performance tuning

Author: jgg
Date: 1999-02-23 06:46:24 GMT
performance tuning

apt-pkg/cacheiterators.h

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: cacheiterators.h,v 1.12 1999/02/01 02:22:11 jgg Exp $
+// $Id: cacheiterators.h,v 1.13 1999/02/23 06:46:24 jgg Exp $
 /* ######################################################################
    
    Cache Iterators - Iterators for navigating the cache structure
@@ -93,17 +93,17 @@ class pkgCache::PkgIterator
 class pkgCache::VerIterator
 {
    Version *Ver;
-   pkgCache &Owner;
+   pkgCache *Owner;
    
    void _dummy();
    
    public:
 
    // Iteration
-   void operator ++(int) {if (Ver != Owner.VerP) Ver = Owner.VerP + Ver->NextVer;};
+   void operator ++(int) {if (Ver != Owner->VerP) Ver = Owner->VerP + Ver->NextVer;};
    inline void operator ++() {operator ++(0);};
-   inline bool end() const {return Ver == Owner.VerP?true:false;};
-   inline void operator =(const VerIterator &B) {Ver = B.Ver;};
+   inline bool end() const {return Ver == Owner->VerP?true:false;};
+   inline void operator =(const VerIterator &B) {Ver = B.Ver; Owner = B.Owner;};
    
    // Comparison
    inline bool operator ==(const VerIterator &B) const {return Ver == B.Ver;};
@@ -115,24 +115,26 @@ class pkgCache::VerIterator
    inline Version const *operator ->() const {return Ver;};
    inline Version &operator *() {return *Ver;};
    inline Version const &operator *() const {return *Ver;};
-   inline operator Version *() {return Ver == Owner.VerP?0:Ver;};
-   inline operator Version const *() const {return Ver == Owner.VerP?0:Ver;};
+   inline operator Version *() {return Ver == Owner->VerP?0:Ver;};
+   inline operator Version const *() const {return Ver == Owner->VerP?0:Ver;};
    
-   inline const char *VerStr() const {return Ver->VerStr == 0?0:Owner.StrP + Ver->VerStr;};
-   inline const char *Section() const {return Ver->Section == 0?0:Owner.StrP + Ver->Section;};
-   inline const char *Arch() const {return Ver->Arch == 0?0:Owner.StrP + Ver->Arch;};
-   inline PkgIterator ParentPkg() const {return PkgIterator(Owner,Owner.PkgP + Ver->ParentPkg);};
+   inline const char *VerStr() const {return Ver->VerStr == 0?0:Owner->StrP + Ver->VerStr;};
+   inline const char *Section() const {return Ver->Section == 0?0:Owner->StrP + Ver->Section;};
+   inline const char *Arch() const {return Ver->Arch == 0?0:Owner->StrP + Ver->Arch;};
+   inline PkgIterator ParentPkg() const {return PkgIterator(*Owner,Owner->PkgP + Ver->ParentPkg);};
    inline DepIterator DependsList() const;
    inline PrvIterator ProvidesList() const;
    inline VerFileIterator FileList() const;
-   inline unsigned long Index() const {return Ver - Owner.VerP;};
+   inline unsigned long Index() const {return Ver - Owner->VerP;};
    bool Downloadable() const;
    const char *PriorityType();
 
    bool Automatic() const;
    VerFileIterator NewestFile() const;
-      
-   inline VerIterator(pkgCache &Owner,Version *Trg = 0) : Ver(Trg), Owner(Owner) 
+
+   inline VerIterator() : Ver(0), Owner(0) {};   
+   inline VerIterator(pkgCache &Owner,Version *Trg = 0) : Ver(Trg), 
+              Owner(&Owner) 
    { 
       if (Ver == 0)
 	 Ver = Owner.VerP;
@@ -330,10 +332,10 @@ inline pkgCache::DepIterator pkgCache::PkgIterator::RevDependsList() const
 inline pkgCache::PrvIterator pkgCache::PkgIterator::ProvidesList() const
        {return PrvIterator(*Owner,Owner->ProvideP + Pkg->ProvidesList,Pkg);};
 inline pkgCache::PrvIterator pkgCache::VerIterator::ProvidesList() const
-       {return PrvIterator(Owner,Owner.ProvideP + Ver->ProvidesList,Ver);};
+       {return PrvIterator(*Owner,Owner->ProvideP + Ver->ProvidesList,Ver);};
 inline pkgCache::DepIterator pkgCache::VerIterator::DependsList() const
-       {return DepIterator(Owner,Owner.DepP + Ver->DependsList,Ver);};
+       {return DepIterator(*Owner,Owner->DepP + Ver->DependsList,Ver);};
 inline pkgCache::VerFileIterator pkgCache::VerIterator::FileList() const
-       {return VerFileIterator(Owner,Owner.VerFileP + Ver->FileList);};
+       {return VerFileIterator(*Owner,Owner->VerFileP + Ver->FileList);};
 
