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 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     guint64 bytes_read;
  53
  54     XferElement *dest_taper;
  55 } XferSourceHolding;
  56
  57 /*
  58  * Class definition
  59  */
  60
  61 typedef struct {
  62     XferElementClass __parent__;
  63 } XferSourceHoldingClass;
  64
  65 /*
  66  * Implementation
  67  */
  68
  69 static gboolean
  70 start_new_chunk(
  71     XferSourceHolding *self)
  72 {
  73     char *hdrbuf = NULL;
  74     dumpfile_t hdr;
  75     size_t bytes_read;
  76
  77     /* try to close an already-open file */
  78     if (self->fd != -1) {
  79         if (close(self->fd) < 0) {
  80             xfer_cancel_with_error(XFER_ELEMENT(self),
  81                 "while closing holding file: %s", strerror(errno));
  82             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
  83             return FALSE;
  84         }
  85
  86         self->fd = -1;
  87     }
  88
  89     /* if we have no next filename, then we're at EOF */
  90     if (!self->next_filename) {
  91         return FALSE;
  92     }
  93
  94     /* otherwise, open up the next file */
  95     self->fd = open(self->next_filename, O_RDONLY);
  96     if (self->fd < 0) {
  97         xfer_cancel_with_error(XFER_ELEMENT(self),
  98             "while opening holding file '%s': %s",
  99             self->next_filename, strerror(errno));
 100         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 101         return FALSE;
 102     }
 103
 104     /* get a downstream XferDestTaper, if one exists.  This check happens
 105      * for each chunk, but chunks are large, so that's OK. */
 106     if (!self->dest_taper) {
 107         XferElement *elt = (XferElement *)self;
 108
 109         /* the xfer may have inserted glue between this element and
 110         * the XferDestTaper. Glue does not change the bytestream, so
 111         * it does not interfere with cache_inform calls. */
 112         XferElement *iter = elt->downstream;
 113         while (iter && IS_XFER_ELEMENT_GLUE(iter)) {
 114             iter = iter->downstream;
 115         }
 116         if (IS_XFER_DEST_TAPER(iter))
 117             self->dest_taper = iter;
 118     }
 119
 120     /* tell a XferDestTaper about the new file */
 121     if (self->dest_taper) {
 122         struct stat st;
 123         if (fstat(self->fd, &st) < 0) {
 124             xfer_cancel_with_error(XFER_ELEMENT(self),
 125                 "while finding size of holding file '%s': %s",
 126                 self->next_filename, strerror(errno));
 127             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 128             return FALSE;
 129         }
 130
 131         xfer_dest_taper_cache_inform(self->dest_taper,
 132             self->next_filename,
 133             DISK_BLOCK_BYTES,
 134             st.st_size - DISK_BLOCK_BYTES);
 135     }
 136
 137     /* read the header from the file and determine the filename of the next chunk */
 138     hdrbuf = g_malloc(DISK_BLOCK_BYTES);
 139     bytes_read = full_read(self->fd, hdrbuf, DISK_BLOCK_BYTES);
 140     if (bytes_read < DISK_BLOCK_BYTES) {
 141         g_free(hdrbuf);
 142         xfer_cancel_with_error(XFER_ELEMENT(self),
 143             "while reading header from holding file '%s': %s",
 144             self->next_filename, strerror(errno));
 145         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 146         return FALSE;
 147     }
 148
 149     parse_file_header(hdrbuf, &hdr, DISK_BLOCK_BYTES);
 150     g_free(hdrbuf);
 151     hdrbuf = NULL;
 152
 153     if (hdr.type != F_DUMPFILE && hdr.type != F_CONT_DUMPFILE) {
 154         dumpfile_free_data(&hdr);
 155         xfer_cancel_with_error(XFER_ELEMENT(self),
 156             "unexpected header type %d in holding file '%s'",
 157             hdr.type, self->next_filename);
 158         wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 159         return FALSE;
 160     }
 161
 162     g_free(self->next_filename);
 163     if (hdr.cont_filename[0]) {
 164         self->next_filename = g_strdup(hdr.cont_filename);
 165     } else {
