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authorArch Librarian <arch@canonical.com>2004-09-20 16:50:36 +0000
committerArch Librarian <arch@canonical.com>2004-09-20 16:50:36 +0000
commit578bfd0aed2ec993f4ad85fa6a7094a852261422 (patch)
tree737f52267f6468a4b6754f8c6665824767352746 /apt-pkg/pkgcache.cc
Base revisions
Author: jgg Date: 1998-07-02 02:58:12 GMT Base revisions
Diffstat (limited to 'apt-pkg/pkgcache.cc')
-rw-r--r--apt-pkg/pkgcache.cc360
1 files changed, 360 insertions, 0 deletions
diff --git a/apt-pkg/pkgcache.cc b/apt-pkg/pkgcache.cc
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+// -*- mode: cpp; mode: fold -*-
+// Description /*{{{*/
+// $Id: pkgcache.cc,v 1.1 1998/07/02 02:58:12 jgg Exp $
+/* ######################################################################
+
+ Package Cache - Accessor code for the cache
+
+ Please see doc/pkglib/cache.sgml for a more detailed description of
+ this format. Also be sure to keep that file up-to-date!!
+
+ This is the general utility functions for cache managment. They provide
+ a complete set of accessor functions for the cache. The cacheiterators
+ header contains the STL-like iterators that can be used to easially
+ navigate the cache as well as seemlessly dereference the mmap'd
+ indexes. Use these always.
+
+ The main class provides for ways to get package indexes and some
+ general lookup functions to start the iterators.
+
+ ##################################################################### */
+ /*}}}*/
+// Include Files /*{{{*/
+#include <pkglib/pkgcache.h>
+#include <pkglib/version.h>
+#include <pkglib/error.h>
+#include <system.h>
+
+#include <string>
+#include <sys/stat.h>
+#include <unistd.h>
+ /*}}}*/
+
+// Cache::Header::Header - Constructor /*{{{*/
+// ---------------------------------------------------------------------
+/* Simply initialize the header */
+pkgCache::Header::Header()
+{
+ Signature = 0x98FE76DC;
+
+ /* Whenever the structures change the major version should be bumped,
+ whenever the generator changes the minor version should be bumped. */
+ MajorVersion = 2;
+ MinorVersion = 0;
+ Dirty = true;
+
+ HeaderSz = sizeof(pkgCache::Header);
+ PackageSz = sizeof(pkgCache::Package);
+ PackageFileSz = sizeof(pkgCache::PackageFile);
+ VersionSz = sizeof(pkgCache::Version);
+ DependencySz = sizeof(pkgCache::Dependency);
+ ProvidesSz = sizeof(pkgCache::Provides);
+
+ PackageCount = 0;
+ VersionCount = 0;
+ DependsCount = 0;
+ PackageFileCount = 0;
+
+ FileList = 0;
+ StringList = 0;
+ memset(HashTable,0,sizeof(HashTable));
+ memset(Pools,0,sizeof(Pools));
+}
+ /*}}}*/
+// Cache::Header::CheckSizes - Check if the two headers have same *sz /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool pkgCache::Header::CheckSizes(Header &Against) const
+{
+ if (HeaderSz == Against.HeaderSz &&
+ PackageSz == Against.PackageSz &&
+ PackageFileSz == Against.PackageFileSz &&
+ VersionSz == Against.VersionSz &&
+ DependencySz == Against.DependencySz &&
+ ProvidesSz == Against.ProvidesSz)
+ return true;
+ return false;
+}
+ /*}}}*/
+
+// Cache::pkgCache - Constructor /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+pkgCache::pkgCache(MMap &Map) : Map(Map)
+{
+ ReMap();
+}
+ /*}}}*/
+// Cache::ReMap - Reopen the cache file /*{{{*/
+// ---------------------------------------------------------------------
+/* If the file is already closed then this will open it open it. */
+bool pkgCache::ReMap()
+{
+ // Apply the typecasts.
