New class for zipping/unzipping gzip streams.

2004-05-10  Jeffrey Stedfast  <fejj@novell.com>

	* camel-mime-filter-gzip.[c,h]: New class for zipping/unzipping
	gzip streams.

	* camel-mime-filter-yenc.[c,h]: New class for encoding/decoding
	the crack known as YEncode.

svn path=/trunk/; revision=25847

1 files changed, 461 insertions, 0 deletions

diff --git a/camel/camel-mime-filter-gzip.c b/camel/camel-mime-filter-gzip.c
new file mode 100644
index 0000000000..f3c640240b
--- /dev/null
+++ b/camel/camel-mime-filter-gzip.c
@@ -0,0 +1,461 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/*
+ *  Authors: Jeffrey Stedfast <fejj@ximian.com>
+ *
+ *  Copyright 2001-2004 Ximian, Inc. (www.ximian.com)
+ *
+ *  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 Street #330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#include <zlib.h>
+
+#include "camel-mime-filter-gzip.h"
+
+
+/* rfc1952 */
+
+enum {
+	GZIP_FLAG_FTEXT     = (1 << 0),
+	GZIP_FLAG_FHCRC     = (1 << 1),
+	GZIP_FLAG_FEXTRA    = (1 << 2),
+	GZIP_FLAG_FNAME     = (1 << 3),
+	GZIP_FLAG_FCOMMENT  = (1 << 4),
+	GZIP_FLAG_RESERVED0 = (1 << 5),
+	GZIP_FLAG_RESERVED1 = (1 << 6),
+	GZIP_FLAG_RESERVED2 = (1 << 7),
+};
+
+#define GZIP_FLAG_RESERVED (GZIP_FLAG_RESERVED0 | GZIP_FLAG_RESERVED1 | GZIP_FLAG_RESERVED2)
+
+typedef union {
+	unsigned char buf[10];
+	struct {
+		guint8 id1;
+		guint8 id2;
+		guint8 cm;
+		guint8 flg;
+		guint32 mtime;
+		guint8 xfl;
+		guint8 os;
+	} v;
+} gzip_hdr_t;
+
+typedef union {
+	struct {
+		guint16 xlen;
+		guint16 xlen_nread;
+		guint16 crc16;
+		
+		guint8 got_hdr:1;
+		guint8 is_valid:1;
+		guint8 got_xlen:1;
+		guint8 got_fname:1;
+		guint8 got_fcomment:1;
+		guint8 got_crc16:1;
+	} unzip;
+	struct {
+		guint32 wrote_hdr:1;
+	} zip;
+} gzip_state_t;
+
+struct _CamelMimeFilterGZipPrivate {
+	z_stream *stream;
+	
+	gzip_state_t state;
+	gzip_hdr_t hdr;
+	
+	guint32 crc32;
+	guint32 isize;
+};
+
+static void camel_mime_filter_gzip_class_init (CamelMimeFilterGZipClass *klass);
+static void camel_mime_filter_gzip_init (CamelMimeFilterGZip *filter, CamelMimeFilterGZipClass *klass);
+static void camel_mime_filter_gzip_finalize (CamelObject *object);
+
+static void filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
+			   char **out, size_t *outlen, size_t *outprespace);
+static void filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
+			     char **out, size_t *outlen, size_t *outprespace);
+static void filter_reset (CamelMimeFilter *filter);
+
+
+static CamelMimeFilterClass *parent_class = NULL;
+
+
+CamelType
+camel_mime_filter_gzip_get_type (void)
+{
+	static CamelType type = CAMEL_INVALID_TYPE;
+	
+	if (type == CAMEL_INVALID_TYPE) {
+		type = camel_type_register (camel_mime_filter_get_type (),
+					    "CamelMimeFilterGZip",
+					    sizeof (CamelMimeFilterGZip),
+					    sizeof (CamelMimeFilterGZipClass),
+					    (CamelObjectClassInitFunc) camel_mime_filter_gzip_class_init,
+					    NULL,
+					    (CamelObjectInitFunc) camel_mime_filter_gzip_init,
+					    (CamelObjectFinalizeFunc) camel_mime_filter_gzip_finalize);
