diff options
Diffstat (limited to 'apt-pkg')
| -rw-r--r-- | apt-pkg/tagfile.cc | 249 | ||||
| -rw-r--r-- | apt-pkg/tagfile.h | 23 |
2 files changed, 229 insertions, 43 deletions
diff --git a/apt-pkg/tagfile.cc b/apt-pkg/tagfile.cc index d5e61baf4..7a263c2b7 100644 --- a/apt-pkg/tagfile.cc +++ b/apt-pkg/tagfile.cc @@ -18,6 +18,8 @@ #include <apt-pkg/strutl.h> #include <apt-pkg/fileutl.h> +#include <list> + #include <string> #include <stdio.h> #include <ctype.h> @@ -29,33 +31,45 @@ using std::string; -class pkgTagFilePrivate +class APT_HIDDEN pkgTagFilePrivate /*{{{*/ { public: - void Reset(FileFd * const pFd, unsigned long long const pSize) + void Reset(FileFd * const pFd, unsigned long long const pSize, pkgTagFile::Flags const pFlags) { if (Buffer != NULL) free(Buffer); Buffer = NULL; Fd = pFd; + Flags = pFlags; Start = NULL; End = NULL; Done = false; iOffset = 0; Size = pSize; + isCommentedLine = false; + chunks.clear(); } - pkgTagFilePrivate(FileFd * const pFd, unsigned long long const Size) : Buffer(NULL) + pkgTagFilePrivate(FileFd * const pFd, unsigned long long const Size, pkgTagFile::Flags const pFlags) : Buffer(NULL) { - Reset(pFd, Size); + Reset(pFd, Size, pFlags); } FileFd * Fd; + pkgTagFile::Flags Flags; char *Buffer; char *Start; char *End; bool Done; unsigned long long iOffset; unsigned long long Size; + bool isCommentedLine; + struct FileChunk + { + bool const good; + size_t length; + FileChunk(bool const pgood, size_t const plength) : good(pgood), length(plength) {} + }; + std::list<FileChunk> chunks; ~pkgTagFilePrivate() { @@ -63,8 +77,8 @@ public: free(Buffer); } }; - -class pkgTagSectionPrivate + /*}}}*/ +class APT_HIDDEN pkgTagSectionPrivate /*{{{*/ { public: pkgTagSectionPrivate() @@ -80,6 +94,7 @@ public: }; std::vector<TagData> Tags; }; + /*}}}*/ static unsigned long AlphaHash(const char *Text, size_t Length) /*{{{*/ { @@ -98,21 +113,23 @@ static unsigned long AlphaHash(const char *Text, size_t Length) /*{{{*/ /*}}}*/ // TagFile::pkgTagFile - Constructor /*{{{*/ -// --------------------------------------------------------------------- -/* */ +pkgTagFile::pkgTagFile(FileFd * const pFd,pkgTagFile::Flags const pFlags, unsigned long long const Size) + : d(new pkgTagFilePrivate(pFd, Size + 4, pFlags)) +{ + Init(pFd, pFlags, Size); +} pkgTagFile::pkgTagFile(FileFd * const pFd,unsigned long long const Size) - : d(new pkgTagFilePrivate(pFd, Size + 4)) + : pkgTagFile(pFd, pkgTagFile::STRICT, Size) { - Init(pFd, Size); } -void pkgTagFile::Init(FileFd * const pFd,unsigned long long Size) +void pkgTagFile::Init(FileFd * const pFd, pkgTagFile::Flags const pFlags, unsigned long long Size) { /* The size is increased by 4 because if we start with the Size of the filename we need to try to read 1 char more to see an EOF faster, 1 char the end-pointer can be on and maybe 2 newlines need to be added to the end of the file -> 4 extra chars */ Size += 4; - d->Reset(pFd, Size); + d->Reset(pFd, Size, pFlags); if (d->Fd->IsOpen() == false) d->Start = d->End = d->Buffer = 0; @@ -129,10 +146,12 @@ void pkgTagFile::Init(FileFd * const pFd,unsigned long long Size) if (d->Done == false) Fill(); } +void pkgTagFile::Init(FileFd * const pFd,unsigned long long Size) +{ + Init(pFd, pkgTagFile::STRICT, Size); +} /*}}}*/ // TagFile::~pkgTagFile - Destructor /*{{{*/ -// --------------------------------------------------------------------- -/* */ pkgTagFile::~pkgTagFile() { delete d; @@ -162,7 +181,7 @@ bool pkgTagFile::Resize(unsigned long long const newSize) unsigned long long const EndSize = d->End - d->Start; // get new buffer and use it - char* newBuffer = (char*)realloc(d->Buffer, sizeof(char) * newSize); + char* const newBuffer = static_cast<char*>(realloc(d->Buffer, sizeof(char) * newSize)); if (newBuffer == NULL) return false; d->Buffer = newBuffer; @@ -199,8 +218,35 @@ bool pkgTagFile::Step(pkgTagSection &Tag) } while (Tag.Scan(d->Start,d->End - d->Start, false) == false); } - d->Start += Tag.size(); - d->iOffset += Tag.size(); + size_t tagSize = Tag.size(); + d->Start += tagSize; + + if ((d->Flags & pkgTagFile::SUPPORT_COMMENTS) == 0) + d->iOffset += tagSize; + else + { + auto