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Public Member Functions | Public Attributes | Private Attributes
nsPipeInputStream Class Reference
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List of all members.

Public Member Functions

NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSIASYNCINPUTSTREAM
NS_DECL_NSISEEKABLESTREAM
NS_DECL_NSISEARCHABLEINPUTSTREAM 
nsPipeInputStream (nsPipe *pipe)
nsresult Fill ()
void SetNonBlocking (PRBool aNonBlocking)
PRUint32 Available ()
void ReduceAvailable (PRUint32 avail)
nsresult Wait ()
PRBool OnInputReadable (PRUint32 bytesWritten, nsPipeEvents &)
PRBool OnInputException (nsresult, nsPipeEvents &)
void closeWithStatus (in nsresult aStatus)
 This method closes the stream and sets its internal status.
void asyncWait (in nsIInputStreamCallback aCallback, in unsigned long aFlags, in unsigned long aRequestedCount, in nsIEventTarget aEventTarget)
 Asynchronously wait for the stream to be readable or closed.
void close ()
 Close the stream.
unsigned long available ()
unsigned long read (in charPtr aBuf, in unsigned long aCount)
 Read data from the stream.
unsigned long readSegments (in nsWriteSegmentFun aWriter, in voidPtr aClosure, in unsigned long aCount)
 Low-level read method that has access to the stream's underlying buffer.
boolean isNonBlocking ()
void seek (in long whence, in long long offset)
 seek
long long tell ()
 tell
void setEOF ()
 setEOF
void search (in string forString, in boolean ignoreCase, out boolean found, out unsigned long offsetSearchedTo)
 Searches for a string in the input stream.

Public Attributes

const unsigned long WAIT_CLOSURE_ONLY = (1<<0)
 If passed to asyncWait, this flag overrides the default behavior, causing the OnInputStreamReady notification to be suppressed until the stream becomes closed (either as a result of closeWithStatus/close being called on the stream or possibly due to some error in the underlying stream).
const PRInt32 NS_SEEK_SET = 0
const PRInt32 NS_SEEK_CUR = 1
const PRInt32 NS_SEEK_END = 2

Private Attributes

nsPipemPipe
nsrefcnt mReaderRefCnt
nsInt64 mLogicalOffset
PRPackedBool mBlocking
PRPackedBool mBlocked
PRUint32 mAvailable
nsCOMPtr< nsIInputStreamCallbackmCallback
PRUint32 mCallbackFlags

Detailed Description

Definition at line 104 of file nsPipe3.cpp.


Constructor & Destructor Documentation

NS_DECL_ISUPPORTS_INHERITED NS_DECL_NSIINPUTSTREAM NS_DECL_NSIASYNCINPUTSTREAM NS_DECL_NSISEEKABLESTREAM NS_DECL_NSISEARCHABLEINPUTSTREAM nsPipeInputStream::nsPipeInputStream ( nsPipe pipe) [inline]

Definition at line 121 of file nsPipe3.cpp.


Member Function Documentation

void nsIAsyncInputStream::asyncWait ( in nsIInputStreamCallback  aCallback,
in unsigned long  aFlags,
in unsigned long  aRequestedCount,
in nsIEventTarget  aEventTarget 
) [inherited]

Asynchronously wait for the stream to be readable or closed.

The notification is one-shot, meaning that each asyncWait call will result in exactly one notification callback. After the OnInputStreamReady event is dispatched, the stream releases its reference to the nsIInputStreamCallback object. It is safe to call asyncWait again from the notification handler.

This method may be called at any time (even if read has not been called). In other words, this method may be called when the stream already has data to read. It may also be called when the stream is closed. If the stream is already readable or closed when AsyncWait is called, then the OnInputStreamReady event will be dispatched immediately. Otherwise, the event will be dispatched when the stream becomes readable or closed.

Parameters:
aCallbackThis object is notified when the stream becomes ready.
aFlagsThis parameter specifies optional flags passed in to configure the behavior of this method. Pass zero to specify no flags.
aRequestedCountWait until at least this many bytes can be read. This is only a suggestion to the underlying stream; it may be ignored. The caller may pass zero to indicate no preference.
aEventTargetSpecify NULL to receive notification on ANY thread (possibly even recursively on the calling thread -- i.e., synchronously), or specify that the notification be delivered to a specific event target.
unsigned long nsIInputStream::available ( ) [inherited]
Returns:
number of bytes currently available in the stream

Definition at line 134 of file nsPipe3.cpp.

{ return mAvailable; }

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void nsIInputStream::close ( ) [inherited]

Close the stream.

This method closes the stream and sets its internal status.

If the stream is already closed, then this method is ignored. Once the stream is closed, the stream's status cannot be changed. Any successful status code passed to this method is treated as NS_BASE_STREAM_CLOSED, which has an effect equivalent to nsIInputStream::close.

NOTE: this method exists in part to support pipes, which have both an input end and an output end. If the input end of a pipe is closed, then writes to the output end of the pipe will fail. The error code returned when an attempt is made to write to a "broken" pipe corresponds to the status code passed in when the input end of the pipe was closed, which greatly simplifies working with pipes in some cases.

Parameters:
aStatusThe error that will be reported if this stream is accessed after it has been closed.
Returns:
true if stream is non-blocking

Definition at line 639 of file nsPipe3.cpp.

