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2 /* ***** BEGIN LICENSE BLOCK *****
3 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 *
5 * The contents of this file are subject to the Mozilla Public License Version
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10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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13 * License.
14 *
15 * The Original Code is Mozilla FastLoad code.
16 *
17 * The Initial Developer of the Original Code is
18 * Netscape Communications Corporation.
19 * Portions created by the Initial Developer are Copyright (C) 2001
20 * the Initial Developer. All Rights Reserved.
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37
38
39 /*
40 * nsISeekableStream
41 *
42 * Note that a stream might not implement all methods (e.g., a readonly stream
43 * won't implement setEOF)
44 *
45 * @status UNDER_REVIEW
46 */
47
48 #include "nsISupports.idl"
49
50 [scriptable, uuid(8429d350-1040-4661-8b71-f2a6ba455980)]
51 interface nsISeekableStream : nsISupports
52 {
53 /*
54 * Sets the stream pointer to the value of the 'offset' parameter
55 */
56 const PRInt32 NS_SEEK_SET = 0;
57
58 /*
59 * Sets the stream pointer to its current location plus the value
60 * of the offset parameter.
61 */
62 const PRInt32 NS_SEEK_CUR = 1;
63
64 /*
65 * Sets the stream pointer to the size of the stream plus the value
66 * of the offset parameter.
67 */
68 const PRInt32 NS_SEEK_END = 2;
69
70 /**
71 * seek
72 *
73 * This method moves the stream offset of the steam implementing this
74 * interface.
75 *
76 * @param whence specifies how to interpret the 'offset' parameter in
77 * setting the stream offset associated with the implementing
78 * stream.
79 *
80 * @param offset specifies a value, in bytes, that is used in conjunction
81 * with the 'whence' parameter to set the stream offset of the
82 * implementing stream. A negative value causes seeking in
83 * the reverse direction.
84 *
85 * @throws NS_BASE_STREAM_CLOSED if called on a closed stream.
86 */
87 void seek(in long whence, in long long offset);
88
89 /**
90 * tell
91 *
92 * This method reports the current offset, in bytes, from the start of the
93 * stream.
94 *
95 * @throws NS_BASE_STREAM_CLOSED if called on a closed stream.
96 */
97 long long tell();
98
99
100 /**
101 * setEOF
102 *
103 * This method truncates the stream at the current offset.
104 *
105 * @throws NS_BASE_STREAM_CLOSED if called on a closed stream.
106 */
107 void setEOF();
108 };