[svn] commit: r939 - in /trunk: ./ doc/Doxyfile src/lib/dns/cpp/ src/lib/dns/cpp/rdata.h src/lib/dns/cpp/rrset.cc src/lib/dns/cpp/rrset.h src/lib/dns/cpp/rrset_unittest.cc
BIND 10 source code commits
bind10-changes at lists.isc.org
Tue Feb 23 19:49:51 UTC 2010
Author: jinmei
Date: Tue Feb 23 19:49:51 2010
New Revision: 939
Log:
merged from the jinmei-dnsrrset branch
Modified:
trunk/ (props changed)
trunk/doc/Doxyfile
trunk/src/lib/dns/cpp/ (props changed)
trunk/src/lib/dns/cpp/rdata.h
trunk/src/lib/dns/cpp/rrset.cc
trunk/src/lib/dns/cpp/rrset.h
trunk/src/lib/dns/cpp/rrset_unittest.cc
Modified: trunk/doc/Doxyfile
==============================================================================
--- trunk/doc/Doxyfile (original)
+++ trunk/doc/Doxyfile Tue Feb 23 19:49:51 2010
@@ -568,7 +568,7 @@
# directories like "/usr/src/myproject". Separate the files or directories
# with spaces.
-INPUT = ../src/lib/cc/cpp ../src/lib/config/cpp
+INPUT = ../src/lib/cc/cpp ../src/lib/config/cpp ../src/lib/dns/cpp
# This tag can be used to specify the character encoding of the source files
# that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
Modified: trunk/src/lib/dns/cpp/rdata.h
==============================================================================
--- trunk/src/lib/dns/cpp/rdata.h (original)
+++ trunk/src/lib/dns/cpp/rdata.h Tue Feb 23 19:49:51 2010
@@ -65,6 +65,7 @@
class Rdata;
typedef boost::shared_ptr<Rdata> RdataPtr;
+typedef boost::shared_ptr<const Rdata> ConstRdataPtr;
/// Abstract RDATA class
class Rdata {
Modified: trunk/src/lib/dns/cpp/rrset.cc
==============================================================================
--- trunk/src/lib/dns/cpp/rrset.cc (original)
+++ trunk/src/lib/dns/cpp/rrset.cc Tue Feb 23 19:49:51 2010
@@ -46,16 +46,20 @@
string s;
RdataIteratorPtr it = getRdataIterator();
- for (it->first(); !it->isLast(); it->next()) {
- s += getName().toText() + " " +
- getTTL().toText() + " " +
- getClass().toText() + " " +
- getType().toText() + " " +
+ it->first();
+ if (it->isLast()) {
+ dns_throw(EmptyRRset, "ToText() is attempted for an empty RRset");
+ }
+
+ do {
+ s += getName().toText() + " " + getTTL().toText() + " " +
+ getClass().toText() + " " + getType().toText() + " " +
it->getCurrent().toText() + "\n";
- }
+ it->next();
+ } while (!it->isLast());
return (s);
-}
+}
namespace {
template <typename T>
@@ -65,9 +69,14 @@
unsigned int n = 0;
RdataIteratorPtr it = rrset.getRdataIterator();
+ it->first();
+ if (it->isLast()) {
+ dns_throw(EmptyRRset, "ToWire() is attempted for an empty RRset");
+ }
+
// sort the set of Rdata based on rrset-order and sortlist, and possible
// other options. Details to be considered.
- for (it->first(); !it->isLast(); it->next(), ++n) {
+ do {
rrset.getName().toWire(output);
rrset.getType().toWire(output);
rrset.getClass().toWire(output);
@@ -77,7 +86,10 @@
output.skip(sizeof(uint16_t)); // leave the space for RDLENGTH
it->getCurrent().toWire(output);
output.writeUint16At(output.getLength() - pos - sizeof(uint16_t), pos);
- }
+
+ it->next();
+ ++n;
+ } while (!it->isLast());
return (n);
}
@@ -102,7 +114,10 @@
return (os);
}
-struct BasicRRsetImpl {
+/// \brief This encapsulates the actual implementation of the \c BasicRRset
+/// class. It's hidden from applications.
+class BasicRRsetImpl {
+public:
BasicRRsetImpl(const Name& name, const RRClass& rrclass,
const RRType& rrtype, const RRTTL& ttl) :
name_(name), rrclass_(rrclass), rrtype_(rrtype), ttl_(ttl) {}
@@ -110,7 +125,10 @@
RRClass rrclass_;
RRType rrtype_;
RRTTL ttl_;
- vector<RdataPtr> rdatalist_;
+ // XXX: "list" is not a good name: It in fact isn't a list; more conceptual
+ // name than a data structure name is generally better. But since this
+ // is only used in the internal implementation we'll live with it.