+	}
+	
+	return type;
+}
+
+
+static void
+camel_mime_filter_gzip_class_init (CamelMimeFilterGZipClass *klass)
+{
+	CamelMimeFilterClass *filter_class = (CamelMimeFilterClass *) klass;
+	
+	parent_class = CAMEL_MIME_FILTER_CLASS (camel_type_get_global_classfuncs (camel_mime_filter_get_type ()));
+	
+	filter_class->reset = filter_reset;
+	filter_class->filter = filter_filter;
+	filter_class->complete = filter_complete;
+}
+
+static void
+camel_mime_filter_gzip_init (CamelMimeFilterGZip *filter, CamelMimeFilterGZipClass *klass)
+{
+	filter->priv = g_new0 (struct _CamelMimeFilterGZipPrivate, 1);
+	filter->priv->stream = g_new0 (z_stream, 1);
+	filter->priv->crc32 = crc32 (0, Z_NULL, 0);
+}
+
+static void
+camel_mime_filter_gzip_finalize (CamelObject *object)
+{
+	CamelMimeFilterGZip *gzip = (CamelMimeFilterGZip *) object;
+	struct _CamelMimeFilterGZipPrivate *priv = gzip->priv;
+	
+	g_free (priv->stream);
+	g_free (priv);
+}
+
+
+static void
+gzip_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
+	     char **out, size_t *outlen, size_t *outprespace, int flush)
+{
+	CamelMimeFilterGZip *gzip = (CamelMimeFilterGZip *) filter;
+	struct _CamelMimeFilterGZipPrivate *priv = gzip->priv;
+	int retval;
+	
+	if (!priv->state.zip.wrote_hdr) {
+		priv->hdr.v.id1 = 31;
+		priv->hdr.v.id2 = 139;
+		priv->hdr.v.cm = Z_DEFLATED;
+		priv->hdr.v.mtime = 0;
+		priv->hdr.v.flg = 0;
+		if (gzip->level == Z_BEST_COMPRESSION)
+			priv->hdr.v.xfl = 2;
+		else if (gzip->level == Z_BEST_SPEED)
+			priv->hdr.v.xfl = 4;
+		else
+			priv->hdr.v.xfl = 0;
+		priv->hdr.v.os = 255;
+		
+		camel_mime_filter_set_size (filter, (len * 2) + 22, FALSE);
+		
+		memcpy (filter->outbuf, priv->hdr.buf, 10);
+		
+		priv->stream->next_out = filter->outbuf + 10;
+		priv->stream->avail_out = filter->outsize - 10;
+		
+		priv->state.zip.wrote_hdr = TRUE;
+	} else {
+		camel_mime_filter_set_size (filter, (len * 2) + 12, FALSE);
+		
+		priv->stream->next_out = filter->outbuf;
+		priv->stream->avail_out = filter->outsize;
+	}
+	
+	priv->stream->next_in = in;
+	priv->stream->avail_in = len;
+	
+	do {
+		/* FIXME: handle error cases? */
+		if ((retval = deflate (priv->stream, flush)) != Z_OK)
+			fprintf (stderr, "gzip: %d: %s\n", retval, priv->stream->msg);
+		
+		if (flush == Z_FULL_FLUSH) {
+			size_t outlen;
+			
+			outlen = filter->outsize - priv->stream->avail_out;
+			camel_mime_filter_set_size (filter, outlen + (priv->stream->avail_in * 2) + 12, TRUE);
+			priv->stream->avail_out = filter->outsize - outlen;
+			priv->stream->next_out = filter->outbuf + outlen;
+			
+			if (priv->stream->avail_in == 0) {
+				guint32 val;
+				
+				val = GUINT32_TO_LE (priv->crc32);
+				memcpy (priv->stream->next_out, &val, 4);
+				priv->stream->avail_out -= 4;
+				priv->stream->next_out += 4;
+				
+				val = GUINT32_TO_LE (priv->isize);
+				memcpy (priv->stream->next_out, &val, 4);
+				priv->stream->avail_out -= 4;
+				priv->stream->next_out += 4;
+				
+				break;
+			}
+		} else {
+			if (priv->stream->avail_in > 0)
