glib: Add optional support for serialization and deserialization with…

… serde

This feature is gated as `serde`

Supports both serialization and deserialization:
- glib::ByteArray
- glib::Bytes
- glib::GString (with in-place deserialization)

Supports serialization only:
- glib::GStr
- glib::StrV

Collection types are also supported  as long as the type parameters implement the necessary traits:
- glib::Slice<T: TransparentType + ..>
- glib::PtrSlice<T: TransparentPtrType + ..>
- glib::List<T: TransparentPtrType + ..>
- glib::SList<T: TransparentPtrType + ..>

.github/workflows/CI.yml

@@ -23,7 +23,7 @@ jobs:
           - { name: "cairo", features: "png,pdf,svg,ps,use_glib,v1_18,freetype,script,xcb,xlib,win32-surface", nightly: "--features 'png,pdf,svg,ps,use_glib,v1_18,freetype,script,xcb,xlib,win32-surface'", test_sys: true }
           - { name: "gdk-pixbuf", features: "v2_42", nightly: "--all-features", test_sys: true }
           - { name: "gio", features: "v2_74", nightly: "--all-features", test_sys: true }
-          - { name: "glib", features: "v2_74", nightly: "--all-features", test_sys: true }
+          - { name: "glib", features: "v2_74,serde", nightly: "--all-features", test_sys: true }
           - { name: "graphene", features: "", nightly: "", test_sys: true }
           - { name: "pango", features: "v1_50", nightly: "--all-features", test_sys: true }
           - { name: "pangocairo", features: "", nightly: "--all-features", test_sys: true }

.github/workflows/windows.yml

@@ -126,7 +126,14 @@ jobs:
         with:
           command: test
           args: --manifest-path ${{ matrix.conf.name }}/sys/Cargo.toml ${{ matrix.conf.args }}
-        if: matrix.conf.name != 'examples' && matrix.conf.name != 'glib-build-tools'
+        if: matrix.conf.name != 'examples' && matrix.conf.name != 'glib' && matrix.conf.name != 'glib-build-tools'
+
+      - name: test glib-sys
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --manifest-path ${{ matrix.conf.name }}/sys/Cargo.toml --features v2_74
+        if: matrix.conf.name == 'glib'
 
       - name: build
         uses: actions-rs/cargo@v1

glib/Cargo.toml

@@ -35,12 +35,14 @@ smallvec = { version = "1.0", features = ["union", "const_generics", "const_new"
 thiserror = "1"
 gio_ffi = { package = "gio-sys", path = "../gio/sys", optional = true }
 memchr = "2.5.0"
+serde = { version = "1.0", optional = true }
 
 [dev-dependencies]
 tempfile = "3"
 gir-format-check = "^0.1"
 trybuild2 = "1"
 criterion = "0.4.0"
+serde_json = "1.0"
 
 [features]
 default = ["gio"]
@@ -59,6 +61,7 @@ log_macros = ["log"]
 dox = ["ffi/dox", "gobject_ffi/dox", "log_macros"]
 compiletests = []
 gio = ["gio_ffi"]
+serde = ["dep:serde"]
 
 [package.metadata.docs.rs]
 features = ["dox"]

glib/src/lib.rs

@@ -213,6 +213,9 @@ pub use self::thread_pool::{ThreadHandle, ThreadPool};
 
 pub mod thread_guard;
 
+#[cfg(feature = "serde")]
+mod serde;
+
 // rustdoc-stripper-ignore-next
 /// This is the log domain used by the [`clone!`][crate::clone!] macro. If you want to use a custom
 /// logger (it prints to stdout by default), you can set your own logger using the corresponding

glib/src/serde/byte_array.rs

@@ -0,0 +1,53 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+use serde::Deserializer;
+
+use super::*;
+
+use crate::ByteArray;
+
+serialize_impl!(ByteArray, Bytes(b) => b);
+
+deserialize_impl! {
+    ByteArray,
+    "a sequence of bytes",
+    Deserializer::deserialize_seq => match impl {
+        Bytes(b) => Ok(ByteArray::from(b)),
+        ByteBuf(buf) => Ok(ByteArray::from(buf.as_slice())),
+        Seq(s) => {
+            // See https://docs.rs/serde/1.0.159/src/serde/de/impls.rs.html#1038
+            // and https://docs.rs/serde/1.0.159/src/serde/private/size_hint.rs.html#13
+            let mut byte_vec = Vec::with_capacity(min(s.size_hint().unwrap_or(0), 4096));
+
+            while let Some(byte) = s.next_element()? {
+                byte_vec.push(byte)
+            }
+
+            Ok(ByteArray::from(byte_vec.as_slice()))
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{gformat, ByteArray};
+
+    #[test]
+    fn serialization() {
+        let json = match serde_json::to_value(ByteArray::from(
+            gformat!("Lorem ipsum dolor sit amet").as_bytes(),
+        )) {
+            Ok(v) => Some(v),
+            Err(_) => None,
+        };
+
+        assert_ne!(json, None);
+    }
+
+    #[test]
+    fn deserialization() {
+        let json_str = r#"[76,111,114,101,109,32,105,112,115,117,109,32,100,111,108,111,114,32,115,105,116,32,97,109,101]"#;
+
+        serde_json::from_str::<ByteArray>(json_str).unwrap();
+    }
+}

