// -*- mode: cpp; mode: fold -*-
// Description /*{{{*/
-// $Id: tagfile.cc,v 1.8 1998/07/16 06:08:39 jgg Exp $
+// $Id: tagfile.cc,v 1.37.2.2 2003/12/31 16:02:30 mdz Exp $
/* ######################################################################
Fast scanner for RFC-822 type header information
- This uses a rotating 64K buffer to load the package information into.
+ This uses a rotating buffer to load the package information into.
The scanner runs over it and isolates and indexes a single section.
##################################################################### */
#include <apt-pkg/tagfile.h>
#include <apt-pkg/error.h>
+#include <apt-pkg/strutl.h>
+#include <apti18n.h>
+
#include <string>
#include <stdio.h>
+#include <ctype.h>
/*}}}*/
+using std::string;
+
// TagFile::pkgTagFile - Constructor /*{{{*/
// ---------------------------------------------------------------------
/* */
-pkgTagFile::pkgTagFile(File &Fd) : Fd(Fd)
+pkgTagFile::pkgTagFile(FileFd *pFd,unsigned long Size) :
+ Fd(*pFd),
+ Size(Size)
{
- Buffer = new char[64*1024];
- Start = End = Buffer + 64*1024;
- Left = Fd.Size();
+ if (Fd.IsOpen() == false || Fd.Size() == 0)
+ {
+ Buffer = 0;
+ Start = End = Buffer = 0;
+ iOffset = 0;
+ Map = NULL;
+ return;
+ }
+
+ Map = new MMap (Fd, MMap::Public | MMap::ReadOnly);
+ Buffer = (char *) Map->Data ();
+ Start = Buffer;
+ End = Buffer + Map->Size ();
iOffset = 0;
- Fill();
+}
+ /*}}}*/
+// TagFile::~pkgTagFile - Destructor /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+pkgTagFile::~pkgTagFile()
+{
+ delete Map;
}
/*}}}*/
// TagFile::Step - Advance to the next section /*{{{*/
/* If the Section Scanner fails we refill the buffer and try again. */
bool pkgTagFile::Step(pkgTagSection &Tag)
{
+ if (Start == End)
+ return false;
+
if (Tag.Scan(Start,End - Start) == false)
{
- if (Fill() == false)
- return false;
-
- if (Tag.Scan(Start,End - Start) == false)
- return _error->Error("Unable to parse package file");
- }
+ return _error->Error(_("Unable to parse package file %s (1)"),
+ Fd.Name().c_str());
+ }
Start += Tag.size();
iOffset += Tag.size();
-
+
+ Tag.Trim();
return true;
}
/*}}}*/
-// TagFile::Fill - Top up the buffer /*{{{*/
+// TagFile::Jump - Jump to a pre-recorded location in the file /*{{{*/
// ---------------------------------------------------------------------
-/* This takes the bit at the end of the buffer and puts it at the start
- then fills the rest from the file */
-bool pkgTagFile::Fill()
+/* This jumps to a pre-recorded file location and reads the record
+ that is there */
+bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long Offset)
{
- unsigned long Size = End - Start;
-
- if (Left == 0)
+ // We are within a buffer space of the next hit..
+ if (Offset >= iOffset && iOffset + (End - Start) > Offset)
{
- if (Size <= 1)
- return false;
- return true;
+ unsigned long Dist = Offset - iOffset;
+ Start += Dist;
+ iOffset += Dist;
+ return Step(Tag);
}
+
+ // Reposition and reload..
+ iOffset = Offset;
+ Start = Buffer + iOffset;
- memmove(Buffer,Start,Size);
- Start = Buffer;
+ // Start != End is a special case to not fail on empty TagFiles
+ if (Start != End && Tag.Scan(Start,End - Start) == false)
+ return _error->Error(_("Unable to parse package file %s (2)"),Fd.Name().c_str());
- // See if only a bit of the file is left or if
- if (Left < End - Buffer - Size)
- {
- if (Fd.Read(Buffer + Size,Left) == false)
- return false;
- End = Buffer + Size + Left;
- Left = 0;
- }
- else
- {
- if (Fd.Read(Buffer + Size, End - Buffer - Size) == false)
- return false;
- Left -= End - Buffer - Size;
- }
return true;
}
/*}}}*/
// 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. */
+ indexes the tags in the section. This very simple hash function for the
+ first 3 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) ^ (Res << 2);
+ return Res & 0xFF;
+}
+
bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength)
{
const char *End = Start + MaxLength;
Stop = Section = Start;
+ memset(AlphaIndexes,0,sizeof(AlphaIndexes));
+
+ if (Stop == 0 || MaxLength == 0)
+ return false;
TagCount = 0;
- Indexes[TagCount++] = Stop - Section;
- Stop++;
- for (; Stop < End; Stop++)
+ while (TagCount+1 < sizeof(Indexes)/sizeof(Indexes[0]) && Stop < End)
{
- if (Stop[-1] != '\n')
- continue;
- if (Stop[0] == '\n')
+ // Start a new index and add it to the hash
+ if (isspace(Stop[0]) == 0)
+ {
+ Indexes[TagCount++] = Stop - Section;
+ AlphaIndexes[AlphaHash(Stop,End)] = TagCount;
+ }
+
+ Stop = (const char *)memchr(Stop,'\n',End - Stop);
+
+ if (Stop == 0)
+ return false;
+
+ for (; Stop+1 < End && Stop[1] == '\r'; Stop++);
+
+ // Double newline marks the end of the record
+ if (Stop+1 < End && Stop[1] == '\n')
{
- // Extra one at the end to simplify find
Indexes[TagCount] = Stop - Section;
- for (; Stop[0] == '\n' && Stop < End; Stop++);
+ for (; Stop < End && (Stop[0] == '\n' || Stop[0] == '\r'); Stop++);
return true;
- break;
}
- if (isspace(Stop[0]) == 0)
- Indexes[TagCount++] = Stop - Section;
-
- // Just in case.
