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-rw-r--r--apt-pkg/tagfile.cc209
-rw-r--r--apt-pkg/tagfile.h63
2 files changed, 173 insertions, 99 deletions
diff --git a/apt-pkg/tagfile.cc b/apt-pkg/tagfile.cc
index 009ed7d74..52f4da2d5 100644
--- a/apt-pkg/tagfile.cc
+++ b/apt-pkg/tagfile.cc
@@ -47,6 +47,22 @@ public:
unsigned long long Size;
};
+static unsigned long AlphaHash(const char *Text, size_t Length) /*{{{*/
+{
+ /* This very simple hash function for the last 8 letters gives
+ very good performance on the debian package files */
+ if (Length > 8)
+ {
+ Text += (Length - 8);
+ Length = 8;
+ }
+ unsigned long Res = 0;
+ for (size_t i = 0; i < Length; ++i)
+ Res = ((unsigned long)(Text[i]) & 0xDF) ^ (Res << 1);
+ return Res & 0xFF;
+}
+ /*}}}*/
+
// TagFile::pkgTagFile - Constructor /*{{{*/
// ---------------------------------------------------------------------
/* */
@@ -139,18 +155,23 @@ bool pkgTagFile::Resize(unsigned long long const newSize)
*/
bool pkgTagFile::Step(pkgTagSection &Tag)
{
- while (Tag.Scan(d->Start,d->End - d->Start) == false)
+ if(Tag.Scan(d->Start,d->End - d->Start) == false)
{
- if (Fill() == false)
- return false;
-
- if(Tag.Scan(d->Start,d->End - d->Start))
- break;
+ do
+ {
+ if (Fill() == false)
+ return false;
+
+ if(Tag.Scan(d->Start,d->End - d->Start, false))
+ break;
+
+ if (Resize() == false)
+ return _error->Error(_("Unable to parse package file %s (1)"),
+ d->Fd.Name().c_str());
- if (Resize() == false)
- return _error->Error(_("Unable to parse package file %s (1)"),
- d->Fd.Name().c_str());
+ } while (Tag.Scan(d->Start,d->End - d->Start, false) == false);
}
+
d->Start += Tag.size();
d->iOffset += Tag.size();
@@ -244,7 +265,7 @@ bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long long Offset)
if (Fill() == false)
return false;
- if (Tag.Scan(d->Start, d->End - d->Start) == false)
+ if (Tag.Scan(d->Start, d->End - d->Start, false) == false)
return _error->Error(_("Unable to parse package file %s (2)"),d->Fd.Name().c_str());
return true;
@@ -254,27 +275,46 @@ bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long long Offset)
// ---------------------------------------------------------------------
/* */
pkgTagSection::pkgTagSection()
- : Section(0), TagCount(0), d(NULL), Stop(0)
+ : Section(0), d(NULL), Stop(0)
{
- memset(&Indexes, 0, sizeof(Indexes));
- memset(&AlphaIndexes, 0, sizeof(AlphaIndexes));
+ memset(&LookupTable, 0, sizeof(LookupTable));
}
/*}}}*/
// TagSection::Scan - Scan for the end of the header information /*{{{*/
-// ---------------------------------------------------------------------
-/* This looks for the first double new line in the data stream.