glib/src/serde/bytes.rs

@@ -0,0 +1,51 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+use serde::Deserializer;
+
+use super::*;
+
+use crate::Bytes;
+
+serialize_impl!(Bytes, Bytes(b) => b);
+
+deserialize_impl! {
+    Bytes,
+    "a sequence of bytes",
+    Deserializer::deserialize_seq => match impl {
+        Bytes(b) => Ok(Bytes::from_owned(b.to_owned())),
+        ByteBuf(buf) => Ok(Bytes::from_owned(buf)),
+        Seq(s) => {
+            let mut byte_vec = Vec::with_capacity(min(s.size_hint().unwrap_or(0), 4096));
+
+            while let Some(byte) = s.next_element()? {
+                byte_vec.push(byte)
+            }
+
+            Ok(Bytes::from_owned(byte_vec))
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{gformat, Bytes};
+
+    #[test]
+    fn serialization() {
+        let json = match serde_json::to_value(Bytes::from_owned(
+            gformat!("Lorem ipsum dolor sit amet").into_bytes(),
+        )) {
+            Ok(v) => Some(v),
+            Err(_) => None,
+        };
+
+        assert_ne!(json, None);
+    }
+
+    #[test]
+    fn deserialization() {
+        let json_str = r#"[76,111,114,101,109,32,105,112,115,117,109,32,100,111,108,111,114,32,115,105,116,32,97,109,101]"#;
+
+        serde_json::from_str::<Bytes>(json_str).unwrap();
+    }
+}

