BaseClasses.cpp

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/* BaseClasses.cpp

   Copyright (C)  David C. J. Matthews 2004  dm at prolingua.co.uk

   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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   Or, point your browser to http://www.gnu.org/copyleft/gpl.html

*/

#include "BaseClasses.h"
#include "ParseNode.h"
#include "Engine.h"
#include "ASN1Codes.h"
#include "Logging.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#define new DEBUG_NEW
#endif

MHOctetString::MHOctetString()
{
    m_nLength = 0;
    m_pChars = NULL;
}

// Construct from a string
MHOctetString::MHOctetString(const char *str, int nLen)
{
    if (nLen < 0)
    {
        nLen = strlen(str);
    }

    m_nLength = nLen;

    if (nLen == 0)
    {
        m_pChars = 0;
    }
    else
    {
        m_pChars = (unsigned char *)malloc(nLen);

        if (! m_pChars)
        {
            throw "Out of memory";
        }

        memcpy(m_pChars, str, nLen);
    }
}

MHOctetString::MHOctetString(const unsigned char *str, int nLen)
{
    m_nLength = nLen;

    if (nLen == 0)
    {
        m_pChars = 0;
    }
    else
    {
        m_pChars = (unsigned char *)malloc(nLen);

        if (! m_pChars)
        {
            throw "Out of memory";
        }

        memcpy(m_pChars, str, nLen);
    }
}

// Construct a substring.
MHOctetString::MHOctetString(const MHOctetString &str, int nOffset, int nLen)
{
    if (nLen < 0)
    {
        nLen = str.Size() - nOffset;    // The rest of the string.
    }

    if (nLen < 0)
    {
        nLen = 0;
    }

    if (nLen > str.Size())
    {
        nLen = str.Size();
    }

    m_nLength = nLen;

    if (nLen == 0)
    {
        m_pChars = 0;
    }
    else
    {
        m_pChars = (unsigned char *)malloc(nLen);

        if (! m_pChars)
        {
            throw "Out of memory";
        }

        memcpy(m_pChars, str.m_pChars + nOffset, nLen);
    }
}

MHOctetString::~MHOctetString()
{
    free(m_pChars);
}

// Copy a string
void MHOctetString::Copy(const MHOctetString &str)
{
    free(m_pChars);
    m_pChars = NULL;
    m_nLength = str.m_nLength;

    if (str.m_pChars)
    {
        // Allocate a copy of the string.  For simplicity we always add a null.
        m_pChars = (unsigned char *)malloc(m_nLength + 1);

        if (m_pChars == NULL)
        {
            throw "Out of memory";
        }

        memcpy(m_pChars, str.m_pChars, m_nLength);
        m_pChars[m_nLength] = 0;
    }
}

// Print the string in a suitable format.
// For the moment it uses quoted printable.
void MHOctetString::PrintMe(FILE *fd, int /*nTabs*/) const
{
    putc('\'', fd);

    for (int i = 0; i < m_nLength; i++)
    {
        unsigned char ch = m_pChars[i];

        // Escape a non-printable character or an equal sign or a quote.
        if (ch == '=' || ch == '\'' || ch < ' ' || ch >= 127)
        {
            fprintf(fd, "=%02X", ch);
        }
        else
        {
            putc(ch, fd);
        }
    }

    putc('\'', fd);
}

// Test strings.
int MHOctetString::Compare(const MHOctetString &str) const
{
    int nLength = m_nLength;

    if (nLength > str.m_nLength)
    {
        nLength = str.m_nLength;
    }

    // Test up to the length of the shorter string.
    int nTest = 0;

    if (nLength > 0)
    {
        nTest = memcmp(str.m_pChars, m_pChars, nLength);
    }

    // If they differ return the result
    if (nTest != 0)
    {
        return nTest;
    }

    // If they are the same then the longer string is greater.
    if (m_nLength == str.m_nLength)
    {
        return 0;
    }
    else if (m_nLength < str.m_nLength)
    {
        return -1;
    }
    else
    {
        return 1;
    }
}

