Re: [Inkscape-devel] Query: I/O cleanup, reorganization?

2 Dec 2004


      Bryce Harrington wrote:
...
Can you show us an example of the before/after code?  I'm curious what
the existing code looks like, and how it'll get streamlined with the new
stuff.
I'll paste below what repr-io.cpp's output section would look like with
streams (omitting some stuff).  It is just an example.  I would expect that
we would have something like Inkscape::IO::ostream or ozstream.  But I
have actually tested it, and it works, and does .svgz without a pipe.  It
looks very readable to me, at least (at least as well as the previous 
printfs).
Note how save_file() and save_file_gzip() can now use the same code.
FYI:  we have been using Mental's Inkscape::SVGOStringStream for
inserting text data into Repr nodes for months now, and it works very, very
well.
...
Also, take a look at my ftos code - this was written as a part of a
iostream subclassing thing I did, and worked pretty good.  I'd love to
see this incorporated since it provides a better approach to formatting
numbers (so you can say x="4.21" instead of x="4.209999999").
I think it would fit in easily as the code that implements the operator
overload for <<(double) and <<(float)
Bob
===== SNIP SNIP ========
//#########################################################################
//### W R I T E
//#########################################################################
static void
sp_repr_quote_write (std::ostream &outs, const gchar * val)
{
    if (!val) return;
for (; *val != '\0'; val++) {
        switch (*val) {
        case '"': outs << "&quot;"; break;
        case '&': outs << "&amp;";  break;
        case '<': outs << "&lt;";   break;
        case '>': outs << "&gt;";   break;
        default : outs << *val;     break;
        }
    }
}
static void
sp_repr_write_stream_element (SPRepr *repr,
                                   std::ostream &outs,
                                   gint indent_level,
                                   gboolean add_whitespace)
{
    gint i;
g_return_if_fail (repr != NULL);
if ( indent_level > 16 )
        indent_level = 16;
if (add_whitespace) {
        for ( i = 0 ; i < indent_level ; i++ ) {
            outs << "  ";
        }
    }
outs << "<" << sp_repr_name (repr);
// if this is a <text> element, suppress formatting whitespace
    // for its content and children:
if (!strcmp(sp_repr_name(repr), "text")) {
        add_whitespace = false;
    }
SPReprAttr *attr;
    for ( attr = repr->attributes ; attr != NULL ; attr = attr->next ) {
        gchar const * const key = SP_REPR_ATTRIBUTE_KEY(attr);
        gchar const * const val = SP_REPR_ATTRIBUTE_VALUE(attr);
        outs << "\n";
        for ( i = 0 ; i < indent_level + 1 ; i++ ) {
            outs << "  ";
        }
        outs << " " << key << '"';
        sp_repr_quote_write (outs, val);
        outs << '"';
    }
gboolean loose = TRUE;
    SPRepr *child;
    for (child = repr->children; child != NULL; child = child->next) {
        if (child->type == SP_XML_TEXT_NODE) {
            loose = FALSE;
            break;
        }
    }
    if (repr->children) {
        outs << ">";
        if (loose && add_whitespace) {
            outs << "\n";
        }
        for (child = repr->children; child != NULL; child = child->next) {
            sp_repr_write_stream (child, outs, (
                      loose) ? (indent_level + 1) : 0, add_whitespace);
        }
if (loose && add_whitespace) {
            for (i = 0; i < indent_level; i++) {
                outs << "  ";
            }
        }
        outs << "</" << sp_repr_name (repr) << ">";
    } else {
        outs << " />";
    }
// text elements cannot nest, so we can output newline
    // after closing text
if (add_whitespace || !strcmp (sp_repr_name (repr), "text")) {
        outs << "\n";
    }
}
static void
sp_repr_write_stream (SPRepr *repr, std::ostream &outs, gint indent_level,
                      gboolean add_whitespace)
{
    if (repr->type == SP_XML_TEXT_NODE) {
        sp_repr_quote_write (outs, sp_repr_content (repr));
    } else if (repr->type == SP_XML_COMMENT_NODE) {
        outs << "<!--" << sp_repr_content (repr) << "-->";
    } else if (repr->type == SP_XML_ELEMENT_NODE) {
        sp_repr_write_stream_element(repr, outs, indent_level, 
add_whitespace);
    } else {
        g_assert_not_reached();
    }
}
void
sp_repr_save_stream (SPReprDoc *doc, std::ostream &outs)
{
outs << "<?xml version=\"1.0\" encoding=\"UTF-8\" 
standalone=\"no\"?>\n";
const gchar *str = sp_repr_attr ((SPRepr *) doc, "doctype");
    if (str)
        outs << str;
SPRepr *repr = sp_repr_document_first_child(doc);
    for ( repr = sp_repr_document_first_child(doc) ;
          repr ; repr = sp_repr_next(repr) )
    {
        sp_repr_write_stream(repr, outs, 0, TRUE);
        if ( repr->type == SP_XML_COMMENT_NODE ) {
            outs << '\n';
        }
    }
}
/* Returns TRUE if file successfully saved; FALSE if not
 */
gboolean
sp_repr_save_file (SPReprDoc *doc, const gchar *filename)
{
    if (filename == NULL) {
        return false;
    }
std::ofstream outs(filename);
sp_repr_save_stream (doc, outs);
outs.close();
return true;
}
/* Returns TRUE if file successfully saved; FALSE if not
 */
gboolean
sp_repr_save_file_gzip (SPReprDoc *doc, const gchar *filename)
{
    if (filename == NULL) {
        return false;
    }
ogzstream outs(filename);
sp_repr_save_stream (doc, outs);
outs.close();
return true;
}
void
sp_repr_print(SPRepr *repr)
{
    sp_repr_write_stream (repr, std::cout, 0, true);
}

Re: [Inkscape-devel] Query: I/O cleanup, reorganization?

Bob Jamison