ncbireg.hpp

ncbi源码

/*
 * ===========================================================================
 * PRODUCTION $Log: ncbireg.hpp,v $
 * PRODUCTION Revision 1000.0  2003/10/29 15:05:14  gouriano
 * PRODUCTION PRODUCTION: IMPORTED [ORIGINAL] Dev-tree R1.32
 * PRODUCTION
 * ===========================================================================
 */

#ifndef CORELIB___NCBIREG__HPP
#define CORELIB___NCBIREG__HPP

/*  $Id: ncbireg.hpp,v 1000.0 2003/10/29 15:05:14 gouriano Exp $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software/database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software/database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Author:  Denis Vakatov
 *
 */

/// @file ncbireg.hpp
/// Process information in the NCBI Registry, including working with
/// configuration files.
///
/// Classes to perform NCBI Registry operations including:
/// - Read and parse configuration file
/// - Search, edit, etc. the retrieved configuration information
/// - Write information back to configuration file
///
/// The Registry is defined as a text file with sections and entries in the 
/// form of "name=value" strings in each section. 
///
/// For an explanation of the syntax of the Registry file, see the
/// C++ Toolkit documentation.


#include <corelib/ncbistd.hpp>
#include <list>
#include <map>


/** @addtogroup Registry
 *
 * @{
 */


BEGIN_NCBI_SCOPE


/////////////////////////////////////////////////////////////////////////////
///
/// CRegistryException --
///
/// Define exceptions generated by CNcbiRegistry.
///
/// CRegistryException inherits its basic functionality from
/// CCParseTemplException<CCoreException> and defines additional error codes
/// for the Registry.

class NCBI_XNCBI_EXPORT CRegistryException :
    public CParseTemplException<CCoreException>
{
public:
    /// Error types that the Registry can generate.
    enum EErrCode {
        eSection,   ///< Section error
        eEntry,     ///< Entry error
        eValue,     ///< Value error
        eErr        ///< Other error
    };

    /// Translate from the error code value to its string representation.
    virtual const char* GetErrCodeString(void) const
    {
        switch (GetErrCode()) {
        case eSection: return "eSection";
        case eEntry:   return "eEntry";
        case eValue:   return "eValue";
        case eErr:     return "eErr";
        default:       return CException::GetErrCodeString();
        }
    }

    // Standard exception boilerplate code
    NCBI_EXCEPTION_DEFAULT2(CRegistryException,
                            CParseTemplException<CCoreException>,
                            std::string::size_type);
};



/////////////////////////////////////////////////////////////////////////////
///
/// CNcbiRegistry --
///
/// Define the Registry.
///
/// Load, access, modify and store runtime information (usually used to
/// work with configuration files).

class NCBI_XNCBI_EXPORT CNcbiRegistry
{
public:
    /// Registry parameter settings.
    ///
    /// A Registry parameter can be either transient or persistent,
    /// overridable or not overridable, truncatable or not truncatable.
    enum EFlags {
        eTransient   = 0x1,     ///< Transient -- Wont be saved (by Write())
        ePersistent  = 0x100,   ///< Persistent -- Saved when file is written
        eOverride    = 0x2,     ///< Existing value can be overriden
        eNoOverride  = 0x200,   ///< Cannot change existing value
        eTruncate    = 0x4,     ///< Leading, trailing blanks can be truncated
        eNoTruncate  = 0x400    ///< Cannot truncate parameter value
    };
    typedef int TFlags;  ///< Binary OR of "EFlags"

    /// Constructor.
    CNcbiRegistry(void);

    /// Destructor.
    ~CNcbiRegistry(void);

    /// Constructor.
    ///
    /// @param is
    ///   Input stream to load the Registry from.
    ///   NOTE:  if the stream is a file, it must be opened in binary mode!
    /// @param flags
    ///   How parameters are stored. The default is to store all parameters as
    ///   persistent unless the  "eTransient" flag is set in which case the
    ///   newly retrieved parameters is stored as transient.
    /// @sa
    ///   Read()
    CNcbiRegistry(CNcbiIstream& is, TFlags flags = 0); 

    /// Verify if Registry is empty.
    ///
    /// @return
    ///   TRUE if the registry contains no entries.
    bool Empty(void) const;

    /// Verify if persistent values have been modified.
    ///
    /// @return
    ///   TRUE if the persistent part of the registry (i.e. persistent
    ///   value(s) and the all-registry comment) was modified since:
    ///   - the last successful Write(), or
    ///   - the registry creation and maybe immediate read after the creation.
    bool Modified(void) const;

    /// Read and parse the stream "is", and merge its content with current
    /// Registry entries.
    ///
    /// Once the Registry has been initialized by the constructor, it is 
    /// possible to load other parameters from other files using this method.
    /// @param is
    ///   Input stream to read and parse.
    ///   NOTE:  if the stream is a file, it must be opened in binary mode!
    /// @param flags
    ///   How parameters are stored. The default is for all values to be read
    ///   as persistent with the capability of overriding any previously
    ///   loaded value associated with the same name. The default can be
    ///   modified by specifying "eTransient", "eNoOverride" or 
    ///   "eTransient | eNoOverride". If there is a conflict between the old
    ///   and the new(loaded) entry value and if "eNoOverride" flag is set,
    ///   then just ignore the new value; otherwise, replace the old value by
    ///   the new one. If "eTransient" flag is set, then store the newly
    ///   retrieved parameters as transient;  otherwise, store them as
    ///   persistent.
    /// @sa
    ///   Write()
    void Read(CNcbiIstream& is, TFlags flags = 0);

    /// Write the registry content to output stream.
    /// @param os
    ///   Output stream to write the registry to.
    ///   NOTE:  if the stream is a file, it must be opened in binary mode!
    /// @return
    ///   TRUE if operation is successful.
    /// @sa
    ///   Read()
    bool Write(CNcbiOstream& os) const;

    /// Reset the registry content.
    void Clear(void);

    /// Get the parameter value.
    ///
    /// Get the parameter with the specified "name" from the specified 
    /// "section".  First, search for the transient parameter value, and if
    /// cannot find in there, then continue the search in the non-transient
    /// paramters. If "ePersistent" flag is set in "flags", then don't search
    /// in the transient transient parameters at all.
    /// @param section
    ///   Section name to search under.
    /// @param name
    ///   Parameter name to search for.
    /// @param flags
    ///   To control search.
    /// @return
    ///   The parameter value, or empty string if the parameter is not found.
    /// @sa
    ///   GetString()
    const string& Get(const string& section, const string& name,
                      TFlags flags = 0) const;

    /// Get the parameter string value.
    ///
    /// Similar to the "Get()", but if the configuration parameter is not
    /// found, then return 'default_value' rather than empty string.
    /// @sa
    ///   Get()
    const string GetString(const string& section, const string& name,
                           const string& default_value, TFlags flags = 0)
        const;

    /// What to do if parameter value is present but cannot be converted into
    /// the requested type.
    enum EErrAction {
        eThrow,   ///< Throw an exception if an error occurs
        eErrPost, ///< Log the error message and return default value
        eReturn   ///< Return default value
    };