feat: add support for text diff

ext/yrb/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "yrb"
-version = "0.5.5"
+version = "0.5.6"
 authors = ["Hannes Moser <[email protected]>"]
 edition = "2021"
 homepage = "https://github.com/y-crdt/yrb"

ext/yrb/src/lib.rs

@@ -2,20 +2,23 @@ extern crate core;
 
 use crate::yarray::YArray;
 use crate::yawareness::{YAwareness, YAwarenessEvent};
+use crate::ydiff::YDiff;
 use crate::ydoc::YDoc;
 use crate::ymap::YMap;
 use crate::ytext::YText;
 use crate::ytransaction::YTransaction;
 use crate::yxml_element::YXmlElement;
 use crate::yxml_fragment::YXmlFragment;
 use crate::yxml_text::YXmlText;
+
 use magnus::{class, define_module, function, method, Error, Module, Object};
 
 mod utils;
 mod yany;
 mod yarray;
 mod yattrs;
 mod yawareness;
+mod ydiff;
 mod ydoc;
 mod ymap;
 mod ytext;
@@ -224,6 +227,9 @@ fn init() -> Result<(), Error> {
         .define_class("Text", class::object())
         .expect("cannot define class Y::Text");
 
+    ytext
+        .define_private_method("ytext_diff", method!(YText::ytext_diff, 1))
+        .expect("cannot define private method: ytext_diff");
     ytext
         .define_private_method("ytext_format", method!(YText::ytext_format, 4))
         .expect("cannot define private method: ytext_format");
@@ -618,7 +624,7 @@ fn init() -> Result<(), Error> {
 
     let yawareness_event = module
         .define_class("AwarenessEvent", class::object())
-        .expect("cannot define class Y:AwarenessEvent");
+        .expect("cannot define class Y::AwarenessEvent");
     yawareness_event
         .define_method("added", method!(YAwarenessEvent::added, 0))
         .expect("cannot define private method: added");
@@ -629,5 +635,15 @@ fn init() -> Result<(), Error> {
         .define_method("removed", method!(YAwarenessEvent::removed, 0))
         .expect("cannot define private method: removed");
 
+    let ydiff = module
+        .define_class("Diff", class::object())
+        .expect("cannot define class Y::Diff");
+    ydiff
+        .define_private_method("ydiff_insert", method!(YDiff::ydiff_insert, 0))
+        .expect("cannot define private method: insert");
+    ydiff
+        .define_private_method("ydiff_attrs", method!(YDiff::ydiff_attrs, 0))
+        .expect("cannot define private method: attrs");
+
     Ok(())
 }

ext/yrb/src/yattrs.rs

@@ -1,16 +1,21 @@
 use crate::yvalue::YValue;
 use magnus::r_hash::ForEach::Continue;
 use magnus::{RHash, Value};
-use std::ops::{Deref, DerefMut};
+use std::cell::RefCell;
 use std::sync::Arc;
 use yrs::types::Attrs;
 use yrs::Any;
 
-pub(crate) struct YAttrs(pub(crate) Attrs);
+#[magnus::wrap(class = "Y::Attrs")]
+#[derive(Clone)]
+pub(crate) struct YAttrs(pub(crate) RefCell<Attrs>);
+
+/// SAFETY: This is safe because we only access this data when the GVL is held.
+unsafe impl Send for YAttrs {}
 
 impl From<Attrs> for YAttrs {
     fn from(value: Attrs) -> Self {
-        YAttrs(value)
+        YAttrs(RefCell::from(value))
     }
 }
 
@@ -29,20 +34,6 @@ impl From<RHash> for YAttrs {
             })
             .expect("cannot iterate attributes hash");
 
-        YAttrs(attrs)
-    }
-}
-
-impl Deref for YAttrs {
-    type Target = Attrs;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl DerefMut for YAttrs {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.0
+        YAttrs(RefCell::from(attrs))
     }
 }

ext/yrb/src/ydiff.rs

@@ -0,0 +1,19 @@
+use magnus::{IntoValue, RHash, Value};
+
+unsafe impl Send for YDiff {}
+
+#[magnus::wrap(class = "Y::Diff")]
+pub(crate) struct YDiff {
+    pub(crate) ydiff_insert: Value,
+    pub(crate) ydiff_attrs: Option<RHash>,
+}
+
+impl YDiff {
+    pub(crate) fn ydiff_insert(&self) -> Value {
+        self.ydiff_insert
+    }
+
+    pub(crate) fn ydiff_attrs(&self) -> Option<Value> {
+        self.ydiff_attrs.as_ref().map(|value| value.into_value())
+    }
+}

ext/yrb/src/ytext.rs

@@ -1,10 +1,13 @@
 use crate::yattrs::YAttrs;
+use crate::ydiff::YDiff;
 use crate::yvalue::YValue;
 use crate::YTransaction;
 use magnus::block::Proc;
 use magnus::value::Qnil;
-use magnus::{Error, RHash, Symbol, Value};
+use magnus::RArray;
+pub(crate) use magnus::{Error, IntoValue, RHash, Symbol, Value};
 use std::cell::RefCell;
+use yrs::types::text::YChange;
 use yrs::types::Delta;
 use yrs::{Any, GetString, Observable, Text, TextRef};
 