- if (TagCount > sizeof(Indexes)/sizeof(Indexes[0]))
- TagCount = sizeof(Indexes)/sizeof(Indexes[0]);
- }
+ Stop++;
+ }
+
+ if ((Stop+1 >= End) && (End[-1] == '\n' || End[-1] == '\r'))
+ {
+ Indexes[TagCount] = (End - 1) - Section;
+ return true;
+ }
+
return false;
}
/*}}}*/
+// TagSection::Trim - Trim off any trailing garbage /*{{{*/
+// ---------------------------------------------------------------------
+/* There should be exactly 1 newline at the end of the buffer, no more. */
+void pkgTagSection::Trim()
+{
+ for (; Stop > Section + 2 && (Stop[-2] == '\n' || Stop[-2] == '\r'); Stop--);
+}
+ /*}}}*/
// 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)
+bool pkgTagSection::Find(const char *Tag,unsigned &Pos) const
{
unsigned int Length = strlen(Tag);
- for (unsigned int I = 0; I != TagCount; I++)
+ unsigned int I = AlphaIndexes[AlphaHash(Tag)];
+ if (I == 0)
+ return false;
+ I--;
+
+ for (unsigned int Counter = 0; Counter != TagCount; Counter++,
+ I = (I+1)%TagCount)
{
- if (strncasecmp(Tag,Section + Indexes[I],Length) != 0)
+ 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 = Section + Length + Indexes[I];
+ const char *C = St + Length;
+ for (; isspace(*C) != 0; C++);
+ if (*C != ':')
+ continue;
+ Pos = I;
+ 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)
+ 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;
}
/*}}}*/
+// TagSection::FindS - Find a string /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string pkgTagSection::FindS(const char *Tag) const
+{
+ const char *Start;
+ const char *End;
+ if (Find(Tag,Start,End) == false)
+ return string();
+ return string(Start,End);
+}
+ /*}}}*/
+// TagSection::FindI - Find an integer /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+signed int pkgTagSection::FindI(const char *Tag,signed long Default) const
+{
+ const char *Start;
+ const char *Stop;
+ if (Find(Tag,Start,Stop) == false)
+ return Default;
+
+ // Copy it into a temp buffer so we can use strtol
+ char S[300];
+ if ((unsigned)(Stop - Start) >= sizeof(S))
+ return Default;
+ strncpy(S,Start,Stop-Start);
+ S[Stop - Start] = 0;
+
+ char *End;
+ signed long Result = strtol(S,&End,10);
+ if (S == End)
+ return Default;
+ return Result;
+}
+ /*}}}*/
+// TagSection::FindFlag - Locate a yes/no type flag /*{{{*/
+// ---------------------------------------------------------------------
+/* The bits marked in Flag are masked on/off in Flags */
+bool pkgTagSection::FindFlag(const char *Tag,unsigned long &Flags,
+ unsigned long Flag) const
+{
+ const char *Start;
+ const char *Stop;
+ if (Find(Tag,Start,Stop) == false)
+ return true;
+
+ switch (StringToBool(string(Start,Stop)))
+ {
+ case 0:
+ Flags &= ~Flag;
+ return true;
+
+ case 1:
+ Flags |= Flag;
+ return true;
+
+ default:
+ _error->Warning("Unknown flag value: %s",string(Start,Stop).c_str());
+ return true;
+ }
+ return true;
+}
+ /*}}}*/
+
+// TFRewrite - Rewrite a control record /*{{{*/
+// ---------------------------------------------------------------------
+/* This writes the control record to stdout rewriting it as necessary. The
+ override map item specificies the rewriting rules to follow. This also
+ takes the time to sort the feild list. */
+
+/* The order of this list is taken from dpkg source lib/parse.c the fieldinfos
+ array. */
+static const char *iTFRewritePackageOrder[] = {
+ "Package",
+ "Essential",
+ "Status",
+ "Priority",
+ "Section",
+ "Installed-Size",
+ "Maintainer",
+ "Architecture",
+ "Source",
+ "Version",
+ "Revision", // Obsolete
+ "Config-Version", // Obsolete
+ "Replaces",
+ "Provides",
+ "Depends",
+ "Pre-Depends",
+ "Recommends",
+ "Suggests",
+ "Conflicts",
+ "Conffiles",
+ "Filename",
+ "Size",
+ "MD5Sum",
+ "SHA1Sum",
+ "MSDOS-Filename", // Obsolete
+ "Description",
+ 0};
+static const char *iTFRewriteSourceOrder[] = {"Package",
+ "Source",
+ "Binary",
+ "Version",
+ "Priority",
+ "Section",
+ "Maintainer",
+ "Build-Depends",
+ "Build-Depends-Indep",
+ "Build-Conflicts",
+ "Build-Conflicts-Indep",
+ "Architecture",
+ "Standards-Version",
+ "Format",
+ "Directory",
+ "Files",
+ 0};
+
+/* Two levels of initialization are used because gcc will set the symbol
+ size of an array to the length of the array, causing dynamic relinking
+ errors. Doing this makes the symbol size constant */
+const char **TFRewritePackageOrder = iTFRewritePackageOrder;
+const char **TFRewriteSourceOrder = iTFRewriteSourceOrder;
+
+bool TFRewrite(FILE *Output,pkgTagSection const &Tags,const char *Order[],
+ TFRewriteData *Rewrite)
+{
+ unsigned char Visited[256]; // Bit 1 is Order, Bit 2 is Rewrite
+ for (unsigned I = 0; I != 256; I++)
+ Visited[I] = 0;
+
+ // Set new tag up as necessary.
