topical media & game development
lib-of-vs-libs-Poco-include-Poco-NestedDiagnosticContext.h / h
//
// NestedDiagnosticContext.h
//
//
//
// Library: Foundation
// Package: Core
// Module: NestedDiagnosticContext
//
// Definition of the NestedDiagnosticContext class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
ifndef Foundation_NestedDiagnosticContext_INCLUDED
define Foundation_NestedDiagnosticContext_INCLUDED
include "Poco/Foundation.h"
include <vector>
include <ostream>
namespace Poco {
class NDCScope;
class Foundation_API NestedDiagnosticContext
This class implements a Nested Diagnostic Context (NDC),
as described in Neil Harrison's article "Patterns for Logging
Diagnostic Messages" in "Pattern Languages of Program Design 3"
(Addison-Wesley).
A NDC maintains a stack of context information, consisting of
an informational string (e.g., a method name), as well as an
optional source code line number and file name.
NDCs are especially useful for tagging log messages with
context information which is very helpful in a multithreaded
server scenario.
Every thread has its own private NDC, which is automatically
created when needed and destroyed when the thread terminates.
The NDCScope (or NDC::Scope) class can be used to automatically
push information at the beginning of a scope, and to pop it
at the end.
The poco_ndc(info) macro augments the information with a
source code line number and file name.
{
public:
typedef NDCScope Scope;
NestedDiagnosticContext();
Creates the NestedDiagnosticContext.
NestedDiagnosticContext(const NestedDiagnosticContext& ctx);
Copy constructor.
~NestedDiagnosticContext();
Destroys the NestedDiagnosticContext.
NestedDiagnosticContext& operator = (const NestedDiagnosticContext& ctx);
Assignment operator.
void push(const std::string& info);
Pushes a context (without line number and filename) onto the stack.
void push(const std::string& info, int line, const char* filename);
Pushes a context (including line number and filename)
onto the stack. Filename must be a static string, such as the
one produced by the __FILE__ preprocessor macro.
void pop();
Pops the top-most context off the stack.
int depth() const;
Returns the depth (number of contexts) of the stack.
std::string toString() const;
Returns the stack as a string with entries
delimited by colons. The string does not contain
line numbers and filenames.
void dump(std::ostream& ostr) const;
Dumps the stack (including line number and filenames)
to the given stream. The entries are delimited by
a newline.
void dump(std::ostream& ostr, const std::string& delimiter) const;
Dumps the stack (including line number and filenames)
to the given stream.
void clear();
Clears the NDC stack.
static NestedDiagnosticContext& current();
Returns the current thread's NDC.
private:
struct Context
{
std::string info;
const char* file;
int line;
};
typedef std::vector<Context> Stack;
Stack _stack;
};
typedef NestedDiagnosticContext NDC;
class Foundation_API NDCScope
This class can be used to automatically push a context onto
the NDC stack at the beginning of a scope, and to pop
the context at the end of the scope.
{
public:
NDCScope(const std::string& info);
Pushes a context on the stack.
NDCScope(const std::string& info, int line, const char* filename);
Pushes a context on the stack.
~NDCScope();
Pops the top-most context off the stack.
};
//
// inlines
//
inline NDCScope::NDCScope(const std::string& info)
{
NestedDiagnosticContext::current().push(info);
}
inline NDCScope::NDCScope(const std::string& info, int line, const char* filename)
{
NestedDiagnosticContext::current().push(info, line, filename);
}
inline NDCScope::~NDCScope()
{
NestedDiagnosticContext::current().pop();
}
//
// helper macros
//
define poco_ndc(func) \
Poco::NDCScope _theNdcScope(#func, __LINE__, __FILE__)
if defined(_DEBUG)
#define poco_ndc_dbg(func) \
Poco::NDCScope _theNdcScope(#func, __LINE__, __FILE__)
else
#define poco_ndc_dbg(func)
endif
} // namespace Poco
endif // Foundation_NestedDiagnosticContext_INCLUDED
(C) Æliens
04/09/2009
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