Merge branch 'juerg/cache-usage' into 'master'

Display cache usage in status bar

See merge request BuildStream/buildstream!1564

5 files changed, 274 insertions, 6 deletions

diff --git a/src/buildstream/_cas/cascache.py b/src/buildstream/_cas/cascache.py
index 21c9f0ad6..b4bba2b6d 100644
--- a/src/buildstream/_cas/cascache.py
+++ b/src/buildstream/_cas/cascache.py
@@ -22,7 +22,9 @@ import os
 import stat
 import errno
 import contextlib
+import multiprocessing
 import shutil
+import signal
 import subprocess
 import tempfile
 import time
@@ -42,7 +44,8 @@ from .casremote import BlobNotFound, _CASBatchRead, _CASBatchUpdate
 _BUFFER_SIZE = 65536
 
 
-CACHE_SIZE_FILE = "cache_size"
+# Refresh interval for disk usage of local cache in seconds
+_CACHE_USAGE_REFRESH = 5
 
 
 # A CASCache manages a CAS repository as specified in the Remote Execution API.
@@ -86,6 +89,7 @@ class CASCache():
 
         self._casd_channel = None
         self._local_cas = None
+        self._cache_usage_monitor = None
 
     def __getstate__(self):
         state = self.__dict__.copy()
@@ -145,6 +149,9 @@ class CASCache():
     # Release resources used by CASCache.
     #
     def release_resources(self, messenger=None):
+        if self._cache_usage_monitor:
+            self._cache_usage_monitor.release_resources()
+
         if self._casd_process:
             if self._casd_channel:
                 self._local_cas = None
@@ -960,6 +967,114 @@ class CASCache():
         # Upload any blobs missing on the server
         self.send_blobs(remote, missing_blobs)
 
+    # get_cache_usage():
+    #
+    # Fetches the current usage of the CAS local cache.
+    #
+    # Returns:
+    #     (CASCacheUsage): The current status
+    #
+    def get_cache_usage(self):
+        if not self._cache_usage_monitor:
+            self._cache_usage_monitor = _CASCacheUsageMonitor(self)
+
+        return self._cache_usage_monitor.get_cache_usage()
+
+
+# _CASCacheUsage
+#
+# A simple object to report the current CAS cache usage details.
+#
+# Args:
+#    used_size (int): Total size used by the local cache, in bytes.
+#    quota_size (int): Disk quota for the local cache, in bytes.
+#
+class _CASCacheUsage():
+
+    def __init__(self, used_size, quota_size):
+        self.used_size = used_size
+        self.quota_size = quota_size
+        if self.quota_size is None:
+            self.used_percent = 0
+        else:
+            self.used_percent = int(self.used_size * 100 / self.quota_size)
+
+    # Formattable into a human readable string
+    #
+    def __str__(self):
+        if self.used_size is None:
+            return "unknown"
+        elif self.quota_size is None:
+            return utils._pretty_size(self.used_size, dec_places=1)
+        else:
+            return "{} / {} ({}%)" \
+                .format(utils._pretty_size(self.used_size, dec_places=1),
+                        utils._pretty_size(self.quota_size, dec_places=1),
+                        self.used_percent)
+
+
+# _CASCacheUsageMonitor
+#
+# This manages the subprocess that tracks cache usage information via
+# buildbox-casd.
+#
+class _CASCacheUsageMonitor:
+    def __init__(self, cas):
+        self.cas = cas
+
+        # Shared memory (64-bit signed integer) for current disk usage and quota
+        self._disk_usage = multiprocessing.Value('q', -1)
+        self._disk_quota = multiprocessing.Value('q', -1)
+
+        # multiprocessing.Process will fork without exec on Unix.
+        # This can't be allowed with background threads or open gRPC channels.
+        assert utils._is_single_threaded() and not cas.has_open_grpc_channels()
+
+        self._subprocess = multiprocessing.Process(target=self._subprocess_run)
+        self._subprocess.start()
+
+    def get_cache_usage(self):
+        disk_usage = self._disk_usage.value
+        disk_quota = self._disk_quota.value
+
+        if disk_usage < 0:
+            # Disk usage still unknown
+            disk_usage = None
+
+        if disk_quota <= 0:
+            # No disk quota
+            disk_quota = None
+
+        return _CASCacheUsage(disk_usage, disk_quota)
+
+    def release_resources(self):
+        # Simply terminate the subprocess, no cleanup required in the subprocess
+        self._subprocess.terminate()
+
+    def _subprocess_run(self):
+        # Reset SIGTERM in subprocess to default as no cleanup is necessary
+        signal.signal(signal.SIGTERM, signal.SIG_DFL)
+
+        disk_usage = self._disk_usage
+        disk_quota = self._disk_quota
+        local_cas = self.cas._get_local_cas()
+
+        while True:
+            try:
+                # Ask buildbox-casd for current value
+                request = local_cas_pb2.GetLocalDiskUsageRequest()
+                response = local_cas.GetLocalDiskUsage(request)
+
+                # Update values in shared memory
+                disk_usage.value = response.size_bytes
+                disk_quota.value = response.quota_bytes
+            except grpc.RpcError:
+                # Terminate loop when buildbox-casd becomes unavailable
+                break
+
+            # Sleep until next refresh
+            time.sleep(_CACHE_USAGE_REFRESH)
+
 
