[buildstream] 16/17: Implement can_destroy flag in _filebaseddirectory.py

[no...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

not-in-ldap pushed a commit to branch jmac/virtual_directories_test
in repository https://gitbox.apache.org/repos/asf/buildstream.git

commit 2e8748a89bad059abf4fd4b218874ed44cd302a1
Author: Jim MacArthur <ji...@codethink.co.uk>
AuthorDate: Wed May 9 13:00:06 2018 +0100

    Implement can_destroy flag in _filebaseddirectory.py
---
 buildstream/sandbox/Directory.py           |  5 ++++-
 buildstream/sandbox/_filebaseddirectory.py | 13 ++++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/buildstream/sandbox/Directory.py b/buildstream/sandbox/Directory.py
index 0a60fce..f37fb98 100644
--- a/buildstream/sandbox/Directory.py
+++ b/buildstream/sandbox/Directory.py
@@ -80,7 +80,7 @@ class Directory():
 
         raise NotImplementedError()
 
-    def export_files(self, to_directory: str, can_link: bool = False) -> None:
+    def export_files(self, to_directory: str, can_link: bool = False, can_destroy: bool = False) -> None:
         """Copies everything from this into to_directory.
 
         Arguments:
@@ -91,6 +91,9 @@ class Directory():
         can_link (bool): Whether we can create hard links in to_directory
         instead of copying. Setting this does not guarantee hard links will be used.
 
+        can_destroy (bool): Can we destroy the data already in this
+        directory when exporting? If set, this may allow data to be
+        moved rather than copied which will be quicker.
         """
 
         raise NotImplementedError()
diff --git a/buildstream/sandbox/_filebaseddirectory.py b/buildstream/sandbox/_filebaseddirectory.py
index 21a15fb..fd27f8e 100644
--- a/buildstream/sandbox/_filebaseddirectory.py
+++ b/buildstream/sandbox/_filebaseddirectory.py
@@ -188,7 +188,7 @@ class FileBasedDirectory(Directory):
         """
         _set_deterministic_user(self.external_directory)
 
-    def export_files(self, to_directory: str, can_link: bool = False) -> None:
+    def export_files(self, to_directory: str, can_link: bool = False, can_destroy: bool = False) -> None:
         """Copies everything from this into to_directory.
 
         Arguments:
@@ -200,6 +200,17 @@ class FileBasedDirectory(Directory):
         instead of copying.
 
         """
+
+        if can_destroy:
+            # Try a simple rename of the sandbox root; if that
+            # doesnt cut it, then do the regular link files code path
+            try:
+                os.rename(self.external_directory, to_directory)
+                return
+            except OSError:
+                # Proceed using normal link/copy
+                pass
+
         if can_link:
             link_files(self.external_directory, to_directory)
         else: