Merge pull request #102 from y-crdt/to_json

`to_json` compatibility with Python `json`

src/json_builder.rs

@@ -0,0 +1,152 @@
+use std::{collections::HashMap, convert::TryFrom};
+
+use lib0::any::Any;
+use pyo3::{exceptions::PyTypeError, PyErr, PyObject, PyResult, Python};
+
+use crate::shared_types::{CompatiblePyType, YPyType};
+
+#[derive(Clone, Debug)]
+pub(crate) struct JsonBuilder(String);
+
+impl JsonBuilder {
+    pub fn new() -> Self {
+        JsonBuilder(String::new())
+    }
+
+    pub fn append_json<T: JsonBuildable>(&mut self, buildable: &T) -> Result<(), T::JsonError> {
+        let buffer = &mut self.0;
+        buildable.build_json(buffer)
+    }
+}
+
+impl From<JsonBuilder> for String {
+    fn from(json_builder: JsonBuilder) -> Self {
+        json_builder.0
+    }
+}
+
+pub(crate) trait JsonBuildable {
+    type JsonError;
+    fn build_json(&self, buffer: &mut String) -> Result<(), Self::JsonError>;
+}
+
+impl<'a> JsonBuildable for CompatiblePyType<'a> {
+    type JsonError = PyErr;
+
+    fn build_json(&self, buffer: &mut String) -> Result<(), Self::JsonError> {
+        match self {
+            CompatiblePyType::Bool(b) => {
+                let t: bool = b.extract().unwrap();
+                buffer.push_str(if t { "true" } else { "false" });
+            }
+            CompatiblePyType::Int(i) => buffer.push_str(&i.to_string()),
+            CompatiblePyType::Float(f) => buffer.push_str(&f.to_string()),
+            CompatiblePyType::String(s) => {
+                let string: String = s.extract().unwrap();
+                buffer.reserve(string.len() + 2);
+                buffer.push_str("\"");
+                buffer.push_str(&string);
+                buffer.push_str("\"");
+            }
+            CompatiblePyType::List(list) => {
+                buffer.push_str("[");
+                let length = list.len();
+                for (i, element) in list.iter().enumerate() {
+                    CompatiblePyType::try_from(element)?.build_json(buffer)?;
+                    if i + 1 < length {
+                        buffer.push_str(",");
+                    }
+                }
+
+                buffer.push_str("]");
+            }
+            CompatiblePyType::Dict(dict) => {
+                buffer.push_str("{");
+                let length = dict.len();
+                for (i, (k, v)) in dict.iter().enumerate() {
+                    CompatiblePyType::try_from(k)?.build_json(buffer)?;
+                    buffer.push_str(":");
+                    CompatiblePyType::try_from(v)?.build_json(buffer)?;
+                    if i + 1 < length {
+                        buffer.push_str(",");
+                    }
+                }
+                buffer.push_str("}");
+            }
+            CompatiblePyType::YType(y_type) => y_type.build_json(buffer)?,
+            CompatiblePyType::None => buffer.push_str("null"),
+        }
+
+        Ok(())
+    }
+}
+
+impl<'a> JsonBuildable for YPyType<'a> {
+    type JsonError = PyErr;
+
+    fn build_json(&self, buffer: &mut String) -> Result<(), Self::JsonError> {
+        let json = match self {
+            YPyType::Text(text) => Ok(text.borrow().to_json()),
+            YPyType::Array(array) => array.borrow().to_json(),
+            YPyType::Map(map) => map.borrow().to_json(),
+            xml => Err(PyTypeError::new_err(format!(
+                "XML elements cannot be converted to a JSON format: {xml}"
+            ))),
+        };
+        buffer.push_str(&json?);
+        Ok(())
+    }
+}
+
+impl JsonBuildable for Any {
+    type JsonError = PyErr;
+    fn build_json(&self, buffer: &mut String) -> Result<(), Self::JsonError> {
+        self.to_json(buffer);
+        Ok(())
+    }
+}
+
+impl JsonBuildable for HashMap<String, PyObject> {
+    type JsonError = PyErr;
+
+    fn build_json(&self, buffer: &mut String) -> Result<(), Self::JsonError> {
+        buffer.push_str("{");
+        let res: PyResult<()> = Python::with_gil(|py| {
+            for (i, (k, py_obj)) in self.iter().enumerate() {
+                let value: CompatiblePyType = py_obj.extract(py)?;
+                if i != 0 {
+                    buffer.push_str(",");
+                }
+                buffer.push_str(k);
+                buffer.push_str(":");
+                value.build_json(buffer)?;
+            }
+            Ok(())
+        });
+        res?;
+
+        buffer.push_str("}");
+        Ok(())
+    }
+}
+
+impl JsonBuildable for Vec<PyObject> {
+    type JsonError = PyErr;
+
+    fn build_json(&self, buffer: &mut String) -> Result<(), Self::JsonError> {
+        buffer.push_str("[");
+        let res: PyResult<()> = Python::with_gil(|py| {
+            self.iter().enumerate().try_for_each(|(i, object)| {
+                let py_type: CompatiblePyType = object.extract(py)?;
+                if i != 0 {
+                    buffer.push_str(",");
+                }
+                py_type.build_json(buffer)?;
+                Ok(())
+            })
+        });
+        res?;
+        buffer.push_str("]");
+        Ok(())
+    }
+}

