mozilla
/
gecko-dev
зеркало из https://github.com/mozilla/gecko-dev.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
gecko-dev/netwerk/base/nsBufferedStreams.cpp

970 строки
26 KiB
C++
Исходник Ответственный История

/* -*- 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 "ipc/IPCMessageUtils.h"
#include "nsBufferedStreams.h"
#include "nsStreamUtils.h"
#include "nsNetCID.h"
#include "nsIClassInfoImpl.h"
#include "mozilla/ipc/InputStreamUtils.h"
#include <algorithm>
#ifdef DEBUG_brendan
# define METERING
#endif
#ifdef METERING
# include <stdio.h>
# define METER(x) x
# define MAX_BIG_SEEKS 20
static struct {
uint32_t mSeeksWithinBuffer;
uint32_t mSeeksOutsideBuffer;
uint32_t mBufferReadUponSeek;
uint32_t mBufferUnreadUponSeek;
uint32_t mBytesReadFromBuffer;
uint32_t mBigSeekIndex;
struct {
int64_t mOldOffset;
int64_t mNewOffset;
} mBigSeek[MAX_BIG_SEEKS];
} bufstats;
#else
# define METER(x) /* nothing */
#endif
using namespace mozilla::ipc;
using mozilla::Maybe;
using mozilla::Nothing;
using mozilla::Some;
////////////////////////////////////////////////////////////////////////////////
// nsBufferedStream
nsBufferedStream::nsBufferedStream()
: mBuffer(nullptr),
mBufferStartOffset(0),
mCursor(0),
mFillPoint(0),
mStream(nullptr),
mBufferDisabled(false),
mEOF(false),
mGetBufferCount(0)
{
}
nsBufferedStream::~nsBufferedStream()
{
Close();
}
NS_IMPL_ISUPPORTS(nsBufferedStream, nsISeekableStream)
nsresult
nsBufferedStream::Init(nsISupports* stream, uint32_t bufferSize)
{
NS_ASSERTION(stream, "need to supply a stream");
NS_ASSERTION(mStream == nullptr, "already inited");
mStream = stream;
NS_IF_ADDREF(mStream);
mBufferSize = bufferSize;
mBufferStartOffset = 0;
mCursor = 0;
mBuffer = new (mozilla::fallible) char[bufferSize];
if (mBuffer == nullptr) {
return NS_ERROR_OUT_OF_MEMORY;
}
return NS_OK;
}
nsresult
nsBufferedStream::Close()
{
NS_IF_RELEASE(mStream);
if (mBuffer) {
delete[] mBuffer;
mBuffer = nullptr;
mBufferSize = 0;
mBufferStartOffset = 0;
mCursor = 0;
mFillPoint = 0;
}
#ifdef METERING
{
static FILE *tfp;
if (!tfp) {
tfp = fopen("/tmp/bufstats", "w");
if (tfp) {
setvbuf(tfp, nullptr, _IOLBF, 0);
}
}
if (tfp) {
fprintf(tfp, "seeks within buffer: %u\n",
bufstats.mSeeksWithinBuffer);
fprintf(tfp, "seeks outside buffer: %u\n",
bufstats.mSeeksOutsideBuffer);
fprintf(tfp, "buffer read on seek: %u\n",
bufstats.mBufferReadUponSeek);
fprintf(tfp, "buffer unread on seek: %u\n",
bufstats.mBufferUnreadUponSeek);
fprintf(tfp, "bytes read from buffer: %u\n",
bufstats.mBytesReadFromBuffer);
for (uint32_t i = 0; i < bufstats.mBigSeekIndex; i++) {
fprintf(tfp, "bigseek[%u] = {old: %u, new: %u}\n",
i,
bufstats.mBigSeek[i].mOldOffset,
bufstats.mBigSeek[i].mNewOffset);
}
}
}
#endif
return NS_OK;
}
NS_IMETHODIMP
nsBufferedStream::Seek(int32_t whence, int64_t offset)
{
if (mStream == nullptr) {
return NS_BASE_STREAM_CLOSED;
}
// If the underlying stream isn't a random access store, then fail early.
