* Optimize parallel-fetch to avoid redundant checksum verification.

* Add parallel-fetch to the default FEATURES since it is more efficient now.

svn path=/main/trunk/; revision=9462

3 files changed, 26 insertions, 3 deletions

diff --git a/cnf/make.globals b/cnf/make.globals
index d36ede9a..9023dab6 100644
--- a/cnf/make.globals
+++ b/cnf/make.globals
@@ -33,7 +33,7 @@ FETCHCOMMAND="/usr/bin/wget -t 5 -T 60 --passive-ftp -O \"\${DISTDIR}/\${FILE}\"
 RESUMECOMMAND="/usr/bin/wget -c -t 5 -T 60 --passive-ftp -O \"\${DISTDIR}/\${FILE}\" \"\${URI}\""
 
 # Default user options
-FEATURES="distlocks metadata-transfer sandbox sfperms strict unmerge-orphans userfetch"
+FEATURES="distlocks parallel-fetch metadata-transfer sandbox sfperms strict unmerge-orphans userfetch"
 
 # Enable for global testing
 FEATURES="${FEATURES} preserve-libs"
diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index 68bf0d97..7a619271 100644
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -4489,6 +4489,7 @@ class MergeTask(object):
 				fetch_env = os.environ.copy()
 				fetch_env["FEATURES"] = fetch_env.get("FEATURES", "") + " -cvs"
 				fetch_env["PORTAGE_NICENESS"] = "0"
+				fetch_env["PORTAGE_PARALLEL_FETCHONLY"] = "1"
 				fetch_args = [sys.argv[0], "--resume", "--fetchonly"]
 				resume_opts = self.myopts.copy()
 				# For automatic resume, we need to prevent
@@ -6920,7 +6921,7 @@ def action_build(settings, trees, mtimedb,
 		if ("--resume" in myopts):
 			favorites=mtimedb["resume"]["favorites"]
 			mergetask = MergeTask(settings, trees, myopts)
-			if "--fetchonly" in myopts:
+			if "PORTAGE_PARALLEL_FETCHONLY" in settings:
 				""" parallel-fetch uses --resume --fetchonly and we don't want
 				it to write the mtimedb"""
 				mtimedb.filename = None
diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index 04f7acec..8e146c45 100644
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -3032,6 +3032,14 @@ def fetch(myuris, mysettings, listonly=0, fetchonly=0, locks_in_subdir=".locks",
 	checksum_failure_primaryuri = 2
 	thirdpartymirrors = mysettings.thirdpartymirrors()
 
+	# In the background parallel-fetch process, it's safe to skip checksum
+	# verification of pre-existing files in $DISTDIR that have the correct
+	# file size. The parent process will verify their checksums prior to
+	# the unpack phase.
+
+	parallel_fetchonly = fetchonly and \
+		"PORTAGE_PARALLEL_FETCHONLY" in mysettings
+
 	check_config_instance(mysettings)
 
 	custommirrors = grabdict(os.path.join(mysettings["PORTAGE_CONFIGROOT"],
@@ -3218,7 +3226,7 @@ def fetch(myuris, mysettings, listonly=0, fetchonly=0, locks_in_subdir=".locks",
 
 			if use_locks and can_fetch:
 				waiting_msg = None
-				if "parallel-fetch" in features:
+				if not parallel_fetchonly and "parallel-fetch" in features:
 					waiting_msg = ("Downloading '%s'... " + \
 						"see /var/log/emerge-fetch.log for details.") % myfile
 				if locks_in_subdir:
@@ -3277,6 +3285,15 @@ def fetch(myuris, mysettings, listonly=0, fetchonly=0, locks_in_subdir=".locks",
 						if mystat.st_size < mydigests[myfile]["size"] and \
 							not restrict_fetch:
 							fetched = 1 # Try to resume this download.
+						elif parallel_fetchonly and \
+							mystat.st_size == mydigests[myfile]["size"]:
+							eout = portage.output.EOutput()
+							eout.quiet = \
+								mysettings.get("PORTAGE_QUIET") == "1"
+							eout.ebegin(
+								"%s size ;-)" % (myfile, ))
+							eout.eend(0)
+							continue
 						else:
 							verified_ok, reason = portage.checksum.verify_all(
 								myfile_path, mydigests[myfile])
@@ -4737,6 +4754,11 @@ def doebuild(myebuild, mydo, myroot, mysettings, debug=0, listonly=0,
 			fetchme = newuris[:]
 			checkme = alist[:]
 
+		if mydo == "fetch":
+			# Files are already checked inside fetch(),
+			# so do not check them again.
+			checkme = []
+
 		# Only try and fetch the files if we are going to need them ...
 		# otherwise, if user has FEATURES=noauto and they run `ebuild clean
 		# unpack compile install`, we will try and fetch 4 times :/