Adapted library for ALT's apt

apt-pkg-c/lib.cpp

@@ -14,7 +14,11 @@
 
 struct PCache {
     // Owned by us.
+    #ifndef ALT_LINUX
     pkgCacheFile *cache_file;
+    #else
+    CacheFile *cache_file;
+    #endif
 
     // Borrowed from cache_file.
     pkgCache *cache;
@@ -74,9 +78,6 @@ extern "C" {
     void init_config_system();
 
     PCache *pkg_cache_create();
-
-
-
     void pkg_cache_release(PCache *cache);
 
     int32_t pkg_cache_compare_versions(PCache *cache, const char *left, const char *right);
@@ -89,7 +90,6 @@ extern "C" {
     #else
     PPkgIterator *pkg_cache_find_name_arch(PCache *cache, const char *name);
     #endif
-    
     void pkg_iter_release(PPkgIterator *iterator);
 
     // pkg_iter mutation
@@ -98,7 +98,6 @@ extern "C" {
 
     // pkg_iter access
     const char *pkg_iter_name(PPkgIterator *iterator);
-    
     const char *pkg_iter_arch(PPkgIterator *iterator);
     const char *pkg_iter_current_version(PPkgIterator *iterator);
     const char *pkg_iter_candidate_version(PPkgIterator *iterator);
@@ -200,17 +199,37 @@ PCache *pkg_cache_create() {
 }
 
 #else
+const char *to_c_string(std::string s);
+
+#include <unistd.h>
+bool can_commit() {
+    // Allow user with effective SU to acquire lock
+   return geteuid() == 0;
+}
+
+
+// See ALT's apt/cmdline
+// Used to print out the progress 
+// Set to stdout for now
+ostream progress_stream(0);
 
 PCache *pkg_cache_create() {
     // Maybe should be set to false sometimes
-    // (Set to true always for now)
+    // (Set to can_commit() for now)
     // We should lock for installation, etc.
     // For read-only access no locking needed
-    // Ideally locking semantic should be simillar to ALT's apt CLI
-    const bool WithLock = true;
+    // In apt-shell, WithLock is always set according to (geteuid() == 0).
+    const bool WithLock = can_commit();
 
-    pkgCacheFile *cache_file = new pkgCacheFile(WithLock);
-    // there is a cast operator from pkgCacheFile to pkgCache*
+    CacheFile *cache_file = new CacheFile(progress_stream, WithLock);
+    cache_file->Open();
+
+    if (cache_file->CheckDeps(true) == false) {
+        delete cache_file;
+        return nullptr;
+    }
+
+	// cast operator from CacheFile to pkgCache*
     pkgCache *cache = *cache_file;
     pkgRecords *records = new pkgRecords(*cache);
 
@@ -306,28 +325,36 @@ const char *pkg_iter_candidate_version(PPkgIterator *wrapper) {
 
 #else
 
-
-// Creates PVerIterator using PPkgIterator data
-// (implementation taken from pkg_iter_ver_iter())
-PVerIterator create_ver_iter(PPkgIterator *pkg_wrapper) {
-    PVerIterator ver_wrapper;
-    ver_wrapper.iterator = pkg_wrapper->iterator.VersionList();
-    ver_wrapper.pkg = &pkg_wrapper->iterator;
-    ver_wrapper.cache = pkg_wrapper->cache;
-    return ver_wrapper;
-}
-
 const char *pkg_iter_arch(PPkgIterator *wrapper) {
-    pkgCache::VerIterator it = create_ver_iter(wrapper).iterator;
+    pkgCache::VerIterator it = wrapper->iterator.VersionList();
 
     if (it.end()) {
-        return nullptr;
+        // It's a virtual package
+        // Let's take some of providers and take it's arch
+        pkgCache::PrvIterator provide_list = wrapper->iterator.ProvidesList();
+        if (provide_list.end()) {
+            // Return 'something' in case of broken packages
+            // I would prefer returning nullptr,
+            // but Rust-side requires it to be non-null
+            return to_c_string("Undefined");
+        }
+        pkgCache::PkgIterator provide = provide_list.OwnerPkg();
+        if (provide.end()) {
+            return to_c_string("Undefined");
+        }
+
+        PPkgIterator new_wrapper;
+        new_wrapper.iterator = provide;
+        new_wrapper.cache = wrapper->cache;
+
+        return pkg_iter_arch(&new_wrapper);
+    } else {
+        return it.Arch();
     }
-    return it.Arch();
 }
 
 const char *pkg_iter_current_version(PPkgIterator *wrapper) {
-    pkgCache::VerIterator it = create_ver_iter(wrapper).iterator;
+    pkgCache::VerIterator it = wrapper->iterator.CurrentVer();
 
     if (it.end()) {
         return nullptr;
@@ -337,7 +364,7 @@ const char *pkg_iter_current_version(PPkgIterator *wrapper) {
 
 const char *pkg_iter_candidate_version(PPkgIterator *wrapper) {
     // pkgCache::VerIterator it = wrapper->cache->cache_file->GetPolicy(Progress)->GetCandidateVer(wrapper->iterator);
-    // Getting rid of GetPolicy call by creating PkgPolicy object with constructor (no need in OpProgress)
+    // Getting rid of GetPolicy call by creating PkgPolicy object via constructor (no need in OpProgress)
     // (This is done this way in cmdline apt utility (see ALT's apt/cmdline sources))
     pkgPolicy plcy(wrapper->cache->cache);
     pkgCache::VerIterator it = plcy.GetCandidateVer(wrapper->iterator);
@@ -404,7 +431,6 @@ int32_t ver_iter_priority(PVerIterator *wrapper) {
 #endif
 
 #ifdef ALT_LINUX
-const char *to_c_string(std::string s);
 
 const char *ver_iter_source_package(PVerIterator *wrapper) { 
     pkgRecords *recs = wrapper->cache->records;
@@ -415,9 +441,10 @@ const char *ver_iter_source_package(PVerIterator *wrapper) {
     return to_c_string(parse.SourcePkg());
 }
 
+// SHOULD BE REMOVED FROM ALT'S VERSION! MEANINGLESS!
+// Apt only works with rpms and not src.rpm
 const char *ver_iter_source_version(PVerIterator *wrapper) {
-    // TODO: haven't found a way to get source version yet!
-    return to_c_string("Not Specified");
+    return wrapper->iterator.VerStr();
 }
 
 int32_t ver_iter_priority(PVerIterator *wrapper) {
@@ -523,6 +550,9 @@ const char *ver_file_parser_homepage(PVerFileParser *parser) {
   return to_c_string(hp);
 }
 #else
+
+// Should be erased from Alt's version or Alt's Apt should provide
+// functionality for getting homepage address 
 const char *ver_file_parser_homepage(PVerFileParser *parser) {
   // Unimplementable in ALT via PVerFileParser
   // Maybe should remove it in ALT version of lib (or just return nullptr)