+ vector<ConstRdataPtr> rdatalist_;
};
BasicRRset::BasicRRset(const Name& name, const RRClass& rrclass,
@@ -125,9 +143,15 @@
}
void
-BasicRRset::addRdata(const RdataPtr rdata)
+BasicRRset::addRdata(ConstRdataPtr rdata)
{
impl_->rdatalist_.push_back(rdata);
+}
+
+void
+BasicRRset::addRdata(const Rdata& rdata)
+{
+ AbstractRRset::addRdata(rdata);
}
unsigned int
@@ -161,9 +185,33 @@
}
void
+BasicRRset::setName(const Name& name)
+{
+ impl_->name_ = name;
+}
+
+void
BasicRRset::setTTL(const RRTTL& ttl)
{
impl_->ttl_ = ttl;
+}
+
+string
+BasicRRset::toText() const
+{
+ return (AbstractRRset::toText());
+}
+
+unsigned int
+BasicRRset::toWire(OutputBuffer& buffer) const
+{
+ return (AbstractRRset::toWire(buffer));
+}
+
+unsigned int
+BasicRRset::toWire(MessageRenderer& renderer) const
+{
+ return (AbstractRRset::toWire(renderer));
}
namespace {
@@ -171,7 +219,7 @@
private:
BasicRdataIterator() {}
public:
- BasicRdataIterator(const std::vector<rdata::RdataPtr>& datavector) :
+ BasicRdataIterator(const std::vector<rdata::ConstRdataPtr>& datavector) :
datavector_(&datavector) {}
~BasicRdataIterator() {}
virtual void first() { it_ = datavector_->begin(); }
@@ -179,8 +227,8 @@
virtual const rdata::Rdata& getCurrent() const { return (**it_); }
virtual bool isLast() const { return (it_ == datavector_->end()); }
private:
- const std::vector<rdata::RdataPtr>* datavector_;
- std::vector<rdata::RdataPtr>::const_iterator it_;
+ const std::vector<rdata::ConstRdataPtr>* datavector_;
+ std::vector<rdata::ConstRdataPtr>::const_iterator it_;
};
}
Modified: trunk/src/lib/dns/cpp/rrset.h
==============================================================================
--- trunk/src/lib/dns/cpp/rrset.h (original)
+++ trunk/src/lib/dns/cpp/rrset.h Tue Feb 23 19:49:51 2010
@@ -19,152 +19,663 @@
#include <iostream>
#include <string>
-#include <vector>
#include <boost/shared_ptr.hpp>
+
+#include <exceptions/exceptions.h>
#include "rdata.h"
namespace isc {
namespace dns {
+///
+/// \brief A standard DNS module exception that is thrown if an RRset object
+/// does not contain any RDATA where required.
+///
+class EmptyRRset : public Exception {
+public:
+ EmptyRRset(const char* file, size_t line, const char* what) :
+ isc::Exception(file, line, what) {}
+};
+
+// forward declarations
class Name;
class RRType;
class RRClass;
class RRTTL;
class OututBuffer;
class MessageRenderer;
-
class AbstractRRset;
+class BasicRRset;
+class RdataIterator;
+class BasicRRsetImpl;
+
+/// \brief A pointer-like type pointing to an \c AbstractRRset object.
+///
+/// This type is commonly used as an argument of various functions defined
+/// in this library in order to handle RRsets in a polymorphic manner.
typedef boost::shared_ptr<AbstractRRset> RRsetPtr;
-class BasicRRset;
+
+/// \brief A pointer-like type pointing to an (immutable) \c AbstractRRset
+/// object.
+///
+/// This type is commonly used as an argument of various functions defined
+/// in this library in order to handle RRsets in a polymorphic manner.
+typedef boost::shared_ptr<const AbstractRRset> ConstRRsetPtr;
+
+/// \brief A convenient abbreviation for the most generic derived RRset class.
typedef BasicRRset RRset;
-class BasicRRsetImpl;
-
-class RdataIterator;
+
+/// \brief A pointer-like type point to an \c RdataIterator object.
typedef boost::shared_ptr<RdataIterator> RdataIteratorPtr;
-/// \brief TBD
-///
-/// An \c RRset object models an RRset as described in the DNS standard:
-/// a set of DNS resource records (RRs) of the same type and class.
+/// \brief The \c AbstractRRset class is an abstract base class that
+/// models a DNS RRset.
+///
+/// An object of (a specific derived class of) \c AbstractRRset
+/// models an RRset as described in the DNS standard:
+/// A set of DNS resource records (RRs) of the same type and class.
/// The standard requires the TTL of all RRs in an RRset be the same;
/// this class follows that requirement.
-/// Note about duplication: we probably don't enforce the RDATA is unique
-/// as a class responsibility - but may revisit the decision.
-///
-// This is a primary class internally used in our major software such as name
-// servers.
-//
-// Note about terminology: there has been a discussion at the IETF namedroppers
-// ML about RRset vs RRSet (case of "s"). While RFC2181 uses the latter,
-// many other RFCs use the former, and most of the list members who showed
-// their opinion seem to prefer RRset. We follow that preference in this
-// implementation.
-//
-// Open Issues:
-// - add more set-like operations, e.g, merge?
-// - add a "sort" method? "search(find)" method?
-// - BIND9 libdns has some special DNSSEC-related methods
-// such as addnoqname(), addclosest(). do we need these?
-// - need to check duplicate rdata in addrdata()?
-// - need a comparison method? if so, should it compare
-// rdata's as a set or as a list (compare each rdata one
-// by one)? ldns has ldns_rr_list_compare(), which takes
-// the latter approach (assuming the caller sorts the lists
-// beforehand?).
+
+/// Note about duplicate RDATA: RFC2181 states that it's meaningless that an
+/// RRset contains two identical RRs and that name servers should suppress
+/// such duplicates.
+/// This class is not responsible for ensuring this requirement: For example,
+/// \c addRdata() method doesn't check if there's already RDATA identical
+/// to the one being added.
+/// This is because such checks can be expensive, and it's often easy to
+/// ensure the uniqueness requirement at the %data preparation phase
+/// (e.g. when loading a zone).
+/// When parsing an incoming DNS message, the uniqueness may not be guaranteed,
+/// so the application needs to detect and ignore any duplicate RDATA
+/// (the \c Message class of this library should provide this responsibility).
+///
+/// Another point to note is that \c AbstractRRset and its derived classes
+/// allow an object to have an empty set of RDATA.
+/// Even though there's no corresponding notion in the protocol specification,
+/// it would be more intuitive for a container-like %data structure
+/// to allow an empty set.
+///
+/// Since \c AbstractRRset is an abstract class, it is generally used
+/// via a pointer (or pointer like object) or a reference.
+/// In particular, \c RRsetPtr, a pointer like type for \c AbstractRRset,
+/// is used for polymorphic RRset operations throughout this library.
