Refactor the cache iterators by using a common base class

[apt.git] / apt-pkg / cacheiterators.h

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
/* ######################################################################
   
   Cache Iterators - Iterators for navigating the cache structure
   
   The iterators all provides ++,==,!=,->,* and end for their type.
   The end function can be used to tell if the list has been fully
   traversed.
   
   Unlike STL iterators these contain helper functions to access the data
   that is being iterated over. This is because the data structures can't
   be formed in a manner that is intuitive to use and also mmapable.
   
   For each variable in the target structure that would need a translation
   to be accessed correctly a translating function of the same name is
   present in the iterator. If applicable the translating function will
   return an iterator.

   The DepIterator can iterate over two lists, a list of 'version depends'
   or a list of 'package reverse depends'. The type is determined by the
   structure passed to the constructor, which should be the structure
   that has the depends pointer as a member. The provide iterator has the
   same system.
   
   This header is not user includable, please use apt-pkg/pkgcache.h
   
   ##################################################################### */
									/*}}}*/
#ifndef PKGLIB_CACHEITERATORS_H
#define PKGLIB_CACHEITERATORS_H
// abstract Iterator template						/*{{{*/
/* This template provides the very basic iterator methods we
   need to have for doing some walk-over-the-cache magic, */
template<typename Str, typename Itr> class pkgCache::Iterator {
	__attribute__ ((deprecated)) void _dummy(); // FIXME: Who on earth uses this method ???

	protected:
	Str *S;
	pkgCache *Owner;

	/** \brief Returns the Pointer for this struct in the owner
	 *  The implementation of this method should be pretty short
	 *  as it will only return the Pointer into the mmap stored
	 *  in the owner but the name of this pointer is different for
	 *  each stucture and we want to abstract here at least for the
	 *  basic methods from the actual structure.
	 *  \return Pointer to the first structure of this type
	 */
	virtual Str* OwnerPointer() const = 0;

	public:
	// Iteration
	virtual void operator ++(int) = 0;
	virtual void operator ++() = 0; // Should be {operator ++(0);};
	inline bool end() const {return Owner == 0 || S == OwnerPointer();};

	// Comparison
	inline bool operator ==(const Itr &B) const {return S == B.S;};
	inline bool operator !=(const Itr &B) const {return S != B.S;};

	// Accessors
	inline Str *operator ->() {return S;};
	inline Str const *operator ->() const {return S;};
	inline operator Str *() {return S == OwnerPointer() ? 0 : S;};
	inline operator Str const *() const {return S == OwnerPointer() ? 0 : S;};
	inline Str const &operator *() const {return *S;};
	inline pkgCache *Cache() {return Owner;};

	// Mixed stuff
	inline void operator =(const Itr &B) {S = B.S; Owner = B.Owner;};
	inline bool IsGood() const { return S && Owner && ! end();};
	inline unsigned long Index() const {return S - OwnerPointer();};

	// Constructors - look out for the variable assigning
	inline Iterator() : S(0), Owner(0) {};
	inline Iterator(pkgCache &Owner,Str *T = 0) : S(T), Owner(&Owner) {};
};
									/*}}}*/
// Package Iterator							/*{{{*/
class pkgCache::PkgIterator: public Iterator<Package, PkgIterator> {
	long HashIndex;

	protected:
	inline Package* OwnerPointer() const {
		return Owner->PkgP;
	};

	public:
	// This constructor is the 'begin' constructor, never use it.
	inline PkgIterator(pkgCache &Owner) : Iterator<Package, PkgIterator>(Owner), HashIndex(-1) {
		S = OwnerPointer();
		operator ++(0);
	};

	virtual void operator ++(int);
	virtual void operator ++() {operator ++(0);};

	enum OkState {NeedsNothing,NeedsUnpack,NeedsConfigure};

