ball_managedattribute.h

Go to the documentation of this file.

/// @file ball_managedattribute.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// ball_managedattribute.h                                            -*-C++-*-
#ifndef INCLUDED_BALL_MANAGEDATTRIBUTE
#define INCLUDED_BALL_MANAGEDATTRIBUTE
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup ball_managedattribute ball_managedattribute
/// @brief  Provide a wrapper for `ball::Attribute` with managed name storage.
/// @addtogroup bal
/// @{
/// @addtogroup ball
/// @{
/// @addtogroup ball_managedattribute
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#ball_managedattribute-purpose"> Purpose</a>
/// * <a href="#ball_managedattribute-classes"> Classes </a>
/// * <a href="#ball_managedattribute-description"> Description </a>
///   * <a href="#ball_managedattribute-usage"> Usage </a>
///     * <a href="#ball_managedattribute-example-1-basic-properties-of-ball-managedattribute"> Example 1: Basic Properties of ball::ManagedAttribute </a>
///
/// # Purpose {#ball_managedattribute-purpose}
/// Provide a wrapper for `ball::Attribute` with managed name storage.
///
/// # Classes {#ball_managedattribute-classes}
///
/// -  ball::ManagedAttribute: wrapper for `ball::Attribute` with managed storage
///
/// @see  ball_attribute
///
/// # Description {#ball_managedattribute-description}
/// This component implements a wrapper for `ball::Attribute`,
/// `ball::ManagedAttribute`, that manages the lifetime of the attribute name.
/// Note that `ball::Attribute` does *not* manage the lifetime of its name (see
/// @ref ball_attribute ).
///
/// ## Usage {#ball_managedattribute-usage}
///
///
/// In this section we show intended usage of this component.
///
/// ### Example 1: Basic Properties of ball::ManagedAttribute {#ball_managedattribute-example-1-basic-properties-of-ball-managedattribute}
///
///
/// This example creates `ball::ManagedAttribute` objects and shows basic
/// properties of those objects:
/// @code
/// ball::ManagedAttribute p1("uuid", 4044457);
/// ball::ManagedAttribute p2("name", "Bloomberg");
///
/// assert("uuid" == p1.key());
/// assert("name" == p2.key());
///
/// assert(true        == p1.value().is<int>());
/// assert(4044457     == p1.value().the<int>());
/// assert(true        == p2.value().is<bsl::string>());
/// assert("Bloomberg" == p2.value().the<bsl::string>());
/// @endcode
/// Finally, we show that `ball::ManagedAttribute` manages the storage for the
/// attribute name after construction:
/// @code
/// char buffer[] = "Hello";
/// ball::ManagedAttribute p3(buffer, 1);
/// bsl::strcpy(buffer, "World");
/// assert("Hello" == p3.key()));
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bal
 * @{
 */
/** @addtogroup ball
 * @{
 */
/** @addtogroup ball_managedattribute
 * @{
 */
 
#include <balscm_version.h>
 
#include <ball_attribute.h>
 
#include <bdlb_variant.h>
 
#include <bslma_allocator.h>
#include <bslma_bslallocator.h>
#include <bslma_usesbslmaallocator.h>
 
#include <bslmf_nestedtraitdeclaration.h>
 
#include <bsls_keyword.h>
#include <bsls_types.h>
 
#include <bsl_string.h>
 
 
namespace ball {
 
                        // ======================
                        // class ManagedAttribute
                        // ======================
 
/// A `ball::ManagedAttribute` object contains a `ball::Attribute` object
/// and provides storage for the attribute's name.
///
/// See @ref ball_managedattribute 
class ManagedAttribute {
 
  private:
    // DATA
    bsl::string  d_name;        // storage for attribute's name
    Attribute    d_attribute;   // attribute
 
