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1
25
26 package org.jrobin.core;
27
28 import java.io.IOException  ;
29
30 abstract class RrdPrimitive {
31 static final int STRING_LENGTH = 20;
32 static final int RRD_INT = 0, RRD_LONG = 1, RRD_DOUBLE = 2, RRD_STRING = 3;
33 static final int[] RRD_PRIM_SIZES = { 4, 8, 8, 2 * STRING_LENGTH };
34
35 private RrdBackend backend;
36 private int byteCount;
37 private final long pointer;
38
39 protected RrdCacher cache = new RrdCacher();
40
41 RrdPrimitive(RrdUpdater updater, int type) throws IOException {
42 this(updater, type, 1);
43 }
44
45 RrdPrimitive(RrdUpdater updater, int type, int count) throws IOException {
46 this.backend = updater.getRrdBackend();
47 this.byteCount = RRD_PRIM_SIZES[type] * count;
48 this.pointer = updater.getRrdAllocator().allocate(byteCount);
49 }
50
51 byte[] readBytes() throws IOException {
52 byte[] b = new byte[byteCount];
53 backend.read(pointer, b);
54 return b;
55 }
56
57 void writeBytes(byte[] b) throws IOException {
58 assert b.length == byteCount: "Invalid number of bytes supplied to RrdPrimitive.write method";
59 backend.write(pointer, b);
60 }
61
62 int readInt() throws IOException {
63 return backend.readInt(pointer);
64 }
65
66 void writeInt(int value) throws IOException {
67 backend.writeInt(pointer, value);
68 }
69
70 long readLong() throws IOException {
71 return backend.readLong(pointer);
72 }
73
74 void writeLong(long value) throws IOException {
75 backend.writeLong(pointer, value);
76 }
77
78 double readDouble() throws IOException {
79 return backend.readDouble(pointer);
80 }
81
82 double readDouble(int index) throws IOException {
83 long offset = pointer + index * RRD_PRIM_SIZES[RRD_DOUBLE];
84 return backend.readDouble(offset);
85 }
86
87 double[] readDouble(int index, int count) throws IOException {
88 long offset = pointer + index * RRD_PRIM_SIZES[RRD_DOUBLE];
89 return backend.readDouble(offset, count);
90 }
91
92 void writeDouble(double value) throws IOException {
93 backend.writeDouble(pointer, value);
94 }
95
96 void writeDouble(int index, double value, int count) throws IOException {
97 long offset = pointer + index * RRD_PRIM_SIZES[RRD_DOUBLE];
98 backend.writeDouble(offset, value, count);
99 }
100
101 void writeDouble(int index, double[] values) throws IOException {
102 long offset = pointer + index * RRD_PRIM_SIZES[RRD_DOUBLE];
103 backend.writeDouble(offset, values);
104 }
105
106 String readString() throws IOException {
107 return backend.readString(pointer);
108 }
109
110 void writeString(String value) throws IOException {
111 backend.writeString(pointer, value);
112 }
113
114 void clearCache() {
115 cache.clearCache();
116 }
117 }
118 |
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Java API By Example, From Geeks To Geeks.