/* -*- 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 * * 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 #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, gint64 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) { CamelSeekableStream *seekable_stream; CAMEL_LOG_FULL_DEBUG ("Entering CamelSeekableSubstream::finalize\n"); seekable_stream = CAMEL_SEEKABLE_STREAM (object); if (seekable_stream->parent_stream) gtk_object_unref (seekable_stream->parent_stream); 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, gint64 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; seekable_substream->cur_pos = 0; CAMEL_LOG_FULL_DEBUG ("In CamelSeekableSubstream::_set_bounds, " "setting inf bound to %lu, " "sup bound to %lld, current position to %lu from %lu\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, gint64 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; gtk_object_ref (parent_stream); /* set the bound of the substream */ _set_bounds (seekable_substream, inf_bound, sup_bound); } CamelSeekableSubstream * camel_seekable_substream_new_with_seekable_stream_and_bounds (CamelSeekableStream *parent_stream, guint32 inf_bound, gint64 sup_bound) { CamelSeekableSubstream *seekable_substream; /* create the seekable substream */ seekable_substream = gtk_type_new (camel_seekable_substream_get_type ()); /* initialize it */ CSS_CLASS (seekable_substream)->init_with_seekable_stream_and_bounds (seekable_substream, parent_stream, inf_bound, sup_bound); return seekable_substream; } /** * _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); /* 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 */ if (parent_stream_current_position != position_in_parent) camel_seekable_stream_seek (seekable_substream->parent_stream, position_in_parent, CAMEL_STREAM_SET); /* compute how much byte should be read */ if (seekable_substream->sup_bound != -1) nb_to_read = MIN (seekable_substream->sup_bound - position_in_parent, n); else nb_to_read = 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; /* 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; gboolean eos; g_assert (stream); if (seekable_substream->sup_bound != -1) { substream_len = seekable_substream->sup_bound - seekable_substream->inf_bound; eos = ( seekable_stream->cur_pos >= substream_len); } else { eos = camel_stream_eos (CAMEL_STREAM (seekable_substream->parent_stream)); } return eos; } /** * _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 = 0; guint32 substream_len; guint32 parent_pos; gboolean seek_done = FALSE; 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: if (seekable_substream->sup_bound != -1) real_offset = substream_len - offset; else { parent_pos = camel_seekable_stream_seek (seekable_substream->parent_stream, offset, CAMEL_STREAM_END); seekable_stream->cur_pos = parent_pos - seekable_substream->inf_bound; seek_done = TRUE; } break; default: return -1; } if (!seek_done) { if (real_offset > 0) { seekable_stream->cur_pos = MIN (real_offset, substream_len); } else seekable_stream->cur_pos = 0; } return seekable_stream->cur_pos; }