Bytecode.h

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/*---------------------------------------------------------------------\
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|                               core system                            |
|                                                        (C) SuSE GmbH |
\----------------------------------------------------------------------/

   File:       Bytecode.h

   Primitive bytecode I/O functions.
   Acts as a namespace wrapper.

   Author:     Klaus Kaempf <kkaempf@suse.de>
   Maintainer: Klaus Kaempf <kkaempf@suse.de>

/-*/
// -*- c++ -*-

#ifndef Bytecode_h
#define Bytecode_h

#include "ycp/YCPValue.h"
#include "ycp/YCode.h"
#include "ycp/YStatement.h"
#include "ycp/YBlock.h"
#include "ycp/Type.h"

class Y2Namespace;

#include <iosfwd>
#include <string>
#include <map>

#include <fstream>

class bytecodeistream : public std::ifstream
{
        int m_major, m_minor, m_release;
    public:
        bytecodeistream (string filename);
        bool isVersion (int major, int minor, int revision);
        bool isVersionAtMost (int major, int minor, int revision);
        
        int major () const { return m_major; }
        int minor () const { return m_minor; }
        int release () const { return m_release; }
};

class Bytecode {
    static int m_namespace_nesting_level;
    static int m_namespace_nesting_array_size;
    static int m_namespace_tare_level;
    
    struct namespaceentry_t {
        const Y2Namespace *name_space;
        bool with_xrefs;        
    };
    static namespaceentry_t *m_namespace_nesting_array;
    static map<string, YBlockPtr>* m_bytecodeCache;

    public:
    class Invalid {};

        // bool I/O
        static std::ostream & writeBool (std::ostream & streamref, bool value);
        static bool readBool (bytecodeistream & streamref);

        // string I/O
        static std::ostream & writeString (std::ostream & streamref, const std::string & stringref);
        static bool readString (bytecodeistream & streamref, std::string & stringref);

        // Ustring I/O
        static std::ostream & writeUstring (std::ostream & streamref, const Ustring ustringref);
        static Ustring readUstring (bytecodeistream & streamref);

        // char * I/O
        static std::ostream & writeCharp (std::ostream & streamref, const char * charp);
        static char * readCharp (bytecodeistream & streamref);

        // bytepointer I/O
        static std::ostream & writeBytep (std::ostream & streamref, const unsigned char * bytep, unsigned int len);
        static unsigned char * readBytep (bytecodeistream & streamref);

        // u_int32_t I/O
        static std::ostream & writeInt32 (std::ostream & str, const u_int32_t value);
        static u_int32_t readInt32 (bytecodeistream & str);

        // Type I/O
        static std::ostream & writeType (std::ostream & str, constTypePtr type);
        static TypePtr readType (bytecodeistream & str);

        // YCPValue I/O
        static std::ostream & writeValue (std::ostream & str, const YCPValue value);
        static YCPValue readValue (bytecodeistream & str);

        // ycodelist_t * I/O
        static std::ostream & writeYCodelist (std::ostream & str, const ycodelist_t *codelist);
        static bool readYCodelist (bytecodeistream & str, ycodelist_t **anchor);

        //-----------------------------------------------------------
        // block nesting handling
        //
        static void namespaceInit ();
        // retrieve ID (nesting level) for namespace
        static int namespaceId (const Y2Namespace *name_space);
        // retrieve namespace for ID
        static const Y2Namespace *namespacePtr (int namespace_id);

        // push given namespace to id stack, return new id, -1 on error
        static int pushNamespace (const Y2Namespace *name_space, bool with_xrefs = false);

        // pop given namespace from id stack, return namespace id, -1 on error
        static int popNamespace (const Y2Namespace *name_space);

        // pop all from id stack until given namespace is reached and popped too
        static void popUptoNamespace (const Y2Namespace *name_space);

        // reset current namespace stack to 'empty' for module loading
        //   returns a tare id needed later
        static int tareStack ();
        static void untareStack (int tare_id);

        //-----------------------------------------------------------
        // SymbolEntry pointer (!) handling
        //   the SymbolEntries itself are 'owned' by Y2Namespace (YBlock in YCP) and referenced via pointers
        //   to SymbolEntry. These functions handle stream I/O for SymbolEntry pointers.
        static std::ostream &writeEntry (std::ostream & str, const SymbolEntryPtr entry);
        static SymbolEntryPtr readEntry (bytecodeistream & str);

        //-----------------------------------------------------------
        // YCode read.
        // Must be implemented outside of YCode since we have derived classes to allocate...
        // see YCode for write
        static YCodePtr readCode (bytecodeistream & str);

        // File I/O
        // reading and writing complete files is done via separate functions
        // which add/check a 'magic value' header denoting "YCode" and its version.

        // read YCode from file in Module path, return YBlock (NULL in case of error)
        static YBlockPtr readModule (const string & mname);

        // read YCode from file, return YCode (YError in case of failure)
        static YCodePtr readFile (const string & filename);

        // write YCode to file, return true on success (check errno for errors)
        static bool writeFile (const YCodePtr code, const string & filename);
};

#endif // Bytecode_h

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