xref: /titanic_50/usr/src/cmd/sort/common/streams_array.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include "streams_array.h"
30 #include "streams_common.h"
31 
32 /*
33  * Single-byte character memory map-based streams implementation
34  */
35 
36 static int
stream_array_prime(stream_t * str)37 stream_array_prime(stream_t *str)
38 {
39 	ASSERT((str->s_status & STREAM_SOURCE_MASK) == STREAM_ARRAY);
40 
41 	str->s_type.LA.s_cur_index = MIN(0, str->s_type.LA.s_array_size - 1);
42 	if (str->s_type.LA.s_cur_index >= 0)
43 		copy_line_rec(
44 		    str->s_type.LA.s_array[str->s_type.LA.s_cur_index],
45 		    &str->s_current);
46 	else {
47 		stream_set(str, STREAM_EOS_REACHED);
48 		stream_unset(str, STREAM_PRIMED);
49 		return (PRIME_FAILED_EMPTY_FILE);
50 	}
51 
52 	stream_set(str, STREAM_PRIMED);
53 
54 	return (PRIME_SUCCEEDED);
55 }
56 
57 static ssize_t
stream_array_fetch(stream_t * str)58 stream_array_fetch(stream_t *str)
59 {
60 	ASSERT(str->s_status & STREAM_OPEN);
61 	ASSERT(str->s_type.LA.s_cur_index < str->s_type.LA.s_array_size);
62 
63 	if (++str->s_type.LA.s_cur_index == str->s_type.LA.s_array_size - 1)
64 		stream_set(str, STREAM_EOS_REACHED);
65 
66 	copy_line_rec(str->s_type.LA.s_array[str->s_type.LA.s_cur_index],
67 	    &str->s_current);
68 
69 	return (NEXT_LINE_COMPLETE);
70 }
71 
72 /*ARGSUSED*/
73 static int
stream_array_is_closable(stream_t * str)74 stream_array_is_closable(stream_t *str)
75 {
76 	/*
77 	 * Array streams are not closable.  That is, there is no open file
78 	 * descriptor directly associated with an array stream.
79 	 */
80 	return (0);
81 }
82 
83 static int
stream_array_close(stream_t * str)84 stream_array_close(stream_t *str)
85 {
86 	stream_unset(str, STREAM_OPEN | STREAM_PRIMED);
87 
88 	return (1);
89 }
90 
91 static int
stream_array_free(stream_t * str)92 stream_array_free(stream_t *str)
93 {
94 	/*
95 	 * It's now safe for us to close the various streams backing the array
96 	 * stream's data.
97 	 */
98 	stream_unset(str, STREAM_PRIMED | STREAM_NOT_FREEABLE);
99 
100 	return (1);
101 }
102 
103 static int
stream_array_eos(stream_t * str)104 stream_array_eos(stream_t *str)
105 {
106 	int retval = 0;
107 
108 	if (str == NULL || str->s_status & STREAM_EOS_REACHED)
109 		return (1);
110 
111 	if (str->s_type.LA.s_cur_index + 1 >= str->s_type.LA.s_array_size) {
112 		retval = 1;
113 		stream_set(str, STREAM_EOS_REACHED);
114 	}
115 
116 	return (retval);
117 }
118 
119 /*ARGSUSED*/
120 static void
stream_array_release_line(stream_t * str)121 stream_array_release_line(stream_t *str)
122 {
123 }
124 
125 const stream_ops_t stream_array_ops = {
126 	stream_array_is_closable,
127 	stream_array_close,
128 	stream_array_eos,
129 	stream_array_fetch,
130 	NULL,
131 	stream_array_free,
132 	NULL,
133 	stream_array_prime,
134 	NULL,
135 	stream_array_release_line,
136 	NULL,
137 	NULL
138 };
139