_artifactcache/artifactcache.py: Ensure no double-setup of remotes

Since ArtifactCache.setup_remotes() can be expensive and should only
happen once, this commit will assert() if it is called a second time
on an artifact cache instance.

Signed-off-by: Daniel Silverstone <daniel.silverstone@codethink.co.uk>

1 files changed, 5 insertions, 0 deletions

diff --git a/buildstream/_artifactcache/artifactcache.py b/buildstream/_artifactcache/artifactcache.py
index eb7759d83..b5c27a165 100644
--- a/buildstream/_artifactcache/artifactcache.py
+++ b/buildstream/_artifactcache/artifactcache.py
@@ -91,6 +91,7 @@ class ArtifactCache():
         self._cache_size = None               # The current cache size, sometimes it's an estimate
         self._cache_quota = None              # The cache quota
         self._cache_lower_threshold = None    # The target cache size for a cleanup
+        self._remotes_setup = False           # Check to prevent double-setup of remotes
 
         os.makedirs(self.extractdir, exist_ok=True)
         os.makedirs(self.tmpdir, exist_ok=True)
@@ -143,6 +144,10 @@ class ArtifactCache():
     #
     def setup_remotes(self, *, use_config=False, remote_url=None):
 
+        # Ensure we do not double-initialise since this can be expensive
+        assert(not self._remotes_setup)
+        self._remotes_setup = True
+
         # Initialize remote artifact caches. We allow the commandline to override
         # the user config in some cases (for example `bst push --remote=...`).
         has_remote_caches = False