mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-05 08:35:26 +00:00
268 lines
11 KiB
C++
268 lines
11 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* 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/. */
|
|
|
|
#ifndef nsStreamUtils_h__
|
|
#define nsStreamUtils_h__
|
|
|
|
#include "nsCOMPtr.h"
|
|
#include "nsStringFwd.h"
|
|
#include "nsIInputStream.h"
|
|
#include "nsTArray.h"
|
|
|
|
class nsIOutputStream;
|
|
class nsIInputStreamCallback;
|
|
class nsIOutputStreamCallback;
|
|
class nsIEventTarget;
|
|
|
|
/**
|
|
* A "one-shot" proxy of the OnInputStreamReady callback. The resulting
|
|
* proxy object's OnInputStreamReady function may only be called once! The
|
|
* proxy object ensures that the real notify object will be free'd on the
|
|
* thread corresponding to the given event target regardless of what thread
|
|
* the proxy object is destroyed on.
|
|
*
|
|
* This function is designed to be used to implement AsyncWait when the
|
|
* aTarget parameter is non-null.
|
|
*/
|
|
extern already_AddRefed<nsIInputStreamCallback>
|
|
NS_NewInputStreamReadyEvent(nsIInputStreamCallback* aNotify,
|
|
nsIEventTarget* aTarget);
|
|
|
|
/**
|
|
* A "one-shot" proxy of the OnOutputStreamReady callback. The resulting
|
|
* proxy object's OnOutputStreamReady function may only be called once! The
|
|
* proxy object ensures that the real notify object will be free'd on the
|
|
* thread corresponding to the given event target regardless of what thread
|
|
* the proxy object is destroyed on.
|
|
*
|
|
* This function is designed to be used to implement AsyncWait when the
|
|
* aTarget parameter is non-null.
|
|
*/
|
|
extern already_AddRefed<nsIOutputStreamCallback>
|
|
NS_NewOutputStreamReadyEvent(nsIOutputStreamCallback* aNotify,
|
|
nsIEventTarget* aTarget);
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
enum nsAsyncCopyMode {
|
|
NS_ASYNCCOPY_VIA_READSEGMENTS,
|
|
NS_ASYNCCOPY_VIA_WRITESEGMENTS
|
|
};
|
|
|
|
/**
|
|
* This function is called when a new chunk of data has been copied. The
|
|
* reported count is the size of the current chunk.
|
|
*/
|
|
typedef void (* nsAsyncCopyProgressFun)(void* closure, uint32_t count);
|
|
|
|
/**
|
|
* This function is called when the async copy process completes. The reported
|
|
* status is NS_OK on success and some error code on failure.
|
|
*/
|
|
typedef void (* nsAsyncCopyCallbackFun)(void* closure, nsresult status);
|
|
|
|
/**
|
|
* This function asynchronously copies data from the source to the sink. All
|
|
* data transfer occurs on the thread corresponding to the given event target.
|
|
* A null event target is not permitted.
|
|
*
|
|
* The copier handles blocking or non-blocking streams transparently. If a
|
|
* stream operation returns NS_BASE_STREAM_WOULD_BLOCK, then the stream will
|
|
* be QI'd to nsIAsync{In,Out}putStream and its AsyncWait method will be used
|
|
* to determine when to resume copying.
|
|
*
|
|
* Source and sink are closed by default when copying finishes or when error
|
|
* occurs. Caller can prevent closing source or sink by setting aCloseSource
|
|
* or aCloseSink to false.
|
|
*
|
|
* Caller can obtain aCopierCtx to be able to cancel copying.
|
|
*/
|
|
extern nsresult
|
|
NS_AsyncCopy(nsIInputStream* aSource,
|
|
nsIOutputStream* aSink,
|
|
nsIEventTarget* aTarget,
|
|
nsAsyncCopyMode aMode = NS_ASYNCCOPY_VIA_READSEGMENTS,
|
|
uint32_t aChunkSize = 4096,
|
|
nsAsyncCopyCallbackFun aCallbackFun = nullptr,
|
|
void* aCallbackClosure = nullptr,
|
|
bool aCloseSource = true,
|
|
bool aCloseSink = true,
|
|
nsISupports** aCopierCtx = nullptr,
|
|
nsAsyncCopyProgressFun aProgressCallbackFun = nullptr);
|
|
|
|
/**
|
|
* This function cancels copying started by function NS_AsyncCopy.
|
|
*
|
|
* @param aCopierCtx
|
|
* Copier context returned by NS_AsyncCopy.
|
|
* @param aReason
|
|
* A failure code indicating why the operation is being canceled.
|
|
* It is an error to pass a success code.
|
|
*/
|
|
extern nsresult
|
|
NS_CancelAsyncCopy(nsISupports* aCopierCtx, nsresult aReason);
|
|
|
|
/**
|
|
* This function copies all of the available data from the stream (up to at
|
|
* most aMaxCount bytes) into the given buffer. The buffer is truncated at
|
|
* the start of the function.
|
|
*
|
|
* If an error occurs while reading from the stream or while attempting to
|
|
* resize the buffer, then the corresponding error code is returned from this
|
|
* function, and any data that has already been read will be returned in the
|
|
* output buffer. This allows one to use this function with a non-blocking
|
|
* input stream that may return NS_BASE_STREAM_WOULD_BLOCK if it only has
|
|
* partial data available.
|
|
*
|
|
* @param aSource
|
|
* The input stream to read.
|
|
* @param aMaxCount
|
|
* The maximum number of bytes to consume from the stream. Pass the
|
|
* value UINT32_MAX to consume the entire stream. The number of
|
|
* bytes actually read is given by the length of aBuffer upon return.
|
|
* @param aBuffer
|
|
* The string object that will contain the stream data upon return.
|
|
* Note: The data copied to the string may contain null bytes and may
|
|
* contain non-ASCII values.
|
|
*/
|
|
extern nsresult
|
|
NS_ConsumeStream(nsIInputStream* aSource, uint32_t aMaxCount,
|
|
nsACString& aBuffer);
|
|
|
|
/**
|
|
* This function tests whether or not the input stream is buffered. A buffered
|
|
* input stream is one that implements readSegments. The test for this is to
|
|
* 1/ check whether the input stream implements nsIBufferedInputStream;
|
|
* 2/ if not, call readSegments, without actually consuming any data from the
|
|
* stream, to verify that it functions.
|
|
*
|
|
* NOTE: If the stream is non-blocking and has no data available yet, then this
|
|
* test will fail. In that case, we return false even though the test is not
|
|
* really conclusive.
|
|
*
|
|
* PERFORMANCE NOTE: If the stream does not implement nsIBufferedInputStream,
|
|
* calling readSegments may cause I/O. Therefore, you should avoid calling
|
|
* this function from the main thread.
|
|
*
|
|
* @param aInputStream
|
|
* The input stream to test.
|
|
*/
|
|
extern bool
|
|
NS_InputStreamIsBuffered(nsIInputStream* aInputStream);
|
|
|
|
/**
|
|
* This function tests whether or not the output stream is buffered. A
|
|
* buffered output stream is one that implements writeSegments. The test for
|
|
* this is to:
|
|
* 1/ check whether the output stream implements nsIBufferedOutputStream;
|
|
* 2/ if not, call writeSegments, without actually writing any data into
|
|
* the stream, to verify that it functions.
|
|
*
|
|
* NOTE: If the stream is non-blocking and has no available space yet, then
|
|
* this test will fail. In that case, we return false even though the test is
|
|
* not really conclusive.
|
|
*
|
|
* PERFORMANCE NOTE: If the stream does not implement nsIBufferedOutputStream,
|
|
* calling writeSegments may cause I/O. Therefore, you should avoid calling
|
|
* this function from the main thread.
|
|
*
|
|
* @param aOutputStream
|
|
* The output stream to test.
|
|
*/
|
|
extern bool
|
|
NS_OutputStreamIsBuffered(nsIOutputStream* aOutputStream);
|
|
|
|
/**
|
|
* This function is intended to be passed to nsIInputStream::ReadSegments to
|
|
* copy data from the nsIInputStream into a nsIOutputStream passed as the
|
|
* aClosure parameter to the ReadSegments function.
|
|
*
|
|
* @see nsIInputStream.idl for a description of this function's parameters.
