C++ trpgReadBuffer::PushLimit方法代码示例

bool trpgLabelPropertyTable::Read(trpgReadBuffer &buf)
{
    trpgLabelProperty property;
    trpgToken propertyTok;
    int32 len;
    bool status;
    int numProperty;
    int i;

    Reset();

    try
    {
        buf.Get(numProperty);
        if (numProperty < 0)
            throw 1;
        //properties.resize(numProperty);
        for (i=0;i<numProperty;i++) {
            buf.GetToken(propertyTok,len);
            if (propertyTok != TRPG_LABEL_PROPERTY) throw 1;
            buf.PushLimit(len);
            property.Reset();
            status = property.Read(buf);
            buf.PopLimit();
            if (!status) throw 1;
            //properties[i] = property;
            AddProperty(property);
        }
    }
    catch (...)
    {
        return false;
    }

    return isValid();
}

/* Parse Buffer
   This runs through the given buffer parsing token sets until
   it (1) runs out of buffer or (2) fails.
   Note: Good place to return an exception, but keep it simple for now.
*/
bool trpgr_Parser::Parse(trpgReadBuffer &buf)
{
    bool ret = true;

    try
    {
        while (!buf.isEmpty())
        {
            /* We're expecting the following
            Token    (int32)
            Length  (int32)
            Data    (variable)
            */
            trpgToken tok;
            int32 len;
            if (!buf.Get(tok))  throw 1;
            // Push and Pop are special - no data
            if (tok != TRPG_PUSH && tok != TRPG_POP)
            {
                if (!buf.Get(len)) throw 1;
                if (!TokenIsValid(tok))  throw 1;
                if (len < 0)  throw 1;
                // Limit what we're reading to the length of this
                buf.PushLimit(len);
            }

            // Call our token handler for this one
            try
            {
                const trpgr_Token *tcb = NULL;
                tok_map::const_iterator p = tokenMap.find(tok);
                if (p != tokenMap.end())
                    tcb = &(*p).second;
                if (!tcb)
                    // No such token, call the default
                    tcb = &defCb;

                // Run the callback
                if (tcb->cb)
                {
                    void *ret = tcb->cb->Parse(tok,buf);
                    // Note: Do something with the return value
                    lastObject = ret;
                }
            }
            catch (...)
            {
                // Don't want to screw up the limit stack
            }
            // No limit to worry about with push and pop
            if (tok != TRPG_PUSH && tok != TRPG_POP)
            {
                buf.SkipToLimit();
                buf.PopLimit();
            }
        }
    }
    catch (...)
    {
        // Failed to parse.
        ret = false;
    }

    return ret;
}