drmsl.c revision d8807b2f 
1/* drmsl.c -- Skip list test
2 * Created: Mon May 10 09:28:13 1999 by faith@precisioninsight.com
3 *
4 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the next
15 * paragraph) shall be included in all copies or substantial portions of the
16 * Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
21 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24 * DEALINGS IN THE SOFTWARE.
25 *
26 * Authors: Rickard E. (Rik) Faith <faith@valinux.com>
27 *
28 * DESCRIPTION
29 *
30 * This file contains a straightforward skip list implementation.n
31 *
32 * FUTURE ENHANCEMENTS
33 *
34 * REFERENCES
35 *
36 * [Pugh90] William Pugh.  Skip Lists: A Probabilistic Alternative to
37 * Balanced Trees. CACM 33(6), June 1990, pp. 668-676.
38 *
39 */
40
41#include <stdio.h>
42#include <stdlib.h>
43#include <sys/time.h>
44
45#include "xf86drm.h"
46
47static void print(void* list)
48{
49    unsigned long key;
50    void          *value;
51
52    if (drmSLFirst(list, &key, &value)) {
53	do {
54	    printf("key = %5lu, value = %p\n", key, value);
55	} while (drmSLNext(list, &key, &value));
56    }
57}
58
59static double do_time(int size, int iter)
60{
61    void           *list;
62    int            i, j;
63    unsigned long  keys[1000000];
64    unsigned long  previous;
65    unsigned long  key;
66    void           *value;
67    struct timeval start, stop;
68    double         usec;
69    void           *ranstate;
70
71    list = drmSLCreate();
72    ranstate = drmRandomCreate(12345);
73
74    for (i = 0; i < size; i++) {
75	keys[i] = drmRandom(ranstate);
76	drmSLInsert(list, keys[i], NULL);
77    }
78
79    previous = 0;
80    if (drmSLFirst(list, &key, &value)) {
81	do {
82	    if (key <= previous) {
83		printf( "%lu !< %lu\n", previous, key);
84	    }
85	    previous = key;
86	} while (drmSLNext(list, &key, &value));
87    }
88
89    gettimeofday(&start, NULL);
90    for (j = 0; j < iter; j++) {
91	for (i = 0; i < size; i++) {
92	    if (drmSLLookup(list, keys[i], &value))
93		printf("Error %lu %d\n", keys[i], i);
94	}
95    }
96    gettimeofday(&stop, NULL);
97
98    usec = (double)(stop.tv_sec * 1000000 + stop.tv_usec
99		    - start.tv_sec * 1000000 - start.tv_usec) / (size * iter);
100
101    printf("%0.2f microseconds for list length %d\n", usec, size);
102
103    drmRandomDouble(ranstate);
104    drmSLDestroy(list);
105
106    return usec;
107}
108
109static void print_neighbors(void *list, unsigned long key,
110                            unsigned long expected_prev,
111                            unsigned long expected_next)
112{
113    unsigned long prev_key = 0;
114    unsigned long next_key = 0;
115    void          *prev_value;
116    void          *next_value;
117    int           retval;
118
119    retval = drmSLLookupNeighbors(list, key,
120				  &prev_key, &prev_value,
121				  &next_key, &next_value);
122    printf("Neighbors of %5lu: %d %5lu %5lu\n",
123	   key, retval, prev_key, next_key);
124    if (prev_key != expected_prev) {
125        fprintf(stderr, "Unexpected neighbor: %5lu. Expected: %5lu\n",
126                prev_key, expected_prev);
127	exit(1);
128    }
129    if (next_key != expected_next) {
130        fprintf(stderr, "Unexpected neighbor: %5lu. Expected: %5lu\n",
131                next_key, expected_next);
132	exit(1);
133    }
134}
135
136int main(void)
137{
138    void*    list;
139    double   usec, usec2, usec3, usec4;
140
141    list = drmSLCreate();
142    printf( "list at %p\n", list);
143
144    print(list);
145    printf("\n==============================\n\n");
146
147    drmSLInsert(list, 123, NULL);
148    drmSLInsert(list, 213, NULL);
149    drmSLInsert(list, 50, NULL);
150    print(list);
151    printf("\n==============================\n\n");
152
153    print_neighbors(list, 0, 0, 50);
154    print_neighbors(list, 50, 0, 50);
155    print_neighbors(list, 51, 50, 123);
156    print_neighbors(list, 123, 50, 123);
157    print_neighbors(list, 200, 123, 213);
158    print_neighbors(list, 213, 123, 213);
159    print_neighbors(list, 256, 213, 256);
160    printf("\n==============================\n\n");
161
162    drmSLDelete(list, 50);
163    print(list);
164    printf("\n==============================\n\n");
165
166    drmSLDump(list);
167    drmSLDestroy(list);
168    printf("\n==============================\n\n");
169
170    usec  = do_time(100, 10000);
171    usec2 = do_time(1000, 500);
172    printf("Table size increased by %0.2f, search time increased by %0.2f\n",
173	   1000.0/100.0, usec2 / usec);
174
175    usec3 = do_time(10000, 50);
176    printf("Table size increased by %0.2f, search time increased by %0.2f\n",
177	   10000.0/100.0, usec3 / usec);
178
179    usec4 = do_time(100000, 4);
180    printf("Table size increased by %0.2f, search time increased by %0.2f\n",
181	   100000.0/100.0, usec4 / usec);
182
183    return 0;
184}
185