From 53b7a3ca7f717c344773360d5c71320650b896f1 Mon Sep 17 00:00:00 2001
From: CPunisher <1343316114@qq.com>
Date: Fri, 20 Sep 2024 13:22:44 +0800
Subject: [PATCH] feat: support `from_reader` (#113)

---
 examples/serde.rs             | 11 +++++++++++
 examples/testdata/person.json |  5 +++++
 src/error.rs                  |  1 -
 src/lib.rs                    |  6 +++---
 src/serde/de.rs               | 13 +++++++++++++
 src/serde/mod.rs              |  4 +++-
 6 files changed, 35 insertions(+), 5 deletions(-)
 create mode 100644 examples/testdata/person.json

diff --git a/examples/serde.rs b/examples/serde.rs
index cbe0181..9853d23 100644
--- a/examples/serde.rs
+++ b/examples/serde.rs
@@ -1,3 +1,5 @@
+use std::fs::File;
+
 use sonic_rs::{Deserialize, Serialize};
 
 #[derive(Serialize, Deserialize)]
@@ -8,6 +10,7 @@ struct Person {
 }
 
 fn main() {
+    // parse a string
     let data = r#"{
   "name": "Xiaoming",
   "age": 18,
@@ -20,4 +23,12 @@ fn main() {
     assert_eq!(p.name, "Xiaoming");
     let out = sonic_rs::to_string_pretty(&p).unwrap();
     assert_eq!(out, data);
+
+    // parse a file reader
+    let p: Person =
+        sonic_rs::from_reader(File::open("examples/testdata/person.json").unwrap()).unwrap();
+    assert_eq!(p.age, 18);
+    assert_eq!(p.name, "Xiaoming");
+    let out = sonic_rs::to_string_pretty(&p).unwrap();
+    assert_eq!(out, data);
 }
diff --git a/examples/testdata/person.json b/examples/testdata/person.json
new file mode 100644
index 0000000..c6b6a44
--- /dev/null
+++ b/examples/testdata/person.json
@@ -0,0 +1,5 @@
+{
+  "name": "Xiaoming",
+  "age": 18,
+  "phones": ["+123456"]
+}
diff --git a/src/error.rs b/src/error.rs
index 17d3897..70cbcfb 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -164,7 +164,6 @@ impl From<Error> for std::io::Error {
 pub enum Category {
     /// The error was caused by a failure to read or write bytes on an I/O
     /// stream.
-    /// TODO: support stream reader in the future
     Io,
 
     /// The error was caused by input that was not syntactically valid JSON.
diff --git a/src/lib.rs b/src/lib.rs
index 8a2e738..0f02986 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -41,9 +41,9 @@ pub use crate::lazyvalue::{
 pub use crate::pointer::{JsonPointer, PointerNode, PointerTree};
 #[doc(inline)]
 pub use crate::serde::{
-    from_slice, from_slice_unchecked, from_str, to_string, to_string_pretty, to_vec, to_vec_pretty,
-    to_writer, to_writer_pretty, Deserializer, JsonNumberTrait, Number, RawNumber, Serializer,
-    StreamDeserializer,
+    from_reader, from_slice, from_slice_unchecked, from_str, to_string, to_string_pretty, to_vec,
+    to_vec_pretty, to_writer, to_writer_pretty, Deserializer, JsonNumberTrait, Number, RawNumber,
+    Serializer, StreamDeserializer,
 };
 #[doc(inline)]
 pub use crate::value::{
diff --git a/src/serde/de.rs b/src/serde/de.rs
index 5d76aaa..e0a4ce1 100644
--- a/src/serde/de.rs
+++ b/src/serde/de.rs
@@ -1370,3 +1370,16 @@ where
 {
     from_trait(Read::new(s.as_bytes(), false))
 }
+
+/// Deserialize an instance of type `T` from a Reader
+pub fn from_reader<R, T>(mut reader: R) -> Result<T>
+where
+    R: std::io::Read,
+    T: de::DeserializeOwned,
+{
+    let mut data = Vec::new();
+    if let Err(e) = reader.read_to_end(&mut data) {
+        return Err(Error::io(e));
+    };
+    from_slice(data.as_slice())
+}
diff --git a/src/serde/mod.rs b/src/serde/mod.rs
index 7dcda6c..7154452 100644
--- a/src/serde/mod.rs
+++ b/src/serde/mod.rs
@@ -7,7 +7,9 @@ pub(crate) mod ser;
 
 pub(crate) use self::de::tri;
 pub use self::{
-    de::{from_slice, from_slice_unchecked, from_str, Deserializer, StreamDeserializer},
+    de::{
+        from_reader, from_slice, from_slice_unchecked, from_str, Deserializer, StreamDeserializer,
+    },
     number::{JsonNumberTrait, Number},
     rawnumber::RawNumber,
     ser::{