+ for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++)
+ {
+ if (Rewrite[J].NewTag == 0)
+ Rewrite[J].NewTag = Rewrite[J].Tag;
+ }
+
+ // Write all all of the tags, in order.
+ for (unsigned int I = 0; Order[I] != 0; I++)
+ {
+ bool Rewritten = false;
+
+ // See if this is a field that needs to be rewritten
+ for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++)
+ {
+ if (strcasecmp(Rewrite[J].Tag,Order[I]) == 0)
+ {
+ Visited[J] |= 2;
+ if (Rewrite[J].Rewrite != 0 && Rewrite[J].Rewrite[0] != 0)
+ {
+ if (isspace(Rewrite[J].Rewrite[0]))
+ fprintf(Output,"%s:%s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite);
+ else
+ fprintf(Output,"%s: %s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite);
+ }
+
+ Rewritten = true;
+ break;
+ }
+ }
+
+ // See if it is in the fragment
+ unsigned Pos;
+ if (Tags.Find(Order[I],Pos) == false)
+ continue;
+ Visited[Pos] |= 1;
+
+ if (Rewritten == true)
+ continue;
+
+ /* Write out this element, taking a moment to rewrite the tag
+ in case of changes of case. */
+ const char *Start;
+ const char *Stop;
+ Tags.Get(Start,Stop,Pos);
+
+ if (fputs(Order[I],Output) < 0)
+ return _error->Errno("fputs","IO Error to output");
+ Start += strlen(Order[I]);
+ if (fwrite(Start,Stop - Start,1,Output) != 1)
+ return _error->Errno("fwrite","IO Error to output");
+ if (Stop[-1] != '\n')
+ fprintf(Output,"\n");
+ }
+
+ // Now write all the old tags that were missed.
+ for (unsigned int I = 0; I != Tags.Count(); I++)
+ {
+ if ((Visited[I] & 1) == 1)
+ continue;
+
+ const char *Start;
+ const char *Stop;
+ Tags.Get(Start,Stop,I);
+ const char *End = Start;
+ for (; End < Stop && *End != ':'; End++);
+
+ // See if this is a field that needs to be rewritten
+ bool Rewritten = false;
+ for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++)
+ {
+ if (stringcasecmp(Start,End,Rewrite[J].Tag) == 0)
+ {
+ Visited[J] |= 2;
+ if (Rewrite[J].Rewrite != 0 && Rewrite[J].Rewrite[0] != 0)
+ {
+ if (isspace(Rewrite[J].Rewrite[0]))
+ fprintf(Output,"%s:%s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite);
+ else
+ fprintf(Output,"%s: %s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite);
+ }
+
+ Rewritten = true;
+ break;
+ }
+ }
+
+ if (Rewritten == true)
+ continue;
+
+ // Write out this element
+ if (fwrite(Start,Stop - Start,1,Output) != 1)
+ return _error->Errno("fwrite","IO Error to output");
+ if (Stop[-1] != '\n')
+ fprintf(Output,"\n");
+ }
+
+ // Now write all the rewrites that were missed
+ for (unsigned int J = 0; Rewrite != 0 && Rewrite[J].Tag != 0; J++)
+ {
+ if ((Visited[J] & 2) == 2)
+ continue;
+
+ if (Rewrite[J].Rewrite != 0 && Rewrite[J].Rewrite[0] != 0)
+ {
+ if (isspace(Rewrite[J].Rewrite[0]))
+ fprintf(Output,"%s:%s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite);
+ else
+ fprintf(Output,"%s: %s\n",Rewrite[J].NewTag,Rewrite[J].Rewrite);
+ }
+ }
+
+ return true;
+}
+ /*}}}*/
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