Add regression test for decoding files on platforms generated with di…

…ffering SIMD support.

.github/workflows/ci.yml

@@ -65,6 +65,17 @@ jobs:
       run: cargo test --verbose --target ${{ matrix.arch }}-${{ fromJSON(env.target_map)[matrix.os] }} --features=no_simd
     - name: Build docs
       run: cargo doc --verbose
+    - name: Run SIMD/no-SIMD tests
+      run: |
+        cd crosstest
+        # Create some no-simd test files
+        cargo run --verbose --features no_simd -- write
+        cargo clean
+        # Create some simd test files and test the no-simd files
+        cargo run --verbose -- write read
+        cargo clean
+        # Test the simd-enabled files we generated in the last step
+        cargo run --verbose --features no_simd -- read
 
   benchmarks:
     strategy:

.gitignore

@@ -1,2 +1,3 @@
 /target
+/crosstest/target
 Cargo.lock

crosstest/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "crosstest"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+odht = { package = "odht", path = ".." }
+
+[features]
+no_simd = ["odht/no_simd"]

crosstest/src/main.rs

@@ -0,0 +1,82 @@
+// This test makes sure that a hash table generated with SIMD support
+// can be loaded on a platform without SIMD support.
+
+struct FxConfig;
+
+impl odht::Config for FxConfig {
+    type Key = u64;
+    type Value = u32;
+
+    type EncodedKey = [u8; 8];
+    type EncodedValue = [u8; 4];
+
+    type H = odht::FxHashFn;
+
+    #[inline]
+    fn encode_key(k: &Self::Key) -> Self::EncodedKey {
+        k.to_le_bytes()
+    }
+
+    #[inline]
+    fn encode_value(v: &Self::Value) -> Self::EncodedValue {
+        v.to_le_bytes()
+    }
+
+    #[inline]
+    fn decode_key(k: &Self::EncodedKey) -> Self::Key {
+        u64::from_le_bytes(*k)
+    }
+
+    #[inline]
+    fn decode_value(v: &Self::EncodedValue) -> Self::Value {
+        u32::from_le_bytes(*v)
+    }
+}
+
+const FILE_NAME_NO_SIMD: &str = "odht_hash_table_no_simd";
+const FILE_NAME_WITH_SIMD: &str = "odht_hash_table_with_simd";
+
+#[cfg(feature = "no_simd")]
+const WRITE_FILE_NAME: &str = FILE_NAME_NO_SIMD;
+#[cfg(not(feature = "no_simd"))]
+const WRITE_FILE_NAME: &str = FILE_NAME_WITH_SIMD;
+
+#[cfg(feature = "no_simd")]
+const READ_FILE_NAME: &'static str = FILE_NAME_WITH_SIMD;
+
+#[cfg(not(feature = "no_simd"))]
+const READ_FILE_NAME: &'static str = FILE_NAME_NO_SIMD;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+
+    let make_entries = || (0 .. 70_000_u64).map(|x| (x * x, x as u32)).collect::<Vec<_>>();
+
+    if std::env::args_os().find(|arg| arg == "write").is_some() {
+        let hash_table = odht::HashTableOwned::<FxConfig>::from_iterator(make_entries(), 85);
+        let mut path = std::env::temp_dir();
+        path.push(WRITE_FILE_NAME);
+        std::fs::write(&path, hash_table.raw_bytes())?;
+        eprintln!("Wrote hash table with {} bytes to {}", hash_table.raw_bytes().len(), path.display());
+    }
+
+    if std::env::args_os().find(|arg| arg == "read").is_some() {
+        let mut path = std::env::temp_dir();
+        path.push(READ_FILE_NAME);
+        eprintln!("Trying to load hash table from {}", path.display());
+        let data = std::fs::read(&path)?;
+        let hash_table = odht::HashTable::<FxConfig, _>::from_raw_bytes(data)?;
+        eprintln!("Loaded hash table with {} bytes from {}", hash_table.raw_bytes().len(), path.display());
+        let expected_entries = make_entries();
+
+        eprintln!("Comparing hash table to expected values.");
+         // Check that we can read the data
+        assert_eq!(hash_table.len(), expected_entries.len());
+        for (key, value) in expected_entries {
+            assert_eq!(hash_table.get(&key), Some(value));
+        }
+
+        eprintln!("Success");
+    }
+
+    Ok(())
+}