- It also indexes the tags in the section. */
-bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength)
+bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength, bool const Restart)
{
+ Section = Start;
const char *End = Start + MaxLength;
- Stop = Section = Start;
- memset(AlphaIndexes,0,sizeof(AlphaIndexes));
+
+ if (Restart == false && Tags.empty() == false)
+ {
+ Stop = Section + Tags.back().StartTag;
+ if (End <= Stop)
+ return false;
+ Stop = (const char *)memchr(Stop,'\n',End - Stop);
+ if (Stop == NULL)
+ return false;
+ ++Stop;
+ }
+ else
+ {
+ Stop = Section;
+ if (Tags.empty() == false)
+ {
+ memset(&LookupTable, 0, sizeof(LookupTable));
+ Tags.clear();
+ }
+ Tags.reserve(0x100);
+ }
+ size_t TagCount = Tags.size();
if (Stop == 0)
return false;
- TagCount = 0;
- while (TagCount+1 < sizeof(Indexes)/sizeof(Indexes[0]) && Stop < End)
+ TagData lastTagData(0);
+ lastTagData.EndTag = 0;
+ unsigned long lastTagHash = 0;
+ while (Stop < End)
{
TrimRecord(true,End);
@@ -286,12 +326,39 @@ bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength)
// Start a new index and add it to the hash
if (isspace(Stop[0]) == 0)
{
- Indexes[TagCount++] = Stop - Section;
- AlphaIndexes[AlphaHash(Stop,End)] = TagCount;
+ // store the last found tag
+ if (lastTagData.EndTag != 0)
+ {
+ if (LookupTable[lastTagHash] != 0)
+ lastTagData.NextInBucket = LookupTable[lastTagHash];
+ LookupTable[lastTagHash] = TagCount;
+ Tags.push_back(lastTagData);
+ }
+
+ ++TagCount;
+ lastTagData = TagData(Stop - Section);
+ // find the colon separating tag and value
+ char const * Colon = (char const *) memchr(Stop, ':', End - Stop);
+ if (Colon == NULL)
+ return false;
+ // find the end of the tag (which might or might not be the colon)
+ char const * EndTag = Colon;
+ --EndTag;
+ for (; EndTag > Stop && isspace(*EndTag) != 0; --EndTag)
+ ;
+ ++EndTag;
+ lastTagData.EndTag = EndTag - Section;
+ lastTagHash = AlphaHash(Stop, EndTag - Stop);
+ // find the beginning of the value
+ Stop = Colon + 1;
+ for (; isspace(*Stop) != 0; ++Stop);
+ if (Stop >= End)
+ return false;
+ lastTagData.StartValue = Stop - Section;
}
Stop = (const char *)memchr(Stop,'\n',End - Stop);
-
+
if (Stop == 0)
return false;
@@ -302,7 +369,16 @@ bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength)
// Double newline marks the end of the record
if (Stop+1 < End && Stop[1] == '\n')
{
- Indexes[TagCount] = Stop - Section;
+ if (lastTagData.EndTag != 0)
+ {
+ if (LookupTable[lastTagHash] != 0)
+ lastTagData.NextInBucket = LookupTable[lastTagHash];
+ LookupTable[lastTagHash] = TagCount;
+ Tags.push_back(lastTagData);
+ }
+
+ TagData const td(Stop - Section);
+ Tags.push_back(td);
TrimRecord(false,End);
return true;
}
@@ -331,8 +407,8 @@ void pkgTagSection::Trim()
for (; Stop > Section + 2 && (Stop[-2] == '\n' || Stop[-2] == '\r'); Stop--);
}
/*}}}*/
-// TagSection::Exists - return True if a tag exists /*{{{*/
-bool pkgTagSection::Exists(const char* const Tag)
+// TagSection::Exists - return True if a tag exists /*{{{*/
+bool pkgTagSection::Exists(const char* const Tag) const
{
unsigned int tmp;
return Find(Tag, tmp);
@@ -343,73 +419,43 @@ bool pkgTagSection::Exists(const char* const Tag)
/* This searches the section for a tag that matches the given string. */
bool pkgTagSection::Find(const char *Tag,unsigned int &Pos) const
{
- unsigned int Length = strlen(Tag);
- unsigned int I = AlphaIndexes[AlphaHash(Tag)];
- if (I == 0)
+ size_t const Length = strlen(Tag);
+ unsigned int Bucket = LookupTable[AlphaHash(Tag, Length)];
+ if (Bucket == 0)
return false;
- I--;
-
- for (unsigned int Counter = 0; Counter != TagCount; Counter++,
- I = (I+1)%TagCount)
+
+ for (; Bucket != 0; Bucket = Tags[Bucket - 1].NextInBucket)
{
- const char *St;
- St = Section + Indexes[I];
- if (strncasecmp(Tag,St,Length) != 0)
+ if ((Tags[Bucket - 1].EndTag - Tags[Bucket - 1].StartTag) != Length)
continue;
- // Make sure the colon is in the right place
- const char *C = St + Length;
- for (; isspace(*C) != 0; C++);
- if (*C != ':')
+ char const * const St = Section + Tags[Bucket - 1].StartTag;
+ if (strncasecmp(Tag,St,Length) != 0)
