gecko-dev/xpcom/io/nsStringStream.cpp

406 строки
9.6 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sts=4 sw=4 cin et: */
/* 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/. */
/**
* Based on original code from nsIStringStream.cpp
*/
#include "ipc/IPCMessageUtils.h"
#include "nsStringStream.h"
#include "nsStreamUtils.h"
#include "nsReadableUtils.h"
#include "nsISeekableStream.h"
#include "nsISupportsPrimitives.h"
#include "nsCRT.h"
#include "prerror.h"
#include "plstr.h"
#include "nsIClassInfoImpl.h"
#include "mozilla/Attributes.h"
#include "mozilla/ipc/InputStreamUtils.h"
#include "nsIIPCSerializableInputStream.h"
using namespace mozilla::ipc;
//-----------------------------------------------------------------------------
// nsIStringInputStream implementation
//-----------------------------------------------------------------------------
class nsStringInputStream MOZ_FINAL : public nsIStringInputStream
, public nsISeekableStream
, public nsISupportsCString
, public nsIIPCSerializableInputStream
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSISTRINGINPUTSTREAM
NS_DECL_NSISEEKABLESTREAM
NS_DECL_NSISUPPORTSPRIMITIVE
NS_DECL_NSISUPPORTSCSTRING
NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
nsStringInputStream()
{
Clear();
}
private:
~nsStringInputStream()
{}
uint32_t Length() const
{
return mData.Length();
}
uint32_t LengthRemaining() const
{
return Length() - mOffset;
}
void Clear()
{
mData.SetIsVoid(true);
}
bool Closed()
{
return mData.IsVoid();
}
nsDependentCSubstring mData;
uint32_t mOffset;
};
// This class needs to support threadsafe refcounting since people often
// allocate a string stream, and then read it from a background thread.
NS_IMPL_ADDREF(nsStringInputStream)
NS_IMPL_RELEASE(nsStringInputStream)
NS_IMPL_CLASSINFO(nsStringInputStream, nullptr, nsIClassInfo::THREADSAFE,
NS_STRINGINPUTSTREAM_CID)
NS_IMPL_QUERY_INTERFACE5_CI(nsStringInputStream,
nsIStringInputStream,
nsIInputStream,
nsISupportsCString,
nsISeekableStream,
nsIIPCSerializableInputStream)
NS_IMPL_CI_INTERFACE_GETTER4(nsStringInputStream,
nsIStringInputStream,
nsIInputStream,
nsISupportsCString,
nsISeekableStream)
/////////
// nsISupportsCString implementation
/////////
NS_IMETHODIMP
nsStringInputStream::GetType(uint16_t *type)
{
*type = TYPE_CSTRING;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::GetData(nsACString &data)
{
// The stream doesn't have any data when it is closed. We could fake it
// and return an empty string here, but it seems better to keep this return
// value consistent with the behavior of the other 'getter' methods.
if (NS_WARN_IF(Closed()))
return NS_BASE_STREAM_CLOSED;
data.Assign(mData);
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::SetData(const nsACString &data)
{
mData.Assign(data);
mOffset = 0;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::ToString(char **result)
{
// NOTE: This method may result in data loss, so we do not implement it.
return NS_ERROR_NOT_IMPLEMENTED;
}
/////////
// nsIStringInputStream implementation
/////////
NS_IMETHODIMP
nsStringInputStream::SetData(const char *data, int32_t dataLen)
{
if (NS_WARN_IF(!data))
return NS_ERROR_INVALID_ARG;
mData.Assign(data, dataLen);
mOffset = 0;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::AdoptData(char *data, int32_t dataLen)
{
if (NS_WARN_IF(!data))
return NS_ERROR_INVALID_ARG;
mData.Adopt(data, dataLen);
mOffset = 0;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::ShareData(const char *data, int32_t dataLen)
{
if (NS_WARN_IF(!data))
return NS_ERROR_INVALID_ARG;
if (dataLen < 0)
dataLen = strlen(data);
mData.Rebind(data, dataLen);
mOffset = 0;
return NS_OK;
}
/////////
// nsIInputStream implementation
/////////
NS_IMETHODIMP
nsStringInputStream::Close()
{
Clear();
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::Available(uint64_t *aLength)
{
NS_ASSERTION(aLength, "null ptr");
if (Closed())
return NS_BASE_STREAM_CLOSED;
*aLength = LengthRemaining();
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::Read(char* aBuf, uint32_t aCount, uint32_t *aReadCount)
{
NS_ASSERTION(aBuf, "null ptr");
return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
}
NS_IMETHODIMP
nsStringInputStream::ReadSegments(nsWriteSegmentFun writer, void *closure,
uint32_t aCount, uint32_t *result)
{
NS_ASSERTION(result, "null ptr");
NS_ASSERTION(Length() >= mOffset, "bad stream state");
if (Closed())
return NS_BASE_STREAM_CLOSED;
// We may be at end-of-file
uint32_t maxCount = LengthRemaining();
if (maxCount == 0) {
*result = 0;
return NS_OK;
}
if (aCount > maxCount)
aCount = maxCount;
nsresult rv = writer(this, closure, mData.BeginReading() + mOffset, 0, aCount, result);
if (NS_SUCCEEDED(rv)) {
NS_ASSERTION(*result <= aCount,
"writer should not write more than we asked it to write");
mOffset += *result;
}
// errors returned from the writer end here!
