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[apt.git] / apt-pkg / version.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: version.cc,v 1.8 1998/12/05 01:44:57 jgg Exp $
/* ######################################################################

   Version - Version string 
   
   Version comparing is done using the == and < operators. STL's
   function.h provides the remaining set of comparitors. A directly
   callable non-string class version is provided for functions manipulating
   the cache file (esp the sort function).
 
   A version is defined to be equal if a case sensitive compare returns
   that the two strings are the same. For compatibility with the QSort
   function this version returns -1,0,1.
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#ifdef __GNUG__
#pragma implementation "apt-pkg/version.h"
#endif 

#include <apt-pkg/version.h>
#include <apt-pkg/pkgcache.h>

#include <stdlib.h>
									/*}}}*/

// StrToLong - Convert the string between two iterators to a long	/*{{{*/
// ---------------------------------------------------------------------
/* */
static unsigned long StrToLong(const char *begin,const char *end)
{
   char S[40];
   char *I = S;
   for (; begin != end && I < S + 40;)
      *I++ = *begin++;
   *I = 0;
   return strtoul(S,0,10);
}
									/*}}}*/
// VersionCompare (op) - Greater than comparison for versions		/*{{{*/
// ---------------------------------------------------------------------
/* */
int pkgVersionCompare(const char *A, const char *B)
{
   return pkgVersionCompare(A,A + strlen(A),B,B + strlen(B));
}
int pkgVersionCompare(string A,string B)
{
   return pkgVersionCompare(A.begin(),A.end(),B.begin(),B.end());
}

									/*}}}*/
// iVersionCompare - Compare versions					/*{{{*/
// ---------------------------------------------------------------------
/* This compares a fragment of the version. */
static int iVersionCompare(const char *A, const char *AEnd, const char *B,
			   const char *BEnd)
{
   if (A >= AEnd && B >= BEnd)
      return 0;
   if (A >= AEnd)
      return -1;
   if (B >= BEnd)
      return 1;
   
   /* Iterate over the whole string
      What this does is to spilt the whole string into groups of 
      numeric and non numeric portions. For instance:
         a67bhgs89
      Has 4 portions 'a', '67', 'bhgs', '89'. A more normal:
         2.7.2-linux-1
      Has '2', '.', '7', '.' ,'-linux-','1' */
   const char *lhs = A;
   const char *rhs = B;
   while (lhs != AEnd && rhs != BEnd)
   {
      // Starting points
      const char *Slhs = lhs;
      const char *Srhs = rhs;
      
      // Compute ending points were we have passed over the portion
      bool Digit = (isdigit(*lhs) > 0?true:false);
      for (;lhs != AEnd && (isdigit(*lhs) > 0?true:false) == Digit; lhs++);
      for (;rhs != BEnd && (isdigit(*rhs) > 0?true:false) == Digit; rhs++);
      
      if (Digit == true)
      {
	 // If the lhs has a digit and the rhs does not then <
	 if (rhs - Srhs == 0)
	    return -1;
	 
	 // Generate integers from the strings.
	 unsigned long Ilhs = StrToLong(Slhs,lhs);
	 unsigned long Irhs = StrToLong(Srhs,rhs);
	 if (Ilhs != Irhs)
	 {
	    if (Ilhs > Irhs)
	       return 1;
	    return -1;
	 }
      }
      else
      {
	 // They are equal length so do a straight text compare
	 for (;Slhs != lhs && Srhs != rhs; Slhs++, Srhs++)
	 {
	    if (*Slhs != *Srhs)
	    {
	       /* We need to compare non alpha chars as higher than alpha
	          chars (a < !) */
	       int lc = *Slhs;
	       int rc = *Srhs;
	       if (isalpha(lc) == 0) lc += 256;
	       if (isalpha(rc) == 0) rc += 256;
	       if (lc > rc)
		  return 1;
	       return -1;
	    }
	 }

	 // If the lhs is shorter than the right it is 'less'
	 if (lhs - Slhs < rhs - Srhs)
	    return -1;

	 // If the lhs is longer than the right it is 'more'
	 if (lhs - Slhs > rhs - Srhs)
	    return 1;		 
      }      
   }

   // The strings must be equal
   if (lhs == AEnd && rhs == BEnd)
      return 0;

   // lhs is shorter
   if (lhs == AEnd)
      return -1;

   // rhs is shorter
   if (rhs == BEnd)
      return 1;
       
   // Shouldnt happen
   return 1;
}
									/*}}}*/
// VersionCompare - Comparison for versions				/*{{{*/
// ---------------------------------------------------------------------
/* This fragments the version into E:V-R triples and compares each 
   portion seperately. */
int pkgVersionCompare(const char *A, const char *AEnd, const char *B,
		      const char *BEnd)
{
   // Strip off the epoch and compare it 
   const char *lhs = A;
   const char *rhs = B;
   for (;lhs != AEnd && *lhs != ':'; lhs++);
   for (;rhs != BEnd && *rhs != ':'; rhs++);
   if (lhs == AEnd)
      lhs = A;
   if (rhs == BEnd)
      rhs = B;
   
   // Compare the epoch
   int Res = iVersionCompare(A,lhs,B,rhs);
   if (Res != 0)
      return Res;

   // Skip the :
   if (lhs != A)
      lhs++;
   if (rhs != B)
      rhs++;
   
   // Find the last - 
   const char *dlhs = AEnd-1;
   const char *drhs = BEnd-1;
   for (;dlhs > lhs && *dlhs != '-'; dlhs--);
   for (;drhs > rhs && *drhs != '-'; drhs--);

   if (dlhs == lhs)
      dlhs = AEnd;
   if (drhs == rhs)
      drhs = BEnd;
   
   // Compare the main version
   Res = iVersionCompare(lhs,dlhs,rhs,drhs);
   if (Res != 0)
      return Res;
   
   // Skip the -
   if (dlhs != lhs)
      dlhs++;
   if (drhs != rhs)
      drhs++;
   return iVersionCompare(dlhs,AEnd,drhs,BEnd);
}
									/*}}}*/
// CheckDep - Check a single dependency					/*{{{*/
// ---------------------------------------------------------------------
/* This simply preforms the version comparison and switch based on 
   operator. */
bool pkgCheckDep(const char *DepVer,const char *PkgVer,int Op)
{
   if (DepVer == 0)
      return true;
   if (PkgVer == 0)
      return false;
   
   // Perform the actuall comparision.
   int Res = pkgVersionCompare(PkgVer,DepVer);
   switch (Op & 0x0F)
   {
      case pkgCache::Dep::LessEq:
      if (Res <= 0)
	 return true;
      break;
      
      case pkgCache::Dep::GreaterEq:
      if (Res >= 0)
	 return true;
      break;
      
      case pkgCache::Dep::Less:
      if (Res < 0)
	 return true;
      break;
      
      case pkgCache::Dep::Greater:
      if (Res > 0)
	 return true;
      break;
      
      case pkgCache::Dep::Equals:
      if (Res == 0)
	 return true;
      break;
      
      case pkgCache::Dep::NotEquals:
      if (Res != 0)
	 return true;
      break;
   }

   return false;
}
									/*}}}*/