| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.jdbc.BinaryToRawStream |
| 4 | |
| 5 | Copyright 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.jdbc; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 24 | |
| 25 | import java.io.InputStream; |
| 26 | import java.io.IOException; |
| 27 | import java.io.EOFException; |
| 28 | |
| 29 | /** |
| 30 | Converts a stream containing the Cloudscape stored binary form |
| 31 | to one that just contains the application's data. |
| 32 | Simply read and save the length information. |
| 33 | */ |
| 34 | final class BinaryToRawStream |
| 35 | extends java.io.FilterInputStream |
| 36 | { |
| 37 | /** |
| 38 | * Length of the value represented by this stream. |
| 39 | * Set to -1 if the length is unknown. |
| 40 | */ |
| 41 | private int length; |
| 42 | |
| 43 | // used by caller to insure that parent can not be GC'd until this |
| 44 | // stream is no longer being used. |
| 45 | private Object parent; |
| 46 | |
| 47 | BinaryToRawStream(InputStream in, Object parent) |
| 48 | throws IOException |
| 49 | { |
| 50 | super(in); |
| 51 | |
| 52 | this.parent = parent; |
| 53 | |
| 54 | int bl = in.read(); |
| 55 | if (bl == -1) |
| 56 | throw new java.io.EOFException(); |
| 57 | |
| 58 | if ((bl & 0x80) != 0) |
| 59 | { |
| 60 | if (bl == 0xC0) |
| 61 | { |
| 62 | int v1 = in.read(); |
| 63 | int v2 = in.read(); |
| 64 | int v3 = in.read(); |
| 65 | int v4 = in.read(); |
| 66 | |
| 67 | if (v1 == -1 || v2 == -1 || v3 == -1 || v4 == -1) |
| 68 | throw new java.io.EOFException(); |
| 69 | length = (((v1 & 0xff) << 24) | |
| 70 | ((v2 & 0xff) << 16) | |
| 71 | ((v3 & 0xff) << 8) | |
| 72 | (v4 & 0xff)); |
| 73 | |
| 74 | } |
| 75 | else if (bl == 0xA0) |
| 76 | { |
| 77 | // read an unsigned short |
| 78 | int v1 = in.read(); |
| 79 | int v2 = in.read(); |
| 80 | if (v1 == -1 || v2 == -1) |
| 81 | throw new java.io.EOFException(); |
| 82 | length = (((v1 & 0xff) << 8) + (v2 & 0xff)); |
| 83 | |
| 84 | } |
| 85 | else |
| 86 | { |
| 87 | length = bl & 0x1F; |
| 88 | } |
| 89 | } |
| 90 | else |
| 91 | { |
| 92 | // old length in bits |
| 93 | int v2 = in.read(); |
| 94 | int v3 = in.read(); |
| 95 | int v4 = in.read(); |
| 96 | if (v2 == -1 || v3 == -1 || v4 == -1) |
| 97 | throw new java.io.EOFException(); |
| 98 | int lenInBits = (((bl & 0xff) << 24) | ((v2 & 0xff) << 16) | ((v3 & 0xff) << 8) | (v4 & 0xff)); |
| 99 | |
| 100 | length = lenInBits / 8; |
| 101 | if ((lenInBits % 8) != 0) |
| 102 | length++; |
| 103 | |
| 104 | // Signifies unknown length |
| 105 | if (length == 0) |
| 106 | length = -1; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Return the length of the value in thie stream in bytes. |
| 112 | * If the value is unknown then -1 is returned. |
| 113 | */ |
| 114 | int getLength() |
| 115 | { |
| 116 | return length; |
| 117 | } |
| 118 | } |