+///
+/// The \c AbstractRRset class is also intended to be a major customization
+/// point. For example, a high performance server implementation may want
+/// to define an optimized "pre-compiled" RRset and provide an optimized
+/// implementation of the \c toWire() method.
+///
+/// Note about design choice: In BIND9, a set of RDATA with a common tuple
+/// of RR class, RR type, and TTL was represented in a structure named
+/// \c rdataset. Unlike the RRset classes, an \c rdataset did not contain
+/// the information of the owner name.
+/// This might be advantageous if we want to handle "RRsets", that is,
+/// a set of different types of RRset for the same owner name, because
+/// a single "name" structure can be used for multiple RRsets, minimizing
+/// %data copy and memory footprint.
+/// On the other hand, it's inconvenient for API users since in many cases
+/// a pair of name and an \c rdataset must be maintained. It's also counter
+/// intuitive in implementing protocol operations as an RRset is often used
+/// as an atomic entity in DNS protocols while an \c rdataset is a component
+/// of an RRset.
+///
+/// We have therefore defined the notion of RRset explicitly in our initial
+/// API design. We believe memory footprint is not a big concern because
+/// RRsets are generally expected to be used as temporary objects, e.g.
+/// while parsing or constructing a DNS message, or searching a DNS %data
+/// source; for longer term purposes such as in-memory %data source entries,
+/// the corresponding %data would be represented in a different, memory
+/// optimized format. As for the concern about %data copy, we believe
+/// it can be mitigated by using copy-efficient implementation for the
+/// \c Name class implementation, such as reference counted objects.
+/// Later, We plan to perform benchmark tests later to see if this assumption
+/// is valid and to revisit the design if necessary.
+///
+/// Note about terminology: there has been a discussion at the IETF
+/// namedroppers ML about RRset vs RRSet (case of "s")
+/// [http://ops.ietf.org/lists/namedroppers/namedroppers.2009/msg02737.html].
+/// While RFC2181 uses the latter, many other RFCs use the former,
+/// and most of the list members who showed their opinion seem to prefer
+/// "RRset". We follow that preference in this implementation.
+///
+/// The current design of \c AbstractRRset is still in flux.
+/// There are many open questions in design details:
+/// - support more set-like operations, e.g, merge two RRsets of the same
+/// type?
+/// - more convenient methods or non member utility functions, e.g.
+/// "sort" and "search(find)" method?
+/// - what about comparing two RRsets of the same type? If we need this,
+/// should it compare rdata's as a set or as a list (i.e. compare
+/// each %rdata one by one or as a whole)? c.f. NLnet Labs' ldns
+/// (http://www.nlnetlabs.nl/projects/ldns/doc/index.html)
+/// has \c ldns_rr_list_compare(), which takes the latter approach
+/// (seemingly assuming the caller sorts the lists beforehand).
+/// - BIND9 libdns has some special DNSSEC-related methods
+/// such as \c addnoqname() or \c addclosest(). Do we need these?
+/// (Probably not. We wouldn't want to make the class design too
+/// monolithic.)
+/// - Do we need to allow the user to remove specific Rdata?
+/// Probably not, according to the current usage of the BIND9 code.
class AbstractRRset {
+ ///
+ /// \name Constructors and Destructor
+ ///
+ /// Note: The copy constructor and the assignment operator are intentionally
+ /// defined as private to make it explicit that this is a pure base class.
+ //@{
+private:
+ AbstractRRset(const AbstractRRset& source);
+ AbstractRRset& operator=(const AbstractRRset& source);
+protected:
+ /// \brief The default constructor.
+ ///
+ /// This is intentionally defined as \c protected as this base class should
+ /// never be instantiated (except as part of a derived class).
+ AbstractRRset() {}
public:
+ /// The destructor.
virtual ~AbstractRRset() {}
- virtual std::string toText() const;
+ //@}
+
+ ///
+ /// \name Getter and Setter Methods
+ ///
+ /// These methods are generally expected to be exception free, but it's
+ /// not guaranteed at the interface level;
+ /// for example, some performance optimized derived class may manage
+ /// the information corresponding to the class "attributes" to get or set,
+ /// and may require dynamic memory allocation to execute the method.
+ /// Consult the derived class description to see if a specific derived
+ /// \c RRset class may throw an exception from these methods.
+ ///
+ /// Note that setter methods are not provided for \c RRClass and
+ /// \c RRType. This is intentional. Since the format and semantics of
+ /// \c Rdata are dependent on the RR type (and RR class for some RR types),
+ /// allowing dynamically modify these attributes can easily lead to a
+ /// bug where the RDATA and type and/or class become inconsistent.
+ /// We want to avoid that situation by restricting the access.
+ //@{
+ /// \brief Returns the number of \c Rdata objects contained in the \c RRset.
+ ///
+ /// Note that an \c RRset with an empty set of \c Rdata can exist, so
+ /// this method may return 0.
+ ///
+ /// \return The number of \c Rdata objects contained.
+ virtual unsigned int getRdataCount() const = 0;
+
+ /// \brief Returns the owner name of the \c RRset.
+ ///
+ /// \return A reference to a \c Name class object corresponding to the
+ /// \c RRset owner name.
+ virtual const Name& getName() const = 0;
+
+ /// \brief Returns the RR Class of the \c RRset.
+ ///
+ /// \return A reference to a \c RRClass class object corresponding to the
+ /// RR class of the \c RRset.
+ virtual const RRClass& getClass() const = 0;
+
+ /// \brief Returns the RR Type of the \c RRset.
+ ///
+ /// \return A reference to a \c RRType class object corresponding to the
+ /// RR type of the \c RRset.
+ virtual const RRType& getType() const = 0;
+
+ /// \brief Returns the TTL of the RRset.
