Mercurial > jhg

comparison src/org/tmatesoft/hg/util/SparseSet.java @ 264:6bb5e7ed051a

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Optimize memory usage (reduce number of objects instantiated) when pooling file names and nodeids during manifest parsing
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Fri, 19 Aug 2011 03:36:25 +0200
parents 61cb6724ff36
children 3dd953c65619
comparison
equal deleted inserted replaced
263:31f67be94e71 264:6bb5e7ed051a
14 * the terms of a license other than GNU General Public License 14 * the terms of a license other than GNU General Public License
15 * contact TMate Software at support@hg4j.com 15 * contact TMate Software at support@hg4j.com
16 */ 16 */
17 package org.tmatesoft.hg.util; 17 package org.tmatesoft.hg.util;
18 18
19 import java.util.Arrays;
20
19 import org.tmatesoft.hg.internal.Experimental; 21 import org.tmatesoft.hg.internal.Experimental;
20 22
21 /** 23 /**
22 * WORK IN PROGRESS, DO NOT USE 24 * WORK IN PROGRESS, DO NOT USE
23 * Memory-friendly alternative to HashMap-backed Pool. Set where object can be obtained (not only queried for presence) 25 * Memory-friendly alternative to HashMap-backed Pool. Set where object can be obtained (not only queried for presence)
45 System.out.println(two == ss.get(Integer.toString(1024))); 47 System.out.println(two == ss.get(Integer.toString(1024)));
46 System.out.println(three == ss.get(Integer.toString(1123123))); 48 System.out.println(three == ss.get(Integer.toString(1123123)));
47 ss.dump(); 49 ss.dump();
48 } 50 }
49 51
50 private static class IndexBranch { 52 @SuppressWarnings("unused")
51 private final LeafBranch[] leafs = new LeafBranch[64]; 53 private static final int MASK_8BIT = 0xFF, MASK_7BIT = 0x7F, MASK_6BIT = 0x3F, MASK_5BIT = 0x1F, MASK_4BIT = 0x0F;
52 } 54 private static final int I1_SHIFT = 15, I2_SHIFT = 6, I3_SHIFT = 0;
53 private static class LeafBranch { 55 // 6, 5, 5
54 private final Object[] data = new Object[64]; 56 private static final int I1_MASK = MASK_5BIT, I2_MASK = MASK_4BIT, I3_MASK = MASK_4BIT;
55 }
56 57
57 private final int[] fixups = new int[] {0x1, 0x10, 0xA, 0xD, 0x1F }; // rehash attempts 58 private final int[] fixups = new int[] {0x1, 0x10, 0xA, 0xD, 0x1F }; // rehash attempts
58 private final IndexBranch[] level2 = new IndexBranch[64]; 59 private final IndexBranch[] level2 = new IndexBranch[I1_MASK + 1];
59 private int size = 0; 60 private int size = 0;
61
62
63 //
64 int directPut, neighborPut;
65 int[] fixupPut1 = new int[fixups.length], fixupPut2 = new int[fixups.length];;
60 66
61 public void put(T o) { 67 public void put(T o) {
62 int hash = o.hashCode(); 68 final int hash = hash(o);
63 // 69 final int i1 = (hash >>> I1_SHIFT) & I1_MASK, i2 = (hash >>> I2_SHIFT) & I2_MASK, i3 = (hash >>> I3_SHIFT) & I3_MASK;
64 // 8 bits per level
65 // int i1 = (hash >>> 24) & 0xFF, i2 = (hash >>> 16) & 0xFF , i3 = (hash >>> 8) & 0xFF, i4 = hash & 0xFF;
66 //
67 // 10, 8, 8 and 6 bits
68 // final int i1 = (hash >>> 22) & 0x3FF, i2 = (hash >>> 14) & 0xFF , i3 = (hash >>> 6) & 0xFF, i4 = hash & 0x3F;
69 //
70 // 8, 6, 6, 6, 6
71 // 10, 6, 6, 6, 4
72 //
73 // 6, 5, 5, 5 = 21 bit
74 // hash = hash ^ (hash >>> 24); // incorporate upper byte we don't use into lower to value it
75 // final int i1 = (hash >>> 18) & 0x3F, i2 = (hash >>> 12) & 0x1F , i3 = (hash >>> 7) & 0x1F, i4 = (hash >>> 2) & 0x1F;
76 // 6, 5, 5
77 // hash = hash ^ (hash >>> 16);
78 // final int i1 = (hash >>> 10) & 0x3F, i2 = (hash >>> 5) & 0x1F , i3 = hash & 0x1F;
79 //
80 // 6, 6, 6
81 final int i1 = (hash >>> 15) & 0x3F, i2 = (hash >>> 6) & 0x3F , i3 = hash & 0x3F;
82 LeafBranch l3 = leafBranchPut(i1, i2); 70 LeafBranch l3 = leafBranchPut(i1, i2);