// Add text to the end of the string.
void MHOctetString::Append(const MHOctetString &str)
{
    if (str.m_nLength == 0)
    {
        return;    // Nothing to do and it simplifies the code
    }

    int newLen = m_nLength + str.m_nLength;
    // Allocate a new string big enough to contain both and initialised to the first string.
    unsigned char *p = (unsigned char *)realloc(m_pChars, newLen);

    if (p == NULL)
    {
        throw "Out of memory";
    }

    m_pChars = p;
    // Copy the second string onto the end of the first.
    memcpy(m_pChars + m_nLength, str.m_pChars, str.m_nLength);
    m_nLength = newLen;
}

// Colour
void MHColour::Initialise(MHParseNode *p, MHEngine * /*engine*/)
{
    if (p->m_nNodeType == MHParseNode::PNInt)
    {
        m_nColIndex = p->GetIntValue();
    }
    else
    {
        p->GetStringValue(m_ColStr);
    }
}

void MHColour::PrintMe(FILE *fd, int nTabs) const
{
    if (m_nColIndex >= 0)
    {
        fprintf(fd, " %d ", m_nColIndex);
    }
    else
    {
        m_ColStr.PrintMe(fd, nTabs);
    }
}

void MHColour::SetFromString(const char *str, int nLen)
{
    m_nColIndex = -1;
    m_ColStr.Copy(MHOctetString(str, nLen));
}

void MHColour::Copy(const MHColour &col)
{
    m_nColIndex = col.m_nColIndex;
    m_ColStr.Copy(col.m_ColStr);
}

// An object reference is used to identify and refer to an object.
// Internal objects have the m_GroupId field empty.

MHObjectRef MHObjectRef::Null; // This has zero for the object number and an empty group id.

// An object reference is either an integer or a pair of a group id and an integer.
void MHObjectRef::Initialise(MHParseNode *p, MHEngine *engine)
{
    if (p->m_nNodeType == MHParseNode::PNInt)
    {
        m_nObjectNo = p->GetIntValue();
        // Set the group id to the id of this group.
        m_GroupId.Copy(engine->GetGroupId());
    }
    else if (p->m_nNodeType == MHParseNode::PNSeq)
    {
        MHParseNode *pFirst = p->GetSeqN(0);
        MHOctetString groupId;
        pFirst->GetStringValue(m_GroupId);
        m_nObjectNo = p->GetSeqN(1)->GetIntValue();
    }
    else
    {
        p->Failure("ObjectRef: Argument is not int or sequence");
    }
}

void MHObjectRef::PrintMe(FILE *fd, int nTabs) const
{
    if (m_GroupId.Size() == 0)
    {
        fprintf(fd, " %d ", m_nObjectNo);
    }
    else
    {
        fprintf(fd, " ( ");
        m_GroupId.PrintMe(fd, nTabs);
        fprintf(fd, " %d ) ", m_nObjectNo);
    }
}

QString MHObjectRef::Printable() const
{
    if (m_GroupId.Size() == 0)
    {
        return QString(" %1 ").arg(m_nObjectNo);
    }
    else
    {
        return QString(" ( ") + m_GroupId.Printable() + QString(" %1 ").arg(m_nObjectNo);
    }
}

// Make a copy of an object reference.
void MHObjectRef::Copy(const MHObjectRef &objr)
{
    m_nObjectNo = objr.m_nObjectNo;
    m_GroupId.Copy(objr.m_GroupId);
}

// The object references may not be identical but may nevertheless refer to the same
// object.  The only safe way to do this is to compare the canonical paths.
bool MHObjectRef::Equal(const MHObjectRef &objr, MHEngine *engine) const
{
    return m_nObjectNo == objr.m_nObjectNo && engine->GetPathName(m_GroupId) == engine->GetPathName(objr.m_GroupId);
}

bool MHContentRef::Equal(const MHContentRef &cr, MHEngine *engine) const
{
    return engine->GetPathName(m_ContentRef) == engine->GetPathName(cr.m_ContentRef);
}

// "Generic" versions of int, bool etc can be either the value or the an indirect reference.

void MHGenericBoolean::Initialise(MHParseNode *pArg, MHEngine *engine)
{
    if (pArg->m_nNodeType == MHParseNode::PNTagged && pArg->GetTagNo() == C_INDIRECTREFERENCE)
    {
        // Indirect reference.
        m_fIsDirect = false;
        m_Indirect.Initialise(pArg->GetArgN(0), engine);
    }
    else   // Simple integer value.
    {
        m_fIsDirect = true;
        m_fDirect = pArg->GetBoolValue();
    }
}

void MHGenericBoolean::PrintMe(FILE *fd, int nTabs) const
{
    if (m_fIsDirect)
    {
        fprintf(fd, "%s ", m_fDirect ? "true" : "false");
    }
    else
    {
        fprintf(fd, ":IndirectRef ");
        m_Indirect.PrintMe(fd, nTabs + 1);
    }
}