first = d->chunks.begin(); + for (; first != d->chunks.end(); ++first) + { + if (first->good == false) + d->iOffset += first->length; + else + { + if (tagSize < first->length) + { + first->length -= tagSize; + d->iOffset += tagSize; + break; + } + else + { + tagSize -= first->length; + d->iOffset += first->length; + } + } + } + d->chunks.erase(d->chunks.begin(), first); + } Tag.Trim(); return true; @@ -210,49 +256,166 @@ bool pkgTagFile::Step(pkgTagSection &Tag) // --------------------------------------------------------------------- /* This takes the bit at the end of the buffer and puts it at the start then fills the rest from the file */ +static bool FillBuffer(pkgTagFilePrivate * const d) +{ + unsigned long long Actual = 0; + // See if only a bit of the file is left + unsigned long long const dataSize = d->Size - ((d->End - d->Buffer) + 1); + if (d->Fd->Read(d->End, dataSize, &Actual) == false) + return false; + if (Actual != dataSize) + d->Done = true; + d->End += Actual; + return true; +} +static void RemoveCommentsFromBuffer(pkgTagFilePrivate * const d) +{ + // look for valid comments in the buffer + char * good_start = nullptr, * bad_start = nullptr; + char * current = d->Start; + if (d->isCommentedLine == false) + { + if (d->Start == d->Buffer) + { + // the start of the buffer is a newline as a record can't start + // in the middle of a line by definition. + if (*d->Start == '#') + { + d->isCommentedLine = true; + ++current; + if (current > d->End) + d->chunks.emplace_back(false, 1); + } + } + if (d->isCommentedLine == false) + good_start = d->Start; + else + bad_start = d->Start; + } + else + bad_start = d->Start; + + std::vector<std::pair<char*, size_t>> good_parts; + while (current <= d->End) + { + size_t const restLength = (d->End - current) + 1; + if (d->isCommentedLine == false) + { + current = static_cast<char*>(memchr(current, '#', restLength)); + if (current == nullptr) + { + size_t const goodLength = d->End - good_start; + d->chunks.emplace_back(true, goodLength); + if (good_start != d->Start) + good_parts.push_back(std::make_pair(good_start, goodLength)); + break; + } + bad_start = current; + --current; + // ensure that this is really a comment and not a '#' in the middle of a line + if (*current == '\n') + { + size_t const goodLength = (current - good_start) + 1; + d->chunks.emplace_back(true, goodLength); + good_parts.push_back(std::make_pair(good_start, goodLength)); + good_start = nullptr; + d->isCommentedLine = true; + } + current += 2; + } + else // the current line is a comment + { + current = static_cast<char*>(memchr(current, '\n', restLength)); + if (current == nullptr) + { + d->chunks.emplace_back(false, (d->End - bad_start)); + break; + } + ++current; + // is the next line a comment, too? + if (current > d->End || *current != '#') + { + d->chunks.emplace_back(false, (current - bad_start)); + good_start = current; + bad_start = nullptr; + d->isCommentedLine = false; + } + ++current; + } + } + + if (good_parts.empty() == false) + { + // we found comments, so move later parts over them + current = d->Start; + for (auto const &good: good_parts) + { + memmove(current, good.first, good.second); + current += good.second; + } + d->End = current; + } + + if (d->isCommentedLine == true) + { + // deal with a buffer containing only comments + // or an (unfinished) comment at the end + if (good_parts.empty() == true) + d->End = d->Start; + else + d->Start = d->End; + } + else + { + // the buffer was all comment, but ended with the buffer + if (good_parts.empty() == true && good_start >= d->End) + d->End = d->Start; + else + d->Start = d->End; + } +} bool pkgTagFile::Fill() { - unsigned long long EndSize = d->End - d->Start; + unsigned long long const EndSize = d->End - d->Start; + if (EndSize != 0) + { + memmove(d->Buffer,d->Start,EndSize); + d->Start = d->End = d->Buffer + EndSize; + } + else + d->Start = d->End = d->Buffer; + unsigned long long Actual = 0; - - memmove(d->Buffer,d->Start,EndSize); - d->Start = d->Buffer; - d->End = d->Buffer + EndSize; - - if (d->Done == false) + while (d->Done == false && d->Size > (Actual + 1)) { - // See if