{
    LOG(("nsPipeInputStream::OnInputException [this=%x reason=%x]\n",
        this, reason));

    PRBool result = PR_FALSE;

    NS_ASSERTION(NS_FAILED(reason), "huh? successful exception");

    // force count of available bytes to zero.
    mAvailable = 0;

    if (mCallback) {
        events.NotifyInputReady(this, mCallback);
        mCallback = 0;
        mCallbackFlags = 0;
    }
    else if (mBlocked)
        result = PR_TRUE;

    return result;
}

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Definition at line 621 of file nsPipe3.cpp.

{
    PRBool result = PR_FALSE;

    mAvailable += bytesWritten;

    if (mCallback && !(mCallbackFlags & WAIT_CLOSURE_ONLY)) {
        events.NotifyInputReady(this, mCallback);
        mCallback = 0;
        mCallbackFlags = 0;
    }
    else if (mBlocked)
        result = PR_TRUE;

    return result;
}

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unsigned long nsIInputStream::read ( in charPtr  aBuf,
in unsigned long  aCount 
) [inherited]

Read data from the stream.

Parameters:
aBufthe buffer into which the data is to be read
aCountthe maximum number of bytes to be read
Returns:
number of bytes read (may be less than aCount).
0 if reached end of file
Exceptions:
NS_BASE_STREAM_WOULD_BLOCKif reading from the input stream would block the calling thread (non-blocking mode only)
<other-error>on failure
unsigned long nsIInputStream::readSegments ( in nsWriteSegmentFun  aWriter,
in voidPtr  aClosure,
in unsigned long  aCount 
) [inherited]

Low-level read method that has access to the stream's underlying buffer.

The writer function may be called multiple times for segmented buffers. ReadSegments is expected to keep calling the writer until either there is nothing left to read or the writer returns an error. ReadSegments should not call the writer with zero bytes to consume.

Parameters:
aWriterthe "consumer" of the data to be read
aClosureopaque parameter passed to writer
aCountthe maximum number of bytes to be read
Returns:
number of bytes read (may be less than aCount)
0 if reached end of file (or if aWriter refused to consume data)
Exceptions:
NS_BASE_STREAM_WOULD_BLOCKif reading from the input stream would block the calling thread (non-blocking mode only)
<other-error>on failure

NOTE: this function may be unimplemented if a stream has no underlying buffer (e.g., socket input stream).

Definition at line 135 of file nsPipe3.cpp.

{ mAvailable -= avail; }

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void nsISearchableInputStream::search ( in string  forString,
in boolean  ignoreCase,
out boolean  found,
out unsigned long  offsetSearchedTo 
) [inherited]

Searches for a string in the input stream.

Since the stream has a notion of EOF, it is possible that the string may at some time be in the buffer, but is is not currently found up to some offset. Consequently, both the found and not found cases return an offset: if found, return offset where it was found if not found, return offset of the first byte not searched In the case the stream is at EOF and the string is not found, the first byte not searched will correspond to the length of the buffer.

void nsISeekableStream::seek ( in long  whence,
in long long  offset 
) [inherited]

seek

This method moves the stream offset of the steam implementing this interface.

Parameters:
whencespecifies how to interpret the 'offset' parameter in setting the stream offset associated with the implementing stream.
offsetspecifies a value, in bytes, that is used in conjunction with the 'whence' parameter to set the stream offset of the implementing stream. A negative value causes seeking in the reverse direction.

setEOF

This method truncates the stream at the current offset.

void nsPipeInputStream::SetNonBlocking ( PRBool  aNonBlocking) [inline]

Definition at line 132 of file nsPipe3.cpp.

{ mBlocking = !aNonBlocking; }

tell

This method reports the current offset, in bytes, from the start of the stream.

Definition at line 600 of file nsPipe3.cpp.

{
    NS_ASSERTION(mBlocking, "wait on non-blocking pipe input stream");

    nsAutoMonitor mon(mPipe->mMonitor);

    while (NS_SUCCEEDED(mPipe->mStatus) && (mAvailable == 0)) {
        LOG(("III pipe input: waiting for data\n"));

        mBlocked = PR_TRUE;
        mon.Wait();
        mBlocked = PR_FALSE;

        LOG(("III pipe input: woke up [pipe-status=%x available=%u]\n",
            mPipe->mStatus, mAvailable));
    }

    return mPipe->mStatus == NS_BASE_STREAM_CLOSED ? NS_OK : mPipe->mStatus;
}

Member Data Documentation

Definition at line 155 of file nsPipe3.cpp.

Definition at line 154 of file nsPipe3.cpp.

Definition at line 151 of file nsPipe3.cpp.

Definition at line 156 of file nsPipe3.cpp.

Definition at line 157 of file nsPipe3.cpp.

Definition at line 150 of file nsPipe3.cpp.

Definition at line 146 of file nsPipe3.cpp.

Definition at line 149 of file nsPipe3.cpp.

Definition at line 62 of file nsISeekableStream.idl.

Definition at line 68 of file nsISeekableStream.idl.

Definition at line 56 of file nsISeekableStream.idl.

const unsigned long nsIAsyncInputStream::WAIT_CLOSURE_ONLY = (1<<0) [inherited]

If passed to asyncWait, this flag overrides the default behavior, causing the OnInputStreamReady notification to be suppressed until the stream becomes closed (either as a result of closeWithStatus/close being called on the stream or possibly due to some error in the underlying stream).

Definition at line 120 of file nsIAsyncInputStream.idl.


The documentation for this class was generated from the following file: