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1
29 package net.metanotion.io.block.index;
30
31 import java.io.IOException  ;
32
33 import net.metanotion.io.RandomAccessInterface;
34 import net.metanotion.io.Serializer;
35 import net.metanotion.io.block.BlockFile;
36 import net.metanotion.io.data.NullBytes;
37 import net.metanotion.util.skiplist.SkipList;
38 import net.metanotion.util.skiplist.SkipSpan;
39
40 public class BSkipSpan extends SkipSpan {
41
42 protected BlockFile bf;
43 protected int page;
44 protected int overflowPage;
45
46 protected int prevPage;
47 protected int nextPage;
48 protected Serializer keySer;
49 protected Serializer valSer;
50
51 public static void init(BlockFile bf, int page, int spanSize) throws IOException {
52 BlockFile.pageSeek(bf.file, page);
53 bf.file.writeInt(0);
54 bf.file.writeInt(0);
55 bf.file.writeInt(0);
56 bf.file.writeShort((short) spanSize);
57 bf.file.writeShort(0);
58 }
59
60 public SkipSpan newInstance(SkipList sl) {
61 try {
62 int newPage = bf.allocPage();
63 init(bf, newPage, bf.spanSize);
64 return new BSkipSpan(bf, (BSkipList) sl, newPage, keySer, valSer);
65 } catch (IOException ioe) { throw new Error (); }
66 }
67
68 public void killInstance() {
69 try {
70 int curPage = overflowPage;
71 int next;
72 while(curPage != 0) {
73 BlockFile.pageSeek(bf.file, curPage);
74 next = bf.file.readInt();
75 bf.freePage(curPage);
76 curPage = next;
77 }
78 bf.freePage(page);
79 } catch(IOException ioe) { throw new Error (); }
80 }
81
82 public void flush() {
83 try {
84 BlockFile.pageSeek(bf.file, page);
85 bf.file.writeInt(overflowPage);
86 bf.file.writeInt((prev != null) ? ((BSkipSpan) prev).page : 0);
87 bf.file.writeInt((next != null) ? ((BSkipSpan) next).page : 0);
88 bf.file.writeShort((short) keys.length);
89 bf.file.writeShort((short) nKeys);
90
91 int ksz, vsz;
92 int curPage = this.page;
93 int[] curNextPage = new int[1];
94 curNextPage[0] = this.overflowPage;
95 int[] pageCounter = new int[1];
96 pageCounter[0] = 16;
97 byte[] keyData;
98 byte[] valData;
99
100 for(int i=0;i<nKeys;i++) {
101 if((pageCounter[0] + 4) > BlockFile.PAGESIZE) {
102 if(curNextPage[0] == 0) {
103 curNextPage[0] = bf.allocPage();
104 BlockFile.pageSeek(bf.file, curNextPage[0]);
105 bf.file.writeInt(0);
106 BlockFile.pageSeek(bf.file, curPage);
107 bf.file.writeInt(curNextPage[0]);
108 }
109 BlockFile.pageSeek(bf.file, curNextPage[0]);
110 curPage = curNextPage[0];
111 curNextPage[0] = bf.file.readInt();
112 pageCounter[0] = 4;
113 }
114 keyData = this.keySer.getBytes(keys[i]);
115 valData = this.valSer.getBytes(vals[i]);
116 pageCounter[0] += 4;
117 bf.file.writeShort(keyData.length);
118 bf.file.writeShort(valData.length);
119 curPage = bf.writeMultiPageData(keyData, curPage, pageCounter, curNextPage);
120 curPage = bf.writeMultiPageData(valData, curPage, pageCounter, curNextPage);
121 }
122 BlockFile.pageSeek(bf.file, this.page);
123 this.overflowPage = bf.file.readInt();
124 } catch(IOException ioe) { throw new Error (); }
125 }
126
127 private static void load(BSkipSpan bss, BlockFile bf, BSkipList bsl, int spanPage, Serializer key, Serializer val) throws IOException {
128 bss.bf = bf;
129 bss.page = spanPage;
130 bss.keySer = key;
131 bss.valSer = val;
132
133 bsl.spanHash.put(new Integer (spanPage), bss);
134
135 BlockFile.pageSeek(bf.file, spanPage);
136
137 bss.overflowPage = bf.file.readInt();
138 bss.prevPage = bf.file.readInt();
139 bss.nextPage = bf.file.readInt();
140 int sz = bf.file.readShort();
141 bss.nKeys = bf.file.readShort();
142
143 bss.keys = new Comparable [sz];
144 bss.vals = new Object [sz];
145
146 int ksz, vsz;
147 int curPage = spanPage;
148 int[] curNextPage = new int[1];
149 curNextPage[0] = bss.overflowPage;
150 int[] pageCounter = new int[1];
151 pageCounter[0] = 16;
152 for(int i=0;i<bss.nKeys;i++) {
154 if((pageCounter[0] + 4) > BlockFile.PAGESIZE) {
155 BlockFile.pageSeek(bf.file, curNextPage[0]);
156 curPage = curNextPage[0];
157 curNextPage[0] = bf.file.readInt();
158 pageCounter[0] = 4;
159 }
160 ksz = bf.file.readShort();
161 vsz = bf.file.readShort();
162 pageCounter[0] +=4;
163 byte[] k = new byte[ksz];
164 byte[] v = new byte[vsz];
165 curPage = bf.readMultiPageData(k, curPage, pageCounter, curNextPage);
166 curPage = bf.readMultiPageData(v, curPage, pageCounter, curNextPage);
167 bss.keys[i] = (Comparable ) bss.keySer.construct(k);
169 bss.vals[i] = bss.valSer.construct(v);
170 }
171
172 }
173
174 protected BSkipSpan() { }
175 public BSkipSpan(BlockFile bf, BSkipList bsl, int spanPage, Serializer key, Serializer val) throws IOException {
176 BSkipSpan.load(this, bf, bsl, spanPage, key, val);
177 this.next = null;
178 this.prev = null;
179
180 BSkipSpan bss = this;
181 BSkipSpan temp;
182 int np = nextPage;
183 while(np != 0) {
184 temp = (BSkipSpan) bsl.spanHash.get(new Integer (np));
185 if(temp != null) {
186 bss.next = temp;
187 break;
188 }
189 bss.next = new BSkipSpan();
190 bss.next.next = null;
191 bss.next.prev = bss;
192 bss = (BSkipSpan) bss.next;
193
194 BSkipSpan.load(bss, bf, bsl, np, key, val);
195 np = bss.nextPage;
196 }
197
198 bss = this;
199 np = prevPage;
200 while(np != 0) {
201 temp = (BSkipSpan) bsl.spanHash.get(new Integer (np));
202 if(temp != null) {
203 bss.next = temp;
204 break;
205 }
206 bss.prev = new BSkipSpan();
207 bss.prev.next = bss;
208 bss.prev.prev = null;
209 bss = (BSkipSpan) bss.prev;
210
211 BSkipSpan.load(bss, bf, bsl, np, key, val);
212 np = bss.prevPage;
213 }
214 }
215 }
216 |
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