src/lib.rs

@@ -1,5 +1,6 @@
 use pyo3::prelude::*;
 use pyo3::wrap_pyfunction;
+mod json_builder;
 mod shared_types;
 mod type_conversions;
 mod y_array;

src/shared_types.rs

@@ -5,8 +5,9 @@ use crate::{
     y_xml::{YXmlElement, YXmlText},
 };
 use pyo3::create_exception;
+use pyo3::types as pytypes;
 use pyo3::{exceptions::PyException, prelude::*};
-use std::{convert::TryFrom, fmt::Display};
+use std::fmt::Display;
 use yrs::types::TYPE_REFS_XML_TEXT;
 use yrs::types::{TypeRefs, TYPE_REFS_ARRAY, TYPE_REFS_MAP, TYPE_REFS_TEXT};
 use yrs::{types::TYPE_REFS_XML_ELEMENT, SubscriptionId};
@@ -50,6 +51,18 @@ pub enum SubId {
     Deep(DeepSubscription),
 }
 
+#[derive(Clone)]
+pub enum CompatiblePyType<'a> {
+    Bool(&'a pytypes::PyBool),
+    Int(&'a pytypes::PyInt),
+    Float(&'a pytypes::PyFloat),
+    String(&'a pytypes::PyString),
+    List(&'a pytypes::PyList),
+    Dict(&'a pytypes::PyDict),
+    YType(YPyType<'a>),
+    None,
+}
+
 #[derive(Clone)]
 pub enum SharedType<I, P> {
     Integrated(I),
@@ -67,68 +80,45 @@ impl<I, P> SharedType<I, P> {
         SharedType::Prelim(prelim)
     }
 }
-
-#[derive(FromPyObject)]
-pub enum Shared {
-    Text(Py<YText>),
-    Array(Py<YArray>),
-    Map(Py<YMap>),
-    XmlElement(Py<YXmlElement>),
-    XmlText(Py<YXmlText>),
+#[derive(Clone)]
+pub enum YPyType<'a> {
+    Text(&'a PyCell<YText>),
+    Array(&'a PyCell<YArray>),
+    Map(&'a PyCell<YMap>),
+    XmlElement(&'a PyCell<YXmlElement>),
+    XmlText(&'a PyCell<YXmlText>),
 }
 
-impl Shared {
+impl<'a> YPyType<'a> {
     pub fn is_prelim(&self) -> bool {
-        Python::with_gil(|py| match self {
-            Shared::Text(v) => v.borrow(py).prelim(),
-            Shared::Array(v) => v.borrow(py).prelim(),
-            Shared::Map(v) => v.borrow(py).prelim(),
-            Shared::XmlElement(_) | Shared::XmlText(_) => false,
-        })
+        match self {
+            YPyType::Text(v) => v.borrow().prelim(),
+            YPyType::Array(v) => v.borrow().prelim(),
+            YPyType::Map(v) => v.borrow().prelim(),
+            YPyType::XmlElement(_) | YPyType::XmlText(_) => false,
+        }
     }
 
     pub fn type_ref(&self) -> TypeRefs {
         match self {
-            Shared::Text(_) => TYPE_REFS_TEXT,
-            Shared::Array(_) => TYPE_REFS_ARRAY,
-            Shared::Map(_) => TYPE_REFS_MAP,
-            Shared::XmlElement(_) => TYPE_REFS_XML_ELEMENT,
-            Shared::XmlText(_) => TYPE_REFS_XML_TEXT,
+            YPyType::Text(_) => TYPE_REFS_TEXT,
+            YPyType::Array(_) => TYPE_REFS_ARRAY,
+            YPyType::Map(_) => TYPE_REFS_MAP,
+            YPyType::XmlElement(_) => TYPE_REFS_XML_ELEMENT,
+            YPyType::XmlText(_) => TYPE_REFS_XML_TEXT,
         }
     }
 }
 
-impl Display for Shared {
+impl<'a> Display for YPyType<'a> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let info = Python::with_gil(|py| match self {
-            Shared::Text(t) => t.borrow(py).__str__(),
-            Shared::Array(a) => a.borrow(py).__str__(),
-            Shared::Map(m) => m.borrow(py).__str__(),
-            Shared::XmlElement(xml) => xml.borrow(py).__str__(),
-            Shared::XmlText(xml) => xml.borrow(py).__str__(),
-        });
+        let info = match self {
+            YPyType::Text(t) => t.borrow().__str__(),
+            YPyType::Array(a) => a.borrow().__str__(),
+            YPyType::Map(m) => m.borrow().__str__(),
+            YPyType::XmlElement(xml) => xml.borrow().__str__(),
+            YPyType::XmlText(xml) => xml.borrow().__str__(),
+        };
         write!(f, "{}", info)
     }
 }
-
-impl TryFrom<PyObject> for Shared {
-    type Error = PyErr;
-
-    fn try_from(value: PyObject) -> Result<Self, Self::Error> {
-        Python::with_gil(|py| {
-            let value = value.as_ref(py);
-
-            if let Ok(text) = value.extract() {
-                Ok(Shared::Text(text))
-            } else if let Ok(array) = value.extract() {
-                Ok(Shared::Array(array))
-            } else if let Ok(map) = value.extract() {
-                Ok(Shared::Map(map))
-            } else {
-                Err(pyo3::exceptions::PyValueError::new_err(
-                    "Could not extract Python value into a shared type.",
-                ))
-            }
-        })
-    }
-}