83 if (l3.data[i3] == null) { 71 int res;
84 l3.data[i3] = o; 72 if ((res = l3.put(i3, o)) != 0) {
85 size++; 73 size++;
74 if (res == 1) {
75 directPut++;
76 } else if (res == 2) {
77 neighborPut++;
78 }
86 return; 79 return;
87 } 80 }
88 int neighbour = (i3+1) & 0x3F; 81 for (int i = 0; i < fixups.length; i++) {
89 if (l3.data[neighbour] == null) { 82 int fixup = fixups[i];
90 l3.data[neighbour] = o;
91 size++;
92 return;
93 }
94 int conflictCount = 0;
95 for (int fixup : fixups) {
96 // if (showConflicts) {
97 // System.out.printf("(fixup: 0x%x) ", fixup);
98 // }
99 l3 = leafBranchPut(i1 ^ fixup, i2); 83 l3 = leafBranchPut(i1 ^ fixup, i2);
100 conflictCount++; 84 if (l3.putIfEmptyOrSame(i3, o)) {
101 if (l3.data[i3] != null) {
102 // if (showConflicts) {
103 // System.out.printf("i1 failed ");
104 // }
105 l3 = leafBranchPut(i1, i2 ^ fixup);
106 conflictCount++;
107 // if (showConflicts) {
108 // System.out.printf("i2 %s ", (l3.data[i3] == null) ? "ok" : "failed");
109 // }
110 // } else {
111 // if (showConflicts) {
112 // System.out.printf("i1 ok");
113 // }
114 }
115 // if (showConflicts) {
116 // System.out.println();
117 // }
118 if (l3.data[i3] == null) {
119 l3.data[i3] = o;
120 // System.out.printf("Resolved conflict in %d steps (fixup 0x%X)\n", conflictCount, fixup);
121 size++; 85 size++;
86 fixupPut1[i]++;
87 return;
88 }
89 l3 = leafBranchPut(i1, i2 ^ fixup);
90 if (l3.putIfEmptyOrSame(i3, o)) {
91 size++;
92 fixupPut2[i]++;
122 return; 93 return;
123 } 94 }
124 } 95 }
125 throw new IllegalStateException(String.valueOf(o)); 96 throw new IllegalStateException(String.valueOf(o));
126 } 97 }
127 98
128 @SuppressWarnings("unchecked") 99 @SuppressWarnings("unchecked")
129 public T get(T o) { 100 public T get(T o) {
130 int hash = o.hashCode(); 101 final int hash = hash(o);
131 //hash = hash ^ (hash >>> 16); 102 final int i1 = (hash >>> I1_SHIFT) & I1_MASK, i2 = (hash >>> I2_SHIFT) & I2_MASK, i3 = (hash >>> I3_SHIFT) & I3_MASK;
132 final int i1 = (hash >>> 15) & 0x3F, i2 = (hash >>> 6) & 0x3F , i3 = hash & 0x3F;
133 // 103 //
134 LeafBranch l3 = leafBranchGet(i1, i2); 104 LeafBranch l3 = leafBranchGet(i1, i2);
135 if (l3 == null || l3.data[i3] == null) { 105 if (l3 == null) {
136 return null; 106 return null;
137 } 107 }
138 if (o.equals(l3.data[i3])) { 108 Object c;
139 return (T) l3.data[i3]; 109 if ((c = l3.get(i3, o)) != null) {
140 } 110 return c == l3 ? null : (T) c;
141 // 111 }
142 int neighbour = (i3+1) & 0x3F; 112 if ((c = l3.get(i3 ^ 0x1, o)) != null) {
143 if (o.equals(l3.data[neighbour])) { 113 return c == l3 ? null : (T) c;
144 return (T) l3.data[neighbour]; 114 }
145 } 115 if ((c = l3.get(i3 ^ 0x2, o)) != null) {
146 116 return c == l3 ? null : (T) c;
147 // 117 }
148 // resolve conflict 118 if ((c = l3.get(i3 ^ 0x3, o)) != null) {
119 return c == l3 ? null : (T) c;
120 }
149 for (int fixup : fixups) { 121 for (int fixup : fixups) {
150 Object data = leafValueGet(i1 ^ fixup, i2, i3); 122 Object data = leafValueGet(i1 ^ fixup, i2, i3);
151 if (data == null) { 123 if (data == null) {
152 return null; 124 return null;
153 } 125 }
179 l2.leafs[i2] = l3 = new LeafBranch(); 151 l2.leafs[i2] = l3 = new LeafBranch();
180 } 152 }
181 return l3; 153 return l3;
182 } 154 }
183 155
156 // unlike regular collection clear, keeps all allocated arrays to minimize gc/reallocate costs
157 // do force clean, use #drop
158 public void clear() {
159 for (int i1 = 0; i1 < level2.length; i1++) {
160 IndexBranch l2 = level2[i1];
161 if (l2 == null) {
162 continue;
163 }
164 for (int i2 = 0; i2 < l2.leafs.length; i2++) {
165 LeafBranch l3 = l2.leafs[i2];
166 if (l3 == null) {
167 continue;
168 }
169 for (int i3 = 0; i3 < l3.data.length; i3++) {
