ClickHouse/base/poco/Foundation/include/Poco/URIStreamOpener.h

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C++

//
// URIStreamOpener.h
//
// Library: Foundation
// Package: URI
// Module: URIStreamOpener
//
// Definition of the URIStreamOpener class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_URIStreamOpener_INCLUDED
#define Foundation_URIStreamOpener_INCLUDED
#include <istream>
#include <map>
#include "Poco/Foundation.h"
#include "Poco/Mutex.h"
namespace Poco
{
class URI;
class URIStreamFactory;
class Path;
class Foundation_API URIStreamOpener
/// The URIStreamOpener class is used to create and open input streams
/// for resourced identified by Uniform Resource Identifiers.
///
/// For every URI scheme used, a URIStreamFactory must be registered.
/// A FileStreamFactory is automatically registered for file URIs.
{
public:
enum
{
MAX_REDIRECTS = 10
};
URIStreamOpener();
/// Creates the URIStreamOpener and registers a FileStreamFactory
/// for file URIs.
~URIStreamOpener();
/// Destroys the URIStreamOpener and deletes all registered
/// URI stream factories.
std::istream * open(const URI & uri) const;
/// Tries to create and open an input stream for the resource specified
/// by the given uniform resource identifier.
///
/// If no URIStreamFactory has been registered for the URI's
/// scheme, a UnknownURIScheme exception is thrown.
/// If the stream cannot be opened for any reason, an
/// IOException is thrown.
///
/// The given URI must be a valid one. This excludes file system paths.
///
/// Whoever calls the method is responsible for deleting
/// the returned stream.
std::istream * open(const std::string & pathOrURI) const;
/// Tries to create and open an input stream for the resource specified
/// by the given path or uniform resource identifier.
///
/// If the stream cannot be opened for any reason, an
/// Exception is thrown.
///
/// The method first tries to interpret the given pathOrURI as an URI.
/// If this fails, the pathOrURI is treated as local filesystem path.
/// If this also fails, an exception is thrown.
///
/// Whoever calls the method is responsible for deleting
/// the returned stream.
std::istream * open(const std::string & basePathOrURI, const std::string & pathOrURI) const;
/// Tries to create and open an input stream for the resource specified
/// by the given path or uniform resource identifier.
///
/// pathOrURI is resolved against basePathOrURI (see URI::resolve() and
/// Path::resolve() for more information).
///
/// If the stream cannot be opened for any reason, an
/// Exception is thrown.
///
/// Whoever calls the method is responsible for deleting
/// the returned stream.
void registerStreamFactory(const std::string & scheme, URIStreamFactory * pFactory);
/// Registers a URIStreamFactory for the given scheme. If another factory
/// has already been registered for the scheme, an ExistsException is thrown.
///
/// The URIStreamOpener takes ownership of the factory and deletes it when it is
/// no longer needed (in other words, when the URIStreamOpener is deleted).
void unregisterStreamFactory(const std::string & scheme);
/// Unregisters and deletes the URIStreamFactory for the given scheme.
///
/// Throws a NotFoundException if no URIStreamFactory has been registered
/// for the given scheme.
bool supportsScheme(const std::string & scheme);
/// Returns true iff a URIStreamFactory for the given scheme
/// has been registered.
static URIStreamOpener & defaultOpener();
/// Returns a reference to the default URIStreamOpener.
protected:
std::istream * openFile(const Path & path) const;
std::istream * openURI(const std::string & scheme, const URI & uri) const;
private:
URIStreamOpener(const URIStreamOpener &);
URIStreamOpener & operator=(const URIStreamOpener &);
typedef std::map<std::string, URIStreamFactory *> FactoryMap;
FactoryMap _map;
mutable FastMutex _mutex;
};
} // namespace Poco
#endif // Foundation_URIStreamOpener_INCLUDED