feat(runtime): cache compiled components

Enable Wasmtime's persistent compilation cache and expose an optional cache directory in RuntimeConfig.

Create and canonicalize the configured directory before Engine construction, and report cache filesystem and configuration failures through dedicated RuntimeError variants.

Cargo.lock

@@ -673,7 +673,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fa961b519f0b462e3a3b4a34b64d119eeaca1d59af726fe450bbba07a9fc0a1"
 dependencies = [
- "thiserror",
+ "thiserror 2.0.19",
 ]
 
 [[package]]
@@ -1042,6 +1042,27 @@ dependencies = [
  "crypto-common",
 ]
 
+[[package]]
+name = "directories-next"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "339ee130d97a610ea5a5872d2bbb130fdf68884ff09d3028b81bec8a1ac23bbc"
+dependencies = [
+ "cfg-if",
+ "dirs-sys-next",
+]
+
+[[package]]
+name = "dirs-sys-next"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
 [[package]]
 name = "displaydoc"
 version = "0.2.6"
@@ -1937,7 +1958,7 @@ dependencies = [
  "jni-sys",
  "log",
  "simd_cesu8",
- "thiserror",
+ "thiserror 2.0.19",
  "walkdir",
  "windows-link",
 ]
@@ -2057,6 +2078,15 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "libredox"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c943259e342f1e06ff2da7a83eabdfe7f92ce10262688dbf1895ff0b3e6e4652"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "linkme"
 version = "0.3.37"
@@ -2654,7 +2684,7 @@ dependencies = [
  "rustc-hash 2.1.3",
  "rustls",
  "socket2",
- "thiserror",
+ "thiserror 2.0.19",
  "tokio",
  "tracing",
  "web-time",
@@ -2677,7 +2707,7 @@ dependencies = [
  "rustls",
  "rustls-pki-types",
  "slab",
- "thiserror",
+ "thiserror 2.0.19",
  "tinyvec",
  "tracing",
  "web-time",
@@ -2856,6 +2886,17 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "redox_users"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba009ff324d1fc1b900bd1fdb31564febe58a8ccc8a6fdbb93b543d33b13ca43"
+dependencies = [
+ "getrandom 0.2.17",
+ "libredox",
+ "thiserror 1.0.69",
+]
+
 [[package]]
 name = "regalloc2"
 version = "0.13.5"
@@ -3582,7 +3623,7 @@ dependencies = [
  "tantivy-stacker",
  "tantivy-tokenizer-api",
  "tempfile",
- "thiserror",
+ "thiserror 2.0.19",
  "time",
  "typetag",
  "uuid",
@@ -3718,13 +3759,33 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
+dependencies = [
+ "thiserror-impl 1.0.69",
+]
+
 [[package]]
 name = "thiserror"
 version = "2.0.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09a43598840e33d5b0331f38c5e30d13bb11c11210a4b58f0d9b18a5a5eefcd9"
 dependencies = [
- "thiserror-impl",
+ "thiserror-impl 2.0.19",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -4084,7 +4145,7 @@ checksum = "050686193eb999b4bb3bc2acfa891a13da00f79734704c4b8b4ef1a10b368a3c"
 dependencies = [
  "crossbeam-channel",
  "symlink",
- "thiserror",
+ "thiserror 2.0.19",
  "time",
  "tracing-subscriber",
 ]
@@ -4152,7 +4213,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6b6c49aecd4abae3ffa88ab1e28b3de7a7497a9732be828e3a6f1855b6ea80fd"
 dependencies = [
  "mimalloc",
- "thiserror",
+ "thiserror 2.0.19",
  "tracing",
  "tracing-subscriber",
  "turso_core",
@@ -4219,7 +4280,7 @@ dependencies = [
  "strum_macros",
  "tantivy",
  "tempfile",
- "thiserror",
+ "thiserror 2.0.19",
  "tracing",
  "tracing-subscriber",
  "turso_ext",
@@ -4264,7 +4325,7 @@ dependencies = [
  "miette",
  "strum",
  "strum_macros",
- "thiserror",
+ "thiserror 2.0.19",
  "turso_macros",
 ]
 
@@ -4312,7 +4373,7 @@ dependencies = [
  "roaring",
  "serde",
  "serde_json",
- "thiserror",
+ "thiserror 2.0.19",
  "tracing",
  "turso_core",
  "turso_parser",
@@ -4645,7 +4706,7 @@ dependencies = [
  "serde",
  "serde_json",
  "tempfile",
- "thiserror",
+ "thiserror 2.0.19",
  "toasty",
  "toasty-driver-turso",
  "tokio",
@@ -4668,7 +4729,7 @@ dependencies = [
  "serde_json",
  "sha2",
  "tempfile",
- "thiserror",
+ "thiserror 2.0.19",
  "toml",
  "wit-component 0.243.0",
  "wit-parser 0.243.0",
@@ -4680,7 +4741,7 @@ name = "wasmeld-runtime"
 version = "0.1.0"
 dependencies = [
  "serde",
- "thiserror",
+ "thiserror 2.0.19",
  "toml",
  "wasmeld-package",
  "wasmtime",
@@ -4755,6 +4816,7 @@ dependencies = [
  "target-lexicon",
  "wasmparser 0.243.0",
  "wasmtime-environ",
+ "wasmtime-internal-cache",
  "wasmtime-internal-component-macro",
  "wasmtime-internal-component-util",
  "wasmtime-internal-cranelift",
@@ -4794,6 +4856,26 @@ dependencies = [
  "wasmtime-internal-component-util",
 ]
 
