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incr.comp.: Make path's of session directories slightly shorter.

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By using "s-" instead of "sess-" as a prefix and encoding numbers as base36 instead of base16.
This commit is contained in:
Michael Woerister 2016-08-26 16:50:24 -04:00
parent b67f57afdd
commit a3dc5f95aa
1 changed files with 75 additions and 38 deletions
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113
src/librustc_incremental/persist/fs.rs
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@ -45,7 +45,7 @@
//! that are consistent with the state of the source code it was compiled
//! from, with no need to change them ever again. At this point, the compiler
//! finalizes and "publishes" its private session directory by renaming it
//! from "sess-{timestamp}-{random}-working" to "sess-{timestamp}-{SVH}".
//! from "s-{timestamp}-{random}-working" to "s-{timestamp}-{SVH}".
//! 6. At this point the "old" session directory that we copied our data from
//! at the beginning of the session has become obsolete because we have just
//! published a more current version. Thus the compiler will delete it.
@ -201,7 +201,7 @@ pub fn prepare_session_directory(tcx: TyCtxt) -> Result<bool, ()> {
loop {
// Generate a session directory of the form:
//
// {incr-comp-dir}/{crate-name-and-disambiguator}/sess-{timestamp}-{random}-working
// {incr-comp-dir}/{crate-name-and-disambiguator}/s-{timestamp}-{random}-working
let session_dir = generate_session_dir_path(&crate_dir);
debug!("session-dir: {}", session_dir.display());
@ -265,7 +265,7 @@ pub fn prepare_session_directory(tcx: TyCtxt) -> Result<bool, ()> {
/// This function finalizes and thus 'publishes' the session directory by
/// renaming it to `sess-{timestamp}-{svh}` and releasing the file lock.
/// renaming it to `s-{timestamp}-{svh}` and releasing the file lock.
/// If there have been compilation errors, however, this function will just
/// delete the presumably invalid session directory.
pub fn finalize_session_directory(sess: &Session, svh: Svh) {
@ -302,7 +302,7 @@ pub fn finalize_session_directory(sess: &Session, svh: Svh) {
.to_string_lossy();
assert_no_characters_lost(&old_sub_dir_name);
// Keep the 'sess-{timestamp}-{random-number}' prefix, but replace the
// Keep the 's-{timestamp}-{random-number}' prefix, but replace the
// '-working' part with the SVH of the crate
let dash_indices: Vec<_> = old_sub_dir_name.match_indices("-")
.map(|(idx, _)| idx)
@ -313,11 +313,11 @@ pub fn finalize_session_directory(sess: &Session, svh: Svh) {
incr_comp_session_dir.display())
}
// State: "sess-{timestamp}-{random-number}-"
// State: "s-{timestamp}-{random-number}-"
let mut new_sub_dir_name = String::from(&old_sub_dir_name[.. dash_indices[2] + 1]);
// Append the svh
new_sub_dir_name.push_str(&svh.to_string());
new_sub_dir_name.push_str(&encode_base_36(svh.as_u64()));
// Create the full path
let new_path = incr_comp_session_dir.parent().unwrap().join(new_sub_dir_name);
@ -405,14 +405,16 @@ fn copy_files(target_dir: &Path,
}
/// Generate unique directory path of the form:
/// {crate_dir}/sess-{timestamp}-{random-number}-working
/// {crate_dir}/s-{timestamp}-{random-number}-working
fn generate_session_dir_path(crate_dir: &Path) -> PathBuf {
let timestamp = timestamp_to_string(SystemTime::now());
debug!("generate_session_dir_path: timestamp = {}", timestamp);
let random_number = thread_rng().next_u32();
debug!("generate_session_dir_path: random_number = {}", random_number);
let directory_name = format!("sess-{}-{:x}-working", timestamp, random_number);
let directory_name = format!("s-{}-{}-working",
timestamp,
encode_base_36(random_number as u64));
debug!("generate_session_dir_path: directory_name = {}", directory_name);
let directory_path = crate_dir.join(directory_name);
debug!("generate_session_dir_path: directory_path = {}", directory_path.display());
@ -517,12 +519,12 @@ fn is_finalized(directory_name: &str) -> bool {
}
fn is_session_directory(directory_name: &str) -> bool {
directory_name.starts_with("sess-") &&
directory_name.starts_with("s-") &&
!directory_name.ends_with(LOCK_FILE_EXT)
}
fn is_session_directory_lock_file(file_name: &str) -> bool {
file_name.starts_with("sess-") && file_name.ends_with(LOCK_FILE_EXT)
file_name.starts_with("s-") && file_name.ends_with(LOCK_FILE_EXT)
}
fn extract_timestamp_from_session_dir(directory_name: &str)
@ -541,15 +543,31 @@ fn extract_timestamp_from_session_dir(directory_name: &str)
string_to_timestamp(&directory_name[dash_indices[0]+1 .. dash_indices[1]])
}
const BASE_36: &'static [u8] = b"0123456789abcdefghijklmnopqrstuvwxyz";
fn encode_base_36(mut n: u64) -> String {
let mut s = Vec::with_capacity(13);
loop {
s.push(BASE_36[(n % 36) as usize]);
n /= 36;