+ ///
+ /// \return A reference to a \c RRTTL class object corresponding to the
+ /// TTL of the \c RRset.
+ virtual const RRTTL& getTTL() const = 0;
+
+ /// \brief Updates the owner name of the \c RRset.
+ ///
+ /// \param name A reference to a \c RRTTL class object to be copied as the
+ /// new TTL.
+ virtual void setName(const Name& name) = 0;
+
+ /// \brief Updates the TTL of the \c RRset.
+ ///
+ /// \param ttl A reference to a \c RRTTL class object to be copied as the
+ /// new TTL.
+ virtual void setTTL(const RRTTL& ttl) = 0;
+ //@}
+
+ ///
+ /// \name Converter Methods
+ ///
+ /// These methods have the default implementation that can be reused by
+ /// derived classes.
+ /// Since they are defined as pure virtual, derived classes
+ /// that want to reuse the default implementation must explicitly
+ /// invoke their base class version (see the description for
+ /// <code>addRdata(const rdata::Rdata&)</code>).
+ ///
+ /// Design Note: the default implementations are defined only using
+ /// other public methods of the \c AbstractRRset class, and could be
+ /// implemented as non member functions (as some C++ textbooks suggest).
+ /// However, since derived classes may want to provide customized versions
+ /// (especially of the \c toWire() method for performance reasons)
+ /// we chose to define them as virtual functions, and, as a result,
+ /// member functions.
+ //@{
+ /// \brief Convert the RRset to a string.
+ ///
+ /// Unlike other similar methods of this library, this method terminates
+ /// the resulting string with a trailing newline character.
+ /// (following the BIND9 convention)
+ ///
+ /// The RRset must contain some RDATA; otherwise, an exception of class
+ /// \c EmptyRRset will be thrown.
+ /// If resource allocation fails, a corresponding standard exception
+ /// will be thrown.
+ /// The default implementation may throw other exceptions if the
+ /// \c toText() method of the RDATA objects throws.
+ /// If a derived class of \c AbstractRRset overrides the default
+ /// implementation, the derived version may throw its own exceptions.
+ ///
+ /// Open issue: We may want to support multiple output formats as
+ /// BIND9 does. For example, we might want to allow omitting the owner
+ /// name when possible in the context of zone dump. This is a future
+ /// TODO item.
+ ///
+ /// \param rrset A reference to a (derived class of) \c AbstractRRset object
+ /// whose content is to be converted.
+ /// \return A string representation of the RRset.
+ virtual std::string toText() const = 0;
+
+ /// \brief Render the RRset in the wire format with name compression and
+ /// truncation handling.
+ ///
+ /// This method compresses the owner name of the RRset and domain names
+ /// used in RDATA that should be compressed.
+ /// In addition, this method detects the case where rendering the entire
+ /// RRset would cause truncation, and handles the case appropriately
+ /// (this is a TODO item, and not implemented in this version).
+ ///
/// Note: perhaps we may want to add more arguments to convey optional
- /// information such as an "rrset-order" policy.
- /// no name compression, no truncation
- virtual unsigned int toWire(OutputBuffer& buffer) const;
- /// name compression when necessary, taking into account truncation
- virtual unsigned int toWire(MessageRenderer& renderer) const;
- virtual unsigned int getRdataCount() const = 0;
- virtual const Name& getName() const = 0;
- virtual const RRClass& getClass() const = 0;
- virtual const RRType& getType() const = 0;
- virtual const RRTTL& getTTL() const = 0;
- ///
- /// once constructed, only TTL and the set of Rdata can be modified,
- /// so \c setTTL() is the only explicit setter method.
- ///
- /// Do we need to allow the user to remove specific Rdata?
- /// Looking at the BIND9 code, don't see the strong need for this at the
- /// moment.
- ///
- virtual void setTTL(const RRTTL& ttl) = 0;
-
- ///
- /// \name RDATA manipulation methods
- ///
- //@{
- virtual void addRdata(const rdata::RdataPtr rdata) = 0;
- /// This method has the default implementation.
- /// Note: since concrete classes would define the pure virtual version
- /// of \c addRdata(), they'll need to declare the use of this method
- /// to avoid name hiding (unless they redefine this method):
- /// \code class CustomizedRRset : public AbstractRRset {
- /// public:
- /// using AbstractRRset::addRdata;
- /// ...
- /// }; \endcode
- virtual void addRdata(const rdata::Rdata& rdata);
+ /// information such as an "rrset-order" policy or how to handle truncation
+ /// case. This is a TODO item.
+ ///
+ /// If resource allocation fails, a corresponding standard exception
+ /// will be thrown.
+ /// The RRset must contain some RDATA; otherwise, an exception of class
+ /// \c EmptyRRset will be thrown.
+ /// The default implementation may throw other exceptions if the
+ /// \c toWire() method of the RDATA objects throws.
+ /// If a derived class of \c AbstractRRset overrides the default
+ /// implementation, the derived version may throw its own exceptions.
+ ///
+ /// \param renderer DNS message rendering context that encapsulates the
+ /// output buffer and name compression information.
+ /// \return The number of RRs rendered. If the truncation is necessary
+ /// this value may be different from the number of RDATA objects contained
+ /// in the RRset.
+ virtual unsigned int toWire(MessageRenderer& renderer) const = 0;
+
+ /// \brief Render the RRset in the wire format without any compression.
+ ///
+ /// See the other toWire() description about possible exceptions.
+ ///
+ /// \param buffer An output buffer to store the wire data.
+ /// \return The number of RRs rendered.
+ virtual unsigned int toWire(OutputBuffer& buffer) const = 0;
+ //@}
+
+ ///
+ /// \name RDATA Manipulation Methods
+ ///
+ //@{
+ /// \brief Add an RDATA to the RRset (pointer version).