only a bit of the file is left - unsigned long long const dataSize = d->Size - ((d->End - d->Buffer) + 1); - if (d->Fd->Read(d->End, dataSize, &Actual) == false) + if (FillBuffer(d) == false) return false; - if (Actual != dataSize) - d->Done = true; - d->End += Actual; + if ((d->Flags & pkgTagFile::SUPPORT_COMMENTS) != 0) + RemoveCommentsFromBuffer(d); + Actual = d->End - d->Buffer; } - + d->Start = d->Buffer; + if (d->Done == true) { if (EndSize <= 3 && Actual == 0) return false; if (d->Size - (d->End - d->Buffer) < 4) return true; - + // Append a double new line if one does not exist unsigned int LineCount = 0; for (const char *E = d->End - 1; E - d->End < 6 && (*E == '\n' || *E == '\r'); E--) if (*E == '\n') - LineCount++; + ++LineCount; if (LineCount < 2) { - if ((unsigned)(d->End - d->Buffer) >= d->Size) + if (static_cast<unsigned long long>(d->End - d->Buffer) >= d->Size) Resize(d->Size + 3); - for (; LineCount < 2; LineCount++) + for (; LineCount < 2; ++LineCount) *d->End++ = '\n'; } - - return true; } - return true; } /*}}}*/ @@ -262,8 +425,9 @@ bool pkgTagFile::Fill() that is there */ bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long long Offset) { + if ((d->Flags & pkgTagFile::SUPPORT_COMMENTS) == 0 && // We are within a buffer space of the next hit.. - if (Offset >= d->iOffset && d->iOffset + (d->End - d->Start) > Offset) + Offset >= d->iOffset && d->iOffset + (d->End - d->Start) > Offset) { unsigned long long Dist = Offset - d->iOffset; d->Start += Dist; @@ -281,7 +445,9 @@ bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long long Offset) if (d->Fd->Seek(Offset) == false) return false; d->End = d->Start = d->Buffer; - + d->isCommentedLine = false; + d->chunks.clear(); + if (Fill() == false) return false; @@ -644,11 +810,12 @@ bool pkgTagSection::FindFlag(unsigned long &Flags, unsigned long Flag, return true; } /*}}}*/ -void pkgTagSection::Get(const char *&Start,const char *&Stop,unsigned int I) const +void pkgTagSection::Get(const char *&Start,const char *&Stop,unsigned int I) const/*{{{*/ { Start = Section + d->Tags[I].StartTag; Stop = Section + d->Tags[I+1].StartTag; } + /*}}}*/ APT_PURE unsigned int pkgTagSection::Count() const { /*{{{*/ if (d->Tags.empty() == true) return 0; diff --git a/apt-pkg/tagfile.h b/apt-pkg/tagfile.h index 922b56f8e..2f26846ef 100644 --- a/apt-pkg/tagfile.h +++ b/apt-pkg/tagfile.h @@ -34,7 +34,15 @@ class FileFd; class pkgTagSectionPrivate; +class pkgTagFilePrivate; +/** \class pkgTagSection parses a single deb822 stanza and provides various Find methods + * to extract the included values. It can also be used to modify and write a + * valid deb822 stanza optionally (re)ordering the fields inside the stanza. + * + * Beware: This class does \b NOT support (#-)comments in in- or output! + * If the input contains comments they have to be stripped first like pkgTagFile + * does with SUPPORT_COMMENTS flag set. */ class pkgTagSection { const char *Section; @@ -139,7 +147,10 @@ class pkgUserTagSection : public pkgTagSection virtual void TrimRecord(bool BeforeRecord, const char* &End) APT_OVERRIDE; }; -class pkgTagFilePrivate; +/** \class pkgTagFile reads and prepares a deb822 formatted file for parsing + * via #pkgTagSection. The default mode tries to be as fast as possible and + * assumes perfectly valid (machine generated) files like Packages. Support + * for comments e.g. needs to be enabled explicitly. */ class pkgTagFile { pkgTagFilePrivate * const d; @@ -148,14 +159,22 @@ class pkgTagFile APT_HIDDEN bool Resize(); APT_HIDDEN bool Resize(unsigned long long const newSize); - public: +public: bool Step(pkgTagSection &Section); unsigned long Offset(); bool Jump(pkgTagSection &Tag,unsigned long long Offset); + enum Flags + { + STRICT = 0, + SUPPORT_COMMENTS = 1 << 0, + }; + + void Init(FileFd * const F, pkgTagFile::Flags const Flags, unsigned long long Size = 32*1024); void Init(FileFd * const F,unsigned long long const Size = 32*1024); + pkgTagFile(FileFd * const F, pkgTagFile::Flags const Flags, unsigned long long Size = 32*1024); pkgTagFile(FileFd * const F,unsigned long long Size = 32*1024); virtual ~pkgTagFile(); }; |