git.gag.com Git - debian/amanda/blob - server-src/xfer-source-holding.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 "xfer-server.h"
  24 #include "xfer-device.h"
  25
  26 /*
  27  * Class declaration
  28  *
  29  * This declaration is entirely private; nothing but xfer_source_holding() references
  30  * it directly.
  31  */
  32
  33 GType xfer_source_holding_get_type(void);
  34 #define XFER_SOURCE_HOLDING_TYPE (xfer_source_holding_get_type())
  35 #define XFER_SOURCE_HOLDING(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_holding_get_type(), XferSourceHolding)
  36 #define XFER_SOURCE_HOLDING_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_holding_get_type(), XferSourceHolding const)
  37 #define XFER_SOURCE_HOLDING_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_source_holding_get_type(), XferSourceHoldingClass)
  38 #define IS_XFER_SOURCE_HOLDING(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_source_holding_get_type ())
  39 #define XFER_SOURCE_HOLDING_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_source_holding_get_type(), XferSourceHoldingClass)
  40
  41 static GObjectClass *parent_class = NULL;
  42
  43 /*
  44  * Main object structure
  45  */
  46
  47 typedef struct XferSourceHolding {
  48     XferElement __parent__;
  49
  50     int fd;
  51     char *next_filename;
  52
  53     XferElement *dest_taper;
  54 } XferSourceHolding;
  55
  56 /*
  57  * Class definition
  58  */
  59
  60 typedef struct {
  61     XferElementClass __parent__;
  62 } XferSourceHoldingClass;
  63
  64 /*
  65  * Implementation
  66  */
  67
  68 static gboolean
  69 start_new_chunk(
  70     XferSourceHolding *self)
  71 {
  72     char *hdrbuf = NULL;
  73     dumpfile_t hdr;
  74     size_t bytes_read;
  75
  76     /* try to close an already-open file */
  77     if (self->fd != -1) {
  78         if (close(self->fd) < 0) {
  79             xfer_cancel_with_error(XFER_ELEMENT(self),
  80                 "while closing holding file: %s", strerror(errno));
  81             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
  82             return FALSE;
  83         }
  84
  85         self->fd = -1;
  86     }
  87
  88     /* if we have no next filename, then we're at EOF */
  89     if (!self->next_filename) {
  90         return FALSE;
  91     }
  92
  93     /* otherwise, open up the next file */
  94     self->fd = open(self->next_filename, O_RDONLY);
  95     if (self->fd < 0) {
  96         xfer_cancel_with_error(XFER_ELEMENT(self),
  97             "while opening holding file '%s': %s",
  98             self->next_filename, strerror(errno));
  99         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 100         return FALSE;
 101     }
 102
 103     /* get a downstream XferDestTaper, if one exists.  This check happens
 104      * for each chunk, but chunks are large, so that's OK. */
 105     if (!self->dest_taper) {
 106         XferElement *elt = (XferElement *)self;
 107
 108         /* the xfer may have inserted glue between this element and
 109         * the XferDestTaper. Glue does not change the bytestream, so
 110         * it does not interfere with cache_inform calls. */
 111         XferElement *iter = elt->downstream;
 112         while (iter && IS_XFER_ELEMENT_GLUE(iter)) {
 113             iter = iter->downstream;
 114         }
 115         if (IS_XFER_DEST_TAPER(iter))
 116             self->dest_taper = iter;
 117     }
 118
 119     /* tell a XferDestTaper about the new file */
 120     if (self->dest_taper) {
 121         struct stat st;
 122         if (fstat(self->fd, &st) < 0) {
 123             xfer_cancel_with_error(XFER_ELEMENT(self),
 124                 "while finding size of holding file '%s': %s",
 125                 self->next_filename, strerror(errno));
 126             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 127             return FALSE;
 128         }
 129
 130         xfer_dest_taper_cache_inform(self->dest_taper,
 131             self->next_filename,
 132             DISK_BLOCK_BYTES,
 133             st.st_size - DISK_BLOCK_BYTES);
 134     }
 135
 136     /* read the header from the file and determine the filename of the next chunk */
 137     hdrbuf = g_malloc(DISK_BLOCK_BYTES);
 138     bytes_read = full_read(self->fd, hdrbuf, DISK_BLOCK_BYTES);
 139     if (bytes_read < DISK_BLOCK_BYTES) {
 140         g_free(hdrbuf);
 141         xfer_cancel_with_error(XFER_ELEMENT(self),
 142             "while reading header from holding file '%s': %s",
 143             self->next_filename, strerror(errno));
