1 files changed, 442 insertions, 0 deletions
diff --git a/camel/camel-seekable-substream.c b/camel/camel-seekable-substream.c
new file mode 100644
index 0000000000..270bae113f
--- /dev/null
+++ b/camel/camel-seekable-substream.c
@@ -0,0 +1,442 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/* camel-stream-fs.c : file system based stream */
+
+/* inspired by gnome-stream-fs.c in bonobo by Miguel de Icaza */
+/* 
+ *
+ * Author : 
+ *  Bertrand Guiheneuf <bertrand@helixcode.com>
+ *
+ * Copyright 1999, 2000 HelixCode (http://www.helixcode.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 Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+#include <config.h>
+#include "camel-seekable-substream.h"
+#include "camel-log.h"
+
+static CamelSeekableStreamClass *parent_class=NULL;
+
+
+/* Returns the class for a CamelSeekableSubStream */
+#define CSS_CLASS(so) CAMEL_SEEKABLE_SUBSTREAM_CLASS (GTK_OBJECT(so)->klass)
+
+
+
+
+static	gint	       _read			      (CamelStream *stream, 
+						       gchar *buffer, gint n);
+static	gint	       _write			      (CamelStream *stream, 
+						       const gchar *buffer, 
+						       gint n);
+static	void	       _flush			      (CamelStream *stream);
+static	gint	       _available		      (CamelStream *stream);
+static	gboolean       _eos			      (CamelStream *stream);
+static	void	       _close			      (CamelStream *stream);
+static	gint	       _seek			      (CamelSeekableStream *stream, 
+						       gint offset, 
+						       CamelStreamSeekPolicy policy);
+
+static	void	       _finalize		      (GtkObject *object);
+static	void	       _destroy			      (GtkObject *object);
+
+static	void	       _init_with_seekable_stream_and_bounds	 (CamelSeekableSubstream *seekable_substream, 
+								  CamelSeekableStream *parent_stream,
+								  guint32 inf_bound, 
+								  guint32 sup_bound);
+
+
+
+
+static void
+camel_seekable_substream_class_init (CamelSeekableSubstreamClass *camel_seekable_substream_class)
+{
+	CamelSeekableStreamClass *camel_seekable_stream_class = CAMEL_SEEKABLE_STREAM_CLASS (camel_seekable_substream_class);
+	CamelStreamClass *camel_stream_class = CAMEL_STREAM_CLASS (camel_seekable_substream_class);
+	GtkObjectClass *gtk_object_class = GTK_OBJECT_CLASS (camel_seekable_substream_class);
+
+	parent_class = gtk_type_class (camel_seekable_stream_get_type ());
+	
+	/* virtual method definition */
+	camel_seekable_substream_class->init_with_seekable_stream_and_bounds = _init_with_seekable_stream_and_bounds;
+	
+	/* virtual method overload */
+	camel_stream_class->read = _read;
+	camel_stream_class->write = _write;
+	camel_stream_class->flush = _flush;
+	camel_stream_class->available = _available;
+	camel_stream_class->eos = _eos;
+	camel_stream_class->close = _close;
+
+	camel_seekable_stream_class->seek = _seek;
+
+	gtk_object_class->finalize = _finalize;
+	gtk_object_class->destroy = _destroy;
+
+}
+
+static void
+camel_seekable_substream_init (gpointer   object,  gpointer   klass)
+{
+	/* does nothing */
+}
+
+
+
+
+GtkType
+camel_seekable_substream_get_type (void)
+{
+	static GtkType camel_seekable_substream_type = 0;
+	
+	if (!camel_seekable_substream_type)	{
+		GtkTypeInfo camel_seekable_substream_info =	
+		{
+			"CamelSeekableSubstream",
+			sizeof (CamelSeekableSubstream),
+			sizeof (CamelSeekableSubstreamClass),
+			(GtkClassInitFunc) camel_seekable_substream_class_init,
+			(GtkObjectInitFunc) camel_seekable_substream_init,
+				/* reserved_1 */ NULL,
+				/* reserved_2 */ NULL,
+			(GtkClassInitFunc) NULL,
+		};
+		
+		camel_seekable_substream_type = gtk_type_unique (camel_seekable_stream_get_type (), &camel_seekable_substream_info);
