// -*- mode: cpp; mode: fold -*- // Description /*{{{*/ // $Id: tagfile.h,v 1.20 2003/05/19 17:13:57 doogie Exp $ /* ###################################################################### Fast scanner for RFC-822 type header information This parser handles Debian package files (and others). Their form is RFC-822 type header fields in groups separated by a blank line. The parser reads the file and provides methods to step linearly over it or to jump to a pre-recorded start point and read that record. A second class is used to perform pre-parsing of the record. It works by indexing the start of each header field and providing lookup functions for header fields. ##################################################################### */ /*}}}*/ #ifndef PKGLIB_TAGFILE_H #define PKGLIB_TAGFILE_H #include <apt-pkg/macros.h> #include <stdio.h> #include <string> #include <vector> #include <list> #ifndef APT_8_CLEANER_HEADERS #include <apt-pkg/fileutl.h> #endif class FileFd; class pkgTagSection { const char *Section; struct TagData { unsigned int StartTag; unsigned int EndTag; unsigned int StartValue; unsigned int NextInBucket; TagData(unsigned int const StartTag) : StartTag(StartTag), EndTag(0), StartValue(0), NextInBucket(0) {} }; std::vector<TagData> Tags; unsigned int LookupTable[0x100]; // dpointer placeholder (for later in case we need it) void *d; protected: const char *Stop; public: inline bool operator ==(const pkgTagSection &rhs) {return Section == rhs.Section;}; inline bool operator !=(const pkgTagSection &rhs) {return Section != rhs.Section;}; bool Find(const char *Tag,const char *&Start, const char *&End) const; bool Find(const char *Tag,unsigned int &Pos) const; std::string FindS(const char *Tag) const; signed int FindI(const char *Tag,signed long Default = 0) const; bool FindB(const char *Tag, bool const &Default = false) const; unsigned long long FindULL(const char *Tag, unsigned long long const &Default = 0) const; bool FindFlag(const char *Tag,unsigned long &Flags, unsigned long Flag) const; bool static FindFlag(unsigned long &Flags, unsigned long Flag, const char* Start, const char* Stop); /** \brief searches the boundaries of the current section * * While parameter Start marks the beginning of the section, this method * will search for the first double newline in the data stream which marks * the end of the section. It also does a first pass over the content of * the section parsing it as encountered for processing later on by Find * * @param Start is the beginning of the section * @param MaxLength is the size of valid data in the stream pointed to by Start * @param Restart if enabled internal state will be cleared, otherwise it is * assumed that now more data is available in the stream and the parsing will * start were it encountered insufficent data the last time. * * @return \b true if section end was found, \b false otherwise. * Beware that internal state will be inconsistent if \b false is returned! */ APT_MUSTCHECK bool Scan(const char *Start, unsigned long MaxLength, bool const Restart = true); inline unsigned long size() const {return Stop - Section;}; void Trim(); virtual void TrimRecord(bool BeforeRecord, const char* &End); /** \brief amount of Tags in the current section * * Note: if a Tag is mentioned repeatly it will be counted multiple * times, but only the last occurrence is available via Find methods. */ unsigned int Count() const; bool Exists(const char* const Tag) const; inline void Get(const char *&Start,const char *&Stop,unsigned int I) const {Start = Section + Tags[I].StartTag; Stop = Section + Tags[I+1].StartTag;} inline void GetSection(const char *&Start,const char *&Stop) const { Start = Section; Stop = this->Stop; }; pkgTagSection(); virtual ~pkgTagSection() {}; }; class pkgTagFilePrivate; class pkgTagFile { pkgTagFilePrivate *d; APT_HIDDEN bool Fill(); APT_HIDDEN bool Resize(); APT_HIDDEN bool Resize(unsigned long long const newSize); public: bool Step(pkgTagSection &Section); unsigned long Offset(); bool Jump(pkgTagSection &Tag,unsigned long long Offset); void Init(FileFd *F,unsigned long long Size = 32*1024); pkgTagFile(FileFd *F,unsigned long long Size = 32*1024); virtual ~pkgTagFile(); }; /* This is the list of things to rewrite. The rewriter goes through and changes or adds each of these headers to suit. A zero forces the header to be erased, an empty string causes the old value to be used. (rewrite rule ignored) */ struct TFRewriteData { const char *Tag; const char *Rewrite; const char *NewTag; }; extern const char **TFRewritePackageOrder; extern const char **TFRewriteSourceOrder; bool TFRewrite(FILE *Output,pkgTagSection const &Tags,const char *Order[], TFRewriteData *Rewrite); #endif