Add payload deserialization support

Author: JojiiOfficial

src/error.rs

@@ -60,7 +60,7 @@ impl Debug for NotA<bool> {
 
 impl Display for NotA<bool> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        f.write_str(concat!("not a bool"))
+        f.write_str("not a bool")
     }
 }
 
@@ -87,7 +87,7 @@ impl Debug for NotA<i64> {
 
 impl Display for NotA<i64> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        f.write_str(concat!("not an i64"))
+        f.write_str("not an i64")
     }
 }
 
@@ -114,7 +114,7 @@ impl Debug for NotA<f64> {
 
 impl Display for NotA<f64> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        f.write_str(concat!("not a f64"))
+        f.write_str("not a f64")
     }
 }
 
@@ -141,7 +141,7 @@ impl Debug for NotA<String> {
 
 impl Display for NotA<String> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        f.write_str(concat!("not a String"))
+        f.write_str("not a String")
     }
 }
 

src/lib.rs

@@ -165,6 +165,9 @@ pub mod prelude;
 #[doc(hidden)]
 pub mod serde;
 
+#[cfg(feature = "serde")]
+pub mod serde_deser;
+
 // Re-exports
 pub use crate::payload::Payload;
 pub use crate::qdrant_client::error::QdrantError;

src/payload.rs

@@ -1,9 +1,13 @@
 use std::collections::HashMap;
 
+#[cfg(feature = "serde")]
+use serde::de::IntoDeserializer;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 use crate::qdrant::{GeoPoint, Struct, Value};
+#[cfg(feature = "serde")]
+use crate::QdrantError;
 
 /// Point payload
 ///
@@ -69,6 +73,15 @@ impl Payload {
     pub fn insert(&mut self, key: impl ToString, val: impl Into<Value>) {
         self.0.insert(key.to_string(), val.into());
     }
+
+    /// Deserializes the payload directly into `T`. This requires T to implement `serde::Deserialize`.
+    /// Returns an error if `T` and the payload have a different structure.
+    #[cfg(feature = "serde")]
+    pub fn deserialize<T: serde::de::DeserializeOwned>(self) -> Result<T, QdrantError> {
+        Ok(T::deserialize(
+            Struct { fields: self.0 }.into_deserializer(),
+        )?)
+    }
 }
 
 impl From<HashMap<String, Value>> for Payload {

src/qdrant_client/error.rs

@@ -1,6 +1,9 @@
 use thiserror::Error;
 use tonic::codegen::http::uri::InvalidUri;
 
+#[cfg(feature = "serde")]
+use crate::serde_deser::DeserPayloadError;
+
 /// Qdrant client error
 #[derive(Error, Debug)]
 pub enum QdrantError {
@@ -47,6 +50,24 @@ pub enum QdrantError {
     #[cfg(feature = "serde")]
     #[error("JSON cannot be converted to payload, only JSON objects are supported")]
     JsonToPayload(serde_json::Value),
+
+    /// Error when failing to deserializing payload using `payload.deserialize()`.
+    #[cfg(feature = "serde")]
+    #[error("Error in payload deserialization")]
+    PayloadDeserialization(#[from] DeserPayloadError),
+}
+
+impl QdrantError {
+    // Only used in tests for now.
+    #[cfg(feature = "serde")]
+    #[allow(dead_code)]
+    pub(crate) fn as_payload_deserialization(&self) -> Option<&DeserPayloadError> {
+        if let QdrantError::PayloadDeserialization(err) = self {
+            Some(err)
+        } else {
+            None
+        }
+    }
 }
 
 impl From<tonic::Status> for QdrantError {