	// Accessors
	inline const char *Name() const {return S->Name == 0?0:Owner->StrP + S->Name;};
	inline const char *Section() const {return S->Section == 0?0:Owner->StrP + S->Section;};
	inline bool Purge() const {return S->CurrentState == pkgCache::State::Purge ||
		(S->CurrentVer == 0 && S->CurrentState == pkgCache::State::NotInstalled);};

	inline VerIterator VersionList() const;
	inline VerIterator CurrentVer() const;
	inline DepIterator RevDependsList() const;
	inline PrvIterator ProvidesList() const;
	OkState State() const;
	const char *CandVersion() const;
	const char *CurVersion() const;

	//Nice printable representation
	friend std::ostream& operator <<(std::ostream& out, PkgIterator i);

	// Constructors
	inline PkgIterator(pkgCache &Owner,Package *Trg) : Iterator<Package, PkgIterator>(Owner, Trg), HashIndex(0) {
		if (S == 0)
			S = OwnerPointer();
	};
	inline PkgIterator() : Iterator<Package, PkgIterator>(), HashIndex(0) {};
};
									/*}}}*/
// Version Iterator							/*{{{*/
class pkgCache::VerIterator : public Iterator<Version, VerIterator> {
	protected:
	inline Version* OwnerPointer() const {
		return Owner->VerP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->VerP) S = Owner->VerP + S->NextVer;};
	inline void operator ++() {operator ++(0);};

	// Comparison
	int CompareVer(const VerIterator &B) const;

	// Accessors
	inline const char *VerStr() const {return S->VerStr == 0?0:Owner->StrP + S->VerStr;};
	inline const char *Section() const {return S->Section == 0?0:Owner->StrP + S->Section;};
	inline const char *Arch() const {return S->Arch == 0?0:Owner->StrP + S->Arch;};
	inline PkgIterator ParentPkg() const {return PkgIterator(*Owner,Owner->PkgP + S->ParentPkg);};

	inline DescIterator DescriptionList() const;
	DescIterator TranslatedDescription() const;
	inline DepIterator DependsList() const;
	inline PrvIterator ProvidesList() const;
	inline VerFileIterator FileList() const;
	bool Downloadable() const;
	inline const char *PriorityType() {return Owner->Priority(S->Priority);};
	string RelStr();

	bool Automatic() const;
	VerFileIterator NewestFile() const;

	inline VerIterator(pkgCache &Owner,Version *Trg = 0) : Iterator<Version, VerIterator>(Owner, Trg) {
		if (S == 0)
			S = OwnerPointer();
	};
	inline VerIterator() : Iterator<Version, VerIterator>() {};
};
									/*}}}*/
// Description Iterator							/*{{{*/
class pkgCache::DescIterator : public Iterator<Description, DescIterator> {
	protected:
	inline Description* OwnerPointer() const {
		return Owner->DescP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->DescP) S = Owner->DescP + S->NextDesc;};
	inline void operator ++() {operator ++(0);};

	// Comparison
	int CompareDesc(const DescIterator &B) const;

	// Accessors
	inline const char *LanguageCode() const {return Owner->StrP + S->language_code;};
	inline const char *md5() const {return Owner->StrP + S->md5sum;};
	inline DescFileIterator FileList() const;

	inline DescIterator() : Iterator<Description, DescIterator>() {};
	inline DescIterator(pkgCache &Owner,Description *Trg = 0) : Iterator<Description, DescIterator>(Owner, Trg) {
		if (S == 0)
			S = Owner.DescP;
	};
};
									/*}}}*/
// Dependency iterator							/*{{{*/
class pkgCache::DepIterator : public Iterator<Dependency, DepIterator> {
	enum {DepVer, DepRev} Type;

	protected:
	inline Dependency* OwnerPointer() const {
		return Owner->DepP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->DepP) S = Owner->DepP +
		(Type == DepVer ? S->NextDepends : S->NextRevDepends);};
	inline void operator ++() {operator ++(0);};