@@ -15,6 +18,38 @@ pub(crate) struct YText(pub(crate) RefCell<TextRef>);
 unsafe impl Send for YText {}
 
 impl YText {
+    pub(crate) fn ytext_diff(&self, transaction: &YTransaction) -> RArray {
+        let tx = transaction.transaction();
+        let tx = tx.as_ref().unwrap();
+
+        RArray::from_iter(
+            self.0
+                .borrow()
+                .diff(tx, YChange::identity)
+                .iter()
+                .map(move |diff| {
+                    let yvalue = YValue::from(diff.insert.clone());
+                    let insert = yvalue.0.into_inner();
+                    let attributes = diff.attributes.as_ref().map_or_else(
+                        || None,
+                        |boxed_attrs| {
+                            let attributes = RHash::new();
+                            for (key, value) in boxed_attrs.iter() {
+                                let key = key.to_string();
+                                let value = YValue::from(value.clone()).0.into_inner();
+                                attributes.aset(key, value).expect("cannot add value");
+                            }
+                            Some(attributes)
+                        },
+                    );
+                    YDiff {
+                        ydiff_insert: insert,
+                        ydiff_attrs: attributes,
+                    }
+                    .into_value()
+                }),
+        )
+    }
     pub(crate) fn ytext_format(
         &self,
         transaction: &YTransaction,
@@ -27,7 +62,9 @@ impl YText {
 
         let a = YAttrs::from(attrs);
 
-        self.0.borrow_mut().format(tx, index, length, a.0)
+        self.0
+            .borrow_mut()
+            .format(tx, index, length, a.0.into_inner())
     }
     pub(crate) fn ytext_insert(&self, transaction: &YTransaction, index: u32, chunk: String) {
         let mut tx = transaction.transaction();
@@ -66,7 +103,7 @@ impl YText {
 
         self.0
             .borrow_mut()
-            .insert_embed_with_attributes(tx, index, avalue, a.0);
+            .insert_embed_with_attributes(tx, index, avalue, a.0.into_inner());
     }
     pub(crate) fn ytext_insert_with_attributes(
         &self,
@@ -82,7 +119,7 @@ impl YText {
 
         self.0
             .borrow_mut()
-            .insert_with_attributes(tx, index, chunk.as_str(), a.0)
+            .insert_with_attributes(tx, index, chunk.as_str(), a.0.into_inner())
     }
     pub(crate) fn ytext_length(&self, transaction: &YTransaction) -> u32 {
         let tx = transaction.transaction();

lib/y-rb.rb

@@ -11,6 +11,7 @@
 
 require_relative "y/array"
 require_relative "y/awareness"
+require_relative "y/diff"
 require_relative "y/doc"
 require_relative "y/map"
 require_relative "y/text"

lib/y/array.rb

@@ -115,8 +115,8 @@ def detach(subscription_id)
     end
 
     # @return [void]
-    def each(&block)
-      document.current_transaction { |tx| yarray_each(tx, &block) }
+    def each(...)
+      document.current_transaction { |tx| yarray_each(tx, ...) }
     end
 
     # Check if the array is empty

lib/y/diff.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Y
+  # A representation of an uniformly-formatted chunk of rich context stored by
+  # Text or XmlText. It contains a value (which could be a string, embedded
+  # object or another shared type) with optional formatting attributes wrapping
+  # around this chunk.
+  class Diff
+    # @return [Object]
+    def insert
+      ydiff_insert
+    end
+
+    # @return [Hash]
+    def attrs
+      ydiff_attrs
+    end
+
+    # Convert the diff to a Hash representation
+    #
+    # @return [Hash]
+    def to_h
+      {
+        insert: ydiff_insert,
+        attrs: ydiff_attrs
+      }
+    end
+
+    # @!method ydiff_insert()
+    #   Returns string representation of text
+    #
+    # @return [Object]
+
+    # @!method ydiff_attrs()
+    #
+    # @return [Hash]
+  end
+end

lib/y/text.rb

@@ -80,6 +80,15 @@ def detach(subscription_id)
       ytext_unobserve(subscription_id)
     end
 
+    # Diff
+    #
+    # @return[Array<YDiff>]
+    def diff
+      document.current_transaction do |tx|
+        ytext_diff(tx)
+      end
+    end
+
     # Checks if text is empty
     #
     # @example Check if text is empty
@@ -284,6 +293,12 @@ def can_insert?(value)
         value.is_a?(Hash)
     end
 
+    # @!method ytext_diff(tx)
+    #   Returns text changes as list of diffs
+    #
+    # @param transaction [Y::Transaction]
+    # @return [Array<YDiff>]
+
     # @!method ytext_insert(tx, index, chunk)
     #   Insert into text at position
     #

lib/y/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Y
-  VERSION = "0.5.5"
+  VERSION = "0.5.6"
 end

spec/y/text_spec.rb

@@ -20,6 +20,21 @@
     expect(text.to_s).to eq("Hello, World!")
   end
 
+  it "get a list of changes" do
+    doc = Y::Doc.new
+    text = doc.get_text("my text")
+
+    text.insert(0, "Hello, World!", { format: "bold" })
+    text.insert(13, " From Hannes.", { format: "italic" })
+
+    expect(text.diff.map(&:to_h)).to eq([
+                                          { insert: "Hello, World!",
+                                            attrs: { "format" => "bold" } },
+                                          { insert: " From Hannes.",
+                                            attrs: { "format" => "italic" } }
+                                        ])
+  end
+
   it "inserts string at position" do
     doc = Y::Doc.new
     text = doc.get_text("my text")