path: root/camel/camel-mime-filter-charset.c

/*
 *  Copyright (C) 2000 Helix Code Inc.
 *
 *  Authors: Michael Zucchi <notzed@helixcode.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library 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 Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <iconv.h>

#include <string.h>
#include <errno.h>

#include "camel-mime-filter-charset.h"

#define d(x)

static void camel_mime_filter_charset_class_init (CamelMimeFilterCharsetClass *klass);
static void camel_mime_filter_charset_init       (CamelMimeFilterCharset *obj);
static void camel_mime_filter_charset_finalize   (CamelObject *o);

static CamelMimeFilterClass *camel_mime_filter_charset_parent;

CamelType
camel_mime_filter_charset_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register (camel_mime_filter_get_type (), "CamelMimeFilterCharset",
                        sizeof (CamelMimeFilterCharset),
                        sizeof (CamelMimeFilterCharsetClass),
                        (CamelObjectClassInitFunc) camel_mime_filter_charset_class_init,
                        NULL,
                        (CamelObjectInitFunc) camel_mime_filter_charset_init,
                        (CamelObjectFinalizeFunc) camel_mime_filter_charset_finalize);
    }
    
    return type;
}

static void
camel_mime_filter_charset_finalize(CamelObject *o)
{
    CamelMimeFilterCharset *f = (CamelMimeFilterCharset *)o;

    g_free(f->from);
    g_free(f->to);
    if (f->ic != (iconv_t)-1) {
        iconv_close(f->ic);
        f->ic = (iconv_t) -1;
    }
}

static void
reset(CamelMimeFilter *mf)
{
    CamelMimeFilterCharset *f = (CamelMimeFilterCharset *)mf;
    char buf[16];
    char *buffer;
    int outlen = 16;

    /* what happens with the output bytes if this resets the state? */
    if (f->ic != (iconv_t) -1) {
        buffer = buf;
        iconv(f->ic, NULL, 0, &buffer, &outlen);
    }
}

static void
complete(CamelMimeFilter *mf, char *in, size_t len, size_t prespace, char **out, size_t *outlenptr, size_t *outprespace)
{
    CamelMimeFilterCharset *f = (CamelMimeFilterCharset *)mf;
    int converted;
    const char *inbuf;
    char *outbuf;
    int inlen, outlen;

    if (f->ic == (iconv_t) -1) {
        goto donothing;
    }

    /* FIXME: there's probably a safer way to size this ...? */
    /* We could always resize if we run out of room in outbuf (but it'd be nice not
       to have to) */
    camel_mime_filter_set_size(mf, len*5+16, FALSE);
    inbuf = in;
    inlen = len;
    outbuf = mf->outbuf;
    outlen = mf->outsize;

    /* temporary fix to find another bug somewhere */
    d(memset(outbuf, 0, outlen));

    if (inlen>0) {
        converted = iconv(f->ic, &inbuf, &inlen, &outbuf, &outlen);
        if (converted == -1) {
            if (errno != EINVAL) {
                g_warning("error occured converting: %s", strerror(errno));
                goto donothing;
            }
        }

        if (inlen>0) {
            g_warning("Output lost in character conversion, invalid sequence encountered?");
        }
    }

    /* this 'resets' the output stream, returning back to the initial
       shift state for multishift charactersets */
    converted = iconv(f->ic, NULL, 0, &outbuf, &outlen);
    if (converted == -1) {
        g_warning("Conversion failed to complete: %s", strerror(errno));
    }

    /* debugging assertion - check for NUL's in output */
    d({
        int i;
        
        for (i=0;i<(mf->outsize - outlen);i++) {
            g_assert(mf->outbuf[i]);
        }
    });

    *out = mf->outbuf;
    *outlenptr = mf->outsize - outlen;
    *outprespace = mf->outpre;
    return;

donothing:
    *out = in;
    *outlenptr = len;
    *outprespace = prespace;
}

static void
filter(CamelMimeFilter *mf, char *in, size_t len, size_t prespace, char **out, size_t *outlenptr, size_t *outprespace)
{
    CamelMimeFilterCharset *f = (CamelMimeFilterCharset *)mf;
    int converted;
    const char *inbuf;
    char *outbuf;
    int inlen, outlen;

    if (f->ic == (iconv_t) -1) {
        goto donothing;
    }

    /* FIXME: there's probably a safer way to size this ...? */
    camel_mime_filter_set_size(mf, len*5+16, FALSE);
    inbuf = in;
    inlen = len;
    outbuf = mf->outbuf;
    outlen = mf->outsize;
    converted = iconv(f->ic, &inbuf, &inlen, &outbuf, &outlen);
    if (converted == -1) {
        if (errno != EINVAL) {
            g_warning("error occured converting: %s", strerror(errno));
            goto donothing;
        }
    }

    /*
      NOTE: This assumes EINVAL only occurs because we ran out of
      bytes for a multibyte sequence, if not, we're in trouble.
    */

    if (inlen>0) {
        camel_mime_filter_backup(mf, inbuf, inlen);
    }

    *out = mf->outbuf;
    *outlenptr = mf->outsize - outlen;
    *outprespace = mf->outpre;
    return;

donothing:
    *out = in;
    *outlenptr = len;
    *outprespace = prespace;
}

static void
camel_mime_filter_charset_class_init (CamelMimeFilterCharsetClass *klass)
{
    CamelMimeFilterClass *filter_class = (CamelMimeFilterClass *) klass;
    
    camel_mime_filter_charset_parent = CAMEL_MIME_FILTER_CLASS (camel_type_get_global_classfuncs (camel_mime_filter_get_type ()));

    filter_class->reset = reset;
    filter_class->filter = filter;
    filter_class->complete = complete;
}

static void
camel_mime_filter_charset_init (CamelMimeFilterCharset *obj)
{
    obj->ic = (iconv_t)-1;
}

/**
 * camel_mime_filter_charset_new:
 *
 * Create a new CamelMimeFilterCharset object.
 * 
 * Return value: A new CamelMimeFilterCharset widget.
 **/
CamelMimeFilterCharset *
camel_mime_filter_charset_new (void)
{
    CamelMimeFilterCharset *new = CAMEL_MIME_FILTER_CHARSET ( camel_object_new (camel_mime_filter_charset_get_type ()));
    return new;
}

CamelMimeFilterCharset *
camel_mime_filter_charset_new_convert(const char *from_charset, const char *to_charset)
{
    CamelMimeFilterCharset *new = CAMEL_MIME_FILTER_CHARSET ( camel_object_new (camel_mime_filter_charset_get_type ()));

    new->ic = iconv_open(to_charset, from_charset);
    if (new->ic == (iconv_t) -1) {
        g_warning("Cannot create charset conversion from %s to %s: %s", from_charset, to_charset, strerror(errno));
        camel_object_unref((CamelObject *)new);
        new = NULL;
    } else {
        new->from = g_strdup(from_charset);
        new->to = g_strdup(to_charset);
    }
    return new;
}