profcollectd: Remove local files once disabled

This saves storage space on users' devices if profcollect is no longer
enabled.

Test: manual
Change-Id: I04f19ba7ddbf9d9f977bb40ac4bc74a09369350f

5 files changed, 42 insertions, 15 deletions

diff --git a/profcollectd/libprofcollectd/config.rs b/profcollectd/libprofcollectd/config.rs
index 0b55d5c9..5f8982cf 100644
--- a/profcollectd/libprofcollectd/config.rs
+++ b/profcollectd/libprofcollectd/config.rs
@@ -22,6 +22,7 @@ use macaddr::MacAddr6;
 use rand::Rng;
 use serde::{Deserialize, Serialize};
 use std::error::Error;
+use std::fs::{read_dir, remove_file};
 use std::path::Path;
 use std::str::FromStr;
 use std::time::Duration;
@@ -31,6 +32,7 @@ const PROFCOLLECT_NODE_ID_PROPERTY: &str = "persist.profcollectd.node_id";
 
 pub const REPORT_RETENTION_SECS: u64 = 14 * 24 * 60 * 60; // 14 days.
 
+// Static configs that cannot be changed.
 lazy_static! {
     pub static ref TRACE_OUTPUT_DIR: &'static Path = Path::new("/data/misc/profcollectd/trace/");
     pub static ref PROFILE_OUTPUT_DIR: &'static Path = Path::new("/data/misc/profcollectd/output/");
@@ -42,6 +44,7 @@ lazy_static! {
         Path::new("/data/misc/profcollectd/output/config.json");
 }
 
+/// Dynamic configs, stored in config.json.
 #[derive(Clone, PartialEq, Eq, Serialize, Deserialize, Debug)]
 pub struct Config {
     /// Version of config file scheme, always equals to 1.
@@ -144,3 +147,19 @@ fn generate_random_node_id() -> MacAddr6 {
     node_id[0] |= 0x1;
     MacAddr6::from(node_id)
 }
+
+pub fn clear_data() -> Result<()> {
+    fn remove_files(path: &Path) -> Result<()> {
+        read_dir(path)?
+            .filter_map(|e| e.ok())
+            .map(|e| e.path())
+            .filter(|e| e.is_file())
+            .try_for_each(remove_file)?;
+        Ok(())
+    }
+
+    remove_files(&TRACE_OUTPUT_DIR)?;
+    remove_files(&PROFILE_OUTPUT_DIR)?;
+    remove_files(&REPORT_OUTPUT_DIR)?;
+    Ok(())
+}
diff --git a/profcollectd/libprofcollectd/lib.rs b/profcollectd/libprofcollectd/lib.rs
index d8a8cc8d..abc11272 100644
--- a/profcollectd/libprofcollectd/lib.rs
+++ b/profcollectd/libprofcollectd/lib.rs
@@ -91,6 +91,12 @@ pub fn report() -> Result<String> {
     Ok(get_profcollectd_service()?.report()?)
 }
 
+/// Clear all local data.
+pub fn reset() -> Result<()> {
+    config::clear_data()?;
+    Ok(())
+}
+
 /// Inits logging for Android
 pub fn init_logging() {
     let min_log_level = if cfg!(feature = "test") { log::Level::Info } else { log::Level::Error };
diff --git a/profcollectd/libprofcollectd/service.rs b/profcollectd/libprofcollectd/service.rs
index 8f998947..89fa8acb 100644
--- a/profcollectd/libprofcollectd/service.rs
+++ b/profcollectd/libprofcollectd/service.rs
@@ -21,15 +21,15 @@ use binder::public_api::Result as BinderResult;
 use binder::Status;
 use profcollectd_aidl_interface::aidl::com::android::server::profcollect::IProfCollectd::IProfCollectd;
 use std::ffi::CString;
-use std::fs::{copy, create_dir, read_dir, read_to_string, remove_dir_all, remove_file, write};
+use std::fs::{copy, read_dir, read_to_string, remove_file, write};
 use std::path::PathBuf;
 use std::str::FromStr;
 use std::sync::{Mutex, MutexGuard};
 use std::time::Duration;
 
 use crate::config::{
-    Config, BETTERBUG_CACHE_DIR_PREFIX, BETTERBUG_CACHE_DIR_SUFFIX, CONFIG_FILE,
-    PROFILE_OUTPUT_DIR, REPORT_OUTPUT_DIR, REPORT_RETENTION_SECS, TRACE_OUTPUT_DIR,
+    clear_data, Config, BETTERBUG_CACHE_DIR_PREFIX, BETTERBUG_CACHE_DIR_SUFFIX, CONFIG_FILE,
+    PROFILE_OUTPUT_DIR, REPORT_OUTPUT_DIR, REPORT_RETENTION_SECS,
 };
 use crate::report::{get_report_ts, pack_report};
 use crate::scheduler::Scheduler;
@@ -147,11 +147,8 @@ impl ProfcollectdBinderService {
             .is_none();
 
         if config_changed {
-            log::info!("Config change detected, clearing traces.");
-            remove_dir_all(*PROFILE_OUTPUT_DIR)?;
-            remove_dir_all(*TRACE_OUTPUT_DIR)?;
-            create_dir(*PROFILE_OUTPUT_DIR)?;
-            create_dir(*TRACE_OUTPUT_DIR)?;
+            log::info!("Config change detected, resetting profcollect.");
+            clear_data()?;
 
             write(*CONFIG_FILE, &new_config.to_string())?;
         }
diff --git a/profcollectd/profcollectctl.rs b/profcollectd/profcollectctl.rs
index c825f550..6778465e 100644
--- a/profcollectd/profcollectctl.rs
+++ b/profcollectd/profcollectctl.rs
@@ -29,8 +29,9 @@ command:
     stop        Terminate periodic collection.
     once        Request an one-off trace.
     process     Convert traces to perf profiles.
-    report      Create a report containing all profiles.
     reconfig    Refresh configuration.
+    report      Create a report containing all profiles.
+    reset       Clear all local data.
     help        Print this message.
 "#;
 
@@ -65,6 +66,10 @@ fn main() -> Result<()> {
             let path = libprofcollectd::report().context("Failed to create profile report.")?;
             println!("Report created at: {}", &path);
         }
+        "reset" => {
+            libprofcollectd::reset().context("Failed to reset.")?;
+            println!("Reset done.");
+        }
         "help" => println!("{}", &HELP_MSG),
         arg => bail!("Unknown argument: {}\n{}", &arg, &HELP_MSG),
     }
diff --git a/profcollectd/profcollectd.rc b/profcollectd/profcollectd.rc
index fd5bf541..312c7003 100644
--- a/profcollectd/profcollectd.rc
+++ b/profcollectd/profcollectd.rc
@@ -6,15 +6,15 @@ service profcollectd /system/bin/profcollectd
     group root shell wakelock
     task_profiles ServiceCapacityLow
 
-on property:persist.device_config.profcollect_native_boot.enabled=true
-    start profcollectd
-
-on property:persist.profcollectd.enabled_override=true
-    start profcollectd
-
 on post-fs-data
     # Create directory for profcollectd.
     mkdir /data/misc/profcollectd 0770 shell shell
     mkdir /data/misc/profcollectd/trace 0770 shell shell
     mkdir /data/misc/profcollectd/output 0770 shell shell
     mkdir /data/misc/profcollectd/report 0770 shell shell
+
+on boot && property:persist.device_config.profcollect_native_boot.enabled=true
+    start profcollectd
+
+on boot && property:persist.device_config.profcollect_native_boot.enabled=
+    exec_background - root shell -- /system/bin/profcollectctl reset