Add LZ4 support to the release tools

The core android build platform has changed to add support for LZ4
compression for ramdisks, but the release tools were not. Fix this.

Bug: 156129966
Merged-In: I39680b91930d2d3cbd0cd565beb78e1ee699397e
Change-Id: I39680b91930d2d3cbd0cd565beb78e1ee699397e
diff --git a/core/Makefile b/core/Makefile
index 08cab36..5d4d886 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -4241,6 +4241,9 @@
 else
 	echo "boot_images=$(foreach b,$(INSTALLED_BOOTIMAGE_TARGET),$(notdir $(b)))" >> $@
 endif
+ifeq ($(BOARD_RAMDISK_USE_LZ4),true)
+	echo "lz4_ramdisks=true" >> $@
+endif
 ifneq ($(INSTALLED_VENDOR_BOOTIMAGE_TARGET),)
 	echo "vendor_boot=true" >> $@
 	echo "vendor_boot_size=$(BOARD_VENDOR_BOOTIMAGE_PARTITION_SIZE)" >> $@
diff --git a/tools/releasetools/Android.bp b/tools/releasetools/Android.bp
index f29ec90..5785688 100644
--- a/tools/releasetools/Android.bp
+++ b/tools/releasetools/Android.bp
@@ -187,6 +187,7 @@
         "bsdiff",
         "imgdiff",
         "minigzip",
+        "lz4",
         "mkbootfs",
         "signapk",
     ],
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 4a91179..ae7da2f 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -1152,7 +1152,7 @@
     assert OPTIONS.aftl_signer_helper is not None, 'No AFTL signer helper provided.'
     # AFTL inclusion proof generation code will go here.
 
-def _MakeRamdisk(sourcedir, fs_config_file=None):
+def _MakeRamdisk(sourcedir, fs_config_file=None, lz4_ramdisks=False):
   ramdisk_img = tempfile.NamedTemporaryFile()
 
   if fs_config_file is not None and os.access(fs_config_file, os.F_OK):
@@ -1161,12 +1161,16 @@
   else:
     cmd = ["mkbootfs", os.path.join(sourcedir, "RAMDISK")]
   p1 = Run(cmd, stdout=subprocess.PIPE)
-  p2 = Run(["minigzip"], stdin=p1.stdout, stdout=ramdisk_img.file.fileno())
+  if lz4_ramdisks:
+    p2 = Run(["lz4", "-l", "-12" , "--favor-decSpeed"], stdin=p1.stdout,
+             stdout=ramdisk_img.file.fileno())
+  else:
+    p2 = Run(["minigzip"], stdin=p1.stdout, stdout=ramdisk_img.file.fileno())
 
   p2.wait()
   p1.wait()
   assert p1.returncode == 0, "mkbootfs of %s ramdisk failed" % (sourcedir,)
-  assert p2.returncode == 0, "minigzip of %s ramdisk failed" % (sourcedir,)
+  assert p2.returncode == 0, "compression of %s ramdisk failed" % (sourcedir,)
 
   return ramdisk_img
 
@@ -1204,7 +1208,8 @@
   img = tempfile.NamedTemporaryFile()
 
   if has_ramdisk:
-    ramdisk_img = _MakeRamdisk(sourcedir, fs_config_file)
+    use_lz4 = info_dict.get("lz4_ramdisks") == 'true'
+    ramdisk_img = _MakeRamdisk(sourcedir, fs_config_file, lz4_ramdisks=use_lz4)
 
   # use MKBOOTIMG from environ, or "mkbootimg" if empty or not set
   mkbootimg = os.getenv('MKBOOTIMG') or "mkbootimg"
@@ -1388,7 +1393,8 @@
 
   img = tempfile.NamedTemporaryFile()
 
-  ramdisk_img = _MakeRamdisk(sourcedir)
+  use_lz4 = info_dict.get("lz4_ramdisks") == 'true'
+  ramdisk_img = _MakeRamdisk(sourcedir, lz4_ramdisks=use_lz4)
 
   # use MKBOOTIMG from environ, or "mkbootimg" if empty or not set
   mkbootimg = os.getenv('MKBOOTIMG') or "mkbootimg"