/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
// -=- Configuration.h
//
// This header defines a set of classes used to represent configuration
// parameters of different types. Instances of the different parameter
// types are associated with instances of the Configuration class, and
// are each given a unique name. The Configuration class provides a
// generic API through which parameters may be located by name and their
// value set, thus removing the need to write platform-specific code.
// Simply defining a new parameter and associating it with a Configuration
// will allow it to be configured by the user.
//
// If no Configuration is specified when creating a Parameter, then the
// global Configuration will be assumed.
//
// Configurations can be "chained" into groups. Each group has a root
// Configuration, a pointer to which should be passed to the constructors
// of the other group members. set() and get() operations called on the
// root will iterate through all of the group's members.
//
// NB: On platforms that support Threading, locking is performed to protect
// complex parameter types from concurrent access (e.g. strings).
// NB: NO LOCKING is performed when linking Configurations to groups
// or when adding Parameters to Configurations.
#ifndef __RFB_CONFIGURATION_H__
#define __RFB_CONFIGURATION_H__
#include <rfb/util.h>
namespace rfb {
class VoidParameter;
struct ParameterIterator;
enum ConfigurationObject { ConfGlobal, ConfServer, ConfViewer };
// -=- Configuration
// Class used to access parameters.
class Configuration {
public:
// - Create a new Configuration object
Configuration(const char* name_) : name(strDup(name_)), head(0), _next(0) {}
// - Return the buffer containing the Configuration's name
const char* getName() const { return name.buf; }
// - Set named parameter to value
bool set(const char* param, const char* value, bool immutable=false);
// - Set parameter to value (separated by "=")
bool set(const char* config, bool immutable=false);
// - Set named parameter to value, with name truncated at len
bool set(const char* name, int len,
const char* val, bool immutable);
// - Get named parameter
VoidParameter* get(const char* param);
// - List the parameters of this Configuration group
void list(int width=79, int nameWidth=10);
// - readFromFile
// Read configuration parameters from the specified file.
void readFromFile(const char* filename);
// - writeConfigToFile
// Write a new configuration parameters file, then mv it
// over the old file.
void writeToFile(const char* filename);
// - Get the Global Configuration object
// NB: This call does NOT lock the Configuration system.
// ALWAYS ensure that if you have ANY global Parameters,
// then they are defined as global objects, to ensure that
// global() is called when only the main thread is running.
static Configuration* global();
// Enable server/viewer specific parameters
static void enableServerParams() { global()->appendConfiguration(server()); }
static void enableViewerParams() { global()->appendConfiguration(viewer()); }
// - Container for process-wide Global parameters
static bool setParam(const char* param, const char* value, bool immutable=false) {
return global()->set(param, value, immutable);
}
static bool setParam(const char* config, bool immutable=false) {
return global()->set(config, immutable);
}
static bool setParam(const char* name, int len,
const char* val, bool immutable) {
return global()->set(name, len, val, immutable);
}
static VoidParameter* getParam(const char* param) { return global()->get(param); }
static void listParams(int width=79, int nameWidth=10) {
global()->list(width, nameWidth);
}
private:
friend class VoidParameter;
friend struct ParameterIterator;
// Name for this Configuration
CharArray name;
// - Pointer to first Parameter in this group
VoidParameter* head;
// Pointer to next Configuration in this group
Configuration* _next;
// The process-wide, Global Configuration object
static Configuration* global_;
// The server only Configuration object
static Configuration* server_;
// The viewer only Configuration object
static Configuration* viewer_;
// Get server/viewer specific configuration object
static Configuration* server();
static Configuration* viewer();
// Append configuration object to this instance.
// NOTE: conf instance can be only one configuration object
void appendConfiguration(Configuration *conf) {
conf->_next = _next; _next = conf;
}
};
// -=- VoidParameter
// Configuration parameter base-class.
class VoidParameter {
public:
VoidParameter(const char* name_, const char* desc_, ConfigurationObject co=ConfGlobal);
virtual ~VoidParameter();
const char* getName() const;
const char* getDescription() const;
virtual bool setParam(const char* value) = 0;
virtual bool setParam();
virtual char* getDefaultStr() const = 0;
virtual char* getValueStr() const = 0;
virtual bool isBool() const;
virtual void setImmutable();
protected:
friend class Configuration;
friend struct ParameterIterator;
VoidParameter* _next;
bool immutable;
const char* name;
const char* description;
};
class AliasParameter : public VoidParameter {
public:
AliasParameter(const char* name_, const char* desc_,VoidParameter* param_,
ConfigurationObject co=ConfGlobal);
virtual bool setParam(const char* value);
virtual bool setParam();
virtual char* getDefaultStr() const;
virtual char* getValueStr() const;
virtual bool isBool() const;
virtual void setImmutable();
private:
VoidParameter* param;
};
class BoolParameter : public VoidParameter {
public:
BoolParameter(const char* name_, const char* desc_, bool v,
ConfigurationObject co=ConfGlobal);
virtual bool setParam(const char* value);
virtual bool setParam();
virtual void setParam(bool b);
virtual char* getDefaultStr() const;
virtual char* getValueStr() const;
virtual bool isBool() const;
operator bool() const;
protected:
bool value;
bool def_value;
};
class IntParameter : public VoidParameter {
public:
IntParameter(const char* name_, const char* desc_, int v,
int minValue=INT_MIN, int maxValue=INT_MAX,
ConfigurationObject co=ConfGlobal);
virtual bool setParam(const char* value);
virtual bool setParam(int v);
virtual char* getDefaultStr() const;
virtual char* getValueStr() const;
operator int() const;
protected:
int value;
int def_value;
int minValue, maxValue;
};
class StringParameter : public VoidParameter {
public:
// StringParameter contains a null-terminated string, which CANNOT
// be Null, and so neither can the default value!
StringParameter(const char* name_, const char* desc_, const char* v,
ConfigurationObject co=ConfGlobal);
virtual ~StringParameter();
virtual bool setParam(const char* value);
virtual char* getDefaultStr() const;
virtual char* getValueStr() const;
void setDefaultStr(const char* v);
operator const char*() const;
// getData() returns a copy of the data - it must be delete[]d by the
// caller.
char* getData() const { return getValueStr(); }
protected:
char* value;
const char* def_value;
};
class BinaryParameter : public VoidParameter {
public:
BinaryParameter(const char* name_, const char* desc_, const void* v, int l,
ConfigurationObject co=ConfGlobal);
virtual ~BinaryParameter();
virtual bool setParam(const char* value);
virtual void setParam(const void* v, int l);
virtual char* getDefaultStr() const;
virtual char* getValueStr() const;
// getData() will return length zero if there is no data
// NB: data may be set to zero, OR set to a zero-length buffer
void getData(void** data, int* length) const;
protected:
char* value;
int length;
char* def_value;
int def_length;
};
// -=- ParameterIterator
// Iterates over all enabled parameters (global + server/viewer).
// Current Parameter is accessed via param, the current Configuration
// via config. The next() method moves on to the next Parameter.
struct ParameterIterator {
ParameterIterator() : config(Configuration::global()), param(config->head) {}
void next() {
param = param->_next;
while (!param) {
config = config->_next;
if (!config) break;
param = config->head;
}
}
Configuration* config;
VoidParameter* param;
};
};
#endif // __RFB_CONFIGURATION_H__