Dropping in software construction toolkit.

site_scons/site_tools/replicate.py

Index: site_scons/site_tools/replicate.py
===================================================================
--- site_scons/site_tools/replicate.py	(revision 0)
+++ site_scons/site_tools/replicate.py	(revision 0)
@@ -0,0 +1,123 @@
+#!/usr/bin/python2.4
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Replicate tool for SCons."""
+
+
+import re
+
+
+def Replicate(env, target, source, **kw):
+  """Replicates (copies) source files/directories to the target directory.
+
+  Much like env.Install(), with the following differences:
+     * If the source is a directory, recurses through it and calls
+       env.Install() on each source file, rather than copying the entire
+       directory at once.  This provides more opportunity for hard linking, and
+       also makes the destination files/directories all writable.
+     * Can take sources which contain env.Glob()-style wildcards.
+     * Can take multiple target directories; will copy to all of them.
+     * Handles duplicate requests.
+
+  Args:
+    env: Environment in which to operate.
+    target: Destination(s) for copy.  Must evaluate to a directory via
+        env.Dir(), or a list of directories.  If more than one directory is
+        passed, the entire source list will be copied to all target
+        directories.
+    source: Source file(s) to copy.  May be a string, Node, or a list of
+        mixed strings or Nodes.  Strings will be passed through env.Glob() to
+        evaluate wildcards.  If a source evaluates to a directory, the entire
+        directory will be recursively copied.
+
+  From env:
+    REPLICATE_RENAME: A list of pairs of regex search and replacement strings.
+        Each full destination path has substitution performed on each pair
+        (search_regex, replacement) in order.
+
+        env.Replicate('destdir', ['footxt.txt'], REPLICATE_REPLACE = [
+            ('\\.txt', '.bar'), ('est', 'ist')])
+        will copy to 'distdir/footxt.bar'
+
+        In the example above, note the use of \\ to escape the '.' character,
+        so that it doesn't act like the regexp '.' and match any character.
+
+  Returns:
+    A list of the destination nodes from the calls to env.Install().
+  """
+  replace_list = kw.get('REPLICATE_REPLACE', env.get('REPLICATE_REPLACE', []))
+
+  dest_nodes = []
+  for target_entry in env.Flatten(target):
+    for source_entry in env.Flatten(source):
+      if type(source_entry) == str:
+        # Search for matches for each source entry
+        source_nodes = env.Glob(source_entry)
+      else:
+        # Source entry is already a file or directory node; no need to glob it
+        source_nodes = [source_entry]
+      for s in source_nodes:
+        target_name = env.Dir(target_entry).abspath + '/' + s.name
+        # We need to use the following incantation rather than s.isdir() in
+        # order to handle chained replicates (A -> B -> C). The isdir()
+        # function is not properly defined in all of the Node type classes in
+        # SCons. This change is particularly crucial if hardlinks are present,
+        # in which case using isdir() can cause files to be unintentionally
+        # deleted.
+        # TODO(bradnelson): Look into fixing the innards of SCons so this isn't
+        # needed.
+        if str(s.__class__) == 'SCons.Node.FS.Dir':
+          # Recursively copy all files in subdir.  Since glob('*') doesn't
+          # match dot files, also glob('.*').
+          dest_nodes += env.Replicate(
+              target_name, [s.abspath + '/*', s.abspath + '/.*'],
+              REPLICATE_REPLACE=replace_list)
+        else:
+          # Apply replacement strings, if any
+          for r in replace_list:
+            target_name = re.sub(r[0], r[1], target_name)
+          target = env.File(target_name)
+          if (target.has_builder()
+              and target.get_builder().name == 'InstallBuilder'
+              and target.sources == [s]):
+            # Already installed that file, so pass through the destination node
+            dest_nodes += [target]
+          else:
+            dest_nodes += env.InstallAs(target_name, s)
+
+  # Return list of destination nodes
+  return dest_nodes
+
+
+def generate(env):
+  # NOTE: SCons requires the use of this name, which fails gpylint.
+  """SCons entry point for this tool."""
+
+  env.AddMethod(Replicate)