+ ///
+ /// This method adds the given RDATA (as a pointer-like type to a
+ /// derived class object of \c rdata::Rdata) to the \c RRset.
+ ///
+ /// \param rdata A pointer (like) type of \c rdata::RdataPtr to be added
+ /// to the \c RRset.
+ virtual void addRdata(rdata::ConstRdataPtr rdata) = 0;
+
+ /// \brief Add an RDATA to the RRset (reference version).
+ ///
+ /// This method adds the given RDATA (as a reference to a
+ /// derived class object of \c rdata::Rdata) to the \c RRset.
+ ///
+ /// This method has the default implementation that can be reused by
+ /// derived classes.
+ /// Since this method is defined as pure virtual, derived classes
+ /// that want to reuse the default implementation must explicitly
+ /// invoke this base class version.
+ /// For example, if the class \c CustomizedRRset, a derived class of
+ /// \c AbstractRRset, wants to reuse the default implementation of
+ /// \c %addRdata() (reference version), it would be defined as follows:
+ /// \code void
+ /// CustomizedRRset::addRdata(const rdata::Rdata& rdata)
+ /// {
+ /// AbstractRRset::addRdata(rdata);
+ /// }
+ /// \endcode
+ ///
+ /// This method is more strictly typed than the pointer version:
+ /// If \c %rdata does not refer to the appropriate derived
+ /// \c Rdata class
+ /// for the \c RRType for this \c RRset, it throws an exception of class
+ /// \c std::bad_cast.
+ /// If resource allocation fails, a corresponding standard exception
+ /// will be thrown.
+ /// The RRset must contain some RDATA; otherwise, an exception of class
+ /// \c EmptyRRset will be thrown.
+ /// The default implementation may throw other exceptions if the
+ /// \c toWire() method of the RDATA objects throws.
+ /// If a derived class of \c AbstractRRset overrides the default
+ /// implementation, the derived version may throw its own exceptions.
+ ///
+ /// The default implementation simply constructs an \c rdata::RdataPtr
+ /// object from a newly allocated RDATA object copying from parameter
+ /// \c rdata, and calls the other version of
+ /// \c addRdata(const rdata::RdataPtr).
+ /// So it is inherently less efficient than the other version.
+ /// Still, this version would offer a more intuitive interface and is
+ /// provided as such.
+ ///
+ /// \param rdata A reference to a \c rdata::RdataPtr (derived) class
+ /// object, a copy of which is to be added to the \c RRset.
+ virtual void addRdata(const rdata::Rdata& rdata) = 0;
+
+ /// \brief Return an iterator to go through all RDATA stored in the
+ /// \c RRset.
+ ///
+ /// Using the design pattern terminology, \c getRdataIterator()
+ /// is an example of a <em>factory method</em>.
+ ///
+ /// Whether this method throws an exception depends on the actual
+ /// implementation of the derived \c AbstractRRset class, but in general
+ /// it will involve resource allocation and can throw a standard exception
+ /// if it fails.
+ ///
+ /// \return A pointer-like object pointing to the derived \c RdataIterator
+ /// object.
virtual RdataIteratorPtr getRdataIterator() const = 0;
//@}
};
+/// \brief The \c RdataIterator class is an abstract base class that
+/// provides an interface for accessing RDATA objects stored in an RRset.
+///
+/// While different derived classes of \c AbstractRRset may maintain the RDATA
+/// objects in different ways, the \c RdataIterator class provides a
+/// unified interface to iterate over the RDATA objects in a polymorphic
+/// manner.
+///
+/// Each derived class of \c AbstractRRset is expected to provide a concrete
+/// derived class of \c RdataIterator, and each derived \c RdataIterator
+/// class implements the unified interface in a way specific to the
+/// implementation of the corresponding derived \c AbstractRRset class.
+/// Using the design pattern terminology, this is a typical example of
+/// the \e Iterator pattern.
+///
+/// The RDATA objects stored in the \c RRset are considered to form
+/// a unidirectional list from the \c RdataIterator point of view (while
+/// the actual implementation in the derived \c RRset may not use a list).
+/// We call this unidirectional list the <em>%rdata list</em>.
+///
+/// An \c RdataIterator object internally (and conceptually) holds a
+/// <em>%rdata cursor</em>, which points to a specific item of the %rdata list.
+///
+/// Note about design choice: as is clear from the interface, \c RdataIterator
+/// is not compatible with the standard iterator classes.
+/// Although it would be useful (for example, we could then use STL algorithms)
+/// and is not necessarily impossible, it would make the iterator implementation
+/// much more complicated.
+/// For instance, any standard iterator must be assignable and
+/// copy-constructible.
+/// So we'd need to implement \c RdataIterator::operator=() in a polymorphic
+/// way. This will require non-trivial implementation tricks.
+/// We believe the simplified iterator interface as provided by the
+/// \c RdataIterator class is sufficient in practice:
+/// Most applications will simply go through the RDATA objects contained in
+/// an RRset, examining (and possibly using) each object, as one path
+/// operation.
class RdataIterator {
+ ///
+ /// \name Constructors and Destructor
+ ///
+ /// Note: The copy constructor and the assignment operator are intentionally
+ /// defined as private to make it explicit that this is a pure base class.
+ //@{
+protected:
+ /// \brief The default constructor.
+ ///
+ /// This is intentionally defined as \c protected as this base class should
+ /// never be instantiated (except as part of a derived class).
+ RdataIterator() {}
public:
+ /// \brief Destructor
virtual ~RdataIterator() {}
+private:
+ RdataIterator(const RdataIterator& source);
+ RdataIterator& operator=(const RdataIterator& source);
+ //@}
+
+public:
+ /// \brief Move the %rdata cursor to the first RDATA in the %rdata list
+ /// (if any).