+				camel_mime_filter_backup (filter, priv->stream->next_in, priv->stream->avail_in);
+			
+			break;
+		}
+	} while (1);
+	
+	priv->crc32 = crc32 (priv->crc32, in, len - priv->stream->avail_in);
+	priv->isize += len - priv->stream->avail_in;
+	
+	*out = filter->outbuf;
+	*outlen = filter->outsize - priv->stream->avail_out;
+	*outprespace = filter->outpre;
+}
+
+static void
+gunzip_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
+	       char **out, size_t *outlen, size_t *outprespace, int flush)
+{
+	CamelMimeFilterGZip *gzip = (CamelMimeFilterGZip *) filter;
+	struct _CamelMimeFilterGZipPrivate *priv = gzip->priv;
+	guint16 need, val;
+	int retval;
+	
+	if (!priv->state.unzip.got_hdr) {
+		if (len < 10) {
+			camel_mime_filter_backup (filter, in, len);
+			return;
+		}
+		
+		memcpy (priv->hdr.buf, in, 10);
+		priv->state.unzip.got_hdr = TRUE;
+		len -= 10;
+		in += 10;
+		
+		priv->state.unzip.is_valid = (priv->hdr.v.id1 == 31 &&
+					      priv->hdr.v.id2 == 139 &&
+					      priv->hdr.v.cm == Z_DEFLATED);
+	}
+	
+	if (!priv->state.unzip.is_valid)
+		return;
+	
+	if (priv->hdr.v.flg & GZIP_FLAG_FEXTRA) {
+		if (!priv->state.unzip.got_xlen) {
+			if (len < 2) {
+				camel_mime_filter_backup (filter, in, len);
+				return;
+			}
+			
+			memcpy (&val, in, 2);
+			priv->state.unzip.xlen = GUINT16_FROM_LE (val);
+			priv->state.unzip.got_xlen = TRUE;
+			len -= 2;
+			in += 2;
+		}
+		
+		if (priv->state.unzip.xlen_nread < priv->state.unzip.xlen) {
+			need = priv->state.unzip.xlen - priv->state.unzip.xlen_nread;
+			
+			if (need < len) {
+				priv->state.unzip.xlen_nread += need;
+				len -= need;
+				in += need;
+			} else {
+				priv->state.unzip.xlen_nread += len;
+				return;
+			}
+		}
+	}
+	
+	if ((priv->hdr.v.flg & GZIP_FLAG_FNAME) && !priv->state.unzip.got_fname) {
+		while (*in && len > 0) {
+			len--;
+			in++;
+		}
+		
+		if (*in == '\0' && len > 0) {
+			priv->state.unzip.got_fname = TRUE;
+			len--;
+			in++;
+		} else {
+			return;
+		}
+	}
+	
+	if ((priv->hdr.v.flg & GZIP_FLAG_FCOMMENT) && !priv->state.unzip.got_fcomment) {
+		while (*in && len > 0) {
+			len--;
+			in++;
+		}
+		
+		if (*in == '\0' && len > 0) {
+			priv->state.unzip.got_fcomment = TRUE;
+			len--;
+			in++;
+		} else {
+			return;
+		}
+	}
+	
+	if ((priv->hdr.v.flg & GZIP_FLAG_FHCRC) && !priv->state.unzip.got_crc16) {
+		if (len < 2) {
+			camel_mime_filter_backup (filter, in, len);
+			return;
+		}
+		
+		memcpy (&val, in, 2);
+		priv->state.unzip.crc16 = GUINT16_FROM_LE (val);
+		len -= 2;
+		in += 2;
+	}
+	
+	if (len == 0)
+		return;
+	
+	camel_mime_filter_set_size (filter, (len * 2) + 12, FALSE);
+	
+	priv->stream->next_in = in;
+	priv->stream->avail_in = len - 8;
+	
+	priv->stream->next_out = filter->outbuf;
+	priv->stream->avail_out = filter->outsize;
+	
+	do {
+		/* FIXME: handle error cases? */
+		if ((retval = inflate (priv->stream, flush)) != Z_OK)
+			fprintf (stderr, "gunzip: %d: %s\n", retval, priv->stream->msg);
+		
+		if (flush == Z_FULL_FLUSH) {
+			size_t outlen;
+			
+			if (priv->stream->avail_in == 0) {
