git.gag.com Git - debian/amanda/blob - device-src/xfer-source-device.c

   1 /*
   2  * Amanda, The Advanced Maryland Automatic Network Disk Archiver
   3  * Copyright (c) 2009 Zmanda, Inc.  All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published
   7  * by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  *
  18  * Contact information: Zmanda Inc., 465 S. Mathilda Ave., Suite 300
  19  * Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
  20  */
  21
  22 #include "amanda.h"
  23 #include "amxfer.h"
  24 #include "device.h"
  25 #include "property.h"
  26 #include "xfer-device.h"
  27
  28 /*
  29  * Class declaration
  30  *
  31  * This declaration is entirely private; nothing but xfer_source_device() references
  32  * it directly.
  33  */
  34
  35 GType xfer_source_device_get_type(void);
  36 #define XFER_SOURCE_DEVICE_TYPE (xfer_source_device_get_type())
  37 #define XFER_SOURCE_DEVICE(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_device_get_type(), XferSourceDevice)
  38 #define XFER_SOURCE_DEVICE_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_device_get_type(), XferSourceDevice const)
  39 #define XFER_SOURCE_DEVICE_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_source_device_get_type(), XferSourceDeviceClass)
  40 #define IS_XFER_SOURCE_DEVICE(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_source_device_get_type ())
  41 #define XFER_SOURCE_DEVICE_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_source_device_get_type(), XferSourceDeviceClass)
  42
  43 static GObjectClass *parent_class = NULL;
  44
  45 /*
  46  * Main object structure
  47  */
  48
  49 typedef struct XferSourceDevice {
  50     XferElement __parent__;
  51
  52     Device *device;
  53     size_t block_size;
  54     gboolean cancelled;
  55 } XferSourceDevice;
  56
  57 /*
  58  * Class definition
  59  */
  60
  61 typedef struct {
  62     XferElementClass __parent__;
  63 } XferSourceDeviceClass;
  64
  65 /*
  66  * Implementation
  67  */
  68
  69 static gpointer
  70 pull_buffer_impl(
  71     XferElement *elt,
  72     size_t *size)
  73 {
  74     XferSourceDevice *self = (XferSourceDevice *)elt;
  75     gpointer buf = NULL;
  76     int result;
  77     int devsize;
  78
  79     /* indicate EOF on an cancel */
  80     if (elt->cancelled) {
  81         *size = 0;
  82         return NULL;
  83     }
  84
  85     /* get the device block size */
  86     if (self->block_size == 0) {
  87         self->block_size = self->device->block_size;
  88     }
  89
  90     do {
  91         buf = g_malloc(self->block_size);
  92         devsize = (int)self->block_size;
  93         result = device_read_block(self->device, buf, &devsize);
  94         *size = devsize;
  95
  96         /* if the buffer was too small, loop around again */
  97         if (result == 0) {
  98             g_assert(*size > self->block_size);
  99             self->block_size = devsize;
 100             amfree(buf);
 101         }
 102     } while (result == 0);
 103
 104     if (result < 0) {
 105         amfree(buf);
 106
 107         /* if we're not at EOF, it's an error */
 108         if (!self->device->is_eof) {
 109             xfer_cancel_with_error(elt,
 110                 _("error reading from %s: %s"),
 111                 self->device->device_name,
 112                 device_error_or_status(self->device));
 113             wait_until_xfer_cancelled(elt->xfer);
 114         }
 115
 116         *size = 0;
 117         return NULL;
 118     }
 119
 120     return buf;
 121 }
 122
 123 static void
 124 instance_init(
 125     XferElement *elt)
 126 {
 127     elt->can_generate_eof = TRUE;
 128 }
 129
 130 static void
 131 class_init(
 132     XferSourceDeviceClass * selfc)
 133 {
 134     XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
 135     static xfer_element_mech_pair_t mech_pairs[] = {
 136         { XFER_MECH_NONE, XFER_MECH_PULL_BUFFER, 0, 1},
 137         { XFER_MECH_NONE, XFER_MECH_NONE, 0, 0},
 138     };
 139
 140     klass->pull_buffer = pull_buffer_impl;
 141
 142     klass->perl_class = "Amanda::Xfer::Source::Device";
 143     klass->mech_pairs = mech_pairs;
 144
 145     parent_class = g_type_class_peek_parent(selfc);
 146 }
 147
 148 GType
 149 xfer_source_device_get_type (void)
 150 {
 151     static GType type = 0;
 152
 153     if G_UNLIKELY(type == 0) {
 154         static const GTypeInfo info = {
 155             sizeof (XferSourceDeviceClass),
 156             (GBaseInitFunc) NULL,
 157             (GBaseFinalizeFunc) NULL,
 158             (GClassInitFunc) class_init,
 159             (GClassFinalizeFunc) NULL,
 160             NULL /* class_data */,
 161             sizeof (XferSourceDevice),
 162             0 /* n_preallocs */,
 163             (GInstanceInitFunc) instance_init,
 164             NULL
 165         };
 166
 167         type = g_type_register_static (XFER_ELEMENT_TYPE, "XferSourceDevice", &info, 0);
 168     }
 169
 170     return type;
 171 }
 172
 173 /* create an element of this class; prototype is in xfer-device.h */
 174 XferElement *
 175 xfer_source_device(
 176     Device *device)
 177 {
 178     XferSourceDevice *self = (XferSourceDevice *)g_object_new(XFER_SOURCE_DEVICE_TYPE, NULL);
 179     XferElement *elt = XFER_ELEMENT(self);
 180
 181     g_assert(device != NULL);
 182
 183     self->device = device;
 184
 185     return elt;
 186 }