// We could possibly succeed for the case where the seek position denotes
// something that happens to be read into the buffer, but that would make
// the failure data-dependent.
nsresult rv;
nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv);
if (NS_FAILED(rv)) {
#ifdef DEBUG
NS_ERROR("mStream doesn't QI to nsISeekableStream");
#endif
return rv;
}
int64_t absPos = 0;
switch (whence) {
case nsISeekableStream::NS_SEEK_SET:
absPos = offset;
break;
case nsISeekableStream::NS_SEEK_CUR:
absPos = mBufferStartOffset;
absPos += mCursor;
absPos += offset;
break;
case nsISeekableStream::NS_SEEK_END:
absPos = -1;
break;
default:
NS_NOTREACHED("bogus seek whence parameter");
return NS_ERROR_UNEXPECTED;
}
// Let mCursor point into the existing buffer if the new position is
// between the current cursor and the mFillPoint "fencepost" -- the
// client may never get around to a Read or Write after this Seek.
// Read and Write worry about flushing and filling in that event.
// But if we're at EOF, make sure to pass the seek through to the
// underlying stream, because it may have auto-closed itself and
// needs to reopen.
uint32_t offsetInBuffer = uint32_t(absPos - mBufferStartOffset);
if (offsetInBuffer <= mFillPoint && !mEOF) {
METER(bufstats.mSeeksWithinBuffer++);
mCursor = offsetInBuffer;
return NS_OK;
}
METER(bufstats.mSeeksOutsideBuffer++);
METER(bufstats.mBufferReadUponSeek += mCursor);
METER(bufstats.mBufferUnreadUponSeek += mFillPoint - mCursor);
rv = Flush();
if (NS_FAILED(rv)) {
#ifdef DEBUG
NS_WARNING("(debug) Flush returned error within nsBufferedStream::Seek, so we exit early.");
#endif
return rv;
}
rv = ras->Seek(whence, offset);
if (NS_FAILED(rv)) {
#ifdef DEBUG
NS_WARNING("(debug) Error: ras->Seek() returned error within nsBufferedStream::Seek, so we exit early.");
#endif
return rv;
}
mEOF = false;
// Recompute whether the offset we're seeking to is in our buffer.
// Note that we need to recompute because Flush() might have
// changed mBufferStartOffset.
offsetInBuffer = uint32_t(absPos - mBufferStartOffset);
if (offsetInBuffer <= mFillPoint) {
// It's safe to just set mCursor to offsetInBuffer. In particular, we
// want to avoid calling Fill() here since we already have the data that
// was seeked to and calling Fill() might auto-close our underlying
// stream in some cases.
mCursor = offsetInBuffer;
return NS_OK;
}
METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS)
bufstats.mBigSeek[bufstats.mBigSeekIndex].mOldOffset =
mBufferStartOffset + int64_t(mCursor));
const int64_t minus1 = -1;
if (absPos == minus1) {
// then we had the SEEK_END case, above
int64_t tellPos;
rv = ras->Tell(&tellPos);
mBufferStartOffset = tellPos;
if (NS_FAILED(rv)) {
return rv;
}
}
else {
mBufferStartOffset = absPos;
}
METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS)
bufstats.mBigSeek[bufstats.mBigSeekIndex++].mNewOffset =
mBufferStartOffset);
mFillPoint = mCursor = 0;
return Fill();
}
NS_IMETHODIMP
nsBufferedStream::Tell(int64_t *result)
{
if (mStream == nullptr) {
return NS_BASE_STREAM_CLOSED;
}
int64_t result64 = mBufferStartOffset;
result64 += mCursor;
*result = result64;
return NS_OK;
}
NS_IMETHODIMP
nsBufferedStream::SetEOF()
{
if (mStream == nullptr) {
return NS_BASE_STREAM_CLOSED;
}
nsresult rv;
nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv);
if (NS_FAILED(rv)) {
return rv;
}
rv = ras->SetEOF();
if (NS_SUCCEEDED(rv)) {
mEOF = true;
}
return rv;
}
////////////////////////////////////////////////////////////////////////////////
// nsBufferedInputStream
NS_IMPL_ADDREF_INHERITED(nsBufferedInputStream, nsBufferedStream)
NS_IMPL_RELEASE_INHERITED(nsBufferedInputStream, nsBufferedStream)
NS_IMPL_CLASSINFO(nsBufferedInputStream, nullptr, nsIClassInfo::THREADSAFE,
NS_BUFFEREDINPUTSTREAM_CID)
NS_INTERFACE_MAP_BEGIN(nsBufferedInputStream)
NS_INTERFACE_MAP_ENTRY(nsIInputStream)
NS_INTERFACE_MAP_ENTRY(nsIBufferedInputStream)
NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess)
NS_INTERFACE_MAP_ENTRY(nsIIPCSerializableInputStream)
NS_IMPL_QUERY_CLASSINFO(nsBufferedInputStream)
NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream)
NS_IMPL_CI_INTERFACE_GETTER(nsBufferedInputStream,
nsIInputStream,
nsIBufferedInputStream,
nsISeekableStream,
nsIStreamBufferAccess)
nsresult
nsBufferedInputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
NS_ENSURE_NO_AGGREGATION(aOuter);
nsBufferedInputStream* stream = new nsBufferedInputStream();
if (stream == nullptr) {
return NS_ERROR_OUT_OF_MEMORY;
}
NS_ADDREF(stream);
nsresult rv = stream->QueryInterface(aIID, aResult);
NS_RELEASE(stream);
return rv;
}
NS_IMETHODIMP
nsBufferedInputStream::Init(nsIInputStream* stream, uint32_t bufferSize)
{
return nsBufferedStream::Init(stream, bufferSize);
}
NS_IMETHODIMP
nsBufferedInputStream::Close()
{
nsresult rv1 = NS_OK, rv2;
if (mStream) {
rv1 = Source()->Close();
#ifdef DEBUG
if (NS_FAILED(rv1)) {
NS_WARNING("(debug) Error: Source()->Close() returned error (rv1) in bsBuffedInputStream::Close().");
};
#endif
NS_RELEASE(mStream);
}
rv2 = nsBufferedStream::Close();
#ifdef DEBUG
if (NS_FAILED(rv2)) {
NS_WARNING("(debug) Error: nsBufferedStream::Close() returned error (rv2) within nsBufferedInputStream::Close().");
};
#endif
if (NS_FAILED(rv1)) {
return rv1;
}
return rv2;
}
NS_IMETHODIMP
nsBufferedInputStream::Available(uint64_t *result)
{
nsresult rv = NS_OK;
*result = 0;
if (mStream) {
rv = Source()->Available(result);
}
*result += (mFillPoint - mCursor);
return rv;
}
NS_IMETHODIMP
nsBufferedInputStream::Read(char * buf, uint32_t count, uint32_t *result)
{
if (mBufferDisabled) {
if (!mStream) {
*result = 0;
return NS_OK;
}
nsresult rv = Source()->Read(buf, count, result);
if (NS_SUCCEEDED(rv)) {
mBufferStartOffset += *result; // so nsBufferedStream::Tell works
if (*result == 0) {
mEOF = true;
}
}
return rv;
}
return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
}
NS_IMETHODIMP
nsBufferedInputStream::ReadSegments(nsWriteSegmentFun writer, void *closure,
uint32_t count, uint32_t *result)
{
*result = 0;
if (!mStream) {
return NS_OK;
}
nsresult rv = NS_OK;
while (count > 0) {
uint32_t amt = std::min(count, mFillPoint - mCursor);
if (amt > 0) {
uint32_t read = 0;
rv = writer(this, closure, mBuffer + mCursor, *result, amt, &read);
if (NS_FAILED(rv)) {
// errors returned from the writer end here!