// Return the value, looking up any indirect ref.
bool MHGenericBoolean::GetValue(MHEngine *engine) const
{
    if (m_fIsDirect)
    {
        return m_fDirect;
    }
    else
    {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);
        result.CheckType(MHUnion::U_Bool);
        return result.m_fBoolVal;
    }
}

// Return the indirect reference or fail if it's direct
MHObjectRef *MHGenericBase::GetReference()
{
    if (m_fIsDirect)
    {
        MHERROR("Expected indirect reference");
    }

    return &m_Indirect;
}

void MHGenericInteger::Initialise(MHParseNode *pArg, MHEngine *engine)
{
    if (pArg->m_nNodeType == MHParseNode::PNTagged && pArg->GetTagNo() == C_INDIRECTREFERENCE)
    {
        // Indirect reference.
        m_fIsDirect = false;
        m_Indirect.Initialise(pArg->GetArgN(0), engine);
    }
    else   // Simple integer value.
    {
        m_fIsDirect = true;
        m_nDirect = pArg->GetIntValue();
    }
}

void MHGenericInteger::PrintMe(FILE *fd, int nTabs) const
{
    if (m_fIsDirect)
    {
        fprintf(fd, "%d ", m_nDirect);
    }
    else
    {
        fprintf(fd, ":IndirectRef ");
        m_Indirect.PrintMe(fd, nTabs + 1);
    }
}

// Return the value, looking up any indirect ref.
int MHGenericInteger::GetValue(MHEngine *engine) const
{
    if (m_fIsDirect)
    {
        return m_nDirect;
    }
    else
    {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);

        // From my reading of the MHEG documents implicit conversion is only
        // performed when assigning variables.  Nevertheless the Channel 4
        // Teletext assumes that implicit conversion takes place here as well.
        if (result.m_Type == MHUnion::U_String)
        {
            // Implicit conversion of string to integer.
            int v = 0;
            int p = 0;
            bool fNegative = false;

            if (result.m_StrVal.Size() > 0 && result.m_StrVal.GetAt(0) == '-')
            {
                p++;
                fNegative = true;
            }

            for (; p < result.m_StrVal.Size(); p++)
            {
                unsigned char ch =  result.m_StrVal.GetAt(p);

                if (ch < '0' || ch > '9')
                {
                    break;
                }

                v = v * 10 + ch - '0';
            }

            if (fNegative)
            {
                return -v;
            }
            else
            {
                return v;
            }
        }
        else
        {
            result.CheckType(MHUnion::U_Int);
            return result.m_nIntVal;
        }
    }
}

void MHGenericOctetString::Initialise(MHParseNode *pArg, MHEngine *engine)
{
    if (pArg->m_nNodeType == MHParseNode::PNTagged && pArg->GetTagNo() == C_INDIRECTREFERENCE)
    {
        // Indirect reference.
        m_fIsDirect = false;
        m_Indirect.Initialise(pArg->GetArgN(0), engine);
    }
    else   // Simple string value.
    {
        m_fIsDirect = true;
        pArg->GetStringValue(m_Direct);
    }
}

void MHGenericOctetString::PrintMe(FILE *fd, int /*nTabs*/) const
{
    if (m_fIsDirect)
    {
        m_Direct.PrintMe(fd, 0);
    }
    else
    {
        fprintf(fd, ":IndirectRef ");
        m_Indirect.PrintMe(fd, 0);
    }
}

// Return the value, looking up any indirect ref.
void MHGenericOctetString::GetValue(MHOctetString &str, MHEngine *engine) const
{
    if (m_fIsDirect)
    {
        str.Copy(m_Direct);
    }
    else
    {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);