 def _grouper(iterable, n):
     while True:
diff --git a/src/buildstream/_frontend/status.py b/src/buildstream/_frontend/status.py
index d0070cef0..a68d0d04e 100644
--- a/src/buildstream/_frontend/status.py
+++ b/src/buildstream/_frontend/status.py
@@ -350,7 +350,7 @@ class _StatusHeader():
         #
         # Public members
         #
-        self.lines = 2
+        self.lines = 3
 
         #
         # Private members
@@ -413,7 +413,38 @@ class _StatusHeader():
 
         line2 = self._centered(text, size, line_length, ' ')
 
-        return line1 + '\n' + line2
+        #
+        # Line 3: Cache usage percentage report
+        #
+        #  ~~~~~~ cache: 44.2G / 64G (69%) ~~~~~~
+        #
+        cas = self._context.get_cascache()
+        usage = cas.get_cache_usage()
+        usage_string = str(usage)
+
+        if usage.used_size is None:
+            # Cache usage is unknown
+            size = 0
+            text = ''
+        else:
+            size = 21
+            size += len(usage_string)
+            if usage.used_percent >= 95:
+                formatted_usage = self._error_profile.fmt(usage_string)
+            elif usage.used_percent >= 80:
+                formatted_usage = self._content_profile.fmt(usage_string)
+            else:
+                formatted_usage = self._success_profile.fmt(usage_string)
+
+            text = self._format_profile.fmt("~~~~~~ ") + \
+                self._content_profile.fmt('cache') + \
+                self._format_profile.fmt(': ') + \
+                formatted_usage + \
+                self._format_profile.fmt(' ~~~~~~')
+
+        line3 = self._centered(text, size, line_length, ' ')
+
+        return line1 + '\n' + line2 + '\n' + line3
 
     ###################################################
     #                 Private Methods                 #
diff --git a/src/buildstream/_protos/build/buildgrid/local_cas.proto b/src/buildstream/_protos/build/buildgrid/local_cas.proto
index 671caef0e..f2955f971 100644
--- a/src/buildstream/_protos/build/buildgrid/local_cas.proto
+++ b/src/buildstream/_protos/build/buildgrid/local_cas.proto
@@ -117,6 +117,9 @@ service LocalContentAddressableStorage {
   // This returns a string that can be used as instance_name to access the
   // specified endpoint in further requests.
   rpc GetInstanceNameForRemote(GetInstanceNameForRemoteRequest) returns (GetInstanceNameForRemoteResponse) {}
+
+  // Query total space used by the local cache.
+  rpc GetLocalDiskUsage(GetLocalDiskUsageRequest) returns (GetLocalDiskUsageResponse) {}
 }
 
