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) 2009-2012 Zmanda, Inc.  All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  *
  19  * Contact information: Zmanda Inc., 465 S. Mathilda Ave., Suite 300
  20  * Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
  21  */
  22
  23 #include "amanda.h"
  24 #include "xfer-server.h"
  25 #include "xfer-device.h"
  26
  27 /*
  28  * Class declaration
  29  *
  30  * This declaration is entirely private; nothing but xfer_source_holding() references
  31  * it directly.
  32  */
  33
  34 GType xfer_source_holding_get_type(void);
  35 #define XFER_SOURCE_HOLDING_TYPE (xfer_source_holding_get_type())
  36 #define XFER_SOURCE_HOLDING(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_holding_get_type(), XferSourceHolding)
  37 #define XFER_SOURCE_HOLDING_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_holding_get_type(), XferSourceHolding const)
  38 #define XFER_SOURCE_HOLDING_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_source_holding_get_type(), XferSourceHoldingClass)
  39 #define IS_XFER_SOURCE_HOLDING(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_source_holding_get_type ())
  40 #define XFER_SOURCE_HOLDING_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_source_holding_get_type(), XferSourceHoldingClass)
  41
  42 static GObjectClass *parent_class = NULL;
  43
  44 /*
  45  * Main object structure
  46  */
  47
  48 typedef struct XferSourceHolding {
  49     XferElement __parent__;
  50
  51     int fd;
  52     char *next_filename;
  53     guint64 bytes_read;
  54
  55     XferElement *dest_taper;
  56 } XferSourceHolding;
  57
  58 /*
  59  * Class definition
  60  */
  61
  62 typedef struct {
  63     XferElementClass __parent__;
  64 } XferSourceHoldingClass;
  65
  66 /*
  67  * Implementation
  68  */
  69
  70 static gboolean
  71 start_new_chunk(
  72     XferSourceHolding *self)
  73 {
  74     char *hdrbuf = NULL;
  75     dumpfile_t hdr;
  76     size_t bytes_read;
  77
  78     /* try to close an already-open file */
  79     if (self->fd != -1) {
  80         if (close(self->fd) < 0) {
  81             xfer_cancel_with_error(XFER_ELEMENT(self),
  82                 "while closing holding file: %s", strerror(errno));
  83             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
  84             return FALSE;
  85         }
  86
  87         self->fd = -1;
  88     }
  89
  90     /* if we have no next filename, then we're at EOF */
  91     if (!self->next_filename) {
  92         return FALSE;
  93     }
  94
  95     /* otherwise, open up the next file */
  96     self->fd = open(self->next_filename, O_RDONLY);
  97     if (self->fd < 0) {
  98         xfer_cancel_with_error(XFER_ELEMENT(self),
  99             "while opening holding file '%s': %s",
 100             self->next_filename, strerror(errno));
 101         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 102         return FALSE;
 103     }
 104
 105     /* get a downstream XferDestTaper, if one exists.  This check happens
 106      * for each chunk, but chunks are large, so that's OK. */
 107     if (!self->dest_taper) {
 108         XferElement *elt = (XferElement *)self;
 109
 110         /* the xfer may have inserted glue between this element and
 111         * the XferDestTaper. Glue does not change the bytestream, so
 112         * it does not interfere with cache_inform calls. */
 113         XferElement *iter = elt->downstream;
 114         while (iter && IS_XFER_ELEMENT_GLUE(iter)) {
 115             iter = iter->downstream;
 116         }
 117         if (IS_XFER_DEST_TAPER(iter))
 118             self->dest_taper = iter;
 119     }
 120
 121     /* tell a XferDestTaper about the new file */
 122     if (self->dest_taper) {
 123         struct stat st;
 124         if (fstat(self->fd, &st) < 0) {
 125             xfer_cancel_with_error(XFER_ELEMENT(self),
 126                 "while finding size of holding file '%s': %s",
 127                 self->next_filename, strerror(errno));
 128             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 129             return FALSE;
 130         }
 131
 132         xfer_dest_taper_cache_inform(self->dest_taper,
 133             self->next_filename,
 134             DISK_BLOCK_BYTES,
 135             st.st_size - DISK_BLOCK_BYTES);
 136     }
 137
 138     /* read the header from the file and determine the filename of the next chunk */
 139     hdrbuf = g_malloc(DISK_BLOCK_BYTES);
 140     bytes_read = full_read(self->fd, hdrbuf, DISK_BLOCK_BYTES);
 141     if (bytes_read < DISK_BLOCK_BYTES) {
 142         g_free(hdrbuf);
 143         xfer_cancel_with_error(XFER_ELEMENT(self),
 144             "while reading header from holding file '%s': %s",
 145             self->next_filename, strerror(errno));