170 l3.data[i3] = null;
171 }
172 }
173 }
174 reset();
175 }
176
177 public void drop() {
178 reset();
179 for (int i1 = 0; i1 < level2.length; level2[i1++] = null);
180 }
181
182 private void reset() {
183 size = 0;
184 directPut = neighborPut = 0;
185 Arrays.fill(fixupPut1, 0);
186 Arrays.fill(fixupPut2, 0);
187 }
188
184 private LeafBranch leafBranchGet(int i1, int i2) { 189 private LeafBranch leafBranchGet(int i1, int i2) {
185 IndexBranch l2 = level2[i1]; 190 IndexBranch l2 = level2[i1];
186 if (l2 == null) { 191 if (l2 == null) {
187 return null; 192 return null;
188 } 193 }
198 if (l3 == null) { 203 if (l3 == null) {
199 return null; 204 return null;
200 } 205 }
201 return l3.data[i3]; 206 return l3.data[i3];
202 } 207 }
208
209 private int hash(Object o) {
210 int h = o.hashCode();
211 // HashMap.newHash()
212 h ^= (h >>> 20) ^ (h >>> 12);
213 return h ^ (h >>> 7) ^ (h >>> 4);
214 }
215
216 @Override
217 public String toString() {
218 return String.format("SparseSet (0x%02X-0x%02X-0x%02X), %d elements. Direct: %d. Resolutions: neighbour: %d, i1: %s. i2: %s", I1_MASK, I2_MASK, I3_MASK, size, directPut, neighborPut, Arrays.toString(fixupPut1), Arrays.toString(fixupPut2));
219 }
203 220
204 public void dump() { 221 public void dump() {
205 int count = 0; 222 int count = 0;
223 System.out.println(toString());
206 for (int i = 0; i < level2.length; i++) { 224 for (int i = 0; i < level2.length; i++) {
207 IndexBranch l2 = level2[i]; 225 IndexBranch l2 = level2[i];
208 if (l2 == null) { 226 if (l2 == null) {
209 continue; 227 continue;
210 } 228 }
220 count++; 238 count++;
221 } 239 }
222 } 240 }
223 } 241 }
224 } 242 }
225 System.out.printf("Total: %d elements", count); 243 System.out.printf("Total: %d elements\n", count);
226 } 244 }
245
246 private static class IndexBranch {
247 private final LeafBranch[] leafs = new LeafBranch[64];
248 }
249
250 private static final class LeafBranch {
251 public final Object[] data = new Object[64];
252
253 public int put(int ix, Object d) {
254 if (putIfEmptyOrSame(ix, d)) {
255 return 1;
256 }
257 // try neighbour elements
258 if (putIfEmptyOrSame(ix ^ 0x1, d) || putIfEmptyOrSame(ix ^ 0x2, d) || putIfEmptyOrSame(ix ^ 0x3, d)) {
259 return 2;
260 }
261 return 0;
262 }
263
264 public boolean putIfEmptyOrSame(int ix, Object d) {
265 if (data[ix] == null || data[ix].equals(d)) {
266 data[ix] = d;
267 return true;
268 }
269 return false;
270 }
271
272 /**
273 * <code>null</code> result indicates further checks make sense
274 * @return <code>this</code> if there's no entry at all, <code>null</code> if entry doesn't match, or entry value itself otherwise
275 */
276 public Object get(int ix, Object o) {
277 if (data[ix] == null) {
278 return this;
279 }
280 if (data[ix].equals(o)) {
281 return data[ix];
282 }
283 return null;
284 }
285 }
286
287 //
288 // 8 bits per level
289 // int i1 = (hash >>> 24) & 0xFF, i2 = (hash >>> 16) & 0xFF , i3 = (hash >>> 8) & 0xFF, i4 = hash & 0xFF;
290 //
291 // 10, 8, 8 and 6 bits
292 // final int i1 = (hash >>> 22) & 0x3FF, i2 = (hash >>> 14) & 0xFF , i3 = (hash >>> 6) & 0xFF, i4 = hash & 0x3F;
293 //
294 // 8, 6, 6, 6, 6
295 // 10, 6, 6, 6, 4
296 //
297 // 6, 5, 5, 5 = 21 bit
298 // hash = hash ^ (hash >>> 24); // incorporate upper byte we don't use into lower to value it
299 //final int i1 = (hash >>> 18) & 0x3F, i2 = (hash >>> 12) & 0x1F , i3 = (hash >>> 7) & 0x1F, i4 = (hash >>> 2) & 0x1F;
300 // 6, 5, 5
301 //hash = hash ^ (hash >>> 16);
302 //final int i1 = (hash >>> 10) & 0x3F, i2 = (hash >>> 5) & 0x1F , i3 = hash & 0x1F;
303 //
304 // 6, 6, 6
305 //final int i1 = (hash >>> 15) & 0x3F, i2 = (hash >>> 6) & 0x3F , i3 = hash & 0x3F;
306 //
307 // 8, 5, 5
308
227 } 309 }