continue;
- Pos = I;
+
+ Pos = Bucket - 1;
return true;
}
Pos = 0;
return false;
}
- /*}}}*/
-// TagSection::Find - Locate a tag /*{{{*/
-// ---------------------------------------------------------------------
-/* This searches the section for a tag that matches the given string. */
bool pkgTagSection::Find(const char *Tag,const char *&Start,
const char *&End) const
{
- unsigned int Length = strlen(Tag);
- unsigned int I = AlphaIndexes[AlphaHash(Tag)];
- if (I == 0)
+ unsigned int Pos;
+ if (Find(Tag, Pos) == false)
return false;
- I--;
-
- for (unsigned int Counter = 0; Counter != TagCount; Counter++,
- I = (I+1)%TagCount)
- {
- const char *St;
- St = Section + Indexes[I];
- if (strncasecmp(Tag,St,Length) != 0)
- continue;
-
- // Make sure the colon is in the right place
- const char *C = St + Length;
- for (; isspace(*C) != 0; C++);
- if (*C != ':')
- continue;
- // Strip off the gunk from the start end
- Start = C;
- End = Section + Indexes[I+1];
- if (Start >= End)
- return _error->Error("Internal parsing error");
-
- for (; (isspace(*Start) != 0 || *Start == ':') && Start < End; Start++);
- for (; isspace(End[-1]) != 0 && End > Start; End--);
-
- return true;
- }
-
- Start = End = 0;
- return false;
+ Start = Section + Tags[Pos].StartValue;
+ // Strip off the gunk from the end
+ End = Section + Tags[Pos + 1].StartTag;
+ if (unlikely(Start > End))
+ return _error->Error("Internal parsing error");
+
+ for (; isspace(End[-1]) != 0 && End > Start; --End);
+
+ return true;
}
/*}}}*/
// TagSection::FindS - Find a string /*{{{*/
@@ -504,6 +550,13 @@ bool pkgTagSection::FindFlag(unsigned long &Flags, unsigned long Flag,
return true;
}
/*}}}*/
+APT_PURE unsigned int pkgTagSection::Count() const { /*{{{*/
+ if (Tags.empty() == true)
+ return 0;
+ // the last element is just marking the end and isn't a real one
+ return Tags.size() - 1;
+}
+ /*}}}*/
// TFRewrite - Rewrite a control record /*{{{*/
// ---------------------------------------------------------------------
/* This writes the control record to stdout rewriting it as necessary. The
diff --git a/apt-pkg/tagfile.h b/apt-pkg/tagfile.h
index d1a24ba45..b0cfab759 100644
--- a/apt-pkg/tagfile.h
+++ b/apt-pkg/tagfile.h
@@ -25,6 +25,8 @@
#include <stdio.h>
#include <string>
+#include <vector>
+#include <list>
#ifndef APT_8_CLEANER_HEADERS
#include <apt-pkg/fileutl.h>
@@ -35,23 +37,20 @@ class FileFd;
class pkgTagSection
{
const char *Section;
- // We have a limit of 256 tags per section.
- unsigned int Indexes[256];
- unsigned int AlphaIndexes[0x100];
- unsigned int TagCount;
+ struct TagData {
+ unsigned int StartTag;
+ unsigned int EndTag;
+ unsigned int StartValue;
+ unsigned int NextInBucket;
+
+ TagData(unsigned int const StartTag) : StartTag(StartTag), NextInBucket(0) {}
+ };
+ std::vector<TagData> Tags;
+ unsigned int LookupTable[0x100];
+
// dpointer placeholder (for later in case we need it)
void *d;
- /* This very simple hash function for the last 8 letters gives
- very good performance on the debian package files */
- inline static unsigned long AlphaHash(const char *Text, const char *End = 0)
- {
- unsigned long Res = 0;
- for (; Text != End && *Text != ':' && *Text != 0; Text++)
- Res = ((unsigned long)(*Text) & 0xDF) ^ (Res << 1);
- return Res & 0xFF;
- }
-
protected:
const char *Stop;
@@ -69,17 +68,39 @@ class pkgTagSection
unsigned long Flag) const;
bool static FindFlag(unsigned long &Flags, unsigned long Flag,
const char* Start, const char* Stop);
- bool Scan(const char *Start,unsigned long MaxLength);
+
+ /** \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);
-
- inline unsigned int Count() const {return TagCount;};
- bool Exists(const char* const Tag);
-
+
+ /** \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 occurance 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 + Indexes[I]; Stop = Section + Indexes[I+1];}
-
+ {Start = Section + Tags[I].StartTag; Stop = Section + Tags[I+1].StartTag;}
+
inline void GetSection(const char *&Start,const char *&Stop) const
{
Start = Section;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-02 01:44:44 +0000