	// Accessors
	inline const char *TargetVer() const {return S->Version == 0?0:Owner->StrP + S->Version;};
	inline PkgIterator TargetPkg() {return PkgIterator(*Owner,Owner->PkgP + S->Package);};
	inline PkgIterator SmartTargetPkg() {PkgIterator R(*Owner,0);SmartTargetPkg(R);return R;};
	inline VerIterator ParentVer() {return VerIterator(*Owner,Owner->VerP + S->ParentVer);};
	inline PkgIterator ParentPkg() {return PkgIterator(*Owner,Owner->PkgP + Owner->VerP[S->ParentVer].ParentPkg);};
	inline bool Reverse() {return Type == DepRev;};
	bool IsCritical();
	void GlobOr(DepIterator &Start,DepIterator &End);
	Version **AllTargets();
	bool SmartTargetPkg(PkgIterator &Result);
	inline const char *CompType() {return Owner->CompType(S->CompareOp);};
	inline const char *DepType() {return Owner->DepType(S->Type);};

	inline DepIterator(pkgCache &Owner, Dependency *Trg, Version* = 0) :
		Iterator<Dependency, DepIterator>(Owner, Trg), Type(DepVer) {
		if (S == 0)
			S = Owner.DepP;
	};
	inline DepIterator(pkgCache &Owner, Dependency *Trg, Package*) :
		Iterator<Dependency, DepIterator>(Owner, Trg), Type(DepRev) {
		if (S == 0)
			S = Owner.DepP;
	};
	inline DepIterator() : Iterator<Dependency, DepIterator>(), Type(DepVer) {};
};
									/*}}}*/
// Provides iterator							/*{{{*/
class pkgCache::PrvIterator : public Iterator<Provides, PrvIterator> {
	enum {PrvVer, PrvPkg} Type;

	protected:
	inline Provides* OwnerPointer() const {
		return Owner->ProvideP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->ProvideP) S = Owner->ProvideP +
		(Type == PrvVer?S->NextPkgProv:S->NextProvides);};
	inline void operator ++() {operator ++(0);};

	// Accessors
	inline const char *Name() const {return Owner->StrP + Owner->PkgP[S->ParentPkg].Name;};
	inline const char *ProvideVersion() const {return S->ProvideVersion == 0?0:Owner->StrP + S->ProvideVersion;};
	inline PkgIterator ParentPkg() {return PkgIterator(*Owner,Owner->PkgP + S->ParentPkg);};
	inline VerIterator OwnerVer() {return VerIterator(*Owner,Owner->VerP + S->Version);};
	inline PkgIterator OwnerPkg() {return PkgIterator(*Owner,Owner->PkgP + Owner->VerP[S->Version].ParentPkg);};

	inline PrvIterator() : Iterator<Provides, PrvIterator>(), Type(PrvVer) {};

	inline PrvIterator(pkgCache &Owner, Provides *Trg, Version*) :
		Iterator<Provides, PrvIterator>(Owner, Trg), Type(PrvVer) {
		if (S == 0)
			S = Owner.ProvideP;
	};
	inline PrvIterator(pkgCache &Owner, Provides *Trg, Package*) :
		Iterator<Provides, PrvIterator>(Owner, Trg), Type(PrvPkg) {
		if (S == 0)
			S = Owner.ProvideP;
	};
};
									/*}}}*/
// Package file								/*{{{*/
class pkgCache::PkgFileIterator : public Iterator<PackageFile, PkgFileIterator> {
	protected:
	inline PackageFile* OwnerPointer() const {
		return Owner->PkgFileP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->PkgFileP) S = Owner->PkgFileP + S->NextFile;};
	inline void operator ++() {operator ++(0);};

	// Accessors
	inline const char *FileName() const {return S->FileName == 0?0:Owner->StrP + S->FileName;};
	inline const char *Archive() const {return S->Archive == 0?0:Owner->StrP + S->Archive;};
	inline const char *Component() const {return S->Component == 0?0:Owner->StrP + S->Component;};
	inline const char *Version() const {return S->Version == 0?0:Owner->StrP + S->Version;};
	inline const char *Origin() const {return S->Origin == 0?0:Owner->StrP + S->Origin;};
	inline const char *Codename() const {return S->Codename ==0?0:Owner->StrP + S->Codename;};
	inline const char *Label() const {return S->Label == 0?0:Owner->StrP + S->Label;};
	inline const char *Site() const {return S->Site == 0?0:Owner->StrP + S->Site;};
	inline const char *Architecture() const {return S->Architecture == 0?0:Owner->StrP + S->Architecture;};
	inline const char *IndexType() const {return S->IndexType == 0?0:Owner->StrP + S->IndexType;};

	bool IsOk();
	string RelStr();

