3 files changed, 105 insertions, 0 deletions

diff --git a/otautil/Android.bp b/otautil/Android.bp
index 5efb12d60..75cf69148 100644
--- a/otautil/Android.bp
+++ b/otautil/Android.bp
@@ -21,6 +21,7 @@ cc_library_static {
         "SysUtil.cpp",
         "DirUtil.cpp",
         "ThermalUtil.cpp",
+        "cache_location.cpp",
         "rangeset.cpp",
     ],
 
diff --git a/otautil/cache_location.cpp b/otautil/cache_location.cpp
new file mode 100644
index 000000000..8f289487f
--- /dev/null
+++ b/otautil/cache_location.cpp
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "otautil/cache_location.h"
+
+constexpr const char kDefaultCacheTempSource[] = "/cache/saved.file";
+constexpr const char kDefaultLastCommandFile[] = "/cache/recovery/last_command";
+constexpr const char kDefaultStashDirectoryBase[] = "/cache/recovery";
+
+CacheLocation& CacheLocation::location() {
+  static CacheLocation cache_location;
+  return cache_location;
+}
+
+void CacheLocation::ResetLocations() {
+  cache_temp_source_ = kDefaultCacheTempSource;
+  last_command_file_ = kDefaultLastCommandFile;
+  stash_directory_base_ = kDefaultStashDirectoryBase;
+}
diff --git a/otautil/include/otautil/cache_location.h b/otautil/include/otautil/cache_location.h
new file mode 100644
index 000000000..85e0d485c
--- /dev/null
+++ b/otautil/include/otautil/cache_location.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OTAUTIL_OTAUTIL_CACHE_LOCATION_H_
+#define _OTAUTIL_OTAUTIL_CACHE_LOCATION_H_
+
+#include <string>
+
+#include "android-base/macros.h"
+
+// A singleton class to maintain the update related locations. The locations should be only set
+// once at the start of the program.
+class CacheLocation {
+ public:
+  static CacheLocation& location();
+
+  // Reset the locations to their default values.
+  void ResetLocations();
+
+  // getter and setter functions.
+  std::string cache_temp_source() const {
+    return cache_temp_source_;
+  }
+  void set_cache_temp_source(const std::string& temp_source) {
+    cache_temp_source_ = temp_source;
+  }
+
+  std::string last_command_file() const {
+    return last_command_file_;
+  }
+  void set_last_command_file(const std::string& last_command) {
+    last_command_file_ = last_command;
+  }
+
+  std::string stash_directory_base() const {
+    return stash_directory_base_;
+  }
+  void set_stash_directory_base(const std::string& base) {
+    stash_directory_base_ = base;
+  }
+
+ private:
+  CacheLocation() {}
+  DISALLOW_COPY_AND_ASSIGN(CacheLocation);
+
+  // When there isn't enough room on the target filesystem to hold the patched version of the file,
+  // we copy the original here and delete it to free up space.  If the expected source file doesn't
+  // exist, or is corrupted, we look to see if the cached file contains the bits we want and use it
+  // as the source instead.  The default location for the cached source is "/cache/saved.file".
+  std::string cache_temp_source_;
+
+  // Location to save the last command that stashes blocks.
+  std::string last_command_file_;
+
+  // The base directory to write stashes during update.
+  std::string stash_directory_base_;
+};
+
+#endif  // _OTAUTIL_OTAUTIL_CACHE_LOCATION_H_