 // A request message for
@@ -371,3 +374,18 @@ message GetInstanceNameForRemoteRequest {
 message GetInstanceNameForRemoteResponse {
   string instance_name = 1;
 }
+
+// A request message for
+// [LocalContentAddressableStorage.GetLocalDiskUsage][build.buildgrid.v2.LocalContentAddressableStorage.GetLocalDiskUsage].
+message GetLocalDiskUsageRequest {
+}
+
+// A response message for
+// [LocalContentAddressableStorage.GetLocalDiskUsage][build.buildgrid.v2.LocalContentAddressableStorage.GetLocalDiskUsage].
+message GetLocalDiskUsageResponse {
+  // Total size used by the local cache, in bytes.
+  int64 size_bytes = 1;
+
+  // Disk quota for the local cache, in bytes. A value of 0 means no quota is set.
+  int64 quota_bytes = 2;
+}
diff --git a/src/buildstream/_protos/build/buildgrid/local_cas_pb2.py b/src/buildstream/_protos/build/buildgrid/local_cas_pb2.py
index d1ef586f8..06df1385c 100644
--- a/src/buildstream/_protos/build/buildgrid/local_cas_pb2.py
+++ b/src/buildstream/_protos/build/buildgrid/local_cas_pb2.py
@@ -23,7 +23,7 @@ DESCRIPTOR = _descriptor.FileDescriptor(
   package='build.buildgrid',
   syntax='proto3',
   serialized_options=None,
-  serialized_pb=_b('\n\x1f\x62uild/buildgrid/local_cas.proto\x12\x0f\x62uild.buildgrid\x1a\x36\x62uild/bazel/remote/execution/v2/remote_execution.proto\x1a\x1cgoogle/api/annotations.proto\x1a\x17google/rpc/status.proto\"p\n\x18\x46\x65tchMissingBlobsRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12=\n\x0c\x62lob_digests\x18\x02 \x03(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\"\xcc\x01\n\x19\x46\x65tchMissingBlobsResponse\x12\x46\n\tresponses\x18\x01 \x03(\x0b\x32\x33.build.buildgrid.FetchMissingBlobsResponse.Response\x1ag\n\x08Response\x12\x37\n\x06\x64igest\x18\x01 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x02 \x01(\x0b\x32\x12.google.rpc.Status\"q\n\x19UploadMissingBlobsRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12=\n\x0c\x62lob_digests\x18\x02 \x03(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\"\xce\x01\n\x1aUploadMissingBlobsResponse\x12G\n\tresponses\x18\x01 \x03(\x0b\x32\x34.build.buildgrid.UploadMissingBlobsResponse.Response\x1ag\n\x08Response\x12\x37\n\x06\x64igest\x18\x01 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x02 \x01(\x0b\x32\x12.google.rpc.Status\"\x81\x01\n\x10\x46\x65tchTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12<\n\x0broot_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\x18\n\x10\x66\x65tch_file_blobs\x18\x03 \x01(\x08\"\x13\n\x11\x46\x65tchTreeResponse\"h\n\x11UploadTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12<\n\x0broot_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\"\x14\n\x12UploadTreeResponse\"u\n\x10StageTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12<\n\x0broot_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\x0c\n\x04path\x18\x03 \x01(\t\"!\n\x11StageTreeResponse\x12\x0c\n\x04path\x18\x01 \x01(\t\"U\n\x12\x43\x61ptureTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12\x0c\n\x04path\x18\x02 \x03(\t\x12\x1a\n\x12\x62ypass_local_cache\x18\x03 \x01(\x08\"\xd3\x01\n\x13\x43\x61ptureTreeResponse\x12@\n\tresponses\x18\x01 \x03(\x0b\x32-.build.buildgrid.CaptureTreeResponse.Response\x1az\n\x08Response\x12\x0c\n\x04path\x18\x01 \x01(\t\x12<\n\x0btree_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x03 \x01(\x0b\x32\x12.google.rpc.Status\"V\n\x13\x43\x61ptureFilesRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12\x0c\n\x04path\x18\x02 \x03(\t\x12\x1a\n\x12\x62ypass_local_cache\x18\x03 \x01(\x08\"\xd0\x01\n\x14\x43\x61ptureFilesResponse\x12\x41\n\tresponses\x18\x01 \x03(\x0b\x32..build.buildgrid.CaptureFilesResponse.Response\x1au\n\x08Response\x12\x0c\n\x04path\x18\x01 \x01(\t\x12\x37\n\x06\x64igest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x03 \x01(\x0b\x32\x12.google.rpc.Status\"\x83\x01\n\x1fGetInstanceNameForRemoteRequest\x12\x0b\n\x03url\x18\x01 \x01(\t\x12\x15\n\rinstance_name\x18\x02 \x01(\t\x12\x13\n\x0bserver_cert\x18\x03 \x01(\x0c\x12\x12\n\nclient_key\x18\x04 \x01(\x0c\x12\x13\n\x0b\x63lient_cert\x18\x05 \x01(\x0c\"9\n GetInstanceNameForRemoteResponse\x12\x15\n\rinstance_name\x18\x01 \x01(\t2\xc7\x06\n\x1eLocalContentAddressableStorage\x12l\n\x11\x46\x65tchMissingBlobs\x12).build.buildgrid.FetchMissingBlobsRequest\x1a*.build.buildgrid.FetchMissingBlobsResponse\"\x00\x12o\n\x12UploadMissingBlobs\x12*.build.buildgrid.UploadMissingBlobsRequest\x1a+.build.buildgrid.UploadMissingBlobsResponse\"\x00\x12T\n\tFetchTree\x12!.build.buildgrid.FetchTreeRequest\x1a\".build.buildgrid.FetchTreeResponse\"\x00\x12W\n\nUploadTree\x12\".build.buildgrid.UploadTreeRequest\x1a#.build.buildgrid.UploadTreeResponse\"\x00\x12X\n\tStageTree\x12!.build.buildgrid.StageTreeRequest\x1a\".build.buildgrid.StageTreeResponse\"\x00(\x01\x30\x01\x12Z\n\x0b\x43\x61ptureTree\x12#.build.buildgrid.CaptureTreeRequest\x1a$.build.buildgrid.CaptureTreeResponse\"\x00\x12]\n\x0c\x43\x61ptureFiles\x12$.build.buildgrid.CaptureFilesRequest\x1a%.build.buildgrid.CaptureFilesResponse\"\x00\x12\x81\x01\n\x18GetInstanceNameForRemote\x12\x30.build.buildgrid.GetInstanceNameForRemoteRequest\x1a\x31.build.buildgrid.GetInstanceNameForRemoteResponse\"\x00\x62\x06proto3')
