1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/io/nsIPipe.idl Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,169 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsISupports.idl"
1.10 +
1.11 +interface nsIAsyncInputStream;
1.12 +interface nsIAsyncOutputStream;
1.13 +
1.14 +/**
1.15 + * nsIPipe represents an in-process buffer that can be read using nsIInputStream
1.16 + * and written using nsIOutputStream. The reader and writer of a pipe do not
1.17 + * have to be on the same thread. As a result, the pipe is an ideal mechanism
1.18 + * to bridge data exchange between two threads. For example, a worker thread
1.19 + * might write data to a pipe from which the main thread will read.
1.20 + *
1.21 + * Each end of the pipe can be either blocking or non-blocking. Recall that a
1.22 + * non-blocking stream will return NS_BASE_STREAM_WOULD_BLOCK if it cannot be
1.23 + * read or written to without blocking the calling thread. For example, if you
1.24 + * try to read from an empty pipe that has not yet been closed, then if that
1.25 + * pipe's input end is non-blocking, then the read call will fail immediately
1.26 + * with NS_BASE_STREAM_WOULD_BLOCK as the error condition. However, if that
1.27 + * pipe's input end is blocking, then the read call will not return until the
1.28 + * pipe has data or until the pipe is closed. This example presumes that the
1.29 + * pipe is being filled asynchronously on some background thread.
1.30 + *
1.31 + * The pipe supports nsIAsyncInputStream and nsIAsyncOutputStream, which give
1.32 + * the user of a non-blocking pipe the ability to wait for the pipe to become
1.33 + * ready again. For example, in the case of an empty non-blocking pipe, the
1.34 + * user can call AsyncWait on the input end of the pipe to be notified when
1.35 + * the pipe has data to read (or when the pipe becomes closed).
1.36 + *
1.37 + * NS_NewPipe2 and NS_NewPipe provide convenient pipe constructors. In most
1.38 + * cases nsIPipe is not actually used. It is usually enough to just get
1.39 + * references to the pipe's input and output end. In which case, the pipe is
1.40 + * automatically closed when the respective pipe ends are released.
1.41 + */
1.42 +[scriptable, uuid(25d0de93-685e-4ea4-95d3-d884e31df63c)]
1.43 +interface nsIPipe : nsISupports
1.44 +{
1.45 + /**
1.46 + * initialize this pipe
1.47 + *
1.48 + * @param nonBlockingInput
1.49 + * true specifies non-blocking input stream behavior
1.50 + * @param nonBlockingOutput
1.51 + * true specifies non-blocking output stream behavior
1.52 + * @param segmentSize
1.53 + * specifies the segment size in bytes (pass 0 to use default value)
1.54 + * @param segmentCount
1.55 + * specifies the max number of segments (pass 0 to use default
1.56 + * value). Passing UINT32_MAX here causes the pipe to have
1.57 + * "infinite" space. This mode can be useful in some cases, but
1.58 + * should always be used with caution. The default value for this
1.59 + * parameter is a finite value.
1.60 + */
1.61 + void init(in boolean nonBlockingInput,
1.62 + in boolean nonBlockingOutput,
1.63 + in unsigned long segmentSize,
1.64 + in unsigned long segmentCount);
1.65 +
1.66 + /**
1.67 + * The pipe's input end, which also implements nsISearchableInputStream.
1.68 + */
1.69 + readonly attribute nsIAsyncInputStream inputStream;
1.70 +
1.71 + /**
1.72 + * The pipe's output end.
1.73 + */
1.74 + readonly attribute nsIAsyncOutputStream outputStream;
1.75 +};
1.76 +
1.77 +/**
1.78 + * XXX this interface doesn't really belong in here. It is here because
1.79 + * currently nsPipeInputStream is the only implementation of this interface.
