Add #[no_std] and WebAssembly support

.github/workflows/build.yml

@@ -14,6 +14,19 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  wasm:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install
+        run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+
+      - run: cd blurhash-rs-wasm
+      - run: cargo test
+      - run: wasm-pack test --headless --chrome -- --package blurhash-rs-wasm
+      - run: wasm-pack test --headless --firefox -- --package blurhash-rs-wasm
+
   build_and_test:
     name: cargo test
     runs-on: ubuntu-latest
@@ -24,9 +37,29 @@ jobs:
       matrix:
         toolchain: ["stable", "beta"]
         coverage: [false]
+        features: [
+          # With std
+          "std,gdk-pixbuf",
+          "std,gdk-pixbuf,fast-linear-to-srgb",
+          "std,image",
+          "std,image,fast-linear-to-srgb",
+          "std,fast-linear-to-srgb",
+          "std",
+        ]
         include:
+          # Coverage on nightly
           - toolchain: "nightly"
             coverage: true
+            features: ""
+
+          # no-std build and tests
+          - toolchain: "nightly"
+            coverage: false
+            features: "fast-linear-to-srgb"
+
+          - toolchain: "nightly"
+            coverage: false
+            features: ""
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
@@ -47,18 +80,25 @@ jobs:
 
       - name: Run tests with default features
         uses: actions-rs/cargo@v1
-        if: ${{ !matrix.coverage }}
+        if: ${{ !matrix.coverage && (matrix.features == '' || matrix.features == 'std')  }}
         with:
           command: test
           args: --all-targets --no-fail-fast
 
       - name: Run tests with all features
         uses: actions-rs/cargo@v1
-        if: ${{ !matrix.coverage }}
+        if: ${{ !matrix.coverage && (matrix.features == '' || matrix.features == 'std') }}
         with:
           command: test
           args: --all-targets --no-fail-fast --all-features
 
+      - name: "Run tests with features: ${{ matrix.features }}"
+        uses: actions-rs/cargo@v1
+        if: ${{ !matrix.coverage }}
+        with:
+          command: test
+          args: --all-targets --no-fail-fast --no-default-features --features "${{ matrix.features }}"
+
       - name: Run doc tests
         uses: actions-rs/cargo@v1
         if: ${{ !matrix.coverage }}

Cargo.toml

@@ -13,14 +13,16 @@ edition = "2018"
 [dependencies]
 image = { version = ">= 0.23, <= 0.25", optional = true }
 gdk-pixbuf = { version = ">= 0.18, <= 0.19", optional = true }
+num-traits = { version = "0.2", default-features = false, features = ["libm"] }
 
 [dev-dependencies]
 image = ">= 0.23, <= 0.25"
 criterion = "0.5"
 proptest = "1"
 
 [features]
-default = ["fast-linear-to-srgb"]
+default = ["fast-linear-to-srgb", "std"]
+std = []
 image = [ "dep:image" ]
 gdk-pixbuf = [ "dep:gdk-pixbuf" ]
 fast-linear-to-srgb = []
@@ -32,3 +34,12 @@ harness = false
 [[bench]]
 name = "encode"
 harness = false
+
+[workspace]
+members = [
+    "blurhash-rs-wasm",
+]
+
+[profile.release] #.package.blurhash-rs-wasm]
+# Tell `rustc` to optimize for small code size.
+opt-level = "z"

README.md

@@ -23,9 +23,27 @@ If this overhead is problematic, you can disable it by instead specifying the fo
 
 ```toml
 [dependencies]
-blurhash = { version = "0.2.3", default-features = false }
+blurhash = { version = "0.2.3", default-features = false, features = ["std"] }
 ```
 
