OpenCAX/entry/src/main/cpp/include/opencascade/OSD_FileSystem.hxx
2026-02-19 19:05:41 +08:00

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5.3 KiB
C++

// Copyright (c) 2021 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.
#ifndef _OSD_FileSystem_HeaderFile
#define _OSD_FileSystem_HeaderFile
#include "OSD_StreamBuffer.hxx"
#include "TCollection_AsciiString.hxx"
#include "NCollection_DefineAlloc.hxx"
//! Base interface for a file stream provider.
//! It is intended to be implemented for specific file protocol.
class OSD_FileSystem : public Standard_Transient
{
DEFINE_STANDARD_RTTIEXT(OSD_FileSystem, Standard_Transient)
public:
//! Returns a global file system, which a selector between registered file systems
//! (OSD_FileSystemSelector).
Standard_EXPORT static const Handle(OSD_FileSystem)& DefaultFileSystem();
//! Registers file system within the global file system selector returned by
//! OSD_FileSystem::DefaultFileSystem(). Note that registering protocols is not thread-safe
//! operation and expected to be done once at application startup.
//! @param[in] theFileSystem file system to register
//! @param[in] theIsPreferred add to the beginning of the list when TRUE, or add to the end
//! otherwise
Standard_EXPORT static void AddDefaultProtocol(const Handle(OSD_FileSystem)& theFileSystem,
bool theIsPreferred = false);
//! Unregisters file system within the global file system selector returned by
//! OSD_FileSystem::DefaultFileSystem().
Standard_EXPORT static void RemoveDefaultProtocol(const Handle(OSD_FileSystem)& theFileSystem);
public:
//! Returns TRUE if URL defines a supported protocol.
virtual Standard_Boolean IsSupportedPath(const TCollection_AsciiString& theUrl) const = 0;
//! Returns TRUE if current input stream is opened for reading operations.
virtual Standard_Boolean IsOpenIStream(const std::shared_ptr<std::istream>& theStream) const = 0;
//! Returns TRUE if current output stream is opened for writing operations.
virtual Standard_Boolean IsOpenOStream(const std::shared_ptr<std::ostream>& theStream) const = 0;
//! Opens stream for specified file URL for reading operations (std::istream).
//! Default implementation create a stream from file buffer returned by
//! OSD_FileSystem::OpenFileBuffer().
//! @param[in] theUrl path to open
//! @param[in] theMode flags describing the requested input mode for the stream
//! (std::ios_base::in will be implicitly added)
//! @param[in] theOffset expected stream position from the beginning of the file (beginning of
//! the stream by default);
//! -1 would keep seek position undefined (in case of reusing
//! theOldStream)
//! @param[in] theOldStream a pointer to existing stream pointing to theUrl to be reused (without
//! re-opening)
//! @return pointer to newly created opened stream, to theOldStream if it can be reused or NULL in
//! case of failure.
Standard_EXPORT virtual std::shared_ptr<std::istream> OpenIStream(
const TCollection_AsciiString& theUrl,
const std::ios_base::openmode theMode,
const int64_t theOffset = 0,
const std::shared_ptr<std::istream>& theOldStream = std::shared_ptr<std::istream>());
//! Opens stream for specified file URL for writing operations (std::ostream).
//! Default implementation create a stream from file buffer returned by
//! OSD_FileSystem::OpenFileBuffer().
//! @param[in] theUrl path to open
//! @param[in] theMode flags describing the requested output mode for the stream
//! (std::ios_base::out will be implicitly added)
//! @return pointer to newly created opened stream or NULL in case of failure.
Standard_EXPORT virtual std::shared_ptr<std::ostream> OpenOStream(
const TCollection_AsciiString& theUrl,
const std::ios_base::openmode theMode);
//! Opens stream buffer for specified file URL.
//! @param[in] theUrl path to open
//! @param[in] theMode flags describing the requested input mode for the stream
//! @param[in] theOffset expected stream position from the beginning of the buffer
//! (beginning of the stream buffer by default)
//! @param[out] theOutBufSize total buffer size (only if buffer is opened for read)
//! @return pointer to newly created opened stream buffer or NULL in case of failure.
virtual std::shared_ptr<std::streambuf> OpenStreamBuffer(const TCollection_AsciiString& theUrl,
const std::ios_base::openmode theMode,
const int64_t theOffset = 0,
int64_t* theOutBufSize = NULL) = 0;
//! Constructor.
Standard_EXPORT OSD_FileSystem();
//! Destructor.
Standard_EXPORT virtual ~OSD_FileSystem();
};
#endif // _OSD_FileSystem_HeaderFile