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Diffstat (limited to '')
| -rw-r--r-- | doc/libapt-pkg2_to_3.txt | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/doc/libapt-pkg2_to_3.txt b/doc/libapt-pkg2_to_3.txt new file mode 100644 index 0000000..6beaafb --- /dev/null +++ b/doc/libapt-pkg2_to_3.txt @@ -0,0 +1,90 @@ +libapt-pkg v2 to v3 incorporates several source-incompatible changes +that people need to be aware of.. Many of these changes are done so that +most old source will continue to function, but perhaps at reduced +functionality. + +* pkgDepCache is no longer self initializing, you have to call the Init + method separately after constructing it. Users of pkgCacheFile do not + need to worry about this +* GetCandidateVer/etc is gone from the pkgCache. It exists only in the + DepCache and is just an inline around the new Policy class +* TargetVer/TargetDist have been eliminated. Nothing should have been using + these. +* There is a policy class. The v0 policy engine which has been used since + APT 0.0.0 is instantiated by the DepCache by default. However pkgCacheFile + constructs and initializes the new v4 engine. People accessing GetCandidate + version outside of a CacheFile/DepCache will need to instantiate and + initialize a policy engine on their own. +* All byte counters are now doubles to advoid 4G wraparound. The compiler + should generate warnings on any incorrect use of these. +* The PriorityType/CompType/DepType functions have been moved out of the + iterators and into generate static functions of pkgCache - inline stubs + are left in the iterators. +* The deb dependency element parser has been made into a static function + of the list parser and enhanced to optionally understand architecture + restrictions. +* TagSections no longer include the trailing \n. This means that the + Offset/Length of a package record in the version structure also does not + include the trailing \n. +* GenCaches::SelectFile accepts a site parameter now too. +* Global version compare functions are gone. If you + #define APT_COMPATIBILITY 1 + They will come back as they were before. Code should be updated to + reference the compare functions to the VersioningSystem (VS) referenced + by the Cache or _system structures. +* Initialization is now two stage (define APT_COMPATIBILITY..) The first + stage, pkgInitConfig is called before commandline parsing, and + pkgInitSystem is called after. This gives the user the opportunity to + override default settings from the config files before startup has been + finalized. +* pkgSourceList has been gutted. All the junk that was in there before is + cleaned up and put in the pkgIndexFile class. There is very little API + correspondence here.. +* pkgMakeStatusCacheMem is gone, pkgMakeStatusCache does the same thing if + you set the AllowMem flag. Also, you can get a copy of the map used to + store the cache to advoid having to remap it in the calling code. A bunch + of other cache related functions are gone, but nobody should have been using + them in the first place! +* Downloading the 'Package' and 'Source' index files is different, use + the GetIndexes call in SourceList. +* SourceRecords::Parser::Source is gone, replaced with Index which does + much the same thing. +* DynamicMap has changed slightly, nobody should care +* pkgMakeOnlyStatusCache exists, which creates a really small cache that + only contains the status file, and in memory. +* The pkgRecords stuff is changed to abstract through the index file list + (should be transparent largely) +* Locking is handled differently, there is no dpkg lock class, the _system + class provides Lock/UnLock methods +* pkgDepCache is not a subclass of pkgCache, it aggregates it now. Some + compatibility functions are provided that make this transition fairly + easy. +* The following functions have had minor argument changes: + - pkgSimulate(pkgDepCache &Cache); + + pkgSimulate(pkgDepCache *Cache); + + - pkgProblemResolver(pkgDepCache &Cache); + + pkgProblemResolver(pkgDepCache *Cache); + + - pkgDepCache(MMap &Map,Policy *Plcy = 0); + + pkgDepCache(pkgCache *Cache,Policy *Plcy = 0); + + - pkgOrderList(pkgDepCache &Cache); + + pkgOrderList(pkgDepCache *Cache); + + - pkgPackageManager(pkgDepCache &Cache); + + pkgPackageManager(pkgDepCache *Cache); + + - pkgCache(MMap &Map,bool DoMap = true); + + pkgCache(MMap *Map,bool DoMap = true); + + - pkgCacheGenerator(DynamicMMap &Map,OpProgress &Progress); + + pkgCacheGenerator(DynamicMMap *Map,OpProgress *Progress); + + - pkgTagFile(FileFd &F,unsigned long Size = 32*1024); + + pkgTagFile(FileFd *F,unsigned long Size = 32*1024); + +* Configuration class is const-correct +* The legacy ability to create a PkgFileIterator that started at Begin + is gone, everyone should be using FileBegin(). +* A new dependency relation called obsoletes that is similar to conflicts. |