        // From my reading of the MHEG documents implicit conversion is only
        // performed when assigning variables.  Nevertheless the Channel 4
        // Teletext assumes that implicit conversion takes place here as well.
        if (result.m_Type == MHUnion::U_Int)
        {
            // Implicit conversion of int to string.
            char buff[30]; // 30 chars is more than enough.
#ifdef _WIN32
            _snprintf(buff, sizeof(buff), "%0d", result.m_nIntVal);
#else
            snprintf(buff, sizeof(buff), "%0d", result.m_nIntVal);
#endif
            str.Copy(buff);
        }
        else
        {
            result.CheckType(MHUnion::U_String);
            str.Copy(result.m_StrVal);
        }
    }
}

void MHGenericObjectRef::Initialise(MHParseNode *pArg, MHEngine *engine)
{
    if (pArg->m_nNodeType == MHParseNode::PNTagged && pArg->GetTagNo() == C_INDIRECTREFERENCE)
    {
        // Indirect reference.
        m_fIsDirect = false;
        m_Indirect.Initialise(pArg->GetArgN(0), engine);
    }
    else   // Direct reference.
    {
        m_fIsDirect = true;
        m_ObjRef.Initialise(pArg, engine);
    }
}

void MHGenericObjectRef::PrintMe(FILE *fd, int nTabs) const
{
    if (m_fIsDirect)
    {
        m_ObjRef.PrintMe(fd, nTabs + 1);
    }
    else
    {
        fprintf(fd, ":IndirectRef ");
        m_Indirect.PrintMe(fd, nTabs + 1);
    }
}

// Return the value, looking up any indirect ref.
void MHGenericObjectRef::GetValue(MHObjectRef &ref, MHEngine *engine) const
{
    if (m_fIsDirect)
    {
        ref.Copy(m_ObjRef);
    }
    else
    {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);
        result.CheckType(MHUnion::U_ObjRef);
        ref.Copy(result.m_ObjRefVal);
    }
}

void MHGenericContentRef::Initialise(MHParseNode *pArg, MHEngine *engine)
{
    if (pArg->GetTagNo() == C_INDIRECTREFERENCE)
    {
        // Indirect reference.
        m_fIsDirect = false;
        m_Indirect.Initialise(pArg->GetArgN(0), engine);
    }
    else if (pArg->GetTagNo() == C_CONTENT_REFERENCE)  // Direct reference.
    {
        m_fIsDirect = true;
        m_Direct.Initialise(pArg->GetArgN(0), engine);
    }
    else
    {
        MHERROR("Expected direct or indirect content reference");
    }
}

void MHGenericContentRef::PrintMe(FILE *fd, int /*nTabs*/) const
{
    if (m_fIsDirect)
    {
        m_Direct.PrintMe(fd, 0);
    }
    else
    {
        fprintf(fd, ":IndirectRef ");
        m_Indirect.PrintMe(fd, 0);
    }
}

// Return the value, looking up any indirect ref.
void MHGenericContentRef::GetValue(MHContentRef &ref, MHEngine *engine) const
{
    if (m_fIsDirect)
    {
        ref.Copy(m_Direct);
    }
    else
    {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);
        result.CheckType(MHUnion::U_ContentRef);
        ref.Copy(result.m_ContentRefVal);
    }
}

// Copies the argument, getting the value of an indirect args.
void MHUnion::GetValueFrom(const MHParameter &value, MHEngine *engine)
{
    switch (value.m_Type)
    {
        case MHParameter::P_Int:
            m_Type = U_Int;
            m_nIntVal = value.m_IntVal.GetValue(engine);
            break;
        case MHParameter::P_Bool:
            m_Type = U_Bool;
            m_fBoolVal = value.m_BoolVal.GetValue(engine);
            break;
        case MHParameter::P_String:
            m_Type = U_String;
            value.m_StrVal.GetValue(m_StrVal, engine);
            break;
        case MHParameter::P_ObjRef:
            m_Type = U_ObjRef;
            value.m_ObjRefVal.GetValue(m_ObjRefVal, engine);
            break;
        case MHParameter::P_ContentRef:
            m_Type = U_ContentRef;
            value.m_ContentRefVal.GetValue(m_ContentRefVal, engine);
            break;
        case MHParameter::P_Null:
            m_Type = U_None;
            break;
    }
}

const char *MHUnion::GetAsString(enum UnionTypes t)
{
    switch (t)
    {
        case U_Int:
            return "int";
        case U_Bool:
            return "bool";
        case U_String:
            return "string";
        case U_ObjRef:
            return "objref";
        case U_ContentRef:
            return "contentref";
        case U_None:
            return "none";
    }

    return ""; // Not reached.
}

void MHUnion::CheckType(enum UnionTypes t) const
{
    if (m_Type != t)
    {
        MHERROR(QString("Type mismatch - expected %1 found %2").arg(GetAsString(m_Type)).arg(GetAsString(t)));
    }
}


