[gnome-ostree] ostbuild: Only keep up to 5 snapshots by default

[Colin Walters <walters src gnome org>]

commit 0193532a1a37fd8fe8e5156c43d415b6b999505a
Author: Colin Walters <walters verbum org>
Date:   Sun Nov 18 14:03:06 2012 -0500

    ostbuild: Only keep up to 5 snapshots by default
    
    There's not a huge reason to keep older versions around, given that
    each build has a resolved snapshot.

 src/ostbuild/pyostbuild/jsondb.py |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/src/ostbuild/pyostbuild/jsondb.py b/src/ostbuild/pyostbuild/jsondb.py
index 3ff2930..e6ca233 100644
--- a/src/ostbuild/pyostbuild/jsondb.py
+++ b/src/ostbuild/pyostbuild/jsondb.py
@@ -26,9 +26,10 @@ import hashlib
 import json
 
 class JsonDB(object):
-    def __init__(self, dirpath, prefix):
+    def __init__(self, dirpath, prefix, max_versions=5):
         self._dirpath = dirpath
         self._prefix = prefix
+        self._max_versions = max_versions
         self._version_csum_re = re.compile(r'-(\d+)\.(\d+)-([0-9a-f]+).json$')
 
     def _cmp_match_by_version(self, a, b):
@@ -128,6 +129,11 @@ class JsonDB(object):
                                             latest_version[1] + 1, digest)
         target_path = os.path.join(self._dirpath, target_name)
         os.rename(tmppath, target_path)
+
+        if (len(files) + 1) > self._max_versions:
+            for f in files[(self._max_versions-1):]:
+                os.unlink(os.path.join(self._dirpath, f[3]))
+
         return (target_path, True)