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1
21 package com.db4o;
22
23 import com.db4o.foundation.*;
24 import com.db4o.inside.mapping.*;
25 import com.db4o.inside.marshall.*;
26
27
30 public final class ReaderPair implements SlotReader {
31 private YapReader _source;
32 private YapReader _target;
33 private DefragContext _mapping;
34 private Transaction _systemTrans;
35
36 public ReaderPair(YapReader source,DefragContext mapping,Transaction systemTrans) {
37 _source = source;
38 _mapping=mapping;
39 _target = new YapReader(source.getLength());
40 _source.copyTo(_target, 0, 0, _source.getLength());
41 _systemTrans=systemTrans;
42 }
43
44 public int offset() {
45 return _source.offset();
46 }
47
48 public void offset(int offset) {
49 _source.offset(offset);
50 _target.offset(offset);
51 }
52
53 public void incrementOffset(int numBytes) {
54 _source.incrementOffset(numBytes);
55 _target.incrementOffset(numBytes);
56 }
57
58 public void incrementIntSize() {
59 incrementOffset(YapConst.INT_LENGTH);
60 }
61
62 public int copyUnindexedID() {
63 int orig=_source.readInt();
64 int mapped=-1;
65 try {
66 mapped=_mapping.mappedID(orig);
67 } catch (MappingNotFoundException exc) {
68 mapped=_mapping.allocateTargetSlot(YapConst.POINTER_LENGTH);
69 _mapping.mapIDs(orig,mapped, false);
70 _mapping.registerUnindexed(orig);
71 }
72 _target.writeInt(mapped);
73 return mapped;
74 }
75
76 public int copyID() {
77
82 int mapped=_mapping.mappedID(_source.readInt(),false);
83 _target.writeInt(mapped);
84 return mapped;
85 }
86
87 public int copyID(boolean flipNegative,boolean lenient) {
88 int id=_source.readInt();
89 return internalCopyID(flipNegative, lenient, id);
90 }
91
92 public MappedIDPair copyIDAndRetrieveMapping() {
93 int id=_source.readInt();
94 return new MappedIDPair(id,internalCopyID(false, false, id));
95 }
96
97 private int internalCopyID(boolean flipNegative, boolean lenient, int id) {
98 if(flipNegative&&id<0) {
99 id=-id;
100 }
101 int mapped=_mapping.mappedID(id,lenient);
102 if(flipNegative&&id<0) {
103 mapped=-mapped;
104 }
105 _target.writeInt(mapped);
106 return mapped;
107 }
108
109 public void readBegin(byte identifier) {
110 _source.readBegin(identifier);
111 _target.readBegin(identifier);
112 }
113
114 public byte readByte() {
115 byte value=_source.readByte();
116 _target.incrementOffset(1);
117 return value;
118 }
119
120 public int readInt() {
121 int value=_source.readInt();
122 _target.incrementOffset(YapConst.INT_LENGTH);
123 return value;
124 }
125
126 public void writeInt(int value) {
127 _source.incrementOffset(YapConst.INT_LENGTH);
128 _target.writeInt(value);
129 }
130
131 public void write(YapFile file,int address) {
132 file.writeBytes(_target,address,0);
133 }
134
135 public String  readShortString(YapStringIO sio) throws CorruptionException {
136 String value=StringMarshaller.readShort(sio,false,_source);
137 StringMarshaller.readShort(sio,false,_target);
138 return value;
139 }
140
141 public YapReader source() {
142 return _source;
143 }
144
145 public YapReader target() {
146 return _target;
147 }
148
149 public IDMapping mapping() {
150 return _mapping;
151 }
152
153 public Transaction systemTrans() {
154 return _systemTrans;
155 }
156
157 public DefragContext context() {
158 return _mapping;
159 }
160
161 public static void processCopy(DefragContext context, int sourceID,SlotCopyHandler command) throws CorruptionException {
162 processCopy(context, sourceID, command, false);
163 }
164
165 public static void processCopy(DefragContext context, int sourceID,SlotCopyHandler command,boolean registerAddressMapping) throws CorruptionException {
166 YapReader sourceReader=(
167 registerAddressMapping
168 ? context.sourceWriterByID(sourceID)
169 : context.sourceReaderByID(sourceID));
170 int targetID=context.mappedID(sourceID);
171
172 int targetLength = sourceReader.getLength();
173 int targetAddress=context.allocateTargetSlot(targetLength);
174
175 if(registerAddressMapping) {
176 int sourceAddress=((YapWriter)sourceReader).getAddress();
177 context.mapIDs(sourceAddress, targetAddress, false);
178 }
179
180 YapReader targetPointerReader=new YapReader(YapConst.POINTER_LENGTH);
181 if(Deploy.debug) {
182 targetPointerReader.writeBegin(YapConst.YAPPOINTER);
183 }
184 targetPointerReader.writeInt(targetAddress);
185 targetPointerReader.writeInt(targetLength);
186 if(Deploy.debug) {
187 targetPointerReader.writeEnd();
188 }
189 context.targetWriteBytes(targetPointerReader,targetID);
190
191 ReaderPair readers=new ReaderPair(sourceReader,context,context.systemTrans());
192 command.processCopy(readers);
193 context.targetWriteBytes(readers,targetAddress);
194 }
195
196 public void append(byte value) {
197 _source.incrementOffset(1);
198 _target.append(value);
199 }
200
201 public long readLong() {
202 long value=_source.readLong();
203 _target.incrementOffset(YapConst.LONG_LENGTH);
204 return value;
205 }
206
207 public void writeLong(long value) {
208 _source.incrementOffset(YapConst.LONG_LENGTH);
209 _target.writeLong(value);
210 }
211
212 public BitMap4 readBitMap(int bitCount) {
213 BitMap4 value=_source.readBitMap(bitCount);
214 _target.incrementOffset(value.marshalledLength());
215 return value;
216 }
217
218 public void copyBytes(byte[] target, int sourceOffset,int targetOffset, int length) {
219 _source.copyBytes(target, sourceOffset, targetOffset, length);
220 }
221
222 public void readEnd() {
223 _source.readEnd();
224 _target.readEnd();
225 }
226
227 public int preparePayloadRead() {
228 int newPayLoadOffset = readInt();
229 readInt();
230 int linkOffSet = offset();
231 offset(newPayLoadOffset);
232 return linkOffSet;
233 }
234 }
235 |
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