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

   1 /*
   2  * Amanda, The Advanced Maryland Automatic Network Disk Archiver
   3  * Copyright (c) 2009, 2010 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_dest_device() references
  32  * it directly.
  33  */
  34
  35 GType xfer_dest_device_get_type(void);
  36 #define XFER_DEST_DEVICE_TYPE (xfer_dest_device_get_type())
  37 #define XFER_DEST_DEVICE(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_dest_device_get_type(), XferDestDevice)
  38 #define XFER_DEST_DEVICE_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_dest_device_get_type(), XferDestDevice const)
  39 #define XFER_DEST_DEVICE_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_dest_device_get_type(), XferDestDeviceClass)
  40 #define IS_XFER_DEST_DEVICE(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_dest_device_get_type ())
  41 #define XFER_DEST_DEVICE_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_dest_device_get_type(), XferDestDeviceClass)
  42
  43 static GObjectClass *parent_class = NULL;
  44
  45 /*
  46  * Main object structure
  47  */
  48
  49 typedef struct XferDestDevice {
  50     XferElement __parent__;
  51
  52     Device *device;
  53
  54     gboolean cancel_at_leom;
  55
  56     gpointer partial;
  57     gsize block_size;
  58     gsize partial_length;
  59 } XferDestDevice;
  60
  61 /*
  62  * Class definition
  63  */
  64
  65 typedef struct {
  66     XferElementClass __parent__;
  67 } XferDestDeviceClass;
  68
  69 /*
  70  * Implementation
  71  */
  72
  73 static gboolean
  74 do_block(
  75     XferDestDevice *self,
  76     guint size,
  77     gpointer data)
  78 {
  79     XferElement *elt = XFER_ELEMENT(self);
  80
  81     if (!device_write_block(self->device, size, data)) {
  82         xfer_cancel_with_error(elt, "%s: %s",
  83                 self->device->device_name, device_error_or_status(self->device));
  84         wait_until_xfer_cancelled(elt->xfer);
  85         return FALSE;
  86     }
  87
  88     /* check for LEOM */
  89     if (self->cancel_at_leom && self->device->is_eom) {
  90         xfer_cancel_with_error(elt, "%s: LEOM detected", self->device->device_name);
  91         wait_until_xfer_cancelled(elt->xfer);
  92         return FALSE;
  93     }
  94
  95     return TRUE;
  96 }
  97
  98 static void
  99 push_buffer_impl(
 100     XferElement *elt,
 101     gpointer buf,
 102     size_t len)
 103 {
 104     XferDestDevice *self = XFER_DEST_DEVICE(elt);
 105     gpointer to_free = buf;
 106
 107     /* Handle EOF */
 108     if (!buf) {
 109         /* write out the partial buffer, if there's anything in it */
 110         if (self->partial_length) {
 111             if (!do_block(self, self->block_size, self->partial)) {
 112                 return;
 113             }
 114             self->partial_length = 0;
 115         }
 116
 117         device_finish_file(self->device);
 118         return;
 119     }
 120
 121     /* set up the block buffer, now that we can depend on having a blocksize
 122      * from the device */
 123     if (!self->partial) {
 124         self->partial = g_malloc(self->device->block_size);
 125         self->block_size = self->device->block_size;
 126         self->partial_length = 0;
 127     }
 128
 129     /* if we already have data in the buffer, add the new data to it */
 130     if (self->partial_length != 0) {
 131         gsize to_copy = min(self->block_size - self->partial_length, len);
 132         memmove(self->partial + self->partial_length, buf, to_copy);
 133         buf = (gpointer)(to_copy + (char *)buf);
 134         len -= to_copy;
 135         self->partial_length += to_copy;
 136     }
 137
 138     /* and if the buffer is now full, write the block */
 139     if (self->partial_length == self->block_size) {
 140         if (!do_block(self, self->block_size, self->partial)) {
 141             g_free(to_free);
 142             return;
 143         }
 144         self->partial_length = 0;
 145     }
 146
 147     /* write any whole blocks directly from the push buffer */
 148     while (len >= self->block_size) {
 149         if (!do_block(self, self->block_size, buf)) {
 150             g_free(to_free);
 151             return;
 152         }
 153
 154         buf = (gpointer)(self->block_size + (char *)buf);
 155         len -= self->block_size;
 156     }
 157
 158     /* and finally store any leftover data in the partial buffer */
 159     if (len) {
 160         memmove(self->partial, buf, len);
 161         self->partial_length = len;
 162     }
 163
 164     g_free(to_free);
 165 }
 166
 167 static void
 168 instance_init(
 169     XferElement *elt)
 170 {
 171     XferDestDevice *self = XFER_DEST_DEVICE(elt);
 172     self->partial = NULL;
 173 }
 174
 175 static void
 176 finalize_impl(
 177     GObject * obj_self)
 178 {
 179     XferDestDevice *self = XFER_DEST_DEVICE(obj_self);
 180
 181     if (self->partial) {
 182         g_free(self->partial);
 183     }
 184 }
 185
 186 static void
 187 class_init(
 188     XferDestDeviceClass * selfc)
 189 {
 190     XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
 191     GObjectClass *goc = (GObjectClass*) klass;
 192     static xfer_element_mech_pair_t mech_pairs[] = {
 193         { XFER_MECH_PUSH_BUFFER, XFER_MECH_NONE, 0, 0},
 194         { XFER_MECH_NONE, XFER_MECH_NONE, 0, 0},
 195     };
 196
 197     klass->push_buffer = push_buffer_impl;
 198
 199     klass->perl_class = "Amanda::Xfer::Dest::Device";
 200     klass->mech_pairs = mech_pairs;
 201
 202     goc->finalize = finalize_impl;
 203
 204     parent_class = g_type_class_peek_parent(selfc);
 205 }
 206
 207 GType
 208 xfer_dest_device_get_type (void)
 209 {
 210     static GType type = 0;
 211
 212     if G_UNLIKELY(type == 0) {
 213         static const GTypeInfo info = {
 214             sizeof (XferDestDeviceClass),
 215             (GBaseInitFunc) NULL,
 216             (GBaseFinalizeFunc) NULL,
 217             (GClassInitFunc) class_init,
 218             (GClassFinalizeFunc) NULL,
 219             NULL /* class_data */,
 220             sizeof (XferDestDevice),
 221             0 /* n_preallocs */,
 222             (GInstanceInitFunc) instance_init,
 223             NULL
 224         };
 225
 226         type = g_type_register_static (XFER_ELEMENT_TYPE, "XferDestDevice", &info, 0);
 227     }
 228
 229     return type;
 230 }
 231
 232 /* create an element of this class; prototype is in xfer-device.h */
 233 XferElement *
 234 xfer_dest_device(
 235     Device *device,
 236     gboolean cancel_at_leom)
 237 {
 238     XferDestDevice *self = (XferDestDevice *)g_object_new(XFER_DEST_DEVICE_TYPE, NULL);
 239     XferElement *elt = XFER_ELEMENT(self);
 240
 241     g_assert(device != NULL);
 242
 243     self->device = device;
 244     self->cancel_at_leom = cancel_at_leom;
 245
 246     return elt;
 247 }