+	}
+	
+	return camel_seekable_substream_type;
+}
+
+
+
+
+
+
+static void           
+_destroy (GtkObject *object)
+{
+	
+	CAMEL_LOG_FULL_DEBUG ("Entering CamelSeekableSubstream::destroy\n");
+	
+	/* does nothing for the moment */
+	GTK_OBJECT_CLASS (parent_class)->destroy (object);
+	
+	CAMEL_LOG_FULL_DEBUG ("Leaving CamelSeekableSubstream::destroy\n");
+}
+
+
+static void           
+_finalize (GtkObject *object)
+{
+
+
+	CAMEL_LOG_FULL_DEBUG ("Entering CamelSeekableSubstream::finalize\n");
+	
+	/* does nothing for the moment */
+	GTK_OBJECT_CLASS (parent_class)->finalize (object);
+	CAMEL_LOG_FULL_DEBUG ("Leaving CamelSeekableSubstream::finalize\n");
+}
+
+
+
+static void 
+_set_bounds (CamelSeekableSubstream *seekable_substream, guint32 inf_bound, guint32 sup_bound)
+{
+	CAMEL_LOG_FULL_DEBUG ("CamelSeekableSubstream::_set_bounds entering\n");
+
+	g_assert (seekable_substream);
+	g_assert (seekable_substream->parent_stream);
+	
+	/* store the bounds */
+	seekable_substream->inf_bound = inf_bound;
+	seekable_substream->sup_bound = sup_bound;
+
+	/* go to the first position */
+	camel_seekable_stream_seek (seekable_substream->parent_stream, inf_bound, SEEK_SET);
+
+	seekable_substream->cur_pos = inf_bound;
+	
+	CAMEL_LOG_FULL_DEBUG ("In CamelSeekableSubstream::_set_bounds, "
+			      "setting inf bound to %u, "
+			      "sup bound to %ld, current postion to %u from %u\n", 
+			      seekable_substream->inf_bound, seekable_substream->sup_bound,
+			      seekable_substream->cur_pos, inf_bound);
+	
+	CAMEL_LOG_FULL_DEBUG ("CamelSeekableSubstream::_set_bounds Leaving\n");
+}
+
+
+
+static void 	   
+_init_with_seekable_stream_and_bounds	 (CamelSeekableSubstream *seekable_substream, 
+					  CamelSeekableStream    *parent_stream,
+					  guint32                 inf_bound, 
+					  guint32                  sup_bound)
+{
+	/* sanity checks */
+	g_assert (seekable_substream);
+	g_assert (!seekable_substream->parent_stream);
+	g_assert (parent_stream);
+	
+	/* store the parent stream */
+	seekable_substream->parent_stream = parent_stream;
+	
+	/* set the bound of the substream */
+	_set_bounds (seekable_substream, inf_bound, sup_bound);
+}
+
+
+void
+camel_seekable_substream_init_with_seekable_stream_and_bounds (CamelSeekableSubstream *seekable_substream, 
+							       CamelSeekableStream    *parent_stream,
+							       guint32                 inf_bound, 
+							       guint32                  sup_bound)
+{
+	
+	CSS_CLASS (seekable_substream)->init_with_seekable_stream_and_bounds (seekable_substream,
+									      parent_stream,
+									      inf_bound,
+									      sup_bound);
+	
+}
+
+
+
+
+
+/**
+ * _read: read bytes from a stream
+ * @stream: stream
+ * @buffer: buffer where bytes are stored
+ * @n: max number of bytes to read
+ * 
+ * 
+ * 
+ * Return value: number of bytes actually read.
+ **/
+static gint
+_read (CamelStream *stream, gchar *buffer, gint n)
+{
+	CamelSeekableStream *seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
+	CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
+	gint v;
+	gint nb_to_read;
+	guint32 parent_stream_current_position;
+	guint32 position_in_parent;
+	
+	g_assert (stream);
+	g_assert (seekable_substream->parent_stream);
+	g_assert (seekable_substream->open);
+
+
+
+	/* 
+	   we are doing something quite infefficient : 
+	   
+	   each time we want to read a block, we store
+	   the parent stream position so that we can 
+	   change it, and restore it before returning 
+
+	   This may change. I don't know yet. 
+	   It may be useless to reseek every time
+	   and is incompatible with buffering. 
