Initial commitv0.1.0

libunit-wasm and example C and Rust WebAssembly modules for NGINX Unit.

Co-developed-by: Timo Stark <t.stark@nginx.com>
Co-developed-by: Liam Crilly <liam@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 101 insertions, 0 deletions

diff --git a/examples/c/luw-upload-reflector.c b/examples/c/luw-upload-reflector.c
new file mode 100644
index 0000000..95bc514
--- /dev/null
+++ b/examples/c/luw-upload-reflector.c
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+
+/*
+ * examples/c/luw-upload-reflector.c - Example of writing a WASM module for
+ *				       use with Unit using libunit-wasm
+ *
+ * Copyright (C) Andrew Clayton
+ * Copyright (C) F5, Inc.
+ */
+
+#define _XOPEN_SOURCE	500
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "unit/unit-wasm.h"
+
+static luw_ctx_t ctx;
+
+static size_t total_response_sent;
+
+static u8 *request_buf;
+
+/*
+ * While these first two _handlers_ aren't technically required, they
+ * could be combined or the code could just go in upload_reflector(),
+ * they demonstrate their use in ensuring the module is in the right
+ * state for a new request.
+ */
+__luw_export_name("luw_response_end_handler")
+void luw_response_end_handler(void)
+{
+	total_response_sent = 0;
+}
+
+__luw_export_name("luw_request_end_handler")
+void luw_request_end_handler(void)
+{
+	if (!request_buf)
+		return;
+
+	free(request_buf);
+	request_buf = NULL;
+}
+
+static int upload_reflector(luw_ctx_t *ctx)
+{
+	size_t write_bytes;
+
+	/* Send headers */
+	if (total_response_sent == 0) {
+		static const char *defct = "application/octet-stream";
+		const char *ct = luw_http_hdr_get_value(ctx, "Content-Type");
+		char clen[32];
+
+		snprintf(clen, sizeof(clen), "%lu",
+			 luw_get_http_content_len(ctx));
+
+		luw_http_init_headers(ctx, 2, 0);
+		luw_http_add_header(ctx, 0, "Content-Type", ct ? ct : defct);
+		luw_http_add_header(ctx, 1, "Content-Length", clen);
+		luw_http_send_headers(ctx);
+	}
+
+	write_bytes = luw_mem_fill_buf_from_req(ctx, total_response_sent);
+	total_response_sent += write_bytes;
+
+	luw_http_send_response(ctx);
+
+	if (total_response_sent == luw_get_http_content_len(ctx)) {
+		/* Tell Unit no more data to send */
+		luw_http_response_end();
+	}
+
+	return 0;
+}
+
+__luw_export_name("luw_request_handler")
+int luw_request_handler(u8 *addr)
+{
+	if (!request_buf) {
+		luw_init_ctx(&ctx, addr, 0 /* Response offset */);
+		/*
+		 * Take a copy of the request and use that, we do this
+		 * in APPEND mode so we can build up request_buf from
+		 * multiple requests.
+		 *
+		 * Just allocate memory for the total amount of data we
+		 * expect to get, this includes the request structure
+		 * itself as well as any body content.
+		 */
+		luw_set_req_buf(&ctx, &request_buf,
+				LUW_SRB_APPEND|LUW_SRB_ALLOC|LUW_SRB_FULL_SIZE);
+	} else {
+		luw_req_buf_append(&ctx, addr);
+	}
+
+	upload_reflector(&ctx);
+
+	return 0;
+}