 #endif

apt-pkg/makefile

@@ -11,7 +11,7 @@ include ../buildlib/defaults.mak
 
 # The library name
 LIBRARY=apt-pkg
-MAJOR=2.1
+MAJOR=2.2
 MINOR=0
 SLIBS=$(PTHREADLIB)
 

apt-pkg/pkgcache.cc

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: pkgcache.cc,v 1.22 1998/12/14 08:07:29 jgg Exp $
+// $Id: pkgcache.cc,v 1.23 1999/02/23 06:46:24 jgg Exp $
 /* ######################################################################
    
    Package Cache - Accessor code for the cache
@@ -44,7 +44,7 @@ pkgCache::Header::Header()
    /* Whenever the structures change the major version should be bumped,
       whenever the generator changes the minor version should be bumped. */
    MajorVersion = 2;
-   MinorVersion = 2;
+   MinorVersion = 3;
    Dirty = true;
    
    HeaderSz = sizeof(pkgCache::Header);
@@ -132,23 +132,20 @@ bool pkgCache::ReMap()
 /* This is used to generate the hash entries for the HashTable. With my
    package list from bo this function gets 94% table usage on a 512 item
    table (480 used items) */
-unsigned long pkgCache::sHash(string Str)
+unsigned long pkgCache::sHash(string Str) const
 {
    unsigned long Hash = 0;
    for (const char *I = Str.begin(); I != Str.end(); I++)
-      Hash += *I * ((Str.end() - I + 1));
-   Header H;
-   return Hash % _count(H.HashTable);
+      Hash = 5*Hash + *I;
+   return Hash % _count(HeaderP->HashTable);
 }
 
-unsigned long pkgCache::sHash(const char *Str)
+unsigned long pkgCache::sHash(const char *Str) const
 {
    unsigned long Hash = 0;
-   const char *End = Str + strlen(Str);
-   for (const char *I = Str; I != End; I++)
-      Hash += *I * ((End - I + 1));
-   Header H;
-   return Hash % _count(H.HashTable);
+   for (const char *I = Str; *I != 0; I++)
+      Hash = 5*Hash + *I;
+   return Hash % _count(HeaderP->HashTable);
 }
 
 									/*}}}*/
@@ -164,6 +161,7 @@ pkgCache::PkgIterator pkgCache::FindPkg(string Name)
       if (Pkg->Name != 0 && StrP[Pkg->Name] == Name[0] &&
 	  StrP + Pkg->Name == Name)
 	 return PkgIterator(*this,Pkg);
+//      cout << "b" << flush;
    }
    return PkgIterator(*this,0);
 }

apt-pkg/pkgcache.h

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: pkgcache.h,v 1.17 1999/02/21 08:38:53 jgg Exp $
+// $Id: pkgcache.h,v 1.18 1999/02/23 06:46:24 jgg Exp $
 /* ######################################################################
    
    Cache - Structure definitions for the cache file
@@ -90,8 +90,8 @@ class pkgCache
    string CacheFile;
    MMap ⤅
 
-   static unsigned long sHash(string S);
-   static unsigned long sHash(const char *S);
+   unsigned long sHash(string S) const;
+   unsigned long sHash(const char *S) const;
    
    public:
    
@@ -165,7 +165,7 @@ struct pkgCache::Header
    DynamicMMap::Pool Pools[7];
    
    // Rapid package name lookup
-   __apt_ptrloc HashTable[2048];
+   __apt_ptrloc HashTable[2*1048];
 
    bool CheckSizes(Header &Against) const;
    Header();

apt-pkg/pkgcachegen.cc

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: pkgcachegen.cc,v 1.28 1999/02/08 07:30:49 jgg Exp $
+// $Id: pkgcachegen.cc,v 1.29 1999/02/23 06:46:24 jgg Exp $
 /* ######################################################################
    
    Package Cache Generator - Generator for the cache structure.
@@ -22,6 +22,7 @@
 #include <apt-pkg/configuration.h>
 #include <apt-pkg/deblistparser.h>
 #include <apt-pkg/strutl.h>
+#include <system.h>
 
 #include <sys/stat.h>
 #include <unistd.h>
@@ -44,6 +45,7 @@ pkgCacheGenerator::pkgCacheGenerator(DynamicMMap &Map,OpProgress &Prog) :
    Cache.HeaderP->Dirty = true;
    Map.Sync(0,sizeof(pkgCache::Header));
    Map.UsePools(*Cache.HeaderP->Pools,sizeof(Cache.HeaderP->Pools)/sizeof(Cache.HeaderP->Pools[0]));
+   memset(UniqHash,0,sizeof(UniqHash));
 }
 									/*}}}*/
 // CacheGenerator::~pkgCacheGenerator - Destructor 			/*{{{*/
@@ -69,11 +71,12 @@ bool pkgCacheGenerator::MergeList(ListParser &List)
 {
    List.Owner = this;
 