+	*/
+
+	parent_stream_current_position = 
+		camel_seekable_stream_get_current_position (seekable_substream->parent_stream);
+
+	/* compute the position in the parent stream */
+	position_in_parent =  
+		seekable_stream->cur_pos + seekable_substream->inf_bound;
+		
+	/* go to our position in the parent stream */
+	camel_seekable_stream_seek (seekable_substream->parent_stream, 
+				    position_in_parent,
+				    CAMEL_STREAM_SET);
+
+
+
+	/* compute how much byte should be read */
+	nb_to_read = 
+		MIN (seekable_substream->sup_bound - position_in_parent, n);
+
+	
+	/* Read the data */
+	if (nb_to_read >0 )
+		v = camel_stream_read ( CAMEL_STREAM (seekable_substream->parent_stream), 
+					buffer, 
+					nb_to_read);
+	else 
+		v = 0;
+
+	/* if the return value is negative, an error occured, 
+	   we must do something  FIXME : handle exception */ 
+	if (v<0)
+		CAMEL_LOG_FULL_DEBUG ("CamelSeekableSubstream::read v=%d\n", v);
+	else 
+		seekable_stream->cur_pos += v;
+
+
+	/* restore the parent position */
+	camel_seekable_stream_seek (seekable_substream->parent_stream, 
+				    parent_stream_current_position,
+				    CAMEL_STREAM_SET);
+
+	
+	/* return the number of bytes read */
+	return v;
+}
+
+
+/**
+ * _write: write bytes to a stream
+ * @stream: the stream
+ * @buffer: byte buffer
+ * @n: number of bytes to write
+ * 
+ * 
+ * 
+ * Return value: the number of bytes actually written
+ *  in the stream.
+ **/
+static gint
+_write (CamelStream *stream, const gchar *buffer, gint n)
+{
+	/* NOT VALID ON SEEKABLE SUBSTREAM */
+	g_warning ("CamelSeekableSubstream:: seekable substream don't have a write method\n");
+	CAMEL_LOG_WARNING ( "CamelSeekableSubstream:: seekable substream don't have a write method\n");
+	return -1;
+}
+
+
+
+/**
+ * _flush: flush pending changes 
+ * @stream: the stream
+ * 
+ * 
+ **/
+static void
+_flush (CamelStream *stream)
+{
+	/* NOT VALID ON SEEKABLE SUBSTREAM */
+	g_warning ("CamelSeekableSubstream:: seekable substream don't have a flush method\n");
+	CAMEL_LOG_WARNING ( "CamelSeekableSubstream:: seekable substream don't have a flush method\n");
+}
+
+
+
+/**
+ * _available: return the number of bytes available for reading
+ * @stream: the stream
+ * 
+ * Return the number of bytes available without blocking.
+ * 
+ * Return value: the number of bytes available
+ **/
+static gint 
+_available (CamelStream *stream)
+{
+	g_warning ("not implemented\n");
+	return -1;
+}
+
+
+/**
+ * _eos: test if there are bytes left to read
+ * @stream: the stream
+ * 
+ * 
+ * 
+ * Return value: true if all stream has been read
+ **/
+static gboolean
+_eos (CamelStream *stream)
+{
+	CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
+	CamelSeekableStream *seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
+	guint32 substream_len;
+
+
+	g_assert (stream);
+	g_assert (seekable_substream->open);
+	
+	substream_len = seekable_substream->sup_bound - seekable_substream->inf_bound;
+	
+	return ( seekable_stream->cur_pos > substream_len);
+}
+
+
+/**
+ * _close: close a stream
+ * @stream: the stream
+ * 
+ * 
+ **/
+static void
+_close (CamelStream *stream)
+{
+	CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
+
+	g_assert (stream);
+	seekable_substream->open = FALSE;
+}
+
+
+static gint
+_seek (CamelSeekableStream *stream, gint offset, CamelStreamSeekPolicy policy)
+{
+	CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
+	CamelSeekableStream *seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
+	gint64 real_offset; 
+	guint32 substream_len;
+
+
+	substream_len = seekable_substream->sup_bound - seekable_substream->inf_bound;
+
+	switch  (policy) {
+
+	case CAMEL_STREAM_SET:
+		real_offset = offset;
+		
+		break;
+
+	case CAMEL_STREAM_CUR:
+		real_offset = seekable_stream->cur_pos + offset;
+		
+		break;
+
+	case CAMEL_STREAM_END:
+		real_offset = substream_len - offset;
+
+		break;
+
+	default:
+		return -1;
+	}
+		
+	if (real_offset > 0) {
+		seekable_stream->cur_pos = MIN (real_offset, substream_len);
+	} else 
+		seekable_stream->cur_pos = 0;
+	
+	
+
+	return seekable_stream->cur_pos;
+}
+
+