feat!: add wasm feature toggle to let parts of git-pack build on wasm32.

It's a breaking change because we also start using the `dep:` syntax for declaring
references to optional dependencies, which will prevent them from being automatically
available as features.

Besides that, it adds the `wasm` feature toggle to allow compiling to `wasm32` targets.

Author: Byron

.github/workflows/wasm.yml

@@ -32,6 +32,7 @@ jobs:
         name: crates without feature toggles
       - run: set +x; for feature in progress fs-walkdir-parallel parallel io-pipe crc32 zlib zlib-rust-backend fast-sha1 rustsha1 cache-efficiency-debug; do (cd git-features && cargo build --features $feature --target ${{ matrix.target }}); done
         name: features of git-features
-      - run: set +x; for name in git-diff; do (cd $name && cargo build --features wasm --target ${{ matrix.target }}); done
+      - run: set +x; for name in git-diff git-pack; do (cd $name && cargo build --features wasm --target ${{ matrix.target }}); done
         name: crates with 'wasm' feature
-#      - run: cargo build -p git-pack --target ${{ matrix.target }} // TODO: make something like it work
+      - run: cd git-pack && cargo build --all-features --target ${{ matrix.target }}
+        name: git-pack with all features (including wasm)

git-pack/Cargo.toml

@@ -17,13 +17,13 @@ doctest = false
 
 ## Provide a fixed-size allocation-free LRU cache for packs. It's useful if caching is desired while keeping the memory footprint
 ## for the LRU-cache itself low.
-pack-cache-lru-static = ["uluru"]
+pack-cache-lru-static = ["dep:uluru"]
 ## Provide a hash-map based LRU cache whose eviction is based a memory cap calculated from object data.
-pack-cache-lru-dynamic = ["clru"]
+pack-cache-lru-dynamic = ["dep:clru"]
 ## If set, select algorithms may additionally use a full-object cache which is queried before the pack itself.
-object-cache-dynamic = ["clru"]
+object-cache-dynamic = ["dep:clru"]
 ## Data structures implement `serde::Serialize` and `serde::Deserialize`.
-serde1 = ["serde", "git-object/serde1"]
+serde1 = ["dep:serde", "git-object/serde1"]
 ## Make it possible to compile to the `wasm32-unknown-unknown` target.
 wasm = ["git-diff/wasm"]
 
@@ -35,20 +35,24 @@ git-chunk = { version = "^0.4.1", path = "../git-chunk" }
 git-object = { version = "^0.26.1", path = "../git-object" }
 git-traverse = { version = "^0.22.1", path = "../git-traverse" }
 git-diff = { version = "^0.26.1", path = "../git-diff" }
-git-tempfile = { version = "^3.0.0", path = "../git-tempfile" }
 git-hashtable = { version = "^0.1.1", path = "../git-hashtable" }
 
-smallvec = "1.3.0"
 memmap2 = "0.5.0"
-serde = { version = "1.0.114", optional = true, default-features = false, features = ["derive"] }
+smallvec = "1.3.0"
 bytesize = "1.0.1"
 parking_lot = { version = "0.12.0", default-features = false }
 thiserror = "1.0.26"
 uluru = { version = "3.0.0", optional = true }
 clru = { version = "0.6.1", optional = true }
-dashmap = "5.1.0"
 
+serde = { version = "1.0.114", optional = true, default-features = false, features = ["derive"] }
+## If enabled, `cargo doc` will see feature documentation from this manifest.
 document-features = { version = "0.2.0", optional = true }
+dashmap = "5.1.0"
+
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+git-tempfile = { version = "^3.0.0", path = "../git-tempfile" }
 
 [dev-dependencies]
 git-testtools = { path = "../tests/tools"}

git-pack/src/bundle/mod.rs

@@ -3,6 +3,7 @@ pub mod init;
 
 mod find;
 ///
+#[cfg(not(feature = "wasm"))]
 pub mod write;
 
 ///

git-pack/src/lib.rs

@@ -17,17 +17,15 @@
 )]
 #![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
 #![deny(missing_docs, rust_2018_idioms, unsafe_code)]
-#![cfg(all(target_arch = "wasm32", target_os = "unknown", not(feature = "wasm")))]
-compile_error!("the wasm32-unknown-unknown target is not supported by default,  and the \"wasm\" feature is required.");
 
 ///
 pub mod bundle;
 /// A bundle of pack data and the corresponding pack index
 pub struct Bundle {
     /// The pack file corresponding to `index`
-    pub pack: crate::data::File,
+    pub pack: data::File,
     /// The index file corresponding to `pack`
-    pub index: crate::index::File,
+    pub index: index::File,
 }
 
 ///
@@ -39,7 +37,6 @@ pub mod cache;
 pub mod data;
 
 mod find_traits;
-
 pub use find_traits::{Find, FindExt};
 
 ///

git-pack/tests/Cargo.toml

@@ -13,7 +13,7 @@ rust-version = "1.64"
 
 ## Provide a fixed-size allocation-free LRU cache for packs. It's useful if caching is desired while keeping the memory footprint
 ## for the LRU-cache itself low.
-pack-cache-lru-static = ["git-pack/uluru"]
+pack-cache-lru-static = ["git-pack/pack-cache-lru-static"]
 ## Provide a hash-map based LRU cache whose eviction is based a memory cap calculated from object data.
 pack-cache-lru-dynamic = ["git-pack/pack-cache-lru-dynamic"]
 ## If set, select algorithms may additionally use a full-object cache which is queried before the pack itself.