Revert "Revert "language: Remove buffer fingerprinting (#9007)"" (#9671)

This reverts commit caed275.

NOTE: this should not be merged until #9668 is on stable and the
`ZedVersion#can_collaborate` is updated to exclude all clients without
that change.

Release Notes:

- N/A

---------

Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>

crates/collab/src/rpc/connection_pool.rs

@@ -31,7 +31,7 @@ impl fmt::Display for ZedVersion {
 
 impl ZedVersion {
     pub fn can_collaborate(&self) -> bool {
-        self.0 >= SemanticVersion::new(0, 127, 3)
+        self.0 >= SemanticVersion::new(0, 129, 2)
     }
 }
 

crates/collab/src/tests/random_project_collaboration_tests.rs

@@ -1347,13 +1347,11 @@ impl RandomizedTest for ProjectCollaborationTest {
                             client.username
                         );
 
-                    let host_saved_version_fingerprint =
-                        host_buffer.read_with(host_cx, |b, _| b.saved_version_fingerprint());
-                    let guest_saved_version_fingerprint =
-                        guest_buffer.read_with(client_cx, |b, _| b.saved_version_fingerprint());
+                    let host_is_dirty = host_buffer.read_with(host_cx, |b, _| b.is_dirty());
+                    let guest_is_dirty = guest_buffer.read_with(client_cx, |b, _| b.is_dirty());
                     assert_eq!(
-                            guest_saved_version_fingerprint, host_saved_version_fingerprint,
-                            "guest {} saved fingerprint does not match host's for path {path:?} in project {project_id}",
+                            guest_is_dirty, host_is_dirty,
+                            "guest {} dirty state does not match host's for path {path:?} in project {project_id}",
                             client.username
                         );
 

crates/copilot/src/copilot.rs

@@ -1255,7 +1255,6 @@ mod tests {
             &self,
             _: BufferId,
             _: &clock::Global,
-            _: language::RopeFingerprint,
             _: language::LineEnding,
             _: Option<std::time::SystemTime>,
             _: &mut AppContext,

crates/editor/src/items.rs

@@ -735,9 +735,8 @@ impl Item for Editor {
                     buffer
                         .update(&mut cx, |buffer, cx| {
                             let version = buffer.saved_version().clone();
-                            let fingerprint = buffer.saved_version_fingerprint();
                             let mtime = buffer.saved_mtime();
-                            buffer.did_save(version, fingerprint, mtime, cx);
+                            buffer.did_save(version, mtime, cx);
                         })
                         .ok();
                 }

crates/language/src/buffer.rs

@@ -45,9 +45,9 @@ use text::operation_queue::OperationQueue;
 use text::*;
 pub use text::{
     Anchor, Bias, Buffer as TextBuffer, BufferId, BufferSnapshot as TextBufferSnapshot, Edit,
-    OffsetRangeExt, OffsetUtf16, Patch, Point, PointUtf16, Rope, RopeFingerprint, Selection,
-    SelectionGoal, Subscription, TextDimension, TextSummary, ToOffset, ToOffsetUtf16, ToPoint,
-    ToPointUtf16, Transaction, TransactionId, Unclipped,
+    OffsetRangeExt, OffsetUtf16, Patch, Point, PointUtf16, Rope, Selection, SelectionGoal,
+    Subscription, TextDimension, TextSummary, ToOffset, ToOffsetUtf16, ToPoint, ToPointUtf16,
+    Transaction, TransactionId, Unclipped,
 };
 use theme::SyntaxTheme;
 #[cfg(any(test, feature = "test-support"))]
@@ -87,8 +87,6 @@ pub struct Buffer {
     /// The version vector when this buffer was last loaded from
     /// or saved to disk.
     saved_version: clock::Global,
-    /// A hash of the current contents of the buffer's file.
-    file_fingerprint: RopeFingerprint,
     transaction_depth: usize,
     was_dirty_before_starting_transaction: Option<bool>,
     reload_task: Option<Task<Result<()>>>,
@@ -379,7 +377,6 @@ pub trait LocalFile: File {
         &self,
         buffer_id: BufferId,
         version: &clock::Global,
-        fingerprint: RopeFingerprint,
         line_ending: LineEnding,
         mtime: Option<SystemTime>,
         cx: &mut AppContext,
@@ -562,7 +559,6 @@ impl Buffer {
             diff_base: self.diff_base.as_ref().map(|h| h.to_string()),
             line_ending: proto::serialize_line_ending(self.line_ending()) as i32,
             saved_version: proto::serialize_version(&self.saved_version),
-            saved_version_fingerprint: proto::serialize_fingerprint(self.file_fingerprint),
             saved_mtime: self.saved_mtime.map(|time| time.into()),
         }
     }
@@ -642,7 +638,6 @@ impl Buffer {
         Self {
             saved_mtime,
             saved_version: buffer.version(),
-            file_fingerprint: buffer.as_rope().fingerprint(),
             reload_task: None,
             transaction_depth: 0,
             was_dirty_before_starting_transaction: None,
@@ -717,11 +712,6 @@ impl Buffer {
         &self.saved_version
     }
 