+ HeaderP = (Header *)Map.Data();
+ PkgP = (Package *)Map.Data();
+ PkgFileP = (PackageFile *)Map.Data();
+ VerP = (Version *)Map.Data();
+ ProvideP = (Provides *)Map.Data();
+ DepP = (Dependency *)Map.Data();
+ StringItemP = (StringItem *)Map.Data();
+ StrP = (char *)Map.Data();
+
+ cout << "Size is " << Map.Size() << endl;
+ if (Map.Size() == 0)
+ return false;
+
+ // Check the header
+ Header DefHeader;
+ if (HeaderP->Signature != DefHeader.Signature ||
+ HeaderP->Dirty == true)
+ return _error->Error("The package cache file is corrupted");
+
+ if (HeaderP->MajorVersion != DefHeader.MajorVersion ||
+ HeaderP->MinorVersion != DefHeader.MinorVersion ||
+ HeaderP->CheckSizes(DefHeader) == false)
+ return _error->Error("The package cache file is an incompatible version");
+
+ return true;
+}
+ /*}}}*/
+// Cache::Hash - Hash a string /*{{{*/
+// ---------------------------------------------------------------------
+/* 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 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);
+}
+
+unsigned long pkgCache::sHash(const char *Str)
+{
+ 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);
+}
+
+ /*}}}*/
+// Cache::FindPkg - Locate a package by name /*{{{*/
+// ---------------------------------------------------------------------
+/* Returns 0 on error, pointer to the package otherwise */
+pkgCache::PkgIterator pkgCache::FindPkg(string Name)
+{
+ // Look at the hash bucket
+ Package *Pkg = PkgP + HeaderP->HashTable[Hash(Name)];
+ for (; Pkg != PkgP; Pkg = PkgP + Pkg->NextPackage)
+ {
+ if (Pkg->Name != 0 && StrP + Pkg->Name == Name)
+ return PkgIterator(*this,Pkg);
+ }
+ return PkgIterator(*this,0);
+}
+ /*}}}*/
+
+// Cache::PkgIterator - operator ++ - Postfix incr /*{{{*/
+// ---------------------------------------------------------------------
+/* This will advance to the next logical package in the hash table. */
+void pkgCache::PkgIterator::operator ++(int)
+{
+ // Follow the current links
+ if (Pkg != Owner->PkgP)
+ Pkg = Owner->PkgP + Pkg->NextPackage;
+
+ // Follow the hash table
+ while (Pkg == Owner->PkgP && HashIndex < (signed)_count(Owner->HeaderP->HashTable))
+ {
+ HashIndex++;
+ Pkg = Owner->PkgP + Owner->HeaderP->HashTable[HashIndex];
+ }
+};
+ /*}}}*/
+// Bases for iterator classes /*{{{*/
+void pkgCache::VerIterator::_dummy() {}
+void pkgCache::DepIterator::_dummy() {}
+void pkgCache::PrvIterator::_dummy() {}
+ /*}}}*/
+// PkgIterator::State - Check the State of the package /*{{{*/
+// ---------------------------------------------------------------------
+/* By this we mean if it is either cleanly installed or cleanly removed. */
+pkgCache::PkgIterator::OkState pkgCache::PkgIterator::State() const
+{
+ if (Pkg->CurrentState == pkgSTATE_UnPacked ||
+ Pkg->CurrentState == pkgSTATE_HalfConfigured)
+ return NeedsConfigure;
+
+ if (Pkg->CurrentState == pkgSTATE_UnInstalled ||
+ Pkg->CurrentState == pkgSTATE_HalfInstalled ||
+ Pkg->InstState != pkgSTATE_Ok)
+ return NeedsUnpack;
+
+ return NeedsNothing;
+}
+ /*}}}*/
+// DepIterator::IsCritical - Returns true if the dep is important /*{{{*/
+// ---------------------------------------------------------------------
+/* Currently critical deps are defined as depends, predepends and
+ conflicts. */
+bool pkgCache::DepIterator::IsCritical()
+{
+ if (Dep->Type == pkgDEP_Conflicts || Dep->Type == pkgDEP_Depends ||
+ Dep->Type == pkgDEP_PreDepends)
+ return true;
+ return false;
+}
+ /*}}}*/
+// DepIterator::SmartTargetPkg - Resolve dep target pointers w/provides /*{{{*/
+// ---------------------------------------------------------------------
+/* This intellegently looks at dep target packages and tries to figure
+ out which package should be used. This is needed to nicely handle
+ provide mapping. If the target package has no other providing packages
+ then it returned. Otherwise the providing list is looked at to
+ see if there is one one unique providing package if so it is returned.