    // FRIENDS
    friend bool operator==(const ManagedAttribute&, const ManagedAttribute&);
    friend bool operator!=(const ManagedAttribute&, const ManagedAttribute&);
    friend bsl::ostream& operator<<(bsl::ostream&, const ManagedAttribute&);
 
  public:
    // TYPES
    typedef bsl::allocator<char> allocator_type;
 
    // TRAITS
    BSLMF_NESTED_TRAIT_DECLARATION(ManagedAttribute,
                                   bslma::UsesBslmaAllocator);
 
    // CLASS METHODS
 
    /// Return a hash value calculated from the specified `attribute` using
    /// the specified `size` as the number of slots.  The hash value is
    /// guaranteed to be in the range `[0 .. size - 1]`.  
    /// 
    /// \pre The behavior is undefined   unless `0 < size`.
    static int hash(const ManagedAttribute& attribute, int size);
 
    // CREATORS
 
    /// Create a `ManagedAttribute` object having the value of the specified
    /// `attribute`.  Optionally specify an `allocator` (e.g., the address
    /// of a `bslma::Allocator` object) to supply memory; otherwise, the
    /// default allocator is used.
    explicit ManagedAttribute(
                           const Attribute&      attribute,
                           const allocator_type& allocator = allocator_type());
 
    /// Create a `ManagedAttribute` object having the specified `name` and
    /// string `value`.  Optionally specify an `allocator` (e.g., the
    /// address of a `bslma::Allocator` object) to supply memory; otherwise,
    /// the default allocator is used.
    ManagedAttribute(const bsl::string_view& name,
                     const bsl::string_view& value,
                     const allocator_type&   allocator = allocator_type());
 
    /// Create a `ManagedAttribute` object having the specified `name` and
    /// the C-style `value` string.  Optionally specify an `allocator`
    /// (e.g., the address of a `bslma::Allocator` object) to supply memory;
    /// otherwise, the default allocator is used.
    ManagedAttribute(const bsl::string_view&  name,
                     const char              *value,
                     const allocator_type&    allocator = allocator_type());
 
    /// Create a `ManagedAttribute` object having the specified `name` and
    /// `value`.  Optionally specify an `allocator` (e.g., the address of a
    /// `bslma::Allocator` object) to supply memory; otherwise, the default
    /// allocator is used.
    ManagedAttribute(const bsl::string_view&  name,
                     int                      value,
                     const allocator_type&    allocator = allocator_type());
    ManagedAttribute(const bsl::string_view&  name,
                     long                     value,
                     const allocator_type&    allocator = allocator_type());
    ManagedAttribute(const bsl::string_view&  name,
                     long long                value,
                     const allocator_type&    allocator = allocator_type());
    ManagedAttribute(const bsl::string_view&  name,
                     unsigned int             value,
                     const allocator_type&    allocator = allocator_type());
    ManagedAttribute(const bsl::string_view&  name,
                     unsigned long            value,
                     const allocator_type&    allocator = allocator_type());
    ManagedAttribute(const bsl::string_view&  name,
                     unsigned long long       value,
                     const allocator_type&    allocator = allocator_type());
 
    /// Create a `ManagedAttribute` object having the specified `name` and
    /// the pointer to the specified `value` of cv-qualified `void` type.
    /// Optionally specify an `allocator` (e.g., the address of a
    /// `bslma::Allocator` object) to supply memory; otherwise, the default
    /// allocator is used.
    ManagedAttribute(const bsl::string_view&  name,
                     const void              *value,
                     const allocator_type&    allocator = allocator_type());
 
    /// Create a `ManagedAttribute` object having the specified `name` and
    /// `value`.  Optionally specify an `allocator` (e.g., the address of a
    /// `bslma::Allocator` object) to supply memory; otherwise, the default
    /// allocator is used.
    ManagedAttribute(const bsl::string_view& name,
                     const Attribute::Value& value,
                     const allocator_type&   allocator = allocator_type());
 
