Packets: Add introductory parse helper documentation

[senf.git] / Packets / MPEGDVBBundle / TLVPacket.cc

diff --git a/Packets/MPEGDVBBundle/TLVPacket.cc b/Packets/MPEGDVBBundle/TLVPacket.cc
index 8d24a3f..628bf55 100644 (file)
--- a/Packets/MPEGDVBBundle/TLVPacket.cc
+++ b/Packets/MPEGDVBBundle/TLVPacket.cc
@@ -28,11 +28,112 @@
 
 // Custom includes
 #include <iomanip>
-
+#include <senf/Utils/hexdump.hh>
 
 #define prefix_
 ///////////////////////////////cc.p////////////////////////////////////////
 
+prefix_ senf::Parse_TLVPacketLength::value_type senf::Parse_TLVPacketLength::value() const 
+{
+    switch (bytes() ) {
+    case 1:
+        return fixed_length_field().value();
+    case 2:
+        return parse<Parse_UInt8>( 1 ).value();
+    case 3:
+        return parse<Parse_UInt16>( 1 ).value();
+    case 4:
+        return parse<Parse_UInt24>( 1 ).value();
+    case 5:
+        return parse<Parse_UInt32>( 1 ).value();
+    default:
+        throw(UnsuportedTLVPacketException());
+    };
+}
+
+prefix_ void senf::Parse_TLVPacketLength::value(value_type const & v) 
+{
+    if (v > 4294967295u)
+        throw(UnsuportedTLVPacketException());
+    
+    SafePacketParser<Parse_TLVPacketLength> safeThis (*this);
+    if (v < 128u) {
+        if (bytes() != 1) {
+            resize(1);
+           safeThis->extended_length_flag() = false;
+       } 
+        safeThis->fixed_length_field() = v;
+        return;
+    }
+    if (v < 256u) {
+        if (bytes() != 2) {
+           resize(2);
+            safeThis->extended_length_flag() = true;
+           safeThis->fixed_length_field() = 1;
+       }
+        safeThis->parse<Parse_UInt8>(1) = v;
+        return;
+    }
+    if (v < 65536u) {
+        if (bytes() != 3) {
+           resize(3);
+           safeThis->extended_length_flag() = true;
+           safeThis->fixed_length_field() = 2;
+       }
+        safeThis->parse<Parse_UInt16>(1) = v;
+        return;
+    }
+    if (v < 16777216u) {
+        if (bytes() != 4) {
+           resize(4);
+           safeThis->extended_length_flag() = true;
+           safeThis->fixed_length_field() = 3;
+       }
+        safeThis->parse<Parse_UInt24>(1) = v;
+        return;
+    }
+    if (v <= 4294967295u) {
+        if (bytes() != 5) {
+           resize(5);
+           safeThis->extended_length_flag() = true;
+           safeThis->fixed_length_field() = 4;
+       }
+        safeThis->parse<Parse_UInt32>(1) = v;
+        return;
+    }
+}
+
+prefix_ senf::Parse_TLVPacketLength const & senf::Parse_TLVPacketLength::operator= (value_type other) 
+{
+    value(other);
+    return *this; 
+}
+
+prefix_ senf::Parse_TLVPacketLength::size_type senf::Parse_TLVPacketLength::bytes() const 
+{
+    if ( extended_length_flag() )
+        return 1 + fixed_length_field();
+    else
+        return 1;
+}
+    
+prefix_ void senf::Parse_TLVPacketLength::init() const 
+{
+    defaultInit();
+    extended_length_flag() = 0;
+}
+
+prefix_ void senf::Parse_TLVPacketLength::resize(size_type size) 
+{
+    size_type current_size (bytes());
+    safe_data_iterator si (data(), i());
+    
+    if (current_size > size)
+        data().erase( si, boost::next(si, current_size-size));
+    else
+        data().insert( si, size-current_size, 0);
+}
+
 prefix_ void senf::TLVPacketType::dump(packet p, std::ostream & os)
 {
     os << "TLVPacket:\n"
@@ -41,10 +142,25 @@ prefix_ void senf::TLVPacketType::dump(packet p, std::ostream & os)
        << "  length: " << unsigned(p->length()) << "\n";
 }
 
+prefix_ senf::PacketParserBase::size_type senf::TLVPacketType::initSize()
+{
+    return 5;  // 4 bytes type + 1 byte length
+}
+
+prefix_ void senf::TLVPacketType::init(packet p)
+{
+    p->init();
+}
+
+prefix_ void senf::TLVPacketType::finalize(packet p)
+{
+    p->length() = p.next().data().size();
+}
+
 prefix_ senf::PacketInterpreterBase::optional_range 
 senf::TLVPacketType::nextPacketRange(packet p) 
 {
-    if (p.data().size() < 6)
+    if (p.data().size() < 5)
         return no_range();
     return range(
             boost::next(p.data().begin(), 4 + senf::bytes(p->length()) ),