+[[package]]
+name = "wasmtime-internal-cache"
+version = "41.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a31a582632f47753e4a9a5412ab5edfbc05a6df9031336a2f2eff46a70a1cac"
+dependencies = [
+ "base64 0.22.1",
+ "directories-next",
+ "log",
+ "postcard",
+ "rustix 1.1.4",
+ "serde",
+ "serde_derive",
+ "sha2",
+ "toml",
+ "wasmtime-environ",
+ "windows-sys 0.61.2",
+ "zstd",
+]
+
 [[package]]
 name = "wasmtime-internal-component-macro"
 version = "41.0.0"
@@ -4834,7 +4916,7 @@ dependencies = [
  "pulley-interpreter",
  "smallvec",
  "target-lexicon",
- "thiserror",
+ "thiserror 2.0.19",
  "wasmparser 0.243.0",
  "wasmtime-environ",
  "wasmtime-internal-math",
@@ -4969,7 +5051,7 @@ dependencies = [
  "io-lifetimes",
  "rustix 1.1.4",
  "system-interface",
- "thiserror",
+ "thiserror 2.0.19",
  "tokio",
  "tracing",
  "url",
@@ -5076,7 +5158,7 @@ dependencies = [
  "regalloc2",
  "smallvec",
  "target-lexicon",
- "thiserror",
+ "thiserror 2.0.19",
  "wasmparser 0.243.0",
  "wasmtime-environ",
  "wasmtime-internal-cranelift",
@@ -5540,7 +5622,7 @@ dependencies = [
  "flate2",
  "indexmap",
  "memchr",
- "thiserror",
+ "thiserror 2.0.19",
  "zopfli",
 ]
 

Cargo.toml

@@ -35,7 +35,7 @@ toml = "0.9.8"
 tower-http = { version = "0.7.0", features = ["cors", "trace"] }
 tracing = "0.1.44"
 tracing-subscriber = { version = "0.3.23", features = ["env-filter", "fmt"] }
-wasmtime = { version = "=41.0.0", default-features = false, features = ["component-model", "cranelift", "runtime", "std"] }
+wasmtime = { version = "=41.0.0", default-features = false, features = ["cache", "component-model", "cranelift", "runtime", "std"] }
 wasmtime-wasi = { version = "=41.0.0", default-features = false, features = ["p2"] }
 wit-bindgen = "=0.41.0"
 wit-component = "=0.243.0"

crates/wasmeld-runtime/src/error.rs

@@ -1,6 +1,6 @@
 //! Runtime error taxonomy exposed to management layers.
 
-use std::time::Duration;
+use std::{path::PathBuf, time::Duration};
 
 use thiserror::Error;
 
@@ -36,6 +36,16 @@ pub enum RuntimeError {
     #[error("runtime creation failed: {0}")]
     RuntimeCreation(#[source] wasmtime::Error),
 
+    #[error("failed to prepare Component compilation cache {path}: {source}")]
+    CacheDirectory {
+        path: PathBuf,
+        #[source]
+        source: std::io::Error,
+    },
+
+    #[error("invalid Component compilation cache configuration: {0}")]
+    CacheConfiguration(#[source] wasmtime::Error),
+
     #[error("failed to read component artifact {path}: {source}")]
     ArtifactRead {
         path: String,

crates/wasmeld-runtime/src/runtime.rs

@@ -8,6 +8,7 @@
 use std::{
     collections::HashMap,
     fs,
+    path::PathBuf,
     sync::{
         Arc, Mutex,
         atomic::{AtomicBool, Ordering},
@@ -18,7 +19,7 @@ use std::{
 };
 
 use wasmtime::{
-    Config, Engine, Store, StoreLimits, StoreLimitsBuilder,
+    Cache, CacheConfig, Config, Engine, Store, StoreLimits, StoreLimitsBuilder,
     component::{Component, HasData, Linker, ResourceTable},
 };
 use wasmtime_wasi::{
@@ -61,6 +62,8 @@ pub struct RuntimeConfig {
     pub epoch_tick: Duration,
     /// Maximum native stack reservation for WebAssembly execution.
     pub max_wasm_stack: usize,
+    /// Optional persistent cache for compiled Component machine code.
+    pub component_cache_dir: Option<PathBuf>,
     /// Service-scoped storage used by Components importing the KV capability.
     pub kv_backend: Option<Arc<dyn KvBackend>>,
 }
@@ -70,6 +73,7 @@ impl Default for RuntimeConfig {
         Self {
             epoch_tick: DEFAULT_EPOCH_TICK,
             max_wasm_stack: DEFAULT_MAX_WASM_STACK,
+            component_cache_dir: None,
             kv_backend: None,
         }
     }
@@ -180,6 +184,21 @@ impl Runtime {
         wasmtime_config.consume_fuel(true);
         wasmtime_config.epoch_interruption(true);
         wasmtime_config.max_wasm_stack(config.max_wasm_stack);
+        if let Some(cache_dir) = &config.component_cache_dir {
+            fs::create_dir_all(cache_dir).map_err(|source| RuntimeError::CacheDirectory {
+                path: cache_dir.clone(),
+                source,
+            })?;
+            let cache_dir =
+                fs::canonicalize(cache_dir).map_err(|source| RuntimeError::CacheDirectory {
+                    path: cache_dir.clone(),
+                    source,
+                })?;
+            let mut cache_config = CacheConfig::new();
+            cache_config.with_directory(cache_dir);
+            let cache = Cache::new(cache_config).map_err(RuntimeError::CacheConfiguration)?;
+            wasmtime_config.cache(Some(cache));
+        }
 
         let engine =
             Arc::new(Engine::new(&wasmtime_config).map_err(RuntimeError::RuntimeCreation)?);