-   int Counter = 0;
+   unsigned int Counter = 0;
    while (List.Step() == true)
    {
       // Get a pointer to the package structure
       string PackageName = List.Package();
+      Pkgs++;
       if (PackageName.empty() == true)
 	 return false;
       
@@ -100,6 +103,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List)
       int Res = 1;
       for (; Ver.end() == false; Last = &Ver->NextVer, Ver++)
       {
+	 Cmps++;
 	 Res = pkgVersionCompare(Version.begin(),Version.end(),Ver.VerStr(),
 				 Ver.VerStr() + strlen(Ver.VerStr()));
 	 if (Res >= 0)
@@ -120,6 +124,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List)
       }      
 
       // Add a new version
+      Vers++;
       *Last = NewVersion(Ver,Version,*Last);
       Ver->ParentPkg = Pkg.Index();
       if (List.NewVersion(Ver) == false)
@@ -250,9 +255,9 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
    // Probe the reverse dependency list for a version string that matches
    if (Version.empty() == false)
    {
-      for (pkgCache::DepIterator I = Pkg.RevDependsList(); I.end() == false; I++)
+/*      for (pkgCache::DepIterator I = Pkg.RevDependsList(); I.end() == false; I++, Hit++)
 	 if (I->Version != 0 && I.TargetVer() == Version)
-	    Dep->Version = I->Version;
+	    Dep->Version = I->Version;*/
       if (Dep->Version == 0)
 	 if ((Dep->Version = WriteString(Version)) == 0)
 	    return false;
@@ -265,19 +270,17 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
    
    /* Link it to the version (at the end of the list)
       Caching the old end point speeds up generation substantially */
-   static pkgCache::VerIterator OldVer(Cache);
-   static __apt_ptrloc *OldLast;
-   if (OldVer != Ver)
+   if (OldDepVer != Ver)
    {
-      OldLast = &Ver->DependsList;
+      OldDepLast = &Ver->DependsList;
       for (pkgCache::DepIterator D = Ver.DependsList(); D.end() == false; D++)
-	 OldLast = &D->NextDepends;
-      OldVer = Ver;
+	 OldDepLast = &D->NextDepends;
+      OldDepVer = Ver;
    }
    
-   Dep->NextDepends = *OldLast;
-   *OldLast = Dep.Index();
-   OldLast = &Dep->NextDepends;
+   Dep->NextDepends = *OldDepLast;
+   *OldDepLast = Dep.Index();
+   OldDepLast = &Dep->NextDepends;
 
    return true;
 }
@@ -362,6 +365,13 @@ bool pkgCacheGenerator::SelectFile(string File,unsigned long Flags)
 unsigned long pkgCacheGenerator::WriteUniqString(const char *S,
 						 unsigned int Size)
 {
+   /* We use a very small transient hash table here, this speeds up generation
+      by a fair amount on slower machines */
+   pkgCache::StringItem *&Bucket = UniqHash[(S[0]*5 + S[1]) % _count(UniqHash)];
+   if (Bucket != 0 && 
+       stringcmp(S,S+Size,Cache.StrP + Bucket->String) == 0)
+      return Bucket->String;
+   
    // Search for an insertion point
    pkgCache::StringItem *I = Cache.StringItemP + Cache.HeaderP->StringList;
    int Res = 1;
@@ -376,7 +386,10 @@ unsigned long pkgCacheGenerator::WriteUniqString(const char *S,
    
    // Match
    if (Res == 0)
+   {
+      Bucket = I;
       return I->String;
+   }
    
    // Get a structure
    unsigned long Item = Map.Allocate(sizeof(pkgCache::StringItem));
@@ -391,6 +404,7 @@ unsigned long pkgCacheGenerator::WriteUniqString(const char *S,
    if (ItemP->String == 0)
       return 0;
    
+   Bucket = ItemP;
    return ItemP->String;
 }
 									/*}}}*/

apt-pkg/pkgcachegen.h

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: pkgcachegen.h,v 1.11 1998/12/14 02:23:47 jgg Exp $
+// $Id: pkgcachegen.h,v 1.12 1999/02/23 06:46:24 jgg Exp $
 /* ######################################################################
    
    Package Cache Generator - Generator for the cache structure.
@@ -31,6 +31,10 @@ class OpProgress;
 
 class pkgCacheGenerator
 {
+   private:
+   
+   pkgCache::StringItem *UniqHash[26];
+   
    public:
    
    class ListParser;
@@ -74,6 +78,10 @@ class pkgCacheGenerator::ListParser
    pkgCacheGenerator *Owner;
    friend pkgCacheGenerator;
    
+   // Some cache items
+   pkgCache::VerIterator OldDepVer;
+   __apt_ptrloc *OldDepLast;
+      
    protected:
    
    inline unsigned long WriteUniqString(string S) {return Owner->WriteUniqString(S);};