+  serialized_pb=_b('\n\x1f\x62uild/buildgrid/local_cas.proto\x12\x0f\x62uild.buildgrid\x1a\x36\x62uild/bazel/remote/execution/v2/remote_execution.proto\x1a\x1cgoogle/api/annotations.proto\x1a\x17google/rpc/status.proto\"p\n\x18\x46\x65tchMissingBlobsRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12=\n\x0c\x62lob_digests\x18\x02 \x03(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\"\xcc\x01\n\x19\x46\x65tchMissingBlobsResponse\x12\x46\n\tresponses\x18\x01 \x03(\x0b\x32\x33.build.buildgrid.FetchMissingBlobsResponse.Response\x1ag\n\x08Response\x12\x37\n\x06\x64igest\x18\x01 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x02 \x01(\x0b\x32\x12.google.rpc.Status\"q\n\x19UploadMissingBlobsRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12=\n\x0c\x62lob_digests\x18\x02 \x03(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\"\xce\x01\n\x1aUploadMissingBlobsResponse\x12G\n\tresponses\x18\x01 \x03(\x0b\x32\x34.build.buildgrid.UploadMissingBlobsResponse.Response\x1ag\n\x08Response\x12\x37\n\x06\x64igest\x18\x01 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x02 \x01(\x0b\x32\x12.google.rpc.Status\"\x81\x01\n\x10\x46\x65tchTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12<\n\x0broot_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\x18\n\x10\x66\x65tch_file_blobs\x18\x03 \x01(\x08\"\x13\n\x11\x46\x65tchTreeResponse\"h\n\x11UploadTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12<\n\x0broot_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\"\x14\n\x12UploadTreeResponse\"u\n\x10StageTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12<\n\x0broot_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\x0c\n\x04path\x18\x03 \x01(\t\"!\n\x11StageTreeResponse\x12\x0c\n\x04path\x18\x01 \x01(\t\"U\n\x12\x43\x61ptureTreeRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12\x0c\n\x04path\x18\x02 \x03(\t\x12\x1a\n\x12\x62ypass_local_cache\x18\x03 \x01(\x08\"\xd3\x01\n\x13\x43\x61ptureTreeResponse\x12@\n\tresponses\x18\x01 \x03(\x0b\x32-.build.buildgrid.CaptureTreeResponse.Response\x1az\n\x08Response\x12\x0c\n\x04path\x18\x01 \x01(\t\x12<\n\x0btree_digest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x03 \x01(\x0b\x32\x12.google.rpc.Status\"V\n\x13\x43\x61ptureFilesRequest\x12\x15\n\rinstance_name\x18\x01 \x01(\t\x12\x0c\n\x04path\x18\x02 \x03(\t\x12\x1a\n\x12\x62ypass_local_cache\x18\x03 \x01(\x08\"\xd0\x01\n\x14\x43\x61ptureFilesResponse\x12\x41\n\tresponses\x18\x01 \x03(\x0b\x32..build.buildgrid.CaptureFilesResponse.Response\x1au\n\x08Response\x12\x0c\n\x04path\x18\x01 \x01(\t\x12\x37\n\x06\x64igest\x18\x02 \x01(\x0b\x32\'.build.bazel.remote.execution.v2.Digest\x12\"\n\x06status\x18\x03 \x01(\x0b\x32\x12.google.rpc.Status\"\x83\x01\n\x1fGetInstanceNameForRemoteRequest\x12\x0b\n\x03url\x18\x01 \x01(\t\x12\x15\n\rinstance_name\x18\x02 \x01(\t\x12\x13\n\x0bserver_cert\x18\x03 \x01(\x0c\x12\x12\n\nclient_key\x18\x04 \x01(\x0c\x12\x13\n\x0b\x63lient_cert\x18\x05 \x01(\x0c\"9\n GetInstanceNameForRemoteResponse\x12\x15\n\rinstance_name\x18\x01 \x01(\t\"\x1a\n\x18GetLocalDiskUsageRequest\"D\n\x19GetLocalDiskUsageResponse\x12\x12\n\nsize_bytes\x18\x01 \x01(\x03\x12\x13\n\x0bquota_bytes\x18\x02 \x01(\x03\x32\xb5\x07\n\x1eLocalContentAddressableStorage\x12l\n\x11\x46\x65tchMissingBlobs\x12).build.buildgrid.FetchMissingBlobsRequest\x1a*.build.buildgrid.FetchMissingBlobsResponse\"\x00\x12o\n\x12UploadMissingBlobs\x12*.build.buildgrid.UploadMissingBlobsRequest\x1a+.build.buildgrid.UploadMissingBlobsResponse\"\x00\x12T\n\tFetchTree\x12!.build.buildgrid.FetchTreeRequest\x1a\".build.buildgrid.FetchTreeResponse\"\x00\x12W\n\nUploadTree\x12\".build.buildgrid.UploadTreeRequest\x1a#.build.buildgrid.UploadTreeResponse\"\x00\x12X\n\tStageTree\x12!.build.buildgrid.StageTreeRequest\x1a\".build.buildgrid.StageTreeResponse\"\x00(\x01\x30\x01\x12Z\n\x0b\x43\x61ptureTree\x12#.build.buildgrid.CaptureTreeRequest\x1a$.build.buildgrid.CaptureTreeResponse\"\x00\x12]\n\x0c\x43\x61ptureFiles\x12$.build.buildgrid.CaptureFilesRequest\x1a%.build.buildgrid.CaptureFilesResponse\"\x00\x12\x81\x01\n\x18GetInstanceNameForRemote\x12\x30.build.buildgrid.GetInstanceNameForRemoteRequest\x1a\x31.build.buildgrid.GetInstanceNameForRemoteResponse\"\x00\x12l\n\x11GetLocalDiskUsage\x12).build.buildgrid.GetLocalDiskUsageRequest\x1a*.build.buildgrid.GetLocalDiskUsageResponse\"\x00\x62\x06proto3')
   ,
   dependencies=[build_dot_bazel_dot_remote_dot_execution_dot_v2_dot_remote__execution__pb2.DESCRIPTOR,google_dot_api_dot_annotations__pb2.DESCRIPTOR,google_dot_rpc_dot_status__pb2.DESCRIPTOR,])
 
