Big-Data-HPC-Platform/common/remote/uri.hpp

/*##############################################################################

    HPCC SYSTEMS software Copyright (C) 2012 HPCC Systems®.

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
############################################################################## */

#ifndef __JURI__
#define __JURI__

#include <uriparser/Uri.h>
#include "jlib.hpp"

// MORE - This is just a stub, structs below need to be commoned up with existing definitions elsewhere

// Supported URI schemes
enum URISchemeType
{
    URIScheme_error,
    URIScheme_hpcc,
    URIScheme_file
};

// Supported server types
enum URIServerType
{
    URIServer_local,  // Local file
    URIServer_dali,   // Names resolved by Dali
    URIServer_host    // Names resolved by DNS
};

// Supported file types
enum URIFileType
{
    URIFile_local,    // Local files
    URIFile_logic,    // Normal files
    URIFile_super,    // Super files
    URIFile_stream    // Stream files (to be implemented)
};

struct URIServerDescription
{
    StringAttr user;
    StringAttr host;
    unsigned port;
};

struct URIPathDescription
{
    StringAttr path;
    URIFileType type;
    StringAttr subname;  // Super files' sub
    unsigned index;      // Stream files
};

// ==================================================================================
/*
 * URIFileResolver is the interface that any resolver should implement to be used
 * by the URIResolution scheme, to provide a seamless interface to any HPCC engine
 * to handle files in a plethora of environments.
 *
 * This has not be thought about properly and does not concern
 * much of the initial URI investigations.
 */
//interface URIFileResolver
//{
//    // Returns a Read-only descriptor of a file. No Dali locks.
//    virtual IFileDescriptor *getFileDescriptor(StringAttr &filePath) = 0;
//    // Returns a distributed dali / local file
//    virtual IResolvedFile *getFile(StringAttr &filePath) = 0;
//    // Returns a distributed dali / local file form a pre-existing descriptor
//    virtual IResolvedFile *getFile(IFileDescriptor &fileDesc) = 0;
//    // Releases any lock and re-reads the information
//    virtual IFileDescriptor *releaseFile(IResolvedFile &file) = 0;
//};

// ==================================================================================
/*
 * URI deals with strings referring to paths that can be resolved in
 * many different ways. This object is immutable.
 *
 * Dali files (logic, super, stream), local files (on disk),
 * Web files (http, ftp, webdav) have different ways of resolving, and all of them
 * should have a consistent query mechanism from the HPCC engines point of view.
 *
 * The URI parser used is uriparser, from http://uriparser.sourceforge.net/
 */
class URI
{
    URISchemeType scheme;
    URIServerDescription server;
    URIPathDescription path;
    UriParserStateA state;
    UriUriA uri;

    void populateFields();

public:
    URI(const char* path);

    // Helper, to validate URI before creating object
    static bool isURI(const char *path);

    // Immutable
    URISchemeType getScheme() const
    {
        return scheme;
    }
    // Immutable
    const URIServerDescription * const getServer() const
    {
        return &server;
    }
    // Immutable
    const URIPathDescription * const getPath() const
    {
        return &path;
    }

    // MORE - is this the best way?
    void appendSchemeStr(StringBuffer& buf);
    void appendServerStr(StringBuffer& buf);
    void appendPathStr(StringBuffer& buf);
};

#endif /* __JURI__ */