feat: add CompiledPlugin (#19)

* feat: add CompiledPlugin

* ci: pin zig 0.13.0

* Apply suggestions from code review

Co-authored-by: Steve Manuel <[email protected]>

---------

Co-authored-by: Steve Manuel <[email protected]>

Author: zshipko

.github/workflows/ci.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        zig_version: ["master"] # eventually use multiple versions once stable
+        zig_version: ["0.13.0"] # eventually use multiple versions once stable
         rust:
           - stable
     steps:

examples/basic.zig

@@ -2,6 +2,7 @@ const std = @import("std");
 const sdk = @import("extism");
 const Plugin = sdk.Plugin;
 const CurrentPlugin = sdk.CurrentPlugin;
+const CompiledPlugin = sdk.CompiledPlugin;
 const Function = sdk.Function;
 const manifest = sdk.manifest;
 
@@ -24,7 +25,7 @@ pub fn main() !void {
     _ = sdk.setLogFile("extism.log", .Debug);
 
     const wasmfile_manifest = manifest.WasmFile{ .path = "wasm/code-functions.wasm" };
-    const man = .{ .wasm = &[_]manifest.Wasm{.{ .wasm_file = wasmfile_manifest }} };
+    const man = manifest.Manifest{ .wasm = &[_]manifest.Wasm{.{ .wasm_file = wasmfile_manifest }} };
     var f = Function.init(
         "hello_world",
         &[_]sdk.c.ExtismValType{sdk.PTR},
@@ -33,7 +34,10 @@ pub fn main() !void {
         @constCast(@as(*const anyopaque, @ptrCast("user data"))),
     );
     defer f.deinit();
-    var my_plugin = try Plugin.initFromManifest(allocator, man, &[_]Function{f}, true);
+    var c = try CompiledPlugin.initFromManifest(allocator, man, &[_]Function{f}, true);
+    defer c.deinit();
+
+    var my_plugin = try Plugin.initFromCompiled(c);
     defer my_plugin.deinit();
 
     var config = std.json.ArrayHashMap([]const u8){};

src/compiled_plugin.zig

@@ -0,0 +1,54 @@
+const std = @import("std");
+const Manifest = @import("manifest.zig").Manifest;
+const Function = @import("function.zig");
+const CancelHandle = @import("cancel_handle.zig");
+const c = @import("ffi.zig");
+
+const Self = @This();
+
+ptr: *c.ExtismCompiledPlugin,
+
+// We have to use this until ziglang/zig#2647 is resolved.
+error_info: ?[]const u8,
+
+/// Create a new plugin from a WASM module
+pub fn init(allocator: std.mem.Allocator, data: []const u8, functions: []const Function, wasi: bool) !Self {
+    var plugin: ?*c.ExtismCompiledPlugin = null;
+    var errmsg: [*c]u8 = null;
+    if (functions.len > 0) {
+        var funcPtrs = try allocator.alloc(?*c.ExtismFunction, functions.len);
+        defer allocator.free(funcPtrs);
+        var i: usize = 0;
+        for (functions) |function| {
+            funcPtrs[i] = function.c_func;
+            i += 1;
+        }
+        plugin = c.extism_compiled_plugin_new(data.ptr, @as(u64, data.len), &funcPtrs[0], functions.len, wasi, &errmsg);
+    } else {
+        plugin = c.extism_compiled_plugin_new(data.ptr, @as(u64, data.len), null, 0, wasi, &errmsg);
+    }
+
+    if (plugin == null) {
+        // TODO: figure out what to do with this error
+        std.debug.print("extism_compiled_plugin_new: {s}\n", .{
+            errmsg,
+        });
+        c.extism_plugin_new_error_free(errmsg);
+        return error.PluginLoadFailed;
+    }
+    return Self{
+        .ptr = plugin.?,
+        .error_info = null,
+    };
+}
+
+/// Create a new plugin from the given manifest
+pub fn initFromManifest(allocator: std.mem.Allocator, manifest: Manifest, functions: []const Function, wasi: bool) !Self {
+    const json = try std.json.stringifyAlloc(allocator, manifest, .{ .emit_null_optional_fields = false });
+    defer allocator.free(json);
+    return init(allocator, json, functions, wasi);
+}
+
+pub fn deinit(self: *Self) void {
+    c.extism_compiled_plugin_free(self.ptr);
+}

src/main.zig

@@ -3,6 +3,7 @@ const testing = std.testing;
 pub const c = @import("ffi.zig");
 
 pub const Plugin = @import("plugin.zig");
+pub const CompiledPlugin = @import("compiled_plugin.zig");
 pub const CurrentPlugin = @import("current_plugin.zig");
 pub const CancelHandle = @import("cancel_handle.zig");
 pub const Function = @import("function.zig");

src/plugin.zig

@@ -3,6 +3,7 @@ const Manifest = @import("manifest.zig").Manifest;
 const Function = @import("function.zig");
 const CancelHandle = @import("cancel_handle.zig");
 const c = @import("ffi.zig");
+const CompiledPlugin = @import("compiled_plugin.zig");
 
 const Self = @This();
 
@@ -49,6 +50,21 @@ pub fn initFromManifest(allocator: std.mem.Allocator, manifest: Manifest, functi
     return init(allocator, json, functions, wasi);
 }
 
+/// Create a new plugin from a pre-compiled plugin
+pub fn initFromCompiled(compiled: *CompiledPlugin) !Self {
+    var errmsg: [*c]u8 = null;
+    const plugin = c.extism_plugin_new_from_compiled(compiled.ptr, &errmsg);
+    if (plugin == null) {
+        // TODO: figure out what to do with this error
+        std.debug.print("extism_plugin_new: {s}\n", .{
+            errmsg,
+        });
+        c.extism_plugin_new_error_free(errmsg);
+        return error.PluginLoadFailed;
+    }
+    return plugin;
+}
+
 pub fn deinit(self: *Self) void {
     c.extism_plugin_free(self.ptr);
 }