	// Constructors
	inline PkgFileIterator() : Iterator<PackageFile, PkgFileIterator>() {};
	inline PkgFileIterator(pkgCache &Owner,PackageFile *Trg = 0) : Iterator<PackageFile, PkgFileIterator>(Owner, Trg) {};
};
									/*}}}*/
// Version File								/*{{{*/
class pkgCache::VerFileIterator : public pkgCache::Iterator<VerFile, VerFileIterator> {
	protected:
	inline VerFile* OwnerPointer() const {
		return Owner->VerFileP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->VerFileP) S = Owner->VerFileP + S->NextFile;};
	inline void operator ++() {operator ++(0);};

	// Accessors
	inline PkgFileIterator File() const {return PkgFileIterator(*Owner,S->File + Owner->PkgFileP);};

	inline VerFileIterator() : Iterator<VerFile, VerFileIterator>() {};
	inline VerFileIterator(pkgCache &Owner,VerFile *Trg) : Iterator<VerFile, VerFileIterator>(Owner, Trg) {};
};
									/*}}}*/
// Description File							/*{{{*/
class pkgCache::DescFileIterator : public Iterator<DescFile, DescFileIterator> {
	protected:
	inline DescFile* OwnerPointer() const {
		return Owner->DescFileP;
	};

	public:
	// Iteration
	void operator ++(int) {if (S != Owner->DescFileP) S = Owner->DescFileP + S->NextFile;};
	inline void operator ++() {operator ++(0);};

	// Accessors
	inline PkgFileIterator File() const {return PkgFileIterator(*Owner,S->File + Owner->PkgFileP);};

	inline DescFileIterator() : Iterator<DescFile, DescFileIterator>() {};
	inline DescFileIterator(pkgCache &Owner,DescFile *Trg) : Iterator<DescFile, DescFileIterator>(Owner, Trg) {};
};
									/*}}}*/
// Inlined Begin functions cant be in the class because of order problems /*{{{*/
inline pkgCache::VerIterator pkgCache::PkgIterator::VersionList() const
       {return VerIterator(*Owner,Owner->VerP + S->VersionList);};
inline pkgCache::VerIterator pkgCache::PkgIterator::CurrentVer() const
       {return VerIterator(*Owner,Owner->VerP + S->CurrentVer);};
inline pkgCache::DepIterator pkgCache::PkgIterator::RevDependsList() const
       {return DepIterator(*Owner,Owner->DepP + S->RevDepends,S);};
inline pkgCache::PrvIterator pkgCache::PkgIterator::ProvidesList() const
       {return PrvIterator(*Owner,Owner->ProvideP + S->ProvidesList,S);};
inline pkgCache::DescIterator pkgCache::VerIterator::DescriptionList() const
       {return DescIterator(*Owner,Owner->DescP + S->DescriptionList);};
inline pkgCache::PrvIterator pkgCache::VerIterator::ProvidesList() const
       {return PrvIterator(*Owner,Owner->ProvideP + S->ProvidesList,S);};
inline pkgCache::DepIterator pkgCache::VerIterator::DependsList() const
       {return DepIterator(*Owner,Owner->DepP + S->DependsList,S);};
inline pkgCache::VerFileIterator pkgCache::VerIterator::FileList() const
       {return VerFileIterator(*Owner,Owner->VerFileP + S->FileList);};
inline pkgCache::DescFileIterator pkgCache::DescIterator::FileList() const
       {return DescFileIterator(*Owner,Owner->DescFileP + S->FileList);};
									/*}}}*/
#endif