+				/* FIXME: extract & compare calculated crc32 and isize values? */
+				break;
+			}
+			
+			outlen = filter->outsize - priv->stream->avail_out;
+			camel_mime_filter_set_size (filter, outlen + (priv->stream->avail_in * 2) + 12, TRUE);
+			priv->stream->avail_out = filter->outsize - outlen;
+			priv->stream->next_out = filter->outbuf + outlen;
+		} else {
+			priv->stream->avail_in += 8;
+			
+			if (priv->stream->avail_in > 0)
+				camel_mime_filter_backup (filter, priv->stream->next_in, priv->stream->avail_in);
+			
+			break;
+		}
+	} while (1);
+	
+	/* FIXME: if we keep this, we could check that the gzip'd
+	 * stream is sane, but how would we tell our consumer if it
+	 * was/wasn't? */
+	/*priv->crc32 = crc32 (priv->crc32, in, len - priv->stream->avail_in - 8);
+	  priv->isize += len - priv->stream->avail_in - 8;*/
+	
+	*out = filter->outbuf;
+	*outlen = filter->outsize - priv->stream->avail_out;
+	*outprespace = filter->outpre;
+}
+
+static void
+filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
+	       char **out, size_t *outlen, size_t *outprespace)
+{
+	CamelMimeFilterGZip *gzip = (CamelMimeFilterGZip *) filter;
+	
+	if (gzip->mode == CAMEL_MIME_FILTER_GZIP_MODE_ZIP)
+		gzip_filter (filter, in, len, prespace, out, outlen, outprespace, Z_SYNC_FLUSH);
+	else
+		gunzip_filter (filter, in, len, prespace, out, outlen, outprespace, Z_SYNC_FLUSH);
+}
+
+static void
+filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
+		 char **out, size_t *outlen, size_t *outprespace)
+{
+	CamelMimeFilterGZip *gzip = (CamelMimeFilterGZip *) filter;
+	
+	if (gzip->mode == CAMEL_MIME_FILTER_GZIP_MODE_ZIP)
+		gzip_filter (filter, in, len, prespace, out, outlen, outprespace, Z_FULL_FLUSH);
+	else
+		gunzip_filter (filter, in, len, prespace, out, outlen, outprespace, Z_FULL_FLUSH);
+}
+
+/* should this 'flush' outstanding state/data bytes? */
+static void
+filter_reset (CamelMimeFilter *filter)
+{
+	CamelMimeFilterGZip *gzip = (CamelMimeFilterGZip *) filter;
+	struct _CamelMimeFilterGZipPrivate *priv = gzip->priv;
+	
+	memset (&priv->state, 0, sizeof (priv->state));
+	
+	if (gzip->mode == CAMEL_MIME_FILTER_GZIP_MODE_ZIP)
+		deflateReset (priv->stream);
+	else
+		inflateReset (priv->stream);
+	
+	priv->crc32 = crc32 (0, Z_NULL, 0);
+	priv->isize = 0;
+}
+
+
+/**
+ * camel_mime_filter_gzip_new:
+ * @mode: zip or unzip
+ * @level: compression level
+ *
+ * Creates a new gzip (or gunzip) filter.
+ *
+ * Returns a new gzip (or gunzip) filter.
+ **/
+CamelMimeFilter *
+camel_mime_filter_gzip_new (CamelMimeFilterGZipMode mode, int level)
+{
+	CamelMimeFilterGZip *new;
+	int retval;
+	
+	new = (CamelMimeFilterGZip *) camel_object_new (CAMEL_TYPE_MIME_FILTER_GZIP);
+	new->mode = mode;
+	new->level = level;
+	
+	if (mode == CAMEL_MIME_FILTER_GZIP_MODE_ZIP)
+		retval = deflateInit2 (new->priv->stream, level, Z_DEFLATED, -MAX_WBITS, MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+	else
+		retval = inflateInit2 (new->priv->stream, -MAX_WBITS);
+	
+	if (retval != Z_OK) {
+		camel_object_unref (new);
+		return NULL;
+	}
+	
+	return (CamelMimeFilter *) new;
+}