 144         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 145         return FALSE;
 146     }
 147
 148     parse_file_header(hdrbuf, &hdr, DISK_BLOCK_BYTES);
 149     g_free(hdrbuf);
 150     hdrbuf = NULL;
 151
 152     if (hdr.type != F_DUMPFILE && hdr.type != F_CONT_DUMPFILE) {
 153         dumpfile_free_data(&hdr);
 154         xfer_cancel_with_error(XFER_ELEMENT(self),
 155             "unexpected header type %d in holding file '%s'",
 156             hdr.type, self->next_filename);
 157         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 158         return FALSE;
 159     }
 160
 161     g_free(self->next_filename);
 162     if (hdr.cont_filename[0]) {
 163         self->next_filename = g_strdup(hdr.cont_filename);
 164     } else {
 165         self->next_filename = NULL;
 166     }
 167     dumpfile_free_data(&hdr);
 168
 169     return TRUE;
 170 }
 171
 172 /* pick an arbitrary block size for reading */
 173 #define HOLDING_BLOCK_SIZE (1024*128)
 174
 175 static gpointer
 176 pull_buffer_impl(
 177     XferElement *elt,
 178     size_t *size)
 179 {
 180     XferSourceHolding *self = (XferSourceHolding *)elt;
 181     char *buf = NULL;
 182     size_t bytes_read;
 183
 184     if (elt->cancelled)
 185         goto return_eof;
 186
 187     if (self->fd == -1) {
 188         if (!start_new_chunk(self))
 189             goto return_eof;
 190     }
 191
 192     buf = g_malloc(HOLDING_BLOCK_SIZE);
 193
 194     while (1) {
 195         bytes_read = full_read(self->fd, buf, HOLDING_BLOCK_SIZE);
 196         if (bytes_read > 0) {
 197             *size = bytes_read;
 198             return buf;
 199         }
 200
 201         /* did an error occur? */
 202         if (errno != 0) {
 203             xfer_cancel_with_error(XFER_ELEMENT(self),
 204                 "while reading holding file: %s", strerror(errno));
 205             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 206             goto return_eof;
 207         }
 208
 209         if (!start_new_chunk(self))
 210             goto return_eof;
 211     }
 212
 213 return_eof:
 214     g_free(buf);
 215     *size = 0;
 216     return NULL;
 217 }
 218
 219 static void
 220 instance_init(
 221     XferElement *elt)
 222 {
 223     XferSourceHolding *self = (XferSourceHolding *)elt;
 224
 225     elt->can_generate_eof = TRUE;
 226     self->fd = -1;
 227 }
 228
 229 static void
 230 finalize_impl(
 231     GObject * obj_self)
 232 {
 233     XferSourceHolding *self = (XferSourceHolding *)obj_self;
 234
 235     if (self->next_filename)
 236         g_free(self->next_filename);
 237
 238     if (self->fd != -1)
 239         close(self->fd); /* ignore error; we were probably already cancelled */
 240
 241     G_OBJECT_CLASS(parent_class)->finalize(obj_self);
 242 }
 243
 244 static void
 245 class_init(
 246     XferSourceHoldingClass * selfc)
 247 {
 248     XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
 249     GObjectClass *goc = G_OBJECT_CLASS(selfc);
 250     static xfer_element_mech_pair_t mech_pairs[] = {
 251         { XFER_MECH_NONE, XFER_MECH_PULL_BUFFER, 1, 0},
 252         { XFER_MECH_NONE, XFER_MECH_NONE, 0, 0},
 253     };
 254
 255     klass->pull_buffer = pull_buffer_impl;
 256
 257     klass->perl_class = "Amanda::Xfer::Source::Holding";
 258     klass->mech_pairs = mech_pairs;
 259
 260     goc->finalize = finalize_impl;
 261
 262     parent_class = g_type_class_peek_parent(selfc);
 263 }
 264
 265 GType
 266 xfer_source_holding_get_type (void)
 267 {
 268     static GType type = 0;
 269
 270     if G_UNLIKELY(type == 0) {
 271         static const GTypeInfo info = {
 272             sizeof (XferSourceHoldingClass),
 273             (GBaseInitFunc) NULL,
 274             (GBaseFinalizeFunc) NULL,
 275             (GClassInitFunc) class_init,
 276             (GClassFinalizeFunc) NULL,
 277             NULL /* class_data */,
 278             sizeof (XferSourceHolding),
 279             0 /* n_preallocs */,
 280             (GInstanceInitFunc) instance_init,
 281             NULL
 282         };
 283
 284         type = g_type_register_static (XFER_ELEMENT_TYPE, "XferSourceHolding", &info, 0);
 285     }
 286
 287     return type;
 288 }
 289
 290 /* create an element of this class; prototype is in xfer-element.h */
 291 XferElement *
 292 xfer_source_holding(
 293     const char *filename)
 294 {
 295     XferSourceHolding *self = (XferSourceHolding *)g_object_new(XFER_SOURCE_HOLDING_TYPE, NULL);
 296     XferElement *elt = XFER_ELEMENT(self);
 297
 298     self->next_filename = g_strdup(filename);
 299
 300     return elt;
 301 }
 302