+ ///
+ /// This method can safely be called multiple times, even after moving
+ /// the %rdata cursor forward by the \c next() method.
+ ///
+ /// This method should never throw an exception.
virtual void first() = 0;
+
+ /// \brief Move the %rdata cursor to the next RDATA in the %rdata list
+ /// (if any).
+ ///
+ /// This method should never throw an exception.
virtual void next() = 0;
+
+ /// \brief Return the current \c Rdata corresponding to the %rdata cursor.
+ ///
+ /// \return A reference to an \c rdata::::Rdata object corresponding
+ /// to the %rdata cursor.
virtual const rdata::Rdata& getCurrent() const = 0;
+
+ /// \brief Return true iff the %rdata cursor has reached the end of the
+ /// %rdata list.
+ ///
+ /// Once this method returns \c true, the behavior of any subsequent
+ /// call to \c next() or \c getCurrent() is undefined.
+ /// Likewise, the result of \c isLast() call followed by such undefined
+ /// operations is also undefined.
+ ///
+ /// This method should never throw an exception.
+ ///
+ /// \return \c true if the %rdata cursor has reached the end of the
+ /// %rdata list; otherwise \c false.
virtual bool isLast() const = 0;
};
-/// Straightforward RRset implementation.
-/// designed to be as portable as possible. performance is a secondary
-/// concern for this class.
+/// \brief The \c BasicRRset class is a concrete derived class of
+/// \c AbstractRRset that defines a straightforward RRset implementation.
+///
+/// This class is designed to be as portable as possible, and so it adopts
+/// the Pimpl idiom to hide as many details as possible.
+/// Performance is a secondary concern for this class.
+///
+/// This class is intended to be used by applications that only need
+/// moderate level of performance with full functionality provided by
+/// the \c AbstractRRset interfaces.
+/// Highly performance-sensitive applications, such as a large scale
+/// authoritative or caching name servers will implement and use a customized
+/// version of derived \c AbstractRRset class.
class BasicRRset : public AbstractRRset {
+ ///
+ /// \name Constructors and Destructor
+ ///
+ /// Note: The copy constructor and the assignment operator are intentionally
+ /// defined as private. The intended use case wouldn't require copies of
+ /// a \c BasicRRset object; once created, it would normally be used
+ /// as a \c const object (via references).
+ //@{
private:
BasicRRset(const BasicRRset& source);
- void operator=(const BasicRRset& source);
+ BasicRRset& operator=(const BasicRRset& source);
public:
+ /// \brief Constructor from (mostly) fixed parameters of the RRset.
+ ///
+ /// This constructor is normally expected to be exception free, but
+ /// copying the name may involve resource allocation, and if it fails
+ /// the corresponding standard exception will be thrown.
+ ///
+ /// \param name The owner name of the RRset.
+ /// \param rrclass The RR class of the RRset.
+ /// \param rrtype The RR type of the RRset.
+ /// \param ttl The TTL of the RRset.
explicit BasicRRset(const Name& name, const RRClass& rrclass,
const RRType& rrtype, const RRTTL& ttl);
+ /// \brief The destructor.
virtual ~BasicRRset();
- ///
- /// See the note for the base class version.
- ///
- using AbstractRRset::addRdata;
- virtual void addRdata(const rdata::RdataPtr rdata);
- ///
- /// We'd use the default implementations for toText() and toWire()
- /// variants as defined in the base class. These are not fully optimized
- /// for performance, but, again, it's a secondary goal for this generic
- /// class.
-
- ///
- /// \name Getter and setter methods
- ///
- //@{
+ //@}
+
+ ///
+ /// \name Getter and Setter Methods
+ ///
+ //@{
+ /// \brief Returns the number of \c Rdata objects contained in the \c RRset.
+ ///
+ /// This method never throws an exception.
+ ///
+ /// \return The number of \c Rdata objects contained.
virtual unsigned int getRdataCount() const;
+
+ /// \brief Returns the owner name of the \c RRset.
+ ///
+ /// This method never throws an exception.
+ ///
+ /// \return A reference to a \c Name class object corresponding to the
+ /// \c RRset owner name.
virtual const Name& getName() const;
+
+ /// \brief Returns the RR Class of the \c RRset.
+ ///
+ /// This method never throws an exception.
+ ///
+ /// \return A reference to a \c RRClass class object corresponding to the
+ /// RR class of the \c RRset.
virtual const RRClass& getClass() const;
+
+ /// \brief Returns the RR Type of the \c RRset.
+ ///
+ /// This method never throws an exception.
+ ///
+ /// \return A reference to a \c RRType class object corresponding to the
+ /// RR type of the \c RRset.
virtual const RRType& getType() const;
+
+ /// \brief Returns the TTL of the \c RRset.
+ ///
+ /// This method never throws an exception.
+ ///
+ /// \return A reference to a \c RRTTL class object corresponding to the
+ /// TTL of the \c RRset.
virtual const RRTTL& getTTL() const;
+
+ /// \brief Updates the owner name of the \c RRset.
+ ///
+ /// This method normally does not throw an exception, but could throw
+ /// some standard exception on resource allocation failure if the
+ /// internal copy of the \c name involves resource allocation and it
+ /// fails.
+ ///
+ /// \param name A reference to a \c RRTTL class object to be copied as the
+ /// new TTL.
+ virtual void setName(const Name& name);
+
+ /// \brief Updates the TTL of the \c RRset.
+ ///
+ /// This method never throws an exception.
+ ///
+ /// \param ttl A reference to a \c RRTTL class object to be copied as the
+ /// new TTL.
virtual void setTTL(const RRTTL& ttl);
//@}
- ///
+
+ ///
+ /// \name Converter Methods
+ ///
+ //@{
+ /// \brief Convert the RRset to a string.
