2 * Amanda, The Advanced Maryland Automatic Network Disk Archiver
3 * Copyright (c) 2008, 2009, 2011 Zmanda, Inc. All Rights Reserved.
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.
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
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
18 * Contact information: Zmanda Inc., 465 S. Mathilda Ave., Suite 300
19 * Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
24 #include "simpleprng.h"
29 * This declaration is entirely private; nothing but xfer_source_pattern() references
33 GType xfer_source_pattern_get_type(void);
34 #define XFER_SOURCE_PATTERN_TYPE (xfer_source_pattern_get_type())
35 #define XFER_SOURCE_PATTERN(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_pattern_get_type(), XferSourcePattern)
36 #define XFER_SOURCE_PATTERN_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_pattern_get_type(), XferSourcePattern const)
37 #define XFER_SOURCE_PATTERN_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_source_pattern_get_type(), XferSourcePatternClass)
38 #define IS_XFER_SOURCE_PATTERN(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_source_pattern_get_type ())
39 #define XFER_SOURCE_PATTERN_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_source_pattern_get_type(), XferSourcePatternClass)
41 static GObjectClass *parent_class = NULL;
44 * Main object structure
47 typedef struct XferSourcePattern {
48 XferElement __parent__;
50 gboolean limited_length;
52 size_t pattern_buffer_length;
53 size_t current_offset;
62 XferElementClass __parent__;
63 } XferSourcePatternClass;
70 * Utility function to fill a buffer buf of size len with the pattern defined
71 * for this instance. We start each copying from the offset where we left the
74 * Note that performance is important: amtapetype uses this very source and
75 * source-random.c to determine whether a tape device uses compression, and
76 * expects the two to run about the same speed. This is why this is a byte
77 * loop and does not use mempcy() and friends: the random source is also byte
81 static void fill_buffer_with_pattern(XferSourcePattern *self, char *buf,
84 char *src = self->pattern, *dst = buf;
85 size_t plen = self->pattern_buffer_length, offset = self->current_offset;
94 if (G_LIKELY(offset < plen))
101 self->current_offset = offset;
109 XferSourcePattern *self = (XferSourcePattern *)elt;
112 /* indicate EOF on an cancel */
113 if (elt->cancelled) {
118 if (self->limited_length) {
119 if (self->length == 0) {
124 *size = MIN(10240, self->length);
125 self->length -= *size;
130 rval = malloc(*size);
132 fill_buffer_with_pattern(self, rval, *size);
141 elt->can_generate_eof = TRUE;
146 XferSourcePatternClass * selfc)
148 XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
149 static xfer_element_mech_pair_t mech_pairs[] = {
150 { XFER_MECH_NONE, XFER_MECH_PULL_BUFFER, XFER_NROPS(1), XFER_NTHREADS(0) },
151 { XFER_MECH_NONE, XFER_MECH_NONE, XFER_NROPS(0), XFER_NTHREADS(0) },
154 klass->pull_buffer = pull_buffer_impl;
156 klass->perl_class = "Amanda::Xfer::Source::Pattern";
157 klass->mech_pairs = mech_pairs;
159 parent_class = g_type_class_peek_parent(selfc);
163 xfer_source_pattern_get_type (void)
165 static GType type = 0;
167 if G_UNLIKELY(type == 0) {
168 static const GTypeInfo info = {
169 sizeof (XferSourcePatternClass),
170 (GBaseInitFunc) NULL,
171 (GBaseFinalizeFunc) NULL,
172 (GClassInitFunc) class_init,
173 (GClassFinalizeFunc) NULL,
174 NULL /* class_data */,
175 sizeof (XferSourcePattern),
177 (GInstanceInitFunc) instance_init,
181 type = g_type_register_static (XFER_ELEMENT_TYPE, "XferSourcePattern", &info, 0);
187 /* create an element of this class; prototype is in xfer-element.h */
188 XferElement * xfer_source_pattern(guint64 length, void * pattern,
189 size_t pattern_length) {
190 XferSourcePattern *xsp =
191 (XferSourcePattern *)g_object_new(XFER_SOURCE_PATTERN_TYPE, NULL);
192 XferElement *elt = XFER_ELEMENT(xsp);
194 xsp->length = length;
195 xsp->limited_length = (length > 0);
196 xsp->pattern = g_memdup(pattern, pattern_length);
197 xsp->pattern_buffer_length = pattern_length;
198 xsp->current_offset = 0;