sstate/path.py: Add copyhardlinktree() function and use for performance optimisation

Add a function which copys a tree as a set of hardlinks to the original
files, then use this in sstate to reduce some of the overhead of sstate
package creation since the file isn't actually copied.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 10 insertions, 2 deletions

diff --git a/meta/classes/sstate.bbclass b/meta/classes/sstate.bbclass
index a79d2b557e..6f77bb9013 100644
--- a/meta/classes/sstate.bbclass
+++ b/meta/classes/sstate.bbclass
@@ -458,14 +458,14 @@ def sstate_package(ss, d):
                 dstpath = srcpath.replace(state[1], sstatebuild + state[0])
                 make_relative_symlink(srcpath, dstpath, d)
         bb.debug(2, "Preparing tree %s for packaging at %s" % (state[1], sstatebuild + state[0]))
-        oe.path.copytree(state[1], sstatebuild + state[0])
+        oe.path.copyhardlinktree(state[1], sstatebuild + state[0])
 
     workdir = d.getVar('WORKDIR', True)
     for plain in ss['plaindirs']:
         pdir = plain.replace(workdir, sstatebuild)
         bb.mkdirhier(plain)
         bb.mkdirhier(pdir)
-        oe.path.copytree(plain, pdir)
+        oe.path.copyhardlinktree(plain, pdir)
 
     d.setVar('SSTATE_BUILDDIR', sstatebuild)
     d.setVar('SSTATE_PKG', sstatepkg)
diff --git a/meta/lib/oe/path.py b/meta/lib/oe/path.py
index 7197b23650..ea58bedc8b 100644
--- a/meta/lib/oe/path.py
+++ b/meta/lib/oe/path.py
@@ -83,6 +83,14 @@ def copytree(src, dst):
     cmd = 'tar -cf - -C %s -ps . | tar -xf - -C %s' % (src, dst)
     check_output(cmd, shell=True, stderr=subprocess.STDOUT)
 
+def copyhardlinktree(src, dst):
+    bb.utils.mkdirhier(dst)
+    if os.path.isdir(src):
+        if not len(os.listdir(src)):
+            return	
+        src = src + "/*"
+    cmd = 'cp -al %s %s' % (src, dst)
+    check_output(cmd, shell=True, stderr=subprocess.STDOUT)
 
 def remove(path, recurse=True):
     """Equivalent to rm -f or rm -rf"""