rv = NS_OK;
break;
}
*result += read;
count -= read;
mCursor += read;
}
else {
rv = Fill();
if (NS_FAILED(rv) || mFillPoint == mCursor) {
break;
}
}
}
return (*result > 0) ? NS_OK : rv;
}
NS_IMETHODIMP
nsBufferedInputStream::IsNonBlocking(bool *aNonBlocking)
{
if (mStream) {
return Source()->IsNonBlocking(aNonBlocking);
}
return NS_ERROR_NOT_INITIALIZED;
}
NS_IMETHODIMP
nsBufferedInputStream::Fill()
{
if (mBufferDisabled) {
return NS_OK;
}
NS_ENSURE_TRUE(mStream, NS_ERROR_NOT_INITIALIZED);
nsresult rv;
int32_t rem = int32_t(mFillPoint - mCursor);
if (rem > 0) {
// slide the remainder down to the start of the buffer
// |<------------->|<--rem-->|<--->|
// b c f s
memcpy(mBuffer, mBuffer + mCursor, rem);
}
mBufferStartOffset += mCursor;
mFillPoint = rem;
mCursor = 0;
uint32_t amt;
rv = Source()->Read(mBuffer + mFillPoint, mBufferSize - mFillPoint, &amt);
if (NS_FAILED(rv)) {
return rv;
}
if (amt == 0) {
mEOF = true;
}
mFillPoint += amt;
return NS_OK;
}
NS_IMETHODIMP_(char*)
nsBufferedInputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask)
{
NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!");
if (mGetBufferCount != 0) {
return nullptr;
}
if (mBufferDisabled) {
return nullptr;
}
char* buf = mBuffer + mCursor;
uint32_t rem = mFillPoint - mCursor;
if (rem == 0) {
if (NS_FAILED(Fill())) {
return nullptr;
}
buf = mBuffer + mCursor;
rem = mFillPoint - mCursor;
}
uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask);
if (mod) {
uint32_t pad = aAlignMask + 1 - mod;
if (pad > rem) {
return nullptr;
}
memset(buf, 0, pad);
mCursor += pad;
buf += pad;
rem -= pad;
}
if (aLength > rem) {
return nullptr;
}
mGetBufferCount++;
return buf;
}
NS_IMETHODIMP_(void)
nsBufferedInputStream::PutBuffer(char* aBuffer, uint32_t aLength)
{
NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!");
if (--mGetBufferCount != 0) {
return;
}
NS_ASSERTION(mCursor + aLength <= mFillPoint, "PutBuffer botch");
mCursor += aLength;
}
NS_IMETHODIMP
nsBufferedInputStream::DisableBuffering()
{
NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!");
NS_ASSERTION(mGetBufferCount == 0,
"DisableBuffer call between GetBuffer and PutBuffer!");
if (mGetBufferCount != 0) {
return NS_ERROR_UNEXPECTED;
}
// Empty the buffer so nsBufferedStream::Tell works.
mBufferStartOffset += mCursor;
mFillPoint = mCursor = 0;
mBufferDisabled = true;
return NS_OK;
}
NS_IMETHODIMP
nsBufferedInputStream::EnableBuffering()
{
NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!");
mBufferDisabled = false;
return NS_OK;
}
NS_IMETHODIMP
nsBufferedInputStream::GetUnbufferedStream(nsISupports* *aStream)
{
// Empty the buffer so subsequent i/o trumps any buffered data.