+ ///
+ /// This method simply uses the default implementation.
+ /// See \c AbstractRRset::toText().
+ virtual std::string toText() const;
+
+ /// \brief Render the RRset in the wire format with name compression and
+ /// truncation handling.
+ ///
+ /// This method simply uses the default implementation.
+ /// See \c AbstractRRset::toWire(MessageRenderer&)const.
+ virtual unsigned int toWire(MessageRenderer& renderer) const;
+
+ /// \brief Render the RRset in the wire format without any compression.
+ ///
+ /// This method simply uses the default implementation.
+ /// See \c AbstractRRset::toWire(OutputBuffer&)const.
+ virtual unsigned int toWire(OutputBuffer& buffer) const;
+ //@}
+
+ ///
+ /// \name RDATA manipulation methods
+ ///
+ //@{
+ /// \brief Add an RDATA to the RRset (pointer version).
+ ///
+ /// This method is normally expected to be exception free, but it may
+ /// involve resource allocation, and if it fails the corresponding
+ /// standard exception will be thrown.
+ ///
+ /// \param rdata A pointer (like) type of \c rdata::RdataPtr to be added
+ /// to the \c BasicRRset.
+ virtual void addRdata(rdata::ConstRdataPtr rdata);
+
+ /// \brief Add an RDATA to the RRset (reference version).
+ ///
+ /// This method simply uses the default implementation.
+ /// See \c AbstractRRset::addRdata(const rdata::Rdata&).
+ virtual void addRdata(const rdata::Rdata& rdata);
+
+ /// \brief Return an iterator to go through all RDATA stored in the
+ /// \c BasicRRset.
+ ///
+ /// This is a concrete derived implementation of
+ /// \c AbstractRRset::getRdataIterator().
+ ///
+ /// This method dynamically allocates resources. If it fails it will
+ /// throw the corresponding standard exception.
+ /// The iterator methods for the \c BasicRRset class are exception free.
+ ///
+ /// \return A pointer-like object pointing to the derived \c RdataIterator
+ /// object for the \c BasicRRset class.
virtual RdataIteratorPtr getRdataIterator() const;
+ //@}
private:
BasicRRsetImpl* impl_;
};
+/// \brief Insert the \c RRset as a string into stream.
+///
+/// This method convert the \c rrset into a string and inserts it into the
+/// output stream \c os.
+///
+/// This function overloads the global \c operator<< to behave as described in
+/// \c %ostream::%operator<< but applied to RRset objects.
+///
+/// \param os A \c std::ostream object on which the insertion operation is
+/// performed.
+/// \param rrset A reference to a (derived class of) \c AbstractRRset object
+/// output by the operation.
+/// \return A reference to the same \c std::ostream object referenced by
+/// parameter \c os after the insertion operation.
std::ostream& operator<<(std::ostream& os, const AbstractRRset& rrset);
} // end of namespace dns
} // end of namespace isc
Modified: trunk/src/lib/dns/cpp/rrset_unittest.cc
==============================================================================
--- trunk/src/lib/dns/cpp/rrset_unittest.cc (original)
+++ trunk/src/lib/dns/cpp/rrset_unittest.cc Tue Feb 23 19:49:51 2010
@@ -14,6 +14,8 @@
// $Id$
+#include <stdexcept>
+
#include "buffer.h"
#include "messagerenderer.h"
#include "name.h"
@@ -42,9 +44,16 @@
test_domain("example.com"),
test_nsname("ns.example.com"),
rrset_a(test_name, RRClass::IN(), RRType::A(), RRTTL(3600)),
+ rrset_a_empty(test_name, RRClass::IN(), RRType::A(),
+ RRTTL(3600)),
rrset_ns(test_domain, RRClass::IN(), RRType::NS(),
- RRTTL(86400))
- {}
+ RRTTL(86400)),
+ rrset_ch_txt(test_domain, RRClass::CH(), RRType::TXT(),
+ RRTTL(0))
+ {
+ rrset_a.addRdata(in::A("192.0.2.1"));
+ rrset_a.addRdata(in::A("192.0.2.2"));
+ }
OutputBuffer buffer;
MessageRenderer renderer;
@@ -52,44 +61,157 @@
Name test_domain;
Name test_nsname;
RRset rrset_a;
+ RRset rrset_a_empty;
RRset rrset_ns;
+ RRset rrset_ch_txt;
std::vector<unsigned char> wiredata;
+
+ // max number of Rdata objects added to a test RRset object.
+ // this is an arbitrary chosen limit, but should be sufficiently large
+ // in practice and reasonable even as an extreme test case.