@@ -778,6 +778,68 @@ _GETINSTANCENAMEFORREMOTERESPONSE = _descriptor.Descriptor(
   serialized_end=2034,
 )
 
+
+_GETLOCALDISKUSAGEREQUEST = _descriptor.Descriptor(
+  name='GetLocalDiskUsageRequest',
+  full_name='build.buildgrid.GetLocalDiskUsageRequest',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  serialized_options=None,
+  is_extendable=False,
+  syntax='proto3',
+  extension_ranges=[],
+  oneofs=[
+  ],
+  serialized_start=2036,
+  serialized_end=2062,
+)
+
+
+_GETLOCALDISKUSAGERESPONSE = _descriptor.Descriptor(
+  name='GetLocalDiskUsageResponse',
+  full_name='build.buildgrid.GetLocalDiskUsageResponse',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    _descriptor.FieldDescriptor(
+      name='size_bytes', full_name='build.buildgrid.GetLocalDiskUsageResponse.size_bytes', index=0,
+      number=1, type=3, cpp_type=2, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='quota_bytes', full_name='build.buildgrid.GetLocalDiskUsageResponse.quota_bytes', index=1,
+      number=2, type=3, cpp_type=2, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  serialized_options=None,
+  is_extendable=False,
+  syntax='proto3',
+  extension_ranges=[],
+  oneofs=[
+  ],
+  serialized_start=2064,
+  serialized_end=2132,
+)
+
 _FETCHMISSINGBLOBSREQUEST.fields_by_name['blob_digests'].message_type = build_dot_bazel_dot_remote_dot_execution_dot_v2_dot_remote__execution__pb2._DIGEST
 _FETCHMISSINGBLOBSRESPONSE_RESPONSE.fields_by_name['digest'].message_type = build_dot_bazel_dot_remote_dot_execution_dot_v2_dot_remote__execution__pb2._DIGEST
 _FETCHMISSINGBLOBSRESPONSE_RESPONSE.fields_by_name['status'].message_type = google_dot_rpc_dot_status__pb2._STATUS
@@ -815,6 +877,8 @@ DESCRIPTOR.message_types_by_name['CaptureFilesRequest'] = _CAPTUREFILESREQUEST
 DESCRIPTOR.message_types_by_name['CaptureFilesResponse'] = _CAPTUREFILESRESPONSE
 DESCRIPTOR.message_types_by_name['GetInstanceNameForRemoteRequest'] = _GETINSTANCENAMEFORREMOTEREQUEST
 DESCRIPTOR.message_types_by_name['GetInstanceNameForRemoteResponse'] = _GETINSTANCENAMEFORREMOTERESPONSE
+DESCRIPTOR.message_types_by_name['GetLocalDiskUsageRequest'] = _GETLOCALDISKUSAGEREQUEST
+DESCRIPTOR.message_types_by_name['GetLocalDiskUsageResponse'] = _GETLOCALDISKUSAGERESPONSE
 _sym_db.RegisterFileDescriptor(DESCRIPTOR)
 
