[WIP] Support no_std

.github/workflows/rust_tests.yml

@@ -53,14 +53,14 @@ jobs:
 
     # If glibc, compile and test all
     - uses: actions-rs/cargo@v1
-      name: "Build"
+      name: "Build glibc"
       if: matrix.target == 'x86_64-unknown-linux-gnu'
       with:
         command: build
         toolchain: ${{ matrix.toolchain }}
         args: --target ${{ matrix.target }} --all-features
     - uses: actions-rs/cargo@v1
-      name: "Test"
+      name: "Test glibc"
       if: matrix.target == 'x86_64-unknown-linux-gnu'
       with:
         command: test
@@ -129,3 +129,31 @@ jobs:
         command: build
         toolchain: ${{ matrix.toolchain }}
         args: --target ${{ matrix.target }} --manifest-path ./example-projects/warp-example/Cargo.toml
+
+  check_no_std:
+    name: Check no_std
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+      # Caching stuff
+      - uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+          key: ${{ runner.os }}-cargo-no-std-deps-${{ hashFiles('**/Cargo.toml') }}
+      - uses: actions/cache@v2
+        with:
+          path: |
+            target/
+          key: ${{ runner.os }}-cargo-no-std-build-${{ hashFiles('**/Cargo.toml') }}
+      - name: Download cargo-nono
+        run: curl -LSfs https://japaric.github.io/trust/install.sh | sh -s -- --git hobofan/cargo-nono
+      - name: Run check
+        run: ./cargo-nono check

Cargo.toml

@@ -11,12 +11,17 @@ repository = "https://github.com/cloudevents/sdk-rust"
 exclude = [
     ".github/*"
 ]
-categories = ["web-programming", "encoding", "data-structures"]
+categories = ["web-programming", "encoding", "data-structures", "no_std"]
 
 [lib]
 name = "cloudevents"
 
 [features]
+# Without default features, the package acts as no_std
+default = ["std"]
+
+std = ["snafu/std", "url"]
+
 actix = ["actix-web", "async-trait", "lazy_static", "bytes", "futures"]
 reqwest = ["reqwest-lib", "async-trait", "lazy_static", "bytes"]
 rdkafka = ["rdkafka-lib", "lazy_static", "bytes", "futures"]
@@ -28,9 +33,9 @@ serde_json = "^1.0"
 chrono = { version = "^0.4", features = ["serde"] }
 delegate-attr = "^0.2"
 base64 = "^0.12"
-url = { version = "^2.1", features = ["serde"] }
-snafu = "^0.6"
+snafu = { version = "^0.6", default-features = false }
 bitflags = "^1.2"
+url = { version = "^2.1", features = ["serde"], optional = true }
 
 # runtime optional deps
 actix-web = { version = "^3", default-features = false, optional = true }
@@ -49,7 +54,7 @@ hostname = "^0.3"
 uuid = { version = "^0.8", features = ["v4"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-web-sys = { version = "^0.3", features = ["Window", "Location"] }
+web-sys = { version = "^0.3", default-features = false, features = ["Window", "Location"] }
 uuid = { version = "^0.8", features = ["v4", "wasm-bindgen"] }
 
 [dev-dependencies]

example-projects/no-std-example/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "no-std-example"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+cloudevents-sdk = { path = "../..", default-features = false }
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"

example-projects/no-std-example/src/main.rs

@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+use cloudevents;
+use cloudevents::EventBuilder;
+
+#[panic_handler]
+fn panic(_info: &PanicInfo) -> ! {
+    loop {}
+}
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    loop {
+        #[allow(dead_code)]
+        let event = cloudevents::EventBuilderV10::new()
+            .id("my_id")
+            .source("my_source")
+            .subject("some_subject")
+            .build()
+            .unwrap();
+    }
+}

src/event/attributes.rs

@@ -1,19 +1,18 @@
 use super::{
-    AttributesIntoIteratorV03, AttributesIntoIteratorV10, AttributesV03, AttributesV10,
-    ExtensionValue, SpecVersion, UriReference,
+    types::*, AttributesIntoIteratorV03, AttributesIntoIteratorV10, AttributesV03, AttributesV10,
+    ExtensionValue, SpecVersion,
 };
 use chrono::{DateTime, Utc};
 use serde::Serializer;
 use std::fmt;
-use url::Url;
 