+ Otherwise true is returned and the target package is set. The return
+ result indicates whether the node should be expandable */
+bool pkgCache::DepIterator::SmartTargetPkg(PkgIterator &Result)
+{
+ Result = TargetPkg();
+
+ // No provides at all
+ if (Result->ProvidesList == 0)
+ return false;
+
+ // There is the Base package and the providing ones which is at least 2
+ if (Result->VersionList != 0)
+ return true;
+
+ /* We have to skip over indirect provisions of the package that
+ owns the dependency. For instance, if libc5-dev depends on the
+ virtual package libc-dev which is provided by libc5-dev and libc6-dev
+ we must ignore libc5-dev when considering the provides list. */
+ PrvIterator PStart = Result.ProvidesList();
+ for (; PStart.end() != true && PStart.OwnerPkg() == ParentPkg(); PStart++);
+
+ // Nothing but indirect self provides
+ if (PStart.end() == true)
+ return false;
+
+ // Check for single packages in the provides list
+ PrvIterator P = PStart;
+ for (; P.end() != true; P++)
+ {
+ // Skip over self provides
+ if (P.OwnerPkg() == ParentPkg())
+ continue;
+ if (PStart.OwnerPkg() != P.OwnerPkg())
+ break;
+ }
+
+ // Check for non dups
+ if (P.end() != true)
+ return true;
+ Result = PStart.OwnerPkg();
+ return false;
+}
+ /*}}}*/
+// DepIterator::AllTargets - Returns the set of all possible targets /*{{{*/
+// ---------------------------------------------------------------------
+/* This is a more usefull version of TargetPkg() that follows versioned
+ provides. It includes every possible package-version that could satisfy
+ the dependency. The last item in the list has a 0. */
+pkgCache::Version **pkgCache::DepIterator::AllTargets()
+{
+ Version **Res = 0;
+ unsigned long Size =0;
+ while (1)
+ {
+ Version **End = Res;
+ PkgIterator DPkg = TargetPkg();
+
+ // Walk along the actual package providing versions
+ for (VerIterator I = DPkg.VersionList(); I.end() == false; I++)
+ {
+ if (pkgCheckDep(TargetVer(),I.VerStr(),Dep->CompareOp) == false)
+ continue;
+
+ if (Dep->Type == pkgDEP_Conflicts && ParentPkg() == I.ParentPkg())
+ continue;
+
+ Size++;
+ if (Res != 0)
+ *End++ = I;
+ }
+
+ // Follow all provides
+ for (PrvIterator I = DPkg.ProvidesList(); I.end() == false; I++)
+ {
+ if (pkgCheckDep(TargetVer(),I.ProvideVersion(),Dep->CompareOp) == false)
+ continue;
+
+ if (Dep->Type == pkgDEP_Conflicts && ParentPkg() == I.OwnerPkg())
+ continue;
+
+ Size++;
+ if (Res != 0)
+ *End++ = I.OwnerVer();
+ }
+
+ // Do it again and write it into the array
+ if (Res == 0)
+ {
+ Res = new Version *[Size+1];
+ Size = 0;
+ }
+ else
+ {
+ *End = 0;
+ break;
+ }
+ }
+
+ return Res;
+}
+ /*}}}*/
+// VerIterator::CompareVer - Fast version compare for same pkgs /*{{{*/
+// ---------------------------------------------------------------------
+/* This just looks over the version list to see if B is listed before A. In
+ most cases this will return in under 4 checks, ver lists are short. */
+int pkgCache::VerIterator::CompareVer(const VerIterator &B) const
+{
+ // Check if they are equal
+ if (*this == B)
+ return 0;
+ if (end() == true)
+ return -1;
+ if (B.end() == true)
+ return 1;
+
+ /* Start at A and look for B. If B is found then A > B otherwise
+ B was before A so A < B */
+ VerIterator I = *this;
+ for (;I.end() == false; I++)
+ if (I == B)
+ return 1;
+ return -1;
+}
+ /*}}}*/
+// PkgFileIterator::IsOk - Checks if the cache is in sync with the file /*{{{*/
+// ---------------------------------------------------------------------
+/* This stats the file and compares its stats with the ones that were
+ stored during generation. Date checks should probably also be
+ included here. */
+bool pkgCache::PkgFileIterator::IsOk()
+{
+ struct stat Buf;
+ if (stat(FileName(),&Buf) != 0)
+ return false;
+
+ if (Buf.st_size != (signed)File->Size || Buf.st_mtime != File->mtime)
+ return false;
+
+ return true;
+}
+ /*}}}*/