-    /// The fingerprint of the buffer's text when the buffer was last saved or reloaded from disk.
-    pub fn saved_version_fingerprint(&self) -> RopeFingerprint {
-        self.file_fingerprint
-    }
-
     /// The mtime of the buffer's file when the buffer was last saved or reloaded from disk.
     pub fn saved_mtime(&self) -> Option<SystemTime> {
         self.saved_mtime
@@ -754,13 +744,11 @@ impl Buffer {
     pub fn did_save(
         &mut self,
         version: clock::Global,
-        fingerprint: RopeFingerprint,
         mtime: Option<SystemTime>,
         cx: &mut ModelContext<Self>,
     ) {
         self.saved_version = version;
         self.has_conflict = false;
-        self.file_fingerprint = fingerprint;
         self.saved_mtime = mtime;
         cx.emit(Event::Saved);
         cx.notify();
@@ -792,13 +780,7 @@ impl Buffer {
                     this.apply_diff(diff, cx);
                     tx.send(this.finalize_last_transaction().cloned()).ok();
                     this.has_conflict = false;
-                    this.did_reload(
-                        this.version(),
-                        this.as_rope().fingerprint(),
-                        this.line_ending(),
-                        new_mtime,
-                        cx,
-                    );
+                    this.did_reload(this.version(), this.line_ending(), new_mtime, cx);
                 } else {
                     if !diff.edits.is_empty()
                         || this
@@ -809,13 +791,7 @@ impl Buffer {
                         this.has_conflict = true;
                     }
 
-                    this.did_reload(
-                        prev_version,
-                        Rope::text_fingerprint(&new_text),
-                        this.line_ending(),
-                        this.saved_mtime,
-                        cx,
-                    );
+                    this.did_reload(prev_version, this.line_ending(), this.saved_mtime, cx);
                 }
 
                 this.reload_task.take();
@@ -828,20 +804,17 @@ impl Buffer {
     pub fn did_reload(
         &mut self,
         version: clock::Global,
-        fingerprint: RopeFingerprint,
         line_ending: LineEnding,
         mtime: Option<SystemTime>,
         cx: &mut ModelContext<Self>,
     ) {
         self.saved_version = version;
-        self.file_fingerprint = fingerprint;
         self.text.set_line_ending(line_ending);
         self.saved_mtime = mtime;
         if let Some(file) = self.file.as_ref().and_then(|f| f.as_local()) {
             file.buffer_reloaded(
                 self.remote_id(),
                 &self.saved_version,
-                self.file_fingerprint,
                 self.line_ending(),
                 self.saved_mtime,
                 cx,

crates/language/src/proto.rs

@@ -10,11 +10,6 @@ use text::*;
 
 pub use proto::{BufferState, Operation};
 
-/// Serializes a [`RopeFingerprint`] to be sent over RPC.
-pub fn serialize_fingerprint(fingerprint: RopeFingerprint) -> String {
-    fingerprint.to_hex()
-}
-
 /// Deserializes a `[text::LineEnding]` from the RPC representation.
 pub fn deserialize_line_ending(message: proto::LineEnding) -> text::LineEnding {
     match message {

crates/project/src/project.rs

@@ -97,7 +97,7 @@ use std::{
 };
 use task::static_source::{StaticSource, TrackedFile};
 use terminals::Terminals;
-use text::{Anchor, BufferId, RopeFingerprint};
+use text::{Anchor, BufferId};
 use util::{
     debug_panic, defer,
     http::{HttpClient, Url},
@@ -8526,7 +8526,6 @@ impl Project {
             buffer_id: buffer_id.into(),
             version: serialize_version(buffer.saved_version()),
             mtime: buffer.saved_mtime().map(|time| time.into()),
-            fingerprint: language::proto::serialize_fingerprint(buffer.saved_version_fingerprint()),
         })
     }
 
@@ -8619,9 +8618,6 @@ impl Project {
                             buffer_id: buffer_id.into(),
                             version: language::proto::serialize_version(buffer.saved_version()),
                             mtime: buffer.saved_mtime().map(|time| time.into()),
-                            fingerprint: language::proto::serialize_fingerprint(
-                                buffer.saved_version_fingerprint(),
-                            ),
                             line_ending: language::proto::serialize_line_ending(
                                 buffer.line_ending(),
                             ) as i32,
@@ -9610,7 +9606,6 @@ impl Project {
         _: Arc<Client>,
         mut cx: AsyncAppContext,
     ) -> Result<()> {
-        let fingerprint = Default::default();
         let version = deserialize_version(&envelope.payload.version);
         let buffer_id = BufferId::new(envelope.payload.buffer_id)?;
         let mtime = envelope.payload.mtime.map(|time| time.into());
@@ -9623,7 +9618,7 @@ impl Project {
                 .or_else(|| this.incomplete_remote_buffers.get(&buffer_id).cloned());
             if let Some(buffer) = buffer {
                 buffer.update(cx, |buffer, cx| {
-                    buffer.did_save(version, fingerprint, mtime, cx);
+                    buffer.did_save(version, mtime, cx);
                 });
             }
             Ok(())
@@ -9638,7 +9633,6 @@ impl Project {
     ) -> Result<()> {
         let payload = envelope.payload;
         let version = deserialize_version(&payload.version);
-        let fingerprint = RopeFingerprint::default();
         let line_ending = deserialize_line_ending(
             proto::LineEnding::from_i32(payload.line_ending)
                 .ok_or_else(|| anyhow!("missing line ending"))?,
@@ -9653,7 +9647,7 @@ impl Project {
                 .or_else(|| this.incomplete_remote_buffers.get(&buffer_id).cloned());
             if let Some(buffer) = buffer {
                 buffer.update(cx, |buffer, cx| {
-                    buffer.did_reload(version, fingerprint, line_ending, mtime, cx);
+                    buffer.did_reload(version, line_ending, mtime, cx);
                 });
             }
             Ok(())