 FetchMissingBlobsRequest = _reflection.GeneratedProtocolMessageType('FetchMissingBlobsRequest', (_message.Message,), dict(
@@ -961,6 +1025,20 @@ GetInstanceNameForRemoteResponse = _reflection.GeneratedProtocolMessageType('Get
   ))
 _sym_db.RegisterMessage(GetInstanceNameForRemoteResponse)
 
+GetLocalDiskUsageRequest = _reflection.GeneratedProtocolMessageType('GetLocalDiskUsageRequest', (_message.Message,), dict(
+  DESCRIPTOR = _GETLOCALDISKUSAGEREQUEST,
+  __module__ = 'build.buildgrid.local_cas_pb2'
+  # @@protoc_insertion_point(class_scope:build.buildgrid.GetLocalDiskUsageRequest)
+  ))
+_sym_db.RegisterMessage(GetLocalDiskUsageRequest)
+
+GetLocalDiskUsageResponse = _reflection.GeneratedProtocolMessageType('GetLocalDiskUsageResponse', (_message.Message,), dict(
+  DESCRIPTOR = _GETLOCALDISKUSAGERESPONSE,
+  __module__ = 'build.buildgrid.local_cas_pb2'
+  # @@protoc_insertion_point(class_scope:build.buildgrid.GetLocalDiskUsageResponse)
+  ))
+_sym_db.RegisterMessage(GetLocalDiskUsageResponse)
+
 