 /// Enum representing a borrowed value of a CloudEvent attribute.
 /// This represents the types defined in the [CloudEvent spec type system](https://github.com/cloudevents/spec/blob/v1.0/spec.md#type-system)
 #[derive(Debug, PartialEq, Eq)]
 pub enum AttributeValue<'a> {
     SpecVersion(SpecVersion),
     String(&'a str),
-    URI(&'a Url),
+    URI(&'a Uri),
     URIRef(&'a UriReference),
     Boolean(&'a bool),
     Integer(&'a i64),
@@ -57,7 +56,7 @@ pub trait AttributesReader {
     /// Get the [datacontenttype](https://github.com/cloudevents/spec/blob/master/spec.md#datacontenttype).
     fn datacontenttype(&self) -> Option<&str>;
     /// Get the [dataschema](https://github.com/cloudevents/spec/blob/master/spec.md#dataschema).
-    fn dataschema(&self) -> Option<&Url>;
+    fn dataschema(&self) -> Option<&Uri>;
     /// Get the [subject](https://github.com/cloudevents/spec/blob/master/spec.md#subject).
     fn subject(&self) -> Option<&str>;
     /// Get the [time](https://github.com/cloudevents/spec/blob/master/spec.md#time).
@@ -87,7 +86,7 @@ pub trait AttributesWriter {
         -> Option<String>;
     /// Set the [dataschema](https://github.com/cloudevents/spec/blob/master/spec.md#dataschema).
     /// Returns the previous value.
-    fn set_dataschema(&mut self, dataschema: Option<impl Into<Url>>) -> Option<Url>;
+    fn set_dataschema(&mut self, dataschema: Option<impl Into<Uri>>) -> Option<Uri>;
 }
 
 pub(crate) trait AttributesConverter {
@@ -154,7 +153,7 @@ impl AttributesReader for Attributes {
         }
     }
 
-    fn dataschema(&self) -> Option<&Url> {
+    fn dataschema(&self) -> Option<&Uri> {
         match self {
             Attributes::V03(a) => a.dataschema(),
             Attributes::V10(a) => a.dataschema(),
@@ -222,7 +221,7 @@ impl AttributesWriter for Attributes {
         }
     }
 
-    fn set_dataschema(&mut self, dataschema: Option<impl Into<Url>>) -> Option<Url> {
+    fn set_dataschema(&mut self, dataschema: Option<impl Into<Uri>>) -> Option<Uri> {
         match self {
             Attributes::V03(a) => a.set_dataschema(dataschema),
             Attributes::V10(a) => a.set_dataschema(dataschema),
@@ -253,31 +252,27 @@ impl Attributes {
 }
 
 #[cfg(not(target_arch = "wasm32"))]
-pub(crate) fn default_hostname() -> Url {
-    Url::parse(
-        format!(
-            "http://{}",
-            hostname::get()
-                .ok()
-                .map(|s| s.into_string().ok())
-                .flatten()
-                .unwrap_or_else(|| "localhost".to_string())
-        )
-        .as_ref(),
+pub(crate) fn default_hostname() -> Uri {
+    format!(
+        "http://{}",
+        hostname::get()
+            .ok()
+            .map(|s| s.into_string().ok())
+            .flatten()
+            .unwrap_or_else(|| "localhost".to_string())
     )
+    .into_uri()
     .unwrap()
 }
 
 #[cfg(target_arch = "wasm32")]
-pub(crate) fn default_hostname() -> Url {
+pub(crate) fn default_hostname() -> Uri {
     use std::str::FromStr;
 