crates/project/src/project_tests.rs

@@ -3122,12 +3122,7 @@ async fn test_buffer_is_dirty(cx: &mut gpui::TestAppContext) {
             &[language::Event::Edited, language::Event::DirtyChanged]
         );
         events.lock().clear();
-        buffer.did_save(
-            buffer.version(),
-            buffer.as_rope().fingerprint(),
-            buffer.file().unwrap().mtime(),
-            cx,
-        );
+        buffer.did_save(buffer.version(), buffer.file().unwrap().mtime(), cx);
     });
 
     // after saving, the buffer is not dirty, and emits a saved event.

crates/rope/Cargo.toml

@@ -13,7 +13,6 @@ path = "src/rope.rs"
 
 [dependencies]
 arrayvec = "0.7.1"
-bromberg_sl2 = { git = "https://github.com/zed-industries/bromberg_sl2", rev = "950bc5482c216c395049ae33ae4501e08975f17f" }
 log.workspace = true
 smallvec.workspace = true
 sum_tree.workspace = true

crates/rope/src/rope.rs

@@ -4,7 +4,6 @@ mod point_utf16;
 mod unclipped;
 
 use arrayvec::ArrayString;
-use bromberg_sl2::HashMatrix;
 use smallvec::SmallVec;
 use std::{
     cmp, fmt, io, mem,
@@ -26,12 +25,6 @@ const CHUNK_BASE: usize = 6;
 #[cfg(not(test))]
 const CHUNK_BASE: usize = 64;
 
-/// Type alias to [`HashMatrix`], an implementation of a homomorphic hash function. Two [`Rope`] instances
-/// containing the same text will produce the same fingerprint. This hash function is special in that
-/// it allows us to hash individual chunks and aggregate them up the [`Rope`]'s tree, with the resulting
-/// hash being equivalent to hashing all the text contained in the [`Rope`] at once.
-pub type RopeFingerprint = HashMatrix;
-
 #[derive(Clone, Default)]
 pub struct Rope {
     chunks: SumTree<Chunk>,
@@ -42,10 +35,6 @@ impl Rope {
         Self::default()
     }
 
-    pub fn text_fingerprint(text: &str) -> RopeFingerprint {
-        bromberg_sl2::hash_strict(text.as_bytes())
-    }
-
     pub fn append(&mut self, rope: Rope) {
         let mut chunks = rope.chunks.cursor::<()>();
         chunks.next(&());
@@ -424,10 +413,6 @@ impl Rope {
         self.clip_point(Point::new(row, u32::MAX), Bias::Left)
             .column
     }
-
-    pub fn fingerprint(&self) -> RopeFingerprint {
-        self.chunks.summary().fingerprint
-    }
 }
 
 impl<'a> From<&'a str> for Rope {
@@ -994,14 +979,12 @@ impl sum_tree::Item for Chunk {
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
 pub struct ChunkSummary {
     text: TextSummary,
-    fingerprint: RopeFingerprint,
 }
 
 impl<'a> From<&'a str> for ChunkSummary {
     fn from(text: &'a str) -> Self {
         Self {
             text: TextSummary::from(text),
-            fingerprint: Rope::text_fingerprint(text),
         }
     }
 }
@@ -1011,7 +994,6 @@ impl sum_tree::Summary for ChunkSummary {
 
     fn add_summary(&mut self, summary: &Self, _: &()) {
         self.text += &summary.text;
-        self.fingerprint = self.fingerprint * summary.fingerprint;
     }
 }
 

crates/rpc/proto/zed.proto

@@ -750,15 +750,15 @@ message BufferSaved {
     uint64 buffer_id = 2;
     repeated VectorClockEntry version = 3;
     Timestamp mtime = 4;
-    string fingerprint = 5;
+    reserved 5;
 }
 
 message BufferReloaded {
     uint64 project_id = 1;
     uint64 buffer_id = 2;
     repeated VectorClockEntry version = 3;
     Timestamp mtime = 4;
-    string fingerprint = 5;
+    reserved 5;
     LineEnding line_ending = 6;
 }
 
@@ -1605,7 +1605,7 @@ message BufferState {
     optional string diff_base = 4;
     LineEnding line_ending = 5;
     repeated VectorClockEntry saved_version = 6;
-    string saved_version_fingerprint = 7;
+    reserved 7;
     Timestamp saved_mtime = 8;
 }