+Blurhash can also run in `no_std` environments (with `alloc`) by disabling the default features:
+
+```toml
+[dependencies]
+blurhash = { version = "0.2.4", default-features = false, features = ["fast-linear-to-srgb"] }
+```
+
+Blurhash requires Rust 1.82 or later when using `no_std`.
+
+Blurhash can also be run with WebAssembly by enabling the `wasm` feature:
+
+```toml
+[dependencies]
+blurhash = { version = "0.2.4", features = ["wasm"] }
+```
+
+The `wasm` feature is compatible with `no_std`.
+
 ### Encoding
 ```rust
 use blurhash::encode;

blurhash-rs-wasm/.gitignore

@@ -0,0 +1,6 @@
+/target
+**/*.rs.bk
+Cargo.lock
+bin/
+pkg/
+wasm-pack.log

blurhash-rs-wasm/.travis.yml

@@ -0,0 +1,69 @@
+language: rust
+sudo: false
+
+cache: cargo
+
+matrix:
+  include:
+
+  # Builds with wasm-pack.
+  - rust: beta
+    env: RUST_BACKTRACE=1
+    addons:
+      firefox: latest
+      chrome: stable
+    before_script:
+      - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+      - (test -x $HOME/.cargo/bin/cargo-generate || cargo install --vers "^0.2" cargo-generate)
+      - cargo install-update -a
+      - curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh -s -- -f
+    script:
+      - cargo generate --git . --name testing
+      # Having a broken Cargo.toml (in that it has curlies in fields) anywhere
+      # in any of our parent dirs is problematic.
+      - mv Cargo.toml Cargo.toml.tmpl
+      - cd testing
+      - wasm-pack build
+      - wasm-pack test --chrome --firefox --headless
+
+  # Builds on nightly.
+  - rust: nightly
+    env: RUST_BACKTRACE=1
+    before_script:
+      - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+      - (test -x $HOME/.cargo/bin/cargo-generate || cargo install --vers "^0.2" cargo-generate)
+      - cargo install-update -a
+      - rustup target add wasm32-unknown-unknown
+    script:
+      - cargo generate --git . --name testing
+      - mv Cargo.toml Cargo.toml.tmpl
+      - cd testing
+      - cargo check
+      - cargo check --target wasm32-unknown-unknown
+      - cargo check                                 --no-default-features
+      - cargo check --target wasm32-unknown-unknown --no-default-features
+      - cargo check                                 --no-default-features --features console_error_panic_hook
+      - cargo check --target wasm32-unknown-unknown --no-default-features --features console_error_panic_hook
+      - cargo check                                 --no-default-features --features "console_error_panic_hook wee_alloc"
+      - cargo check --target wasm32-unknown-unknown --no-default-features --features "console_error_panic_hook wee_alloc"
+
+  # Builds on beta.
+  - rust: beta
+    env: RUST_BACKTRACE=1
+    before_script:
+      - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+      - (test -x $HOME/.cargo/bin/cargo-generate || cargo install --vers "^0.2" cargo-generate)
+      - cargo install-update -a
+      - rustup target add wasm32-unknown-unknown
+    script:
+      - cargo generate --git . --name testing
+      - mv Cargo.toml Cargo.toml.tmpl
+      - cd testing
+      - cargo check
+      - cargo check --target wasm32-unknown-unknown
+      - cargo check                                 --no-default-features
+      - cargo check --target wasm32-unknown-unknown --no-default-features
+      - cargo check                                 --no-default-features --features console_error_panic_hook
+      - cargo check --target wasm32-unknown-unknown --no-default-features --features console_error_panic_hook
+      # Note: no enabling the `wee_alloc` feature here because it requires
+      # nightly for now.

blurhash-rs-wasm/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name = "blurhash-rs-wasm"
+version = "0.1.0"
+authors = ["Ruben De Smet <[email protected]>", "Raincal <[email protected]>"]
+edition = "2018"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[features]
+default = ["console_error_panic_hook", "fast-linear-to-srgb"]
+fast-linear-to-srgb = ["blurhash/fast-linear-to-srgb"]
+
+[dependencies]
+wasm-bindgen = "0.2.84"
+js-sys = { version = "0.3" }
+
+# The `console_error_panic_hook` crate provides better debugging of panics by
+# logging them with `console.error`. This is great for development, but requires
+# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
+# code size when deploying.
+console_error_panic_hook = { version = "0.1.7", optional = true }
+
+blurhash = { path = "../", default-features = false, features = []}
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3.34"