1.80 + */
1.81 +[scriptable, uuid(8C39EF62-F7C9-11d4-98F5-001083010E9B)]
1.82 +interface nsISearchableInputStream : nsISupports
1.83 +{
1.84 + /**
1.85 + * Searches for a string in the input stream. Since the stream has a notion
1.86 + * of EOF, it is possible that the string may at some time be in the
1.87 + * buffer, but is is not currently found up to some offset. Consequently,
1.88 + * both the found and not found cases return an offset:
1.89 + * if found, return offset where it was found
1.90 + * if not found, return offset of the first byte not searched
1.91 + * In the case the stream is at EOF and the string is not found, the first
1.92 + * byte not searched will correspond to the length of the buffer.
1.93 + */
1.94 + void search(in string forString,
1.95 + in boolean ignoreCase,
1.96 + out boolean found,
1.97 + out unsigned long offsetSearchedTo);
1.98 +};
1.99 +
1.100 +%{C++
1.101 +
1.102 +class nsIInputStream;
1.103 +class nsIOutputStream;
1.104 +
1.105 +/**
1.106 + * NS_NewPipe2
1.107 + *
1.108 + * This function supersedes NS_NewPipe. It differs from NS_NewPipe in two
1.109 + * major ways:
1.110 + * (1) returns nsIAsyncInputStream and nsIAsyncOutputStream, so it is
1.111 + * not necessary to QI in order to access these interfaces.
1.112 + * (2) the size of the pipe is determined by the number of segments
1.113 + * times the size of each segment.
1.114 + *
1.115 + * @param pipeIn
1.116 + * resulting input end of the pipe
1.117 + * @param pipeOut
1.118 + * resulting output end of the pipe
1.119 + * @param nonBlockingInput
1.120 + * true specifies non-blocking input stream behavior
1.121 + * @param nonBlockingOutput
1.122 + * true specifies non-blocking output stream behavior
1.123 + * @param segmentSize
1.124 + * specifies the segment size in bytes (pass 0 to use default value)
1.125 + * @param segmentCount
1.126 + * specifies the max number of segments (pass 0 to use default value)
1.127 + * passing UINT32_MAX here causes the pipe to have "infinite" space.
1.128 + * this mode can be useful in some cases, but should always be used with
1.129 + * caution. the default value for this parameter is a finite value.
1.130 + */
1.131 +extern nsresult
1.132 +NS_NewPipe2(nsIAsyncInputStream **pipeIn,
1.133 + nsIAsyncOutputStream **pipeOut,
1.134 + bool nonBlockingInput = false,
1.135 + bool nonBlockingOutput = false,
1.136 + uint32_t segmentSize = 0,
1.137 + uint32_t segmentCount = 0);
1.138 +
1.139 +/**
1.140 + * NS_NewPipe
1.141 + *
1.142 + * Preserved for backwards compatibility. Plus, this interface is more
1.143 + * amiable in certain contexts (e.g., when you don't need the pipe's async
1.144 + * capabilities).
1.145 + *
1.146 + * @param pipeIn
1.147 + * resulting input end of the pipe
1.148 + * @param pipeOut
1.149 + * resulting output end of the pipe
1.150 + * @param segmentSize
1.151 + * specifies the segment size in bytes (pass 0 to use default value)
1.152 + * @param maxSize
1.153 + * specifies the max size of the pipe (pass 0 to use default value)
1.154 + * number of segments is maxSize / segmentSize, and maxSize must be a
1.155 + * multiple of segmentSize. passing UINT32_MAX here causes the
1.156 + * pipe to have "infinite" space. this mode can be useful in some
1.157 + * cases, but should always be used with caution. the default value
1.158 + * for this parameter is a finite value.
1.159 + * @param nonBlockingInput
1.160 + * true specifies non-blocking input stream behavior
1.161 + * @param nonBlockingOutput
1.162 + * true specifies non-blocking output stream behavior
1.163 + */
1.164 +extern nsresult
1.165 +NS_NewPipe(nsIInputStream **pipeIn,
1.166 + nsIOutputStream **pipeOut,
1.167 + uint32_t segmentSize = 0,
1.168 + uint32_t maxSize = 0,
1.169 + bool nonBlockingInput = false,
1.170 + bool nonBlockingOutput = false);
1.171 +
1.172 +%}
