Increase the size of the tables used for storing package information

Signed-off-by: Adam D. Barratt <adam@adam-barratt.org.uk>

If the internal tables used in the C module are not large enough to store
the list of discovered packages then checking installability becomes very
slow.

britney.py

@@ -245,6 +245,8 @@ class Britney:
         self.systems = {}
 
         # if requested, build the non-installable status and save it
+        # if this or the population of self.binaries below takes a very
+        # long time, try increasing SIZEOFHASHMAP in lib/dpkg.c and rebuilding
         if not self.options.nuninst_cache:
             self.__log("Building the list of not installable packages for the full archive", type="I")
             self.sources = {'testing': self.read_sources(self.options.testing)}
@@ -270,6 +272,8 @@ class Britney:
             return
 
         # read the source and binary packages for the involved distributions
+        # if this takes a very long time, try increasing SIZEOFHASHMAP in
+        # lib/dpkg.c and rebuilding
         self.sources = {'testing': self.read_sources(self.options.testing),
                         'unstable': self.read_sources(self.options.unstable),
                         'tpu': self.read_sources(self.options.tpu),}

lib/dpkg.c

@@ -7,6 +7,10 @@
 #include "dpkg.h"
 #include "memory.h"
 
+// enlarge this if britney has issues parsing packages
+// (e.g. very slow installability checks)
+#define SIZEOFHASHMAP 16
+
 /* #define DIAGNOSE 1 */
 
 #define insert_packagenamelist(x,y) insert_l_packagenamelist(x,y,__LINE__)
@@ -562,9 +566,9 @@ void free_packages(dpkg_packages *pkgs) {
 }
 
 
-HASH_IMPL(packagetbl, char *, dpkg_collected_package *, 15, strhash, strcmp,
+HASH_IMPL(packagetbl, char *, dpkg_collected_package *, SIZEOFHASHMAP, strhash, strcmp,
 	  KEEP(char*),free_collected_package);
-HASH_IMPL(virtualpkgtbl, char *, virtualpkg *, 15, strhash, strcmp,
+HASH_IMPL(virtualpkgtbl, char *, virtualpkg *, SIZEOFHASHMAP, strhash, strcmp,
 	  KEEP(char*), free_virtualpkg);
 
 /* dpkg_provision refers to memory allocated elsewhere */