if n == 0 {
break;
}
}
s.reverse();
String::from_utf8(s).unwrap()
}
fn timestamp_to_string(timestamp: SystemTime) -> String {
let duration = timestamp.duration_since(UNIX_EPOCH).unwrap();
let micros = duration.as_secs() * 1_000_000 +
(duration.subsec_nanos() as u64) / 1000;
format!("{:x}", micros)
encode_base_36(micros)
}
fn string_to_timestamp(s: &str) -> Result<SystemTime, ()> {
let micros_since_unix_epoch = u64::from_str_radix(s, 16);
let micros_since_unix_epoch = u64::from_str_radix(s, 36);
if micros_since_unix_epoch.is_err() {
return Err(())
@ -591,7 +609,8 @@ pub fn find_metadata_hashes_for(tcx: TyCtxt, cnum: ast::CrateNum) -> Option<Path
}
};
let target_svh = tcx.sess.cstore.crate_hash(cnum).to_string();
let target_svh = tcx.sess.cstore.crate_hash(cnum);
let target_svh = encode_base_36(target_svh.as_u64());
let sub_dir = find_metadata_hashes_iter(&target_svh, dir_entries.filter_map(|e| {
e.ok().map(|e| e.file_name().to_string_lossy().into_owned())
@ -638,7 +657,7 @@ fn crate_path(sess: &Session,
let mut hasher = SipHasher::new();
crate_disambiguator.hash(&mut hasher);
let crate_name = format!("{}-{:x}", crate_name, hasher.finish());
let crate_name = format!("{}-{}", crate_name, encode_base_36(hasher.finish()));
incr_dir.join(crate_name)
}
@ -914,17 +933,17 @@ fn test_find_source_directory_in_iter() {
// Find newest
assert_eq!(find_source_directory_in_iter(
vec![PathBuf::from("crate-dir/sess-3234-0000-svh"),
PathBuf::from("crate-dir/sess-2234-0000-svh"),
PathBuf::from("crate-dir/sess-1234-0000-svh")].into_iter(), &already_visited),
Some(PathBuf::from("crate-dir/sess-3234-0000-svh")));
vec![PathBuf::from("crate-dir/s-3234-0000-svh"),
PathBuf::from("crate-dir/s-2234-0000-svh"),
PathBuf::from("crate-dir/s-1234-0000-svh")].into_iter(), &already_visited),
Some(PathBuf::from("crate-dir/s-3234-0000-svh")));
// Filter out "-working"
assert_eq!(find_source_directory_in_iter(
vec![PathBuf::from("crate-dir/sess-3234-0000-working"),
PathBuf::from("crate-dir/sess-2234-0000-svh"),
PathBuf::from("crate-dir/sess-1234-0000-svh")].into_iter(), &already_visited),
Some(PathBuf::from("crate-dir/sess-2234-0000-svh")));
vec![PathBuf::from("crate-dir/s-3234-0000-working"),
PathBuf::from("crate-dir/s-2234-0000-svh"),
PathBuf::from("crate-dir/s-1234-0000-svh")].into_iter(), &already_visited),
Some(PathBuf::from("crate-dir/s-2234-0000-svh")));
// Handle empty
assert_eq!(find_source_directory_in_iter(vec![].into_iter(), &already_visited),
@ -932,9 +951,9 @@ fn test_find_source_directory_in_iter() {
// Handle only working
assert_eq!(find_source_directory_in_iter(
vec![PathBuf::from("crate-dir/sess-3234-0000-working"),
PathBuf::from("crate-dir/sess-2234-0000-working"),
PathBuf::from("crate-dir/sess-1234-0000-working")].into_iter(), &already_visited),
vec![PathBuf::from("crate-dir/s-3234-0000-working"),
PathBuf::from("crate-dir/s-2234-0000-working"),
PathBuf::from("crate-dir/s-1234-0000-working")].into_iter(), &already_visited),
None);
}
@ -943,36 +962,36 @@ fn test_find_metadata_hashes_iter()
{
assert_eq!(find_metadata_hashes_iter("testsvh2",
vec![
String::from("sess-timestamp1-testsvh1"),
String::from("sess-timestamp2-testsvh2"),
String::from("sess-timestamp3-testsvh3"),
String::from("s-timestamp1-testsvh1"),
String::from("s-timestamp2-testsvh2"),
String::from("s-timestamp3-testsvh3"),
].into_iter()),
Some(OsString::from("sess-timestamp2-testsvh2"))
Some(OsString::from("s-timestamp2-testsvh2"))
);
assert_eq!(find_metadata_hashes_iter("testsvh2",
vec![
String::from("sess-timestamp1-testsvh1"),
String::from("sess-timestamp2-testsvh2"),
String::from("s-timestamp1-testsvh1"),
String::from("s-timestamp2-testsvh2"),
String::from("invalid-name"),
].into_iter()),
Some(OsString::from("sess-timestamp2-testsvh2"))
Some(OsString::from("s-timestamp2-testsvh2"))
);
assert_eq!(find_metadata_hashes_iter("testsvh2",
vec![
String::from("sess-timestamp1-testsvh1"),
String::from("sess-timestamp2-testsvh2-working"),
String::from("sess-timestamp3-testsvh3"),
String::from("s-timestamp1-testsvh1"),
String::from("s-timestamp2-testsvh2-working"),
String::from("s-timestamp3-testsvh3"),
].into_iter()),
None
);
assert_eq!(find_metadata_hashes_iter("testsvh1",
vec![
String::from("sess-timestamp1-random1-working"),
String::from("sess-timestamp2-random2-working"),
String::from("sess-timestamp3-random3-working"),
String::from("s-timestamp1-random1-working"),
String::from("s-timestamp2-random2-working"),
String::from("s-timestamp3-random3-working"),
].into_iter()),
None
);
@ -986,3 +1005,21 @@ fn test_find_metadata_hashes_iter()
None
);
}
#[test]
fn test_encode_base_36() {
fn test(n: u64) {
assert_eq!(Ok(n), u64::from_str_radix(&encode_base_36(n)[..], 36));
}
test(0);
test(1);
test(35);
test(36);
test(37);
test(u64::max_value());
for i in 0 .. 1_000 {
test(i * 983);
}
}