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::IsNonBlocking(bool *aNonBlocking)
{
*aNonBlocking = true;
return NS_OK;
}
/////////
// nsISeekableStream implementation
/////////
NS_IMETHODIMP
nsStringInputStream::Seek(int32_t whence, int64_t offset)
{
if (Closed())
return NS_BASE_STREAM_CLOSED;
// Compute new stream position. The given offset may be a negative value.
int64_t newPos = offset;
switch (whence) {
case NS_SEEK_SET:
break;
case NS_SEEK_CUR:
newPos += mOffset;
break;
case NS_SEEK_END:
newPos += Length();
break;
default:
NS_ERROR("invalid whence");
return NS_ERROR_INVALID_ARG;
}
if (NS_WARN_IF(newPos < 0) || NS_WARN_IF(newPos > Length()))
return NS_ERROR_INVALID_ARG;
mOffset = (uint32_t)newPos;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::Tell(int64_t* outWhere)
{
if (Closed())
return NS_BASE_STREAM_CLOSED;
*outWhere = mOffset;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::SetEOF()
{
if (Closed())
return NS_BASE_STREAM_CLOSED;
mOffset = Length();
return NS_OK;
}
void
nsStringInputStream::Serialize(InputStreamParams& aParams)
{
StringInputStreamParams params;
params.data() = PromiseFlatCString(mData);
aParams = params;
}
bool
nsStringInputStream::Deserialize(const InputStreamParams& aParams)
{
if (aParams.type() != InputStreamParams::TStringInputStreamParams) {
NS_ERROR("Received unknown parameters from the other process!");
return false;
}
const StringInputStreamParams& params =
aParams.get_StringInputStreamParams();
if (NS_FAILED(SetData(params.data()))) {
NS_WARNING("SetData failed!");
return false;
}
return true;
}
nsresult
NS_NewByteInputStream(nsIInputStream** aStreamResult,
const char* aStringToRead, int32_t aLength,
nsAssignmentType aAssignment)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
nsStringInputStream* stream = new nsStringInputStream();
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
nsresult rv;
switch (aAssignment) {
case NS_ASSIGNMENT_COPY:
rv = stream->SetData(aStringToRead, aLength);
break;
case NS_ASSIGNMENT_DEPEND:
rv = stream->ShareData(aStringToRead, aLength);
break;
case NS_ASSIGNMENT_ADOPT:
rv = stream->AdoptData(const_cast<char*>(aStringToRead), aLength);
break;
default:
NS_ERROR("invalid assignment type");
rv = NS_ERROR_INVALID_ARG;
}
if (NS_FAILED(rv)) {
NS_RELEASE(stream);
return rv;
}
*aStreamResult = stream;
return NS_OK;
}
nsresult
NS_NewStringInputStream(nsIInputStream** aStreamResult,
const nsAString& aStringToRead)
{
NS_LossyConvertUTF16toASCII data(aStringToRead); // truncates high-order bytes
return NS_NewCStringInputStream(aStreamResult, data);
}
nsresult
NS_NewCStringInputStream(nsIInputStream** aStreamResult,
const nsACString& aStringToRead)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
nsStringInputStream* stream = new nsStringInputStream();
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
stream->SetData(aStringToRead);
*aStreamResult = stream;
return NS_OK;
}
// factory method for constructing a nsStringInputStream object
nsresult
nsStringInputStreamConstructor(nsISupports *outer, REFNSIID iid, void **result)
{
*result = nullptr;
if (NS_WARN_IF(outer))
return NS_ERROR_NO_AGGREGATION;
nsStringInputStream *inst = new nsStringInputStream();
if (!inst)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(inst);
nsresult rv = inst->QueryInterface(iid, result);
NS_RELEASE(inst);
return rv;
}