 
 _LOCALCONTENTADDRESSABLESTORAGE = _descriptor.ServiceDescriptor(
@@ -969,8 +1047,8 @@ _LOCALCONTENTADDRESSABLESTORAGE = _descriptor.ServiceDescriptor(
   file=DESCRIPTOR,
   index=0,
   serialized_options=None,
-  serialized_start=2037,
-  serialized_end=2876,
+  serialized_start=2135,
+  serialized_end=3084,
   methods=[
   _descriptor.MethodDescriptor(
     name='FetchMissingBlobs',
@@ -1044,6 +1122,15 @@ _LOCALCONTENTADDRESSABLESTORAGE = _descriptor.ServiceDescriptor(
     output_type=_GETINSTANCENAMEFORREMOTERESPONSE,
     serialized_options=None,
   ),
+  _descriptor.MethodDescriptor(
+    name='GetLocalDiskUsage',
+    full_name='build.buildgrid.LocalContentAddressableStorage.GetLocalDiskUsage',
+    index=8,
+    containing_service=None,
+    input_type=_GETLOCALDISKUSAGEREQUEST,
+    output_type=_GETLOCALDISKUSAGERESPONSE,
+    serialized_options=None,
+  ),
 ])
 _sym_db.RegisterServiceDescriptor(_LOCALCONTENTADDRESSABLESTORAGE)
 
diff --git a/src/buildstream/_protos/build/buildgrid/local_cas_pb2_grpc.py b/src/buildstream/_protos/build/buildgrid/local_cas_pb2_grpc.py
index 7ea06a3a7..8dfaec7f3 100644
--- a/src/buildstream/_protos/build/buildgrid/local_cas_pb2_grpc.py
+++ b/src/buildstream/_protos/build/buildgrid/local_cas_pb2_grpc.py
@@ -54,6 +54,11 @@ class LocalContentAddressableStorageStub(object):
         request_serializer=build_dot_buildgrid_dot_local__cas__pb2.GetInstanceNameForRemoteRequest.SerializeToString,
         response_deserializer=build_dot_buildgrid_dot_local__cas__pb2.GetInstanceNameForRemoteResponse.FromString,
         )
+    self.GetLocalDiskUsage = channel.unary_unary(
+        '/build.buildgrid.LocalContentAddressableStorage/GetLocalDiskUsage',
+        request_serializer=build_dot_buildgrid_dot_local__cas__pb2.GetLocalDiskUsageRequest.SerializeToString,
+        response_deserializer=build_dot_buildgrid_dot_local__cas__pb2.GetLocalDiskUsageResponse.FromString,
+        )
 
 
 class LocalContentAddressableStorageServicer(object):
@@ -189,6 +194,13 @@ class LocalContentAddressableStorageServicer(object):
     context.set_details('Method not implemented!')
     raise NotImplementedError('Method not implemented!')
 
+  def GetLocalDiskUsage(self, request, context):
+    """Query total space used by the local cache.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
 
 def add_LocalContentAddressableStorageServicer_to_server(servicer, server):
   rpc_method_handlers = {
@@ -232,6 +244,11 @@ def add_LocalContentAddressableStorageServicer_to_server(servicer, server):
           request_deserializer=build_dot_buildgrid_dot_local__cas__pb2.GetInstanceNameForRemoteRequest.FromString,
           response_serializer=build_dot_buildgrid_dot_local__cas__pb2.GetInstanceNameForRemoteResponse.SerializeToString,
       ),
+      'GetLocalDiskUsage': grpc.unary_unary_rpc_method_handler(
+          servicer.GetLocalDiskUsage,
+          request_deserializer=build_dot_buildgrid_dot_local__cas__pb2.GetLocalDiskUsageRequest.FromString,
+          response_serializer=build_dot_buildgrid_dot_local__cas__pb2.GetLocalDiskUsageResponse.SerializeToString,
+      ),
   }
   generic_handler = grpc.method_handlers_generic_handler(
       'build.buildgrid.LocalContentAddressableStorage', rpc_method_handlers)