+ static const int MAX_RDATA_COUNT = 100;
};
-TEST_F(RRsetTest, addRdata)
-{
- rrset_a.addRdata(in::A("192.0.2.1"));
- rrset_a.addRdata(in::A("192.0.2.2"));
-
- RdataIteratorPtr it = rrset_a.getRdataIterator();
+TEST_F(RRsetTest, getRdataCount)
+{
+ for (int i = 0; i < MAX_RDATA_COUNT; ++i) {
+ EXPECT_EQ(i, rrset_a_empty.getRdataCount());
+ rrset_a_empty.addRdata(in::A("192.0.2.1"));
+ }
+}
+
+TEST_F(RRsetTest, getName)
+{
+ EXPECT_EQ(test_name, rrset_a.getName());
+ EXPECT_EQ(test_domain, rrset_ns.getName());
+}
+
+TEST_F(RRsetTest, getClass)
+{
+ EXPECT_EQ(RRClass("IN"), rrset_a.getClass());
+ EXPECT_EQ(RRClass("CH"), rrset_ch_txt.getClass());
+}
+
+TEST_F(RRsetTest, getType)
+{
+ EXPECT_EQ(RRType("A"), rrset_a.getType());
+ EXPECT_EQ(RRType("NS"), rrset_ns.getType());
+ EXPECT_EQ(RRType("TXT"), rrset_ch_txt.getType());
+}
+
+TEST_F(RRsetTest, getTTL)
+{
+ EXPECT_EQ(RRTTL(3600), rrset_a.getTTL());
+ EXPECT_EQ(RRTTL(86400), rrset_ns.getTTL());
+ EXPECT_EQ(RRTTL(0), rrset_ch_txt.getTTL());
+}
+
+TEST_F(RRsetTest, setTTL)
+{
+ rrset_a.setTTL(RRTTL(86400));
+ EXPECT_EQ(RRTTL(86400), rrset_a.getTTL());
+ rrset_a.setTTL(RRTTL(0));
+ EXPECT_EQ(RRTTL(0), rrset_a.getTTL());
+}
+
+TEST_F(RRsetTest, setName)
+{
+ rrset_a.setName(test_nsname);
+ EXPECT_EQ(test_nsname, rrset_a.getName());
+}
+
+void
+addRdataTestCommon(const RRset& rrset)
+{
+ EXPECT_EQ(2, rrset.getRdataCount());
+
+ RdataIteratorPtr it = rrset.getRdataIterator();
it->first();
EXPECT_FALSE(it->isLast());
- EXPECT_EQ("192.0.2.1", it->getCurrent().toText());
+ EXPECT_EQ(0, it->getCurrent().compare(in::A("192.0.2.1")));
it->next();
EXPECT_FALSE(it->isLast());
- EXPECT_EQ("192.0.2.2", it->getCurrent().toText());
+ EXPECT_EQ(0, it->getCurrent().compare(in::A("192.0.2.2")));
it->next();
EXPECT_TRUE(it->isLast());
-
+}
+
+TEST_F(RRsetTest, addRdata)
+{
+ addRdataTestCommon(rrset_a);
+
+ // Reference version of addRdata() doesn't allow to add a different
+ // type of Rdata.
+ EXPECT_THROW(rrset_a.addRdata(generic::NS(test_nsname)), std::bad_cast);
+}
+
+TEST_F(RRsetTest, addRdataPtr)
+{
+ rrset_a_empty.addRdata(createRdata(rrset_a_empty.getType(),
+ rrset_a_empty.getClass(),
+ "192.0.2.1"));
+ rrset_a_empty.addRdata(createRdata(rrset_a_empty.getType(),
+ rrset_a_empty.getClass(),
+ "192.0.2.2"));
+
+ addRdataTestCommon(rrset_a);
+
+ // Pointer version of addRdata() doesn't type check and does allow to
+ //add a different type of Rdata as a result.
+ rrset_a_empty.addRdata(createRdata(RRType::NS(), RRClass::IN(),
+ "ns.example.com"));
+ EXPECT_EQ(3, rrset_a_empty.getRdataCount());
+}
+
+TEST_F(RRsetTest, iterator)
+{
+ // Iterator for an empty RRset.
+ RdataIteratorPtr it = rrset_a_empty.getRdataIterator();
+ it->first();
+ EXPECT_TRUE(it->isLast());
+
+ // Normal case (already tested, but do it again just in case)
+ rrset_a_empty.addRdata(in::A("192.0.2.1"));
+ rrset_a_empty.addRdata(in::A("192.0.2.2"));
+ addRdataTestCommon(rrset_a_empty);
+
+ // Rewind test: should be repeat the iteration by calling first().
+ for (int i = 0; i < 2; ++i) {
+ it = rrset_a_empty.getRdataIterator();
+ it->first();
+ EXPECT_FALSE(it->isLast());
+ it->next();
+ EXPECT_FALSE(it->isLast());
+ it->next();
+ EXPECT_TRUE(it->isLast());
+ }
+}
+
+TEST_F(RRsetTest, toText)
+{
EXPECT_EQ("test.example.com. 3600 IN A 192.0.2.1\n"
- "test.example.com. 3600 IN A 192.0.2.2\n", rrset_a.toText());
+ "test.example.com. 3600 IN A 192.0.2.2\n",
+ rrset_a.toText());
+
+ // toText() cannot be performed for an empty RRset.
+ EXPECT_THROW(rrset_a_empty.toText(), EmptyRRset);
}
TEST_F(RRsetTest, toWireBuffer)
{
- rrset_a.addRdata(in::A("192.0.2.1"));
- rrset_a.addRdata(in::A("192.0.2.2"));
rrset_a.toWire(buffer);
UnitTestUtil::readWireData("testdata/rrset_toWire1", wiredata);
EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
buffer.getLength(), &wiredata[0], wiredata.size());
+
+ // toWire() cannot be performed for an empty RRset.
+ buffer.clear();
+ EXPECT_THROW(rrset_a_empty.toWire(buffer), EmptyRRset);
}
TEST_F(RRsetTest, toWireRenderer)
{
- rrset_a.addRdata(in::A("192.0.2.1"));
- rrset_a.addRdata(in::A("192.0.2.2"));
rrset_ns.addRdata(generic::NS(test_nsname));
rrset_a.toWire(renderer);
@@ -98,6 +220,17 @@
UnitTestUtil::readWireData("testdata/rrset_toWire2", wiredata);
EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
buffer.getLength(), &wiredata[0], wiredata.size());
-}
-
-}
+
+ // toWire() cannot be performed for an empty RRset.
+ renderer.clear();
+ EXPECT_THROW(rrset_a_empty.toWire(renderer), EmptyRRset);
+}
+
+// test operator<<. We simply confirm it appends the result of toText().
+TEST_F(RRsetTest, LeftShiftOperator)
+{
+ ostringstream oss;
+ oss << rrset_a;
+ EXPECT_EQ(rrset_a.toText(), oss.str());
+}
+}
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