          buffer+pbSize+num);
+
+    return *gptr();
+}
+
 // ---------------------------------------------------------
 
 Streambuf::Streambuf(const std::string& data)

src/Base/Stream.h

@@ -35,6 +35,7 @@
 class QByteArray;
 class QIODevice;
 class QBuffer;
+typedef struct _object PyObject;
 
 namespace Base {
 
@@ -232,6 +233,21 @@ protected:
     static const int bufSize = 1024;    // size of the data buffer
     char buffer[bufSize+pbSize];        // data buffer
 };
+
+class BaseExport PyStreambuf : public std::streambuf
+{
+public:
+    PyStreambuf(PyObject* o);
+
+protected:
+    int underflow();
+
+private:
+    static const int pbSize = 4;
+    static const int bufSize = 1024;
+    char buffer[bufSize+pbSize];
+    PyObject* inp;
+};
 
 class BaseExport Streambuf : public std::streambuf
 {