From c791921951ace5d4f08fab510fb5d55ece69d168 Mon Sep 17 00:00:00 2001
From: Marian Beermann <public@enkore.de>
Date: Tue, 13 Jun 2017 20:03:39 +0200
Subject: [PATCH] fuse: instrument caches

note: signal processing can be arbitrarily delayed;
Python processes signals as soon as the code returns into the interpreter
loop, which doesn't happen unless libfuse returns control, i.e.
some request has been sent to the file system.
---
 src/borg/fuse.py   | 21 +++++++++++++++++++--
 src/borg/remote.py |  8 +++++++-
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/borg/fuse.py b/src/borg/fuse.py
index 4441c4063..b561bbb56 100644
--- a/src/borg/fuse.py
+++ b/src/borg/fuse.py
@@ -2,6 +2,7 @@ import errno
 import io
 import os
 import stat
+import sys
 import tempfile
 import time
 from collections import defaultdict
@@ -16,7 +17,7 @@ from .logger import create_logger
 logger = create_logger()
 
 from .archive import Archive
-from .helpers import daemonize, hardlinkable
+from .helpers import daemonize, hardlinkable, signal_handler, format_file_size
 from .item import Item
 from .lrucache import LRUCache
 
@@ -97,6 +98,20 @@ class FuseOperations(llfuse.Operations):
                     self.contents[1][os.fsencode(name)] = archive_inode
                     self.pending_archives[archive_inode] = archive
 
+    def sig_info_handler(self, sig_no, stack):
+        logger.debug('fuse: %d inodes, %d synth inodes, %d edges (%s)',
+                     self._inode_count, len(self.items), len(self.parent),
+                     # getsizeof is the size of the dict itself; key and value are two small-ish integers,
+                     # which are shared due to code structure (this has been verified).
+                     format_file_size(sys.getsizeof(self.parent) + len(self.parent) * sys.getsizeof(self._inode_count)))
+        logger.debug('fuse: %d pending archives', len(self.pending_archives))
+        logger.debug('fuse: ItemCache %d entries, %s',
+                     self._inode_count - len(self.items),
+                     format_file_size(os.stat(self.cache.fd.fileno()).st_size))
+        logger.debug('fuse: data cache: %d/%d entries, %s', len(self.data_cache.items()), self.data_cache._capacity,
+                     format_file_size(sum(len(chunk) for key, chunk in self.data_cache.items())))
+        self.repository.log_instrumentation()
+
     def mount(self, mountpoint, mount_options, foreground=False):
         """Mount filesystem on *mountpoint* with *mount_options*."""
         options = ['fsname=borgfs', 'ro']
@@ -124,7 +139,9 @@ class FuseOperations(llfuse.Operations):
         # mirror.
         umount = False
         try:
-            signal = fuse_main()
+            with signal_handler('SIGUSR1', self.sig_info_handler), \
+                 signal_handler('SIGINFO', self.sig_info_handler):
+                signal = fuse_main()
             # no crash and no signal (or it's ^C and we're in the foreground) -> umount request
             umount = (signal is None or (signal == SIGINT and foreground))
         finally:
diff --git a/src/borg/remote.py b/src/borg/remote.py
index a961384f0..670179a44 100644
--- a/src/borg/remote.py
+++ b/src/borg/remote.py
@@ -1088,6 +1088,9 @@ class RepositoryNoCache:
         for key, data in zip(keys, self.repository.get_many(keys)):
             yield self.transform(key, data)
 
+    def log_instrumentation(self):
+        pass
+
 
 class RepositoryCache(RepositoryNoCache):
     """
@@ -1161,12 +1164,15 @@ class RepositoryCache(RepositoryNoCache):
                 self.backoff()
         return transformed
 
-    def close(self):
+    def log_instrumentation(self):
         logger.debug('RepositoryCache: current items %d, size %s / %s, %d hits, %d misses, %d slow misses (+%.1fs), '
                      '%d evictions, %d ENOSPC hit',
                      len(self.cache), format_file_size(self.size), format_file_size(self.size_limit),
                      self.hits, self.misses, self.slow_misses, self.slow_lat,
                      self.evictions, self.enospc)
+
+    def close(self):
+        self.log_instrumentation()
         self.cache.clear()
         shutil.rmtree(self.basedir)