 166         self->next_filename = NULL;
 167     }
 168     dumpfile_free_data(&hdr);
 169
 170     return TRUE;
 171 }
 172
 173 /* pick an arbitrary block size for reading */
 174 #define HOLDING_BLOCK_SIZE (1024*128)
 175
 176 static gpointer
 177 pull_buffer_impl(
 178     XferElement *elt,
 179     size_t *size)
 180 {
 181     XferSourceHolding *self = (XferSourceHolding *)elt;
 182     char *buf = NULL;
 183     size_t bytes_read;
 184
 185     if (elt->cancelled)
 186         goto return_eof;
 187
 188     if (self->fd == -1) {
 189         if (!start_new_chunk(self))
 190             goto return_eof;
 191     }
 192
 193     buf = g_malloc(HOLDING_BLOCK_SIZE);
 194
 195     while (1) {
 196         bytes_read = full_read(self->fd, buf, HOLDING_BLOCK_SIZE);
 197         if (bytes_read > 0) {
 198             *size = bytes_read;
 199             self->bytes_read += bytes_read;
 200             return buf;
 201         }
 202
 203         /* did an error occur? */
 204         if (errno != 0) {
 205             xfer_cancel_with_error(XFER_ELEMENT(self),
 206                 "while reading holding file: %s", strerror(errno));
 207             wait_until_xfer_cancelled(XFER_ELEMENT(self)->xfer);
 208             goto return_eof;
 209         }
 210
 211         if (!start_new_chunk(self))
 212             goto return_eof;
 213     }
 214
 215 return_eof:
 216     g_free(buf);
 217     *size = 0;
 218     return NULL;
 219 }
 220
 221 static void
 222 instance_init(
 223     XferElement *elt)
 224 {
 225     XferSourceHolding *self = (XferSourceHolding *)elt;
 226
 227     elt->can_generate_eof = TRUE;
 228     self->fd = -1;
 229 }
 230
 231 static void
 232 finalize_impl(
 233     GObject * obj_self)
 234 {
 235     XferSourceHolding *self = (XferSourceHolding *)obj_self;
 236
 237     if (self->next_filename)
 238         g_free(self->next_filename);
 239
 240     if (self->fd != -1)
 241         close(self->fd); /* ignore error; we were probably already cancelled */
 242
 243     G_OBJECT_CLASS(parent_class)->finalize(obj_self);
 244 }
 245
 246 static void
 247 class_init(
 248     XferSourceHoldingClass * selfc)
 249 {
 250     XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
 251     GObjectClass *goc = G_OBJECT_CLASS(selfc);
 252     static xfer_element_mech_pair_t mech_pairs[] = {
 253         { XFER_MECH_NONE, XFER_MECH_PULL_BUFFER, 1, 0},
 254         { XFER_MECH_NONE, XFER_MECH_NONE, 0, 0},
 255     };
 256
 257     klass->pull_buffer = pull_buffer_impl;
 258
 259     klass->perl_class = "Amanda::Xfer::Source::Holding";
 260     klass->mech_pairs = mech_pairs;
 261
 262     goc->finalize = finalize_impl;
 263
 264     parent_class = g_type_class_peek_parent(selfc);
 265 }
 266
 267 GType
 268 xfer_source_holding_get_type (void)
 269 {
 270     static GType type = 0;
 271
 272     if G_UNLIKELY(type == 0) {
 273         static const GTypeInfo info = {
 274             sizeof (XferSourceHoldingClass),
 275             (GBaseInitFunc) NULL,
 276             (GBaseFinalizeFunc) NULL,
 277             (GClassInitFunc) class_init,
 278             (GClassFinalizeFunc) NULL,
 279             NULL /* class_data */,
 280             sizeof (XferSourceHolding),
 281             0 /* n_preallocs */,
 282             (GInstanceInitFunc) instance_init,
 283             NULL
 284         };
 285
 286         type = g_type_register_static (XFER_ELEMENT_TYPE, "XferSourceHolding", &info, 0);
 287     }
 288
 289     return type;
 290 }
 291
 292 /* create an element of this class; prototype is in xfer-element.h */
 293 XferElement *
 294 xfer_source_holding(
 295     const char *filename)
 296 {
 297     XferSourceHolding *self = (XferSourceHolding *)g_object_new(XFER_SOURCE_HOLDING_TYPE, NULL);
 298     XferElement *elt = XFER_ELEMENT(self);
 299
 300     self->next_filename = g_strdup(filename);
 301     self->bytes_read = 0;
 302
 303     return elt;
 304 }
 305
 306 guint64
 307 xfer_source_holding_get_bytes_read(
 308     XferElement *elt)
 309 {
 310     XferSourceHolding *self = (XferSourceHolding *)elt;
 311
 312     return self->bytes_read;
 313 }
 314