Add flag to skip writing output from soong_zip.
We want to measure how much of build time is spent on writing large
zips to disk. We can do this by doing the rest of the work but
skipping the write itself.
Some local and trivial testing shows this is probably a lot of the
cost of these rules:
$ python -m timeit -s "import os" -r 10 "os.system('soong_zip -write_if_changed -o foo.zip -D prebuilts/sdk')"
1 loop, best of 10: 8.37 sec per loop
$ python -m timeit -s "import os" -r 10 "os.system('soong_zip -o foo.zip -D prebuilts/sdk')"
1 loop, best of 10: 5.39 sec per loop
$ python -m timeit -s "import os" -r 10 "os.system('soong_zip -n -o foo.zip -D prebuilts/sdk')"
1 loop, best of 10: 3.66 sec per loop
Bug: None
Test: treehugger
Change-Id: I43acdb08d0e00efaba9e5d7add972a7ec41646d2
diff --git a/zip/zip.go b/zip/zip.go
index 5e1a104..30a2ee7 100644
--- a/zip/zip.go
+++ b/zip/zip.go
@@ -282,6 +282,7 @@
StoreSymlinks bool
IgnoreMissingFiles bool
Sha256Checksum bool
+ DoNotWrite bool
Stderr io.Writer
Filesystem pathtools.FileSystem
@@ -400,7 +401,9 @@
var zipErr error
- if !args.WriteIfChanged {
+ if args.DoNotWrite {
+ out = io.Discard
+ } else if !args.WriteIfChanged {
f, err := os.Create(args.OutputFilePath)
if err != nil {
return err
@@ -421,7 +424,7 @@
return zipErr
}
- if args.WriteIfChanged {
+ if args.WriteIfChanged && !args.DoNotWrite {
err := pathtools.WriteFileIfChanged(args.OutputFilePath, buf.Bytes(), 0666)
if err != nil {
return err