Charset converter.

1 files changed, 167 insertions, 0 deletions

diff --git a/src/charsetConverter.cpp b/src/charsetConverter.cpp
new file mode 100644
index 00000000..ecfb1811
--- /dev/null
+++ b/src/charsetConverter.cpp
@@ -0,0 +1,167 @@
+//
+// VMime library (http://www.vmime.org)
+// Copyright (C) 2002-2005 Vincent Richard <[email protected]>
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+//
+// Linking this library statically or dynamically with other modules is making
+// a combined work based on this library.  Thus, the terms and conditions of
+// the GNU General Public License cover the whole combination.
+//
+
+#include "vmime/charsetConverter.hpp"
+#include "vmime/exception.hpp"
+
+
+extern "C"
+{
+#ifndef VMIME_BUILDING_DOC
+
+	#include <iconv.h>
+	#include <errno.h>
+
+	// HACK: prototypes may differ depending on the compiler and/or system (the
+	// second parameter may or may not be 'const'). This redeclaration is a hack
+	// to have a common prototype "iconv_cast".
+	class ICONV_HACK
+	{
+	public:
+
+		ICONV_HACK(const char** ptr) : m_ptr(ptr) { }
+
+		operator const char**() { return m_ptr; }
+		operator char**() { return const_cast <char**>(m_ptr); }
+
+	private:
+
+		const char** m_ptr;
+	};
+
+#endif // VMIME_BUILDING_DOC
+}
+
+
+namespace vmime
+{
+
+
+charsetConverter::charsetConverter(const charset& source, const charset& dest)
+	: m_desc(NULL), m_source(source), m_dest(dest)
+{
+	// Get an iconv descriptor
+	const iconv_t cd = iconv_open(dest.getName().c_str(), source.getName().c_str());
+
+	if (cd != reinterpret_cast <iconv_t>(-1))
+	{
+		iconv_t* p = new iconv_t;
+		*p= cd;
+
+		m_desc = p;
+	}
+}
+
+
+charsetConverter::~charsetConverter()
+{
+	if (m_desc != NULL)
+	{
+		// Close iconv handle
+		iconv_close(*static_cast <iconv_t*>(m_desc));
+
+		delete static_cast <iconv_t*>(m_desc);
+	}
+}
+
+
+void charsetConverter::convert(utility::inputStream& in, utility::outputStream& out)
+{
+	if (m_desc == NULL)
+		throw exceptions::charset_conv_error("Cannot initialize converter.");
+
+	const iconv_t cd = *static_cast <iconv_t*>(m_desc);
+
+	char inBuffer[32768];
+	char outBuffer[32768];
+	size_t inPos = 0;
+
+	bool prevIsInvalid = false;
+
+	while (true)
+	{
+		// Fullfill the buffer
+		size_t inLength = static_cast <size_t>(in.read(inBuffer + inPos, sizeof(inBuffer) - inPos) + inPos);
+		size_t outLength = sizeof(outBuffer);
+
+		const char* inPtr = inBuffer;
+		char* outPtr = outBuffer;
+
+		// Convert input bytes
+		if (iconv(cd, ICONV_HACK(&inPtr), &inLength,
+			      &outPtr, &outLength) == static_cast <size_t>(-1))
+		{
+			// Illegal input sequence or input sequence has no equivalent
+			// sequence in the destination charset.
+			if (prevIsInvalid)
+			{
+				// Write successfully converted bytes
+				out.write(outBuffer, sizeof(outBuffer) - outLength);
+
+				// Output a special character to indicate we don't known how to
+				// convert the sequence at this position
+				out.write("?", 1);
+
+				// Skip a byte and leave unconverted bytes in the input buffer
+				std::copy(const_cast <char*>(inPtr + 1), inBuffer + sizeof(inBuffer), inBuffer);
+				inPos = inLength - 1;
+			}
+			else
+			{
+				// Write successfully converted bytes
+				out.write(outBuffer, sizeof(outBuffer) - outLength);
+
+				// Leave unconverted bytes in the input buffer
+				std::copy(const_cast <char*>(inPtr), inBuffer + sizeof(inBuffer), inBuffer);
+				inPos = inLength;
+
+				if (errno != E2BIG)
+					prevIsInvalid = true;
+			}
+		}
+		else
+		{
+			// Write successfully converted bytes
+			out.write(outBuffer, sizeof(outBuffer) - outLength);
+
+			inPos = 0;
+			prevIsInvalid = false;
+		}
+
+		// Check for end of data
+		if (in.eof() && inPos == 0)
+			break;
+	}
+}
+
+
+void charsetConverter::convert(const string& in, string& out)
+{
+	utility::inputStreamStringAdapter is(in);
+	utility::outputStreamStringAdapter os(out);
+
+	convert(is, os);
+}
+
+
+} // vmime