mBufferStartOffset += mCursor;
mFillPoint = mCursor = 0;
*aStream = mStream;
NS_IF_ADDREF(*aStream);
return NS_OK;
}
void
nsBufferedInputStream::Serialize(InputStreamParams& aParams,
FileDescriptorArray& aFileDescriptors)
{
BufferedInputStreamParams params;
if (mStream) {
nsCOMPtr<nsIInputStream> stream = do_QueryInterface(mStream);
MOZ_ASSERT(stream);
InputStreamParams wrappedParams;
SerializeInputStream(stream, wrappedParams, aFileDescriptors);
params.optionalStream() = wrappedParams;
}
else {
params.optionalStream() = mozilla::void_t();
}
params.bufferSize() = mBufferSize;
aParams = params;
}
bool
nsBufferedInputStream::Deserialize(const InputStreamParams& aParams,
const FileDescriptorArray& aFileDescriptors)
{
if (aParams.type() != InputStreamParams::TBufferedInputStreamParams) {
NS_ERROR("Received unknown parameters from the other process!");
return false;
}
const BufferedInputStreamParams& params =
aParams.get_BufferedInputStreamParams();
const OptionalInputStreamParams& wrappedParams = params.optionalStream();
nsCOMPtr<nsIInputStream> stream;
if (wrappedParams.type() == OptionalInputStreamParams::TInputStreamParams) {
stream = DeserializeInputStream(wrappedParams.get_InputStreamParams(),
aFileDescriptors);
if (!stream) {
NS_WARNING("Failed to deserialize wrapped stream!");
return false;
}
}
else {
NS_ASSERTION(wrappedParams.type() == OptionalInputStreamParams::Tvoid_t,
"Unknown type for OptionalInputStreamParams!");
}
nsresult rv = Init(stream, params.bufferSize());
NS_ENSURE_SUCCESS(rv, false);
return true;
}
Maybe<uint64_t>
nsBufferedInputStream::ExpectedSerializedLength()
{
nsCOMPtr<nsIIPCSerializableInputStream> stream = do_QueryInterface(mStream);
if (stream) {
return stream->ExpectedSerializedLength();
}
return Nothing();
}
////////////////////////////////////////////////////////////////////////////////
// nsBufferedOutputStream
NS_IMPL_ADDREF_INHERITED(nsBufferedOutputStream, nsBufferedStream)
NS_IMPL_RELEASE_INHERITED(nsBufferedOutputStream, nsBufferedStream)
// This QI uses NS_INTERFACE_MAP_ENTRY_CONDITIONAL to check for
// non-nullness of mSafeStream.
NS_INTERFACE_MAP_BEGIN(nsBufferedOutputStream)
NS_INTERFACE_MAP_ENTRY(nsIOutputStream)
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISafeOutputStream, mSafeStream)
NS_INTERFACE_MAP_ENTRY(nsIBufferedOutputStream)
NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess)
NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream)
nsresult
nsBufferedOutputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
NS_ENSURE_NO_AGGREGATION(aOuter);
nsBufferedOutputStream* stream = new nsBufferedOutputStream();
if (stream == nullptr) {
return NS_ERROR_OUT_OF_MEMORY;
}
NS_ADDREF(stream);
nsresult rv = stream->QueryInterface(aIID, aResult);
NS_RELEASE(stream);
return rv;
}
NS_IMETHODIMP
nsBufferedOutputStream::Init(nsIOutputStream* stream, uint32_t bufferSize)
{
// QI stream to an nsISafeOutputStream, to see if we should support it
mSafeStream = do_QueryInterface(stream);
return nsBufferedStream::Init(stream, bufferSize);
}
NS_IMETHODIMP
nsBufferedOutputStream::Close()
{
nsresult rv1, rv2 = NS_OK, rv3;
rv1 = Flush();
#ifdef DEBUG
if (NS_FAILED(rv1)) {
NS_WARNING("(debug) Flush() inside nsBufferedOutputStream::Close() returned error (rv1).");
}
#endif
// If we fail to Flush all the data, then we close anyway and drop the
// remaining data in the buffer. We do this because it's what Unix does
// for fclose and close. However, we report the error from Flush anyway.
if (mStream) {
rv2 = Sink()->Close();
#ifdef DEBUG
if (NS_FAILED(rv2)) {
NS_WARNING("(debug) Sink->Close() inside nsBufferedOutputStream::Close() returned error (rv2).");
}
#endif
NS_RELEASE(mStream);
}
rv3 = nsBufferedStream::Close();
#ifdef DEBUG
if (NS_FAILED(rv3)) {
NS_WARNING("(debug) nsBufferedStream:Close() inside nsBufferedOutputStream::Close() returned error (rv3).");
}
#endif
if (NS_FAILED(rv1)) {
return rv1;
}
if (NS_FAILED(rv2)) {
return rv2;
}
return rv3;
}
NS_IMETHODIMP
nsBufferedOutputStream::Write(const char *buf, uint32_t count, uint32_t *result)
{
nsresult rv = NS_OK;
uint32_t written = 0;
*result = 0;
if (!mStream) {
// We special case this situtaion.
