Use a filtering_istream with custom filters to chain file -> decoder -> encoder.

1 files changed, 17 insertions, 0 deletions

diff --git a/decoder.h b/decoder.h
index b4dcdb6..a7aaad9 100644
--- a/decoder.h
+++ b/decoder.h
@@ -5,6 +5,8 @@
 #include <boost/function.hpp>
 #include <boost/functional/factory.hpp>
 #include <boost/functional/value_factory.hpp>
+#include <boost/iostreams/concepts.hpp>
+#include <boost/iostreams/operations.hpp>
 
 #include <string>
 
@@ -13,6 +15,21 @@ class DecoderBase {
 		virtual size_t decode(const uint8_t *input, size_t input_size, uint8_t *output, size_t output_size) = 0;
 };
 
+class DecoderFilter : public boost::iostreams::multichar_input_filter {
+	private:
+		DecoderBase& decoder;
+	public:
+		DecoderFilter(DecoderBase& decoder_) : decoder(decoder_) {};
+		template<typename Source>
+		std::streamsize read(Source& src, char *s, std::streamsize n) {
+			char src_data[0x2000];
+			std::streamsize src_read = boost::iostreams::read(src, src_data, 0x2000);
+			if(src_read < 0)
+				src_read = 0;
+			return decoder.decode((const uint8_t*)src_data, src_read, (uint8_t*)s, n);
+		};
+};
+
 namespace decoder {
 	void init();
 	DecoderBase *get_decoder(const std::string& name);