    /// Create a `ManagedAttribute` object having the same value as the
    /// specified `original` object.  Optionally specify an `allocator`
    /// (e.g., the address of a `bslma::Allocator` object) to supply memory;
    /// otherwise, the default allocator is used.
    ManagedAttribute(const ManagedAttribute&  original,
                     const allocator_type&    allocator = allocator_type());
 
    /// Destroy this object.
     ~ManagedAttribute() = default;
 
    // MANIPULATORS
 
    /// Assign to this object the value of the specified `rhs` object, and
    /// return a non-`const` reference to this object.
    ManagedAttribute& operator=(const ManagedAttribute& rhs);
 
    /// Set the attribute name of this object to the specified `name`.
    void setName(const bsl::string_view& name);
 
    /// Set the attribute value of this object to the specified `value`.
    void setValue(int                      value);
    void setValue(long                     value);
    void setValue(long long                value);
    void setValue(unsigned int             value);
    void setValue(unsigned long            value);
    void setValue(unsigned long long       value);
    void setValue(const bsl::string_view&  value);
    void setValue(const Attribute::Value&  value);
    void setValue(const char              *value);
    void setValue(const void              *value);
 
    // ACCESSORS
 
    /// Return a `const` reference to the attribute of this object.
    const Attribute& attribute() const;
 
    /// Return the allocator used by this object to supply memory.  
    /// 
    /// \note Note that   if no allocator was supplied at construction the default
    /// allocator in effect at construction is used.
    allocator_type get_allocator() const;
 
    /// Format this object to the specified output `stream` at the (absolute
    /// value of) the optionally specified indentation `level` and return a
    /// reference to `stream`.  If `level` is specified, optionally specify
    /// `spacesPerLevel`, the number of spaces per indentation level for
    /// this and all of its nested objects.  If `level` is negative,
    /// suppress indentation of the first line.  If `spacesPerLevel` is
    /// negative, format the entire output on one line, suppressing all but
    /// the initial indentation (as governed by `level`).  If `stream` is
    /// not valid on entry, this operation has no effect.
    bsl::ostream& print(bsl::ostream& stream,
                        int           level = 0,
                        int           spacesPerLevel = 4) const;
 
    /// Return a `const` reference to the attribute name of this object.
    const bsl::string& key() const;
 
    /// Return the attribute name of this object.  
    /// \note Note that  this accessor
    /// should not be used to get the attribute name if the name string
    /// contains embedded zeros.
    ///
    /// @deprecated  Use @ref key() instead.
    const char *name() const;
 
    /// Return a `const` reference to the attribute value of this object.
    const Attribute::Value& value() const;
};
 
// FREE OPERATORS
 
/// Return `true` if the specified `lhs` and `rhs` objects have the same
/// value, and `false` otherwise.  Two `ManagedAttribute` objects have the
/// same value if they have the same name, same attribute value type, and
/// the same attribute value.
bool operator==(const ManagedAttribute& lhs, const ManagedAttribute& rhs);
bool operator==(const ManagedAttribute& lhs, const Attribute& rhs);
bool operator==(const Attribute& lhs, const ManagedAttribute& rhs);
 
/// Return `true` if the specified `lhs` and `rhs` objects do not have the
/// same value, and `false` otherwise.  Two `ManagedAttribute` objects do
/// not have the same value if any of their respective names, attribute
/// value types, or attribute values differ.
bool operator!=(const ManagedAttribute& lhs, const ManagedAttribute& rhs);
bool operator!=(const ManagedAttribute& lhs, const Attribute& rhs);
bool operator!=(const Attribute& lhs, const ManagedAttribute& rhs);
 
/// Write the value of the specified `attribute` to the specified `output`
/// stream.  Return the specified `output` stream.
bsl::ostream& operator<<(bsl::ostream&           output,
                         const ManagedAttribute& attribute);
 
// ============================================================================
//                              INLINE DEFINITIONS
// ============================================================================
 