// We should catch the failure, NS_BASE_STREAM_CLOSED ASAP, here.
// If we don't, eventually Flush() is called in the while loop below
// after so many writes.
// However, Flush() returns NS_OK when mStream is null (!!),
// and we don't get a meaningful error, NS_BASE_STREAM_CLOSED,
// soon enough when we use buffered output.
#ifdef DEBUG
NS_WARNING("(info) nsBufferedOutputStream::Write returns NS_BASE_STREAM_CLOSED immediately (mStream==null).");
#endif
return NS_BASE_STREAM_CLOSED;
}
while (count > 0) {
uint32_t amt = std::min(count, mBufferSize - mCursor);
if (amt > 0) {
memcpy(mBuffer + mCursor, buf + written, amt);
written += amt;
count -= amt;
mCursor += amt;
if (mFillPoint < mCursor)
mFillPoint = mCursor;
}
else {
NS_ASSERTION(mFillPoint, "loop in nsBufferedOutputStream::Write!");
rv = Flush();
if (NS_FAILED(rv)) {
#ifdef DEBUG
NS_WARNING("(debug) Flush() returned error in nsBufferedOutputStream::Write.");
#endif
break;
}
}
}
*result = written;
return (written > 0) ? NS_OK : rv;
}
NS_IMETHODIMP
nsBufferedOutputStream::Flush()
{
nsresult rv;
uint32_t amt;
if (!mStream) {
// Stream already cancelled/flushed; probably because of previous error.
return NS_OK;
}
// optimize : some code within C-C needs to call Seek -> Flush() often.
if (mFillPoint == 0) {
return NS_OK;
}
rv = Sink()->Write(mBuffer, mFillPoint, &amt);
if (NS_FAILED(rv)) {
return rv;
}
mBufferStartOffset += amt;
if (amt == mFillPoint) {
mFillPoint = mCursor = 0;
return NS_OK; // flushed everything
}
// slide the remainder down to the start of the buffer
// |<-------------->|<---|----->|
// b a c s
uint32_t rem = mFillPoint - amt;
memmove(mBuffer, mBuffer + amt, rem);
mFillPoint = mCursor = rem;
return NS_ERROR_FAILURE; // didn't flush all
}
// nsISafeOutputStream
NS_IMETHODIMP
nsBufferedOutputStream::Finish()
{
// flush the stream, to write out any buffered data...
nsresult rv1 = nsBufferedOutputStream::Flush();
nsresult rv2 = NS_OK, rv3;
if (NS_FAILED(rv1)) {
NS_WARNING("(debug) nsBufferedOutputStream::Flush() failed in nsBufferedOutputStream::Finish()! Possible dataloss.");
rv2 = Sink()->Close();
if (NS_FAILED(rv2)) {
NS_WARNING("(debug) Sink()->Close() failed in nsBufferedOutputStream::Finish()! Possible dataloss.");
}
} else {
rv2 = mSafeStream->Finish();
if (NS_FAILED(rv2)) {
NS_WARNING("(debug) mSafeStream->Finish() failed within nsBufferedOutputStream::Flush()! Possible dataloss.");
}
}
// ... and close the buffered stream, so any further attempts to flush/close
// the buffered stream won't cause errors.
rv3 = nsBufferedStream::Close();
// We want to return the errors precisely from Finish()
// and mimick the existing error handling in
// nsBufferedOutputStream::Close() as reference.
