feat: Add Zig example that only makes dynamic allocations if necessary

vmware-labs · Feb 23, 2024 · 3c9b560 · 3c9b560
1 parent 3bd939b
commit 3c9b560
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diff --git a/examples/zig-examples/build.zig b/examples/zig-examples/build.zig
@@ -24,6 +24,10 @@ const examples = &[_]Example{
         .name = "no-alloc-kv",
         .root_source_file = .{ .path = "src/no-alloc-kv.zig" },
     },
+    .{
+        .name = "mixed-alloc-kv",
+        .root_source_file = .{ .path = "src/mixed-alloc-kv.zig" },
+    },
     .{
         .name = "mount",
         .root_source_file = .{ .path = "src/mount.zig" },

diff --git a/examples/zig-examples/src/mixed-alloc-kv.zig b/examples/zig-examples/src/mixed-alloc-kv.zig
@@ -0,0 +1,68 @@
+const std = @import("std");
+const wws = @import("wws");
+
+const tmpl =
+    \\<!DOCTYPE html>
+    \\<head>
+    \\<title>
+    \\Wasm Workers Server - KV example</title>
+    \\<meta name="viewport" content="width=device-width,initial-scale=1">
+    \\<meta charset="UTF-8">
+    \\</head>
+    \\<body>
+    \\<h1>Key / Value store in Zig</h1>
+    \\<p>Counter: {d}</p>
+    \\<p>This page was generated by a Zig⚡️ file running in WebAssembly.</p>
+    \\</body>
+;
+var tmpl_buf: [tmpl.len + 8]u8 = undefined;
+
+fn handle(arena: std.mem.Allocator, request: wws.Request) !wws.Response {
+    const value = request.kv.map.get("counter") orelse "0";
+    var counter = std.fmt.parseInt(i32, value, 10) catch 0;
+
+    counter += 1;
+
+    const body = try std.fmt.bufPrint(&tmpl_buf, tmpl, .{counter});
+
+    var response = wws.Response{
+        .data = body,
+    };
+
+    const num_s = try std.fmt.allocPrint(arena, "{d}", .{counter});
+    try response.kv.map.put(arena, "counter", num_s);
+
+    try response.headers.map.put(arena, "x-generated-by", "wasm-workers-server");
+
+    return response;
+}
+
+pub fn main() !void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+
+    var arena = std.heap.ArenaAllocator.init(gpa.allocator());
+    defer arena.deinit();
+
+    var sfa = std.heap.stackFallback(4096 * 2, arena.allocator());
+
+    const allocator = sfa.get();
+
+    const parse_result = wws.parseStream(allocator, .{}) catch {
+        std.debug.print("Failed to read request\n", .{});
+        return error.ReadRequestFailed;
+    };
+    defer parse_result.deinit();
+
+    const request = parse_result.value;
+    const response = handle(allocator, request) catch {
+        std.debug.print("Failed to handle request\n", .{});
+        return error.HandleRequestFailed;
+    };
+
+    const stdout = std.io.getStdOut();
+    wws.writeResponse(response, stdout.writer()) catch {
+        std.debug.print("Failed to write response\n", .{});
+        return error.WriteResponseFailed;
+    };
+}