// A parameter is a generic whose argument is either the value itself or an indirect reference.
void MHParameter::Initialise(MHParseNode *p, MHEngine *engine)
{
    switch (p->GetTagNo())
    {
        case C_NEW_GENERIC_BOOLEAN:
            m_Type = P_Bool;
            m_BoolVal.Initialise(p->GetArgN(0), engine);
            break;
        case C_NEW_GENERIC_INTEGER:
            m_Type = P_Int;
            m_IntVal.Initialise(p->GetArgN(0), engine);
            break;
        case C_NEW_GENERIC_OCTETSTRING:
            m_Type = P_String;
            m_StrVal.Initialise(p->GetArgN(0), engine);
            break;
        case C_NEW_GENERIC_OBJECT_REF:
            m_Type = P_ObjRef;
            m_ObjRefVal.Initialise(p->GetArgN(0), engine);
            break;
        case C_NEW_GENERIC_CONTENT_REF:
            m_Type = P_ContentRef;
            m_ContentRefVal.Initialise(p->GetArgN(0), engine);
            break;
        default:
            p->Failure("Expected generic");
    }
}

void MHParameter::PrintMe(FILE *fd, int nTabs) const
{
    PrintTabs(fd, nTabs);

    switch (m_Type)
    {
            // Direct values.
        case P_Int:
            fprintf(fd, ":GInteger ");
            m_IntVal.PrintMe(fd, 0);
            break;
        case P_Bool:
            fprintf(fd, ":GBoolean ");
            m_BoolVal.PrintMe(fd, 0);
            break;
        case P_String:
            fprintf(fd, ":GOctetString ");
            m_StrVal.PrintMe(fd, 0);
            break;
        case P_ObjRef:
            fprintf(fd, ":GObjectRef ");
            m_ObjRefVal.PrintMe(fd, 0);
            break;
        case P_ContentRef:
            fprintf(fd, ":GObjectRef ");
            m_ContentRefVal.PrintMe(fd, 0);
            break;
        case P_Null:
            break;
    }
}

// Return the indirect reference so that it can be updated.  We don't need to check
// the type at this stage.  If we assign the wrong value that will be picked up in
// the assignment.
MHObjectRef *MHParameter::GetReference()
{
    switch (m_Type)
    {
        case P_Int:
            return m_IntVal.GetReference();
        case P_Bool:
            return m_BoolVal.GetReference();
        case P_String:
            return m_StrVal.GetReference();
        case P_ObjRef:
            return m_ObjRefVal.GetReference();
        case P_ContentRef:
            return m_ContentRefVal.GetReference();
        case P_Null:
            return NULL;
    }

    return NULL; // To keep VC++ happy
}

// A content reference is simply a string.
MHContentRef MHContentRef::Null; // This is the empty string.

void MHContentRef::Initialise(MHParseNode *p, MHEngine *)
{
    p->GetStringValue(m_ContentRef);
}

void MHFontBody::Initialise(MHParseNode *p, MHEngine *engine)
{
    if (p->m_nNodeType == MHParseNode::PNString)
    {
        p->GetStringValue(m_DirFont);
    }
    else
    {
        m_IndirFont.Initialise(p, engine);
    }
}

void MHFontBody::PrintMe(FILE *fd, int nTabs) const
{
    if (m_DirFont.Size() > 0)
    {
        m_DirFont.PrintMe(fd, nTabs);
    }
    else
    {
        m_IndirFont.PrintMe(fd, nTabs);
    }
}

void MHFontBody::Copy(const MHFontBody &fb)
{
    m_DirFont.Copy(fb.m_DirFont);
    m_IndirFont.Copy(fb.m_IndirFont);
}

void MHPointArg::Initialise(MHParseNode *p, MHEngine *engine)
{
    x.Initialise(p->GetSeqN(0), engine);
    y.Initialise(p->GetSeqN(1), engine);
}

void MHPointArg::PrintMe(FILE *fd, int nTabs) const
{
    fprintf(fd, "( ");
    x.PrintMe(fd, nTabs);
    y.PrintMe(fd, nTabs);
    fprintf(fd, ") ");
}

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