if (NS_FAILED(rv1)) {
return rv1;
}
if (NS_FAILED(rv2)) {
return rv2;
}
return rv3;
}
static nsresult
nsReadFromInputStream(nsIOutputStream* outStr,
void* closure,
char* toRawSegment,
uint32_t offset,
uint32_t count,
uint32_t *readCount)
{
nsIInputStream* fromStream = (nsIInputStream*)closure;
return fromStream->Read(toRawSegment, count, readCount);
}
NS_IMETHODIMP
nsBufferedOutputStream::WriteFrom(nsIInputStream *inStr, uint32_t count, uint32_t *_retval)
{
return WriteSegments(nsReadFromInputStream, inStr, count, _retval);
}
NS_IMETHODIMP
nsBufferedOutputStream::WriteSegments(nsReadSegmentFun reader, void * closure, uint32_t count, uint32_t *_retval)
{
*_retval = 0;
nsresult rv;
while (count > 0) {
uint32_t left = std::min(count, mBufferSize - mCursor);
if (left == 0) {
rv = Flush();
if (NS_FAILED(rv)) {
return (*_retval > 0) ? NS_OK : rv;
}
continue;
}
uint32_t read = 0;
rv = reader(this, closure, mBuffer + mCursor, *_retval, left, &read);
if (NS_FAILED(rv)) { // If we have read some data, return ok
return (*_retval > 0) ? NS_OK : rv;
}
mCursor += read;
*_retval += read;
count -= read;
mFillPoint = std::max(mFillPoint, mCursor);
}
return NS_OK;
}
NS_IMETHODIMP
nsBufferedOutputStream::IsNonBlocking(bool *aNonBlocking)
{
if (mStream) {
return Sink()->IsNonBlocking(aNonBlocking);
}
return NS_ERROR_NOT_INITIALIZED;
}
NS_IMETHODIMP_(char*)
nsBufferedOutputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask)
{
NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!");
if (mGetBufferCount != 0) {
return nullptr;
}
if (mBufferDisabled) {
return nullptr;
}
char* buf = mBuffer + mCursor;
uint32_t rem = mBufferSize - mCursor;
if (rem == 0) {
if (NS_FAILED(Flush())) {
return nullptr;
}
buf = mBuffer + mCursor;
rem = mBufferSize - mCursor;
}
uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask);
if (mod) {
uint32_t pad = aAlignMask + 1 - mod;
if (pad > rem) {
return nullptr;
}
memset(buf, 0, pad);
mCursor += pad;
buf += pad;
rem -= pad;
}
if (aLength > rem) {
return nullptr;
}
mGetBufferCount++;
return buf;
}
NS_IMETHODIMP_(void)
nsBufferedOutputStream::PutBuffer(char* aBuffer, uint32_t aLength)
{
NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!");
if (--mGetBufferCount != 0) {
return;
}
NS_ASSERTION(mCursor + aLength <= mBufferSize, "PutBuffer botch");
mCursor += aLength;
if (mFillPoint < mCursor) {
mFillPoint = mCursor;
}
}
NS_IMETHODIMP
nsBufferedOutputStream::DisableBuffering()
{
NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!");
NS_ASSERTION(mGetBufferCount == 0,
"DisableBuffer call between GetBuffer and PutBuffer!");
if (mGetBufferCount != 0) {
return NS_ERROR_UNEXPECTED;
}
// Empty the buffer so nsBufferedStream::Tell works.
nsresult rv = Flush();
if (NS_FAILED(rv)) {
return rv;
}
mBufferDisabled = true;
return NS_OK;
}
NS_IMETHODIMP
nsBufferedOutputStream::EnableBuffering()
{
NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!");
mBufferDisabled = false;
return NS_OK;
}
NS_IMETHODIMP
nsBufferedOutputStream::GetUnbufferedStream(nsISupports* *aStream)
{
// Empty the buffer so subsequent i/o trumps any buffered data.
if (mFillPoint) {
nsresult rv = Flush();
if (NS_FAILED(rv)) {
return rv;
}
}
*aStream = mStream;
NS_IF_ADDREF(*aStream);
return NS_OK;
}
#undef METER
////////////////////////////////////////////////////////////////////////////////
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку