1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsISupports.idl"
interface nsIOutputStream;
interface nsIInputStream;
%{C++
/**
* The signature for the reader function passed to WriteSegments. This
* is the "provider" of data that gets written into the stream's buffer.
*
* @param aOutStream stream being written to
* @param aClosure opaque parameter passed to WriteSegments
* @param aToSegment pointer to memory owned by the output stream
* @param aFromOffset amount already written (since WriteSegments was called)
* @param aCount length of toSegment
* @param aReadCount number of bytes written
*
* Implementers should return the following:
*
* @throws <any-error> if not interested in providing any data
*
* Errors are never passed to the caller of WriteSegments.
*/
typedef nsresult (*nsReadSegmentFun)(nsIOutputStream *aOutStream,
void *aClosure,
char *aToSegment,
uint32_t aFromOffset,
uint32_t aCount,
uint32_t *aReadCount);
%}
native nsReadSegmentFun(nsReadSegmentFun);
/**
* nsIOutputStream
*
* An interface describing a writable stream of data. An output stream may be
* "blocking" or "non-blocking" (see the IsNonBlocking method). A blocking
* output stream may suspend the calling thread in order to satisfy a call to
* Close, Flush, Write, WriteFrom, or WriteSegments. A non-blocking output
* stream, on the other hand, must not block the calling thread of execution.
*
* NOTE: blocking output streams are often written to on a background thread to
* avoid locking up the main application thread. For this reason, it is
* generally the case that a blocking output stream should be implemented using
* thread- safe AddRef and Release.
*/
[scriptable, uuid(0d0acd2a-61b4-11d4-9877-00c04fa0cf4a)]
interface nsIOutputStream : nsISupports
{
/**
* Close the stream. Forces the output stream to flush any buffered data.
*
* @throws NS_BASE_STREAM_WOULD_BLOCK if unable to flush without blocking
* the calling thread (non-blocking mode only)
*/
void close();
/**
* Flush the stream.
*
* @throws NS_BASE_STREAM_WOULD_BLOCK if unable to flush without blocking
* the calling thread (non-blocking mode only)
*/
void flush();
/**
* Write data into the stream.
*
* @param aBuf the buffer containing the data to be written
* @param aCount the maximum number of bytes to be written
*
* @return number of bytes written (may be less than aCount)
*
* @throws NS_BASE_STREAM_WOULD_BLOCK if writing to the output stream would
* block the calling thread (non-blocking mode only)
* @throws <other-error> on failure
*/
unsigned long write(in string aBuf, in unsigned long aCount);
/**
* Writes data into the stream from an input stream.
*
* @param aFromStream the stream containing the data to be written
* @param aCount the maximum number of bytes to be written
*
* @return number of bytes written (may be less than aCount)
*
* @throws NS_BASE_STREAM_WOULD_BLOCK if writing to the output stream would
* block the calling thread (non-blocking mode only). This failure
* means no bytes were transferred.
* @throws <other-error> on failure
*
* NOTE: This method is defined by this interface in order to allow the
* output stream to efficiently copy the data from the input stream into
* its internal buffer (if any). If this method was provided as an external
* facility, a separate char* buffer would need to be used in order to call
* the output stream's other Write method.
*/
unsigned long writeFrom(in nsIInputStream aFromStream,
in unsigned long aCount);
/**
* Low-level write method that has access to the stream's underlying buffer.
* The reader function may be called multiple times for segmented buffers.
* WriteSegments is expected to keep calling the reader until either there
* is nothing left to write or the reader returns an error. WriteSegments
* should not call the reader with zero bytes to provide.
*
* @param aReader the "provider" of the data to be written
* @param aClosure opaque parameter passed to reader
* @param aCount the maximum number of bytes to be written
*
* @return number of bytes written (may be less than aCount)
*
* @throws NS_BASE_STREAM_WOULD_BLOCK if writing to the output stream would
* block the calling thread (non-blocking mode only). This failure
* means no bytes were transferred.
* @throws NS_ERROR_NOT_IMPLEMENTED if the stream has no underlying buffer
* @throws <other-error> on failure
*
* NOTE: this function may be unimplemented if a stream has no underlying
* buffer (e.g., socket output stream).
*/
[noscript] unsigned long writeSegments(in nsReadSegmentFun aReader,
in voidPtr aClosure,
in unsigned long aCount);
/**
* @return true if stream is non-blocking
*
* NOTE: writing to a blocking output stream will block the calling thread
* until all given data can be consumed by the stream.
*
* NOTE: a non-blocking output stream may implement nsIAsyncOutputStream to
* provide consumers with a way to wait for the stream to accept more data
* once its write method is unable to accept any data without blocking.
*/
boolean isNonBlocking();
};
|