 146         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 147         return FALSE;
 148     }
 149
 150     parse_file_header(hdrbuf, &hdr, DISK_BLOCK_BYTES);
 151     g_free(hdrbuf);
 152     hdrbuf = NULL;
 153
 154     if (hdr.type != F_DUMPFILE && hdr.type != F_CONT_DUMPFILE) {
 155         dumpfile_free_data(&hdr);
 156         xfer_cancel_with_error(XFER_ELEMENT(self),
 157             "unexpected header type %d in holding file '%s'",
 158             hdr.type, self->next_filename);
 159         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 160         return FALSE;
 161     }
 162
 163     g_free(self->next_filename);
 164     if (hdr.cont_filename[0]) {
 165         self->next_filename = g_strdup(hdr.cont_filename);
 166     } else {
 167         self->next_filename = NULL;
 168     }
 169     dumpfile_free_data(&hdr);
 170
 171     return TRUE;
 172 }
 173
 174 /* pick an arbitrary block size for reading */
 175 #define HOLDING_BLOCK_SIZE (1024*128)
 176
 177 static gpointer
 178 pull_buffer_impl(
 179     XferElement *elt,
 180     size_t *size)
 181 {
 182     XferSourceHolding *self = (XferSourceHolding *)elt;
 183     char *buf = NULL;
 184     size_t bytes_read;
 185
 186     if (elt->cancelled)
 187         goto return_eof;
 188
 189     if (self->fd == -1) {
 190         if (!start_new_chunk(self))
 191             goto return_eof;
 192     }
 193
 194     buf = g_malloc(HOLDING_BLOCK_SIZE);
 195
 196     while (1) {
 197         bytes_read = full_read(self->fd, buf, HOLDING_BLOCK_SIZE);
 198         if (bytes_read > 0) {
 199             *size = bytes_read;
 200             self->bytes_read += bytes_read;
 201             return buf;
 202         }
 203
 204         /* did an error occur? */
 205         if (errno != 0) {
 206             xfer_cancel_with_error(XFER_ELEMENT(self),
 207                 "while reading holding file: %s", strerror(errno));
 208             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 209             goto return_eof;
 210         }
 211
 212         if (!start_new_chunk(self))
 213             goto return_eof;
 214     }
 215
 216 return_eof:
 217     g_free(buf);
 218     *size = 0;
 219     return NULL;
 220 }
 221
 222 static void
 223 instance_init(
 224     XferElement *elt)
 225 {
 226     XferSourceHolding *self = (XferSourceHolding *)elt;
 227
 228     elt->can_generate_eof = TRUE;
 229     self->fd = -1;
 230 }
 231
 232 static void
 233 finalize_impl(
 234     GObject * obj_self)
 235 {
 236     XferSourceHolding *self = (XferSourceHolding *)obj_self;
 237
 238     if (self->next_filename)
 239         g_free(self->next_filename);
 240
 241     if (self->fd != -1)
 242         close(self->fd); /* ignore error; we were probably already cancelled */
 243
 244     G_OBJECT_CLASS(parent_class)->finalize(obj_self);
 245 }
 246
 247 static void
 248 class_init(
 249     XferSourceHoldingClass * selfc)
 250 {
 251     XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
 252     GObjectClass *goc = G_OBJECT_CLASS(selfc);
 253     static xfer_element_mech_pair_t mech_pairs[] = {
 254         { XFER_MECH_NONE, XFER_MECH_PULL_BUFFER, 1, 0},
 255         { XFER_MECH_NONE, XFER_MECH_NONE, 0, 0},
 256     };
 257
 258     klass->pull_buffer = pull_buffer_impl;
 259
 260     klass->perl_class = "Amanda::Xfer::Source::Holding";
 261     klass->mech_pairs = mech_pairs;
 262
 263     goc->finalize = finalize_impl;
 264
 265     parent_class = g_type_class_peek_parent(selfc);
 266 }
 267
 268 GType
 269 xfer_source_holding_get_type (void)
 270 {
 271     static GType type = 0;
 272
 273     if G_UNLIKELY(type == 0) {
 274         static const GTypeInfo info = {
 275             sizeof (XferSourceHoldingClass),
 276             (GBaseInitFunc) NULL,
 277             (GBaseFinalizeFunc) NULL,
 278             (GClassInitFunc) class_init,
 279             (GClassFinalizeFunc) NULL,
 280             NULL /* class_data */,
 281             sizeof (XferSourceHolding),
 282             0 /* n_preallocs */,
 283             (GInstanceInitFunc) instance_init,
 284             NULL
 285         };
 286
 287         type = g_type_register_static (XFER_ELEMENT_TYPE, "XferSourceHolding", &info, 0);
 288     }
 289
 290     return type;
 291 }
 292
 293 /* create an element of this class; prototype is in xfer-element.h */
 294 XferElement *
 295 xfer_source_holding(
 296     const char *filename)
 297 {
 298     XferSourceHolding *self = (XferSourceHolding *)g_object_new(XFER_SOURCE_HOLDING_TYPE, NULL);
 299     XferElement *elt = XFER_ELEMENT(self);
 300
 301     self->next_filename = g_strdup(filename);
 302     self->bytes_read = 0;
 303
 304     return elt;
 305 }
 306
 307 guint64
 308 xfer_source_holding_get_bytes_read(
 309     XferElement *elt)
 310 {
 311     XferSourceHolding *self = (XferSourceHolding *)elt;
 312
 313     return self->bytes_read;
 314 }
 315