simplify default optimization levels logic

docs/dfx-json-schema.json

@@ -381,7 +381,7 @@
         },
         "optimize": {
           "title": "Optimize Canister WASM",
-          "description": "Invoke wasm level optimizations after building the Canister. Optimization level can be set to \\\"cycles\\\" to optimize for cycle usage, \\\"size\\\" to optimize for binary size, or any of \\\"O4, O3, O2, O1, O0, Oz, Os\\\". Disabled by default.",
+          "description": "Invoke wasm level optimizations after building the canister. Optimization level can be set to \"cycles\" to optimize for cycle usage, \"size\" to optimize for binary size, or any of \"O4, O3, O2, O1, O0, Oz, Os\". Disabled by default.",
           "default": null,
           "anyOf": [
             {
@@ -872,34 +872,16 @@
     },
     "WasmOptLevel": {
       "title": "Wasm Optimization Levels",
-      "description": "Wasm optimization levels that are passed to `wasm-opt`. \"cycles\" defaults to O3, \"size\" defaults to Oz. O4 through O0 focus on performance (with O0 being no optimizations), and Oz and Os focus on reducing binary size, where Oz is more aggressive than Os.",
-      "oneOf": [
-        {
-          "type": "string",
-          "enum": [
-            "O4",
-            "O3",
-            "O2",
-            "O1",
-            "O0",
-            "Oz",
-            "Os"
-          ]
-        },
-        {
-          "description": "Defaults to O3",
-          "type": "string",
-          "enum": [
-            "cycles"
-          ]
-        },
-        {
-          "description": "Defaults to Oz",
-          "type": "string",
-          "enum": [
-            "size"
-          ]
-        }
+      "description": "Wasm optimization levels that are passed to `wasm-opt`. \"cycles\" defaults to O3, \"size\" defaults to Oz. O4 through O0 focus on performance (with O0 performing no optimizations), and Oz and Os focus on reducing binary size, where Oz is more aggressive than Os. O3 and Oz empirically give best cycle savings and code size savings respectively.",
+      "type": "string",
+      "enum": [
+        "O4",
+        "O3",
+        "O2",
+        "O1",
+        "O0",
+        "Oz",
+        "Os"
       ]
     }
   }

src/dfx-core/src/config/model/dfinity.rs

@@ -77,22 +77,18 @@ pub struct ConfigCanistersCanisterRemote {
 
 /// # Wasm Optimization Levels
 /// Wasm optimization levels that are passed to `wasm-opt`. "cycles" defaults to O3, "size" defaults to Oz.
-/// O4 through O0 focus on performance (with O0 being no optimizations), and Oz and Os focus on reducing binary size, where Oz is more aggressive than Os.
+/// O4 through O0 focus on performance (with O0 performing no optimizations), and Oz and Os focus on reducing binary size, where Oz is more aggressive than Os.
+/// O3 and Oz empirically give best cycle savings and code size savings respectively.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
 pub enum WasmOptLevel {
-    /// Defaults to O3
-    #[serde(rename = "cycles")]
-    Cycles,
-    /// Defaults to Oz
-    #[serde(rename = "size")]
-    Size,
-    // Specific performance levels
     O4,
+    #[serde(alias = "cycles")]
     O3,
     O2,
     O1,
     O0,
-    // Specific size levels
+
+    #[serde(alias = "size")]
     Oz,
     Os,
 }
@@ -224,7 +220,8 @@ pub struct ConfigCanistersCanister {
     pub shrink: Option<bool>,
 
     /// # Optimize Canister WASM
-    /// Invoke wasm level optimizations after building the Canister. Optimization level can be set to \"cycles\" to optimize for cycle usage, \"size\" to optimize for binary size, or any of \"O4, O3, O2, O1, O0, Oz, Os\". Disabled by default.
+    /// Invoke wasm level optimizations after building the canister. Optimization level can be set to "cycles" to optimize for cycle usage, "size" to optimize for binary size, or any of "O4, O3, O2, O1, O0, Oz, Os".
+    /// Disabled by default.
     #[serde(default)]
     pub optimize: Option<WasmOptLevel>,
 

src/dfx/src/lib/builders/custom.rs

@@ -151,7 +151,10 @@ impl CanisterBuilder for CustomBuilder {
         // Custom canister may have WASM gzipped
         if is_wasm_format(&wasm)? {
             if let Some(level) = optimize {
-                info!(self.logger, "Optimize and shrink WASM module.");
+                info!(
+                    self.logger,
+                    "Optimize and shrink WASM module at level {}", level
+                );
                 super::optimize_wasm(&wasm, level)?;
             } else if shrink {
                 info!(self.logger, "Shrink WASM module size.");

src/dfx/src/lib/builders/mod.rs

@@ -527,13 +527,8 @@ fn optimize_wasm(wasm_path: impl AsRef<Path>, level: &WasmOptLevel) -> DfxResult
     let wasm = std::fs::read(wasm_path).context("Could not read the WASM module.")?;
     let mut module =
         ic_wasm::utils::parse_wasm(&wasm, true).context("Could not parse the WASM module.")?;
-    match level {
-        // O3 and Oz empirically give best cycle savings and code size savings respectively
-        WasmOptLevel::Cycles => ic_wasm::shrink::shrink_with_wasm_opt(&mut module, "O3"),
-        WasmOptLevel::Size => ic_wasm::shrink::shrink_with_wasm_opt(&mut module, "Oz"),
-        _ => ic_wasm::shrink::shrink_with_wasm_opt(&mut module, &level.to_string()),
-    }
-    .context("Could not optimize the WASM module.")?;
+    ic_wasm::shrink::shrink_with_wasm_opt(&mut module, &level.to_string())
+        .context("Could not optimize the WASM module.")?;
 
     module
         .emit_wasm_file(wasm_path)

src/dfx/src/lib/builders/motoko.rs

@@ -169,7 +169,10 @@ impl CanisterBuilder for MotokoBuilder {
         let optimize = canister_info.get_optimize();
         let shrink = canister_info.get_shrink().unwrap_or(true);
         if let Some(level) = optimize {
-            info!(self.logger, "Optimize and shrink WASM module.");
+            info!(
+                self.logger,
+                "Optimize and shrink WASM module at level {}", level
+            );
             super::optimize_wasm(motoko_info.get_output_wasm_path(), level)?;
         } else if shrink {
             info!(self.logger, "Shrink WASM module size.");

src/dfx/src/lib/builders/rust.rs

@@ -100,7 +100,10 @@ impl CanisterBuilder for RustBuilder {
         let optimize = canister_info.get_optimize();
         let shrink = canister_info.get_shrink().unwrap_or(true);
         if let Some(level) = optimize {
-            info!(self.logger, "Optimize and shrink WASM module.");
+            info!(
+                self.logger,
+                "Optimize and shrink WASM module at level {}", level
+            );
             super::optimize_wasm(rust_info.get_output_wasm_path(), level)?;
         } else if shrink {
             info!(self.logger, "Shrink WASM module size.");