|
|
*/
|
|
extern NS_METHOD
|
|
NS_CopySegmentToStream(nsIInputStream* aInputStream, void* aClosure,
|
|
const char* aFromSegment, uint32_t aToOffset,
|
|
uint32_t aCount, uint32_t* aWriteCount);
|
|
|
|
/**
|
|
* This function is intended to be passed to nsIInputStream::ReadSegments to
|
|
* copy data from the nsIInputStream into a character buffer passed as the
|
|
* aClosure parameter to the ReadSegments function. The character buffer
|
|
* must be at least as large as the aCount parameter passed to ReadSegments.
|
|
*
|
|
* @see nsIInputStream.idl for a description of this function's parameters.
|
|
*/
|
|
extern NS_METHOD
|
|
NS_CopySegmentToBuffer(nsIInputStream* aInputStream, void* aClosure,
|
|
const char* aFromSegment, uint32_t aToOffset,
|
|
uint32_t aCount, uint32_t* aWriteCount);
|
|
|
|
/**
|
|
* This function is intended to be passed to nsIOutputStream::WriteSegments to
|
|
* copy data into the nsIOutputStream from a character buffer passed as the
|
|
* aClosure parameter to the WriteSegments function.
|
|
*
|
|
* @see nsIOutputStream.idl for a description of this function's parameters.
|
|
*/
|
|
extern NS_METHOD
|
|
NS_CopySegmentToBuffer(nsIOutputStream* aOutputStream, void* aClosure,
|
|
char* aToSegment, uint32_t aFromOffset,
|
|
uint32_t aCount, uint32_t* aReadCount);
|
|
|
|
/**
|
|
* This function is intended to be passed to nsIInputStream::ReadSegments to
|
|
* discard data from the nsIInputStream. This can be used to efficiently read
|
|
* data from the stream without actually copying any bytes.
|
|
*
|
|
* @see nsIInputStream.idl for a description of this function's parameters.
|
|
*/
|
|
extern NS_METHOD
|
|
NS_DiscardSegment(nsIInputStream* aInputStream, void* aClosure,
|
|
const char* aFromSegment, uint32_t aToOffset,
|
|
uint32_t aCount, uint32_t* aWriteCount);
|
|
|
|
/**
|
|
* This function is intended to be passed to nsIInputStream::ReadSegments to
|
|
* adjust the aInputStream parameter passed to a consumer's WriteSegmentFun.
|
|
* The aClosure parameter must be a pointer to a nsWriteSegmentThunk object.
|
|
* The mStream and mClosure members of that object will be passed to the mFun
|
|
* function, with the remainder of the parameters being what are passed to
|
|
* NS_WriteSegmentThunk.
|
|
*
|
|
* This function comes in handy when implementing ReadSegments in terms of an
|
|
* inner stream's ReadSegments.
|
|
*/
|
|
extern NS_METHOD
|
|
NS_WriteSegmentThunk(nsIInputStream* aInputStream, void* aClosure,
|
|
const char* aFromSegment, uint32_t aToOffset,
|
|
uint32_t aCount, uint32_t* aWriteCount);
|
|
|
|
struct MOZ_STACK_CLASS nsWriteSegmentThunk
|
|
{
|
|
nsCOMPtr<nsIInputStream> mStream;
|
|
nsWriteSegmentFun mFun;
|
|
void* mClosure;
|
|
};
|
|
|
|
/**
|
|
* Read data from aInput and store in aDest. A non-zero aKeep will keep that
|
|
* many bytes from aDest (from the end). New data is appended after the kept
|
|
* bytes (if any). aDest's new length on returning from this function is
|
|
* aKeep + aNewBytes and is guaranteed to be less than or equal to aDest's
|
|
* current capacity.
|
|
* @param aDest the array to fill
|
|
* @param aInput the stream to read from
|
|
* @param aKeep number of bytes to keep (0 <= aKeep <= aDest.Length())
|
|
* @param aNewBytes (out) number of bytes read from aInput or zero if Read()
|
|
* failed
|
|
* @return the result from aInput->Read(...)
|
|
*/
|
|
extern NS_METHOD
|
|
NS_FillArray(FallibleTArray<char>& aDest, nsIInputStream* aInput,
|
|
uint32_t aKeep, uint32_t* aNewBytes);
|
|
|
|
#endif // !nsStreamUtils_h__
|