glib/src/serde/collections.rs

@@ -0,0 +1,194 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+use super::*;
+
+use crate::{
+    translate::{TransparentPtrType, TransparentType},
+    List, PtrSlice, SList, Slice, StrV,
+};
+
+serialize_impl!(Slice<T: TransparentType>, Sequence(iter) => iter);
+
+deserialize_impl! {
+    Slice<T: TransparentType>,
+    "a sequence of GLib transparent values",
+    Deserializer::deserialize_seq => match impl {
+        Seq(s) => {
+            let mut slice = Slice::with_capacity(min(s.size_hint().unwrap_or(0), 4096));
+
+            while let Some(item) = s.next_element()? {
+                slice.push(item)
+            }
+
+            Ok(slice)
+        },
+        @in_place(this) => match impl {
+            Seq(s) => {
+                this.clear();
+                this.reserve(min(s.size_hint().unwrap_or(0), 4096));
+
+                while let Some(item) = s.next_element()? {
+                    this.push(item)
+                }
+
+                Ok(())
+            },
+        },
+    }
+}
+
+serialize_impl!(PtrSlice<T: TransparentPtrType>, Sequence(iter) => iter);
+
+deserialize_impl! {
+    PtrSlice<T: TransparentPtrType>,
+    "a sequence of GLib transparent pointer values",
+    Deserializer::deserialize_seq => match impl {
+        Seq(s) => {
+            let mut slice = PtrSlice::with_capacity(min(s.size_hint().unwrap_or(0), 4096));
+
+            while let Some(item) = s.next_element()? {
+                slice.push(item)
+            }
+
+            Ok(slice)
+        },
+        @in_place(this) => match impl {
+            Seq(s) => {
+                this.clear();
+                this.reserve(min(s.size_hint().unwrap_or(0), 4096));
+
+                while let Some(item) = s.next_element()? {
+                    this.push(item)
+                }
+
+                Ok(())
+            },
+        },
+    }
+}
+
+serialize_impl!(List<T: TransparentPtrType>, Sequence(iter) => iter.iter());
+
+deserialize_impl! {
+    List<T: TransparentPtrType>,
+    "a sequence of GLib transparent pointer values",
+    Deserializer::deserialize_seq => match impl {
+        Seq(s) => {
+            let mut list = List::new();
+
+            while let Some(item) = s.next_element()? {
+                list.push_front(item)
+            }
+            list.reverse();
+
+            Ok(list)
+        },
+        @in_place(this) => match impl {
+            Seq(s) => {
+                this.clear();
+
+                while let Some(item) = s.next_element()? {
+                    this.push_front(item)
+                }
+                this.reverse();
+
+                Ok(())
+            },
+        },
+    }
+}
+
+serialize_impl!(SList<T: TransparentPtrType>, Sequence(iter) => iter.iter());
+
+deserialize_impl! {
+    SList<T: TransparentPtrType>,
+    "a sequence of GLib transparent pointer values",
+    Deserializer::deserialize_seq => match impl {
+        Seq(s) => {
+            let mut list = SList::new();
+
+            while let Some(item) = s.next_element()? {
+                list.push_front(item)
+            }
+            list.reverse();
+
+            Ok(list)
+        },
+        @in_place(this) => match impl {
+            Seq(s) => {
+                this.clear();
+
+                while let Some(item) = s.next_element()? {
+                    this.push_front(item)
+                }
+                this.reverse();
+
+                Ok(())
+            },
+        },
+    }
+}
+
+serialize_impl!(StrV, Sequence(iter) => iter);
+
+#[cfg(test)]
+mod tests {
+    use serde_json::json;
+
+    use crate::{gformat, Bytes, List, PtrSlice, SList, Slice};
+
+    #[test]
+    fn serialization_equality() {
+        let bytes = gformat!("Lorem ipsum dolor sit amet").into_bytes();
+
+        let slice = Slice::from([
+            Bytes::from_owned(bytes[..].to_vec()),
+            Bytes::from_owned(bytes[1..].to_vec()),
+            Bytes::from_owned(bytes[2..].to_vec()),
+            Bytes::from_owned(bytes[3..].to_vec()),
+        ]);
+
+        let ptr_slice = PtrSlice::from([
+            Bytes::from_owned(bytes[..].to_vec()),
+            Bytes::from_owned(bytes[1..].to_vec()),
+            Bytes::from_owned(bytes[2..].to_vec()),
+            Bytes::from_owned(bytes[3..].to_vec()),
+        ]);
+
+        let mut list = List::<Bytes>::new();
+        list.push_front(Bytes::from_owned(bytes[..].to_vec()));
+        list.push_front(Bytes::from_owned(bytes[1..].to_vec()));
+        list.push_front(Bytes::from_owned(bytes[2..].to_vec()));
+        list.push_front(Bytes::from_owned(bytes[3..].to_vec()));
+        list.reverse();
+
+        let mut slist = SList::<Bytes>::new();
+        slist.push_front(Bytes::from_owned(bytes[..].to_vec()));
+        slist.push_front(Bytes::from_owned(bytes[1..].to_vec()));
+        slist.push_front(Bytes::from_owned(bytes[2..].to_vec()));
+        slist.push_front(Bytes::from_owned(bytes[3..].to_vec()));
+        slist.reverse();
+
+        assert_eq!(json!(&slice), json!(&list));
+        assert_eq!(json!(&slice), json!(&slist));
+        assert_eq!(json!(&ptr_slice), json!(&list));
+        assert_eq!(json!(&ptr_slice), json!(&slist));
+        assert_eq!(json!(&slice), json!(&ptr_slice));
+        assert_eq!(json!(&list), json!(&slist));
+    }
+
+    #[test]
+    fn deserialization() {
+        let json_str = r#"
+[
+    [76,111,114,101,109,32,105,112,115,117,109,32,100,111,108,111,114,32,115,105,116,32,97,109,101],
+    [111,114,101,109,32,105,112,115,117,109,32,100,111,108,111,114,32,115,105,116,32,97,109,101],
+    [114,101,109,32,105,112,115,117,109,32,100,111,108,111,114,32,115,105,116,32,97,109,101],
+    [101,109,32,105,112,115,117,109,32,100,111,108,111,114,32,115,105,116,32,97,109,101]
+]"#;
+        serde_json::from_str::<Slice<Bytes>>(json_str).unwrap();
+        serde_json::from_str::<PtrSlice<Bytes>>(json_str).unwrap();
+        serde_json::from_str::<List<Bytes>>(json_str).unwrap();
+        serde_json::from_str::<SList<Bytes>>(json_str).unwrap();
+    }
+}