-    Url::from_str(
-        web_sys::window()
-            .map(|w| w.location().host().ok())
-            .flatten()
-            .unwrap_or(String::from("http://localhost"))
-            .as_str(),
-    )
-    .unwrap()
+    web_sys::window()
+        .map(|w| w.location().host().ok())
+        .flatten()
+        .unwrap_or(String::from("http://localhost"))
+        .into_uri()
+        .unwrap()
 }

src/event/builder.rs

@@ -1,11 +1,11 @@
+use super::types;
 use super::Event;
 use snafu::Snafu;
 
 /// Trait to implement a builder for [`Event`]:
 /// ```
 /// use cloudevents::event::{EventBuilderV10, EventBuilder};
 /// use chrono::Utc;
-/// use url::Url;
 ///
 /// let event = EventBuilderV10::new()
 ///     .id("my_event.my_application")
@@ -48,9 +48,9 @@ pub enum Error {
         attribute_name,
         source
     ))]
-    ParseUrlError {
+    ParseUriError {
         attribute_name: &'static str,
-        source: url::ParseError,
+        source: types::ParseUriError,
     },
     #[snafu(display(
         "Invalid value setting attribute '{}' with uriref type",

src/event/mod.rs

@@ -8,7 +8,7 @@ mod extensions;
 mod format;
 mod message;
 mod spec_version;
-mod types;
+pub mod types;
 
 pub use attributes::Attributes;
 pub use attributes::{AttributeValue, AttributesReader, AttributesWriter};
@@ -20,7 +20,6 @@ pub(crate) use message::EventBinarySerializer;
 pub(crate) use message::EventStructuredSerializer;
 pub use spec_version::SpecVersion;
 pub use spec_version::UnknownSpecVersion;
-pub use types::{TryIntoTime, TryIntoUrl, UriReference};
 
 mod v03;
 
@@ -38,11 +37,10 @@ pub use v10::EventBuilder as EventBuilderV10;
 pub(crate) use v10::EventFormatDeserializer as EventFormatDeserializerV10;
 pub(crate) use v10::EventFormatSerializer as EventFormatSerializerV10;
 
-use chrono::{DateTime, Utc};
 use delegate_attr::delegate;
 use std::collections::HashMap;
 use std::fmt;
-use url::Url;
+use types::*;
 
 /// Data structure that represents a [CloudEvent](https://github.com/cloudevents/spec/blob/master/spec.md).
 /// It provides methods to get the attributes through [`AttributesReader`]
@@ -89,7 +87,7 @@ impl AttributesReader for Event {
     fn specversion(&self) -> SpecVersion;
     fn ty(&self) -> &str;
     fn datacontenttype(&self) -> Option<&str>;
-    fn dataschema(&self) -> Option<&Url>;
+    fn dataschema(&self) -> Option<&Uri>;
     fn subject(&self) -> Option<&str>;
     fn time(&self) -> Option<&DateTime<Utc>>;
 }
@@ -103,7 +101,7 @@ impl AttributesWriter for Event {
     fn set_time(&mut self, time: Option<impl Into<DateTime<Utc>>>) -> Option<DateTime<Utc>>;
     fn set_datacontenttype(&mut self, datacontenttype: Option<impl Into<String>>)
         -> Option<String>;
-    fn set_dataschema(&mut self, dataschema: Option<impl Into<Url>>) -> Option<Url>;
+    fn set_dataschema(&mut self, dataschema: Option<impl Into<Uri>>) -> Option<Uri>;
 }
 
 impl Default for Event {
@@ -165,10 +163,10 @@ impl Event {
     ///
     /// let (datacontenttype, dataschema, data) = e.take_data();
     /// ```
-    pub fn take_data(&mut self) -> (Option<String>, Option<Url>, Option<Data>) {
+    pub fn take_data(&mut self) -> (Option<String>, Option<Uri>, Option<Data>) {
         (
             self.attributes.set_datacontenttype(None as Option<String>),
-            self.attributes.set_dataschema(None as Option<Url>),
+            self.attributes.set_dataschema(None as Option<Uri>),
             self.data.take(),
         )
     }