                        // ----------------------
                        // class ManagedAttribute
                        // ----------------------
 
//CLASS METHODS
inline
int ManagedAttribute::hash(const ManagedAttribute& attribute, int size)
{
    return Attribute::hash(attribute.d_attribute, size);
}
 
// CREATORS
inline
ManagedAttribute::ManagedAttribute(const Attribute&      attribute,
                                   const allocator_type& allocator)
: d_name(attribute.name(), allocator)
, d_attribute(d_name.c_str(), attribute.value(), allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   const bsl::string_view&  value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   const char              *value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   int                      value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   long                     value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   long long                value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   unsigned int             value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   unsigned long            value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   unsigned long long       value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   const void              *value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const bsl::string_view&  name,
                                   const Attribute::Value&  value,
                                   const allocator_type&    allocator)
: d_name(name, allocator)
, d_attribute(d_name.c_str(), value, allocator)
{
}
 
inline
ManagedAttribute::ManagedAttribute(const ManagedAttribute&  original,
                                   const allocator_type&    allocator)
: d_name(original.d_name, allocator)
, d_attribute(d_name.c_str(), original.d_attribute.value(), allocator)
{
}
 
// MANIPULATORS
inline
ManagedAttribute& ManagedAttribute::operator=(const ManagedAttribute& rhs)
{
    d_name       = rhs.d_name;
    d_attribute.setName(d_name.c_str());
    d_attribute.setValue(rhs.d_attribute.value());
    return *this;
}
 
inline
void ManagedAttribute::setName(const bsl::string_view& name)
{
    d_name.assign(name);
    d_attribute.setName(d_name.c_str());
}
 
inline
void ManagedAttribute::setValue(int value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(long value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(long long value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(unsigned int value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(unsigned long value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(unsigned long long value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(const bsl::string_view& value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(const Attribute::Value& value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(const char *value)
{
    d_attribute.setValue(value);
}
 
inline
void ManagedAttribute::setValue(const void *value)
{
    d_attribute.setValue(value);
}
 
// ACCESSORS
inline
const Attribute& ManagedAttribute::attribute() const
{
    return d_attribute;
}
 
inline
const bsl::string& ManagedAttribute::key() const
{
    return d_name;
}
 
inline
const char *ManagedAttribute::name() const
{
    return d_attribute.name();
}
 
inline
const Attribute::Value& ManagedAttribute::value() const
{
    return d_attribute.value();
}
 
                                  // Aspects
 
inline
ManagedAttribute::allocator_type ManagedAttribute::get_allocator() const
{
    return d_name.get_allocator();
}
 
}  // close package namespace
 
// FREE OPERATORS
inline
bool ball::operator==(const ManagedAttribute& lhs,
                      const ManagedAttribute& rhs)
{
    return (lhs.d_name == rhs.d_name
        && lhs.d_attribute.value() == rhs.d_attribute.value());
}
 
inline
bool ball::operator==(const ManagedAttribute& lhs,
                      const Attribute&        rhs)
{
    return (lhs.key() == rhs.name() && lhs.value() == rhs.value());
}
 
inline
bool ball::operator==(const Attribute&        lhs,
                      const ManagedAttribute& rhs)
{
    return (lhs.name() == rhs.key() && lhs.value() == rhs.value());
}
 
inline
bool ball::operator!=(const ManagedAttribute& lhs,
                      const ManagedAttribute& rhs)
{
    return !(lhs == rhs);
}
 
inline
bool ball::operator!=(const ManagedAttribute& lhs,
                      const Attribute&        rhs)
{
    return !(lhs == rhs);
}
 
inline
bool ball::operator!=(const Attribute&        lhs,
                      const ManagedAttribute& rhs)
{
    return !(lhs == rhs);
}
 
 
 
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2020 Bloomberg Finance L.P.
//
// 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.
// ----------------------------- END-OF-FILE ----------------------------------
 
/** @} */
/** @} */
/** @} */