examples: Add C and Rust examples of handling large uploads

The programs demonstrate handling requests with payloads larger than
4GiB which means they need to be written out to disk and so also
demonstrates the use of the file-system access mechanism.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 49 insertions, 3 deletions

diff --git a/README.md b/README.md
index 286551a..76dec73 100644
--- a/README.md
+++ b/README.md
@@ -264,7 +264,7 @@ repository root for more details) but will instead assume you already have a
 Unit with the WebAssembly language module already running, perhaps installed
 via a package.
 
-Create the following Unit config
+Create the following Unit config (editing the module paths as appropriate)
 
 ```JSON
 {
@@ -276,7 +276,7 @@ Create the following Unit config
 
     "settings": {
         "http": {
-            "max_body_size": 1073741824
+            "max_body_size": 8589934592
         }
     },
 
@@ -299,6 +299,14 @@ Create the following Unit config
         },
         {
             "match": {
+                "uri": "/large-upload*"
+            },
+            "action": {
+                "pass": "applications/large-upload"
+            }
+        },
+        {
+            "match": {
                 "uri": "/rust-echo*"
             },
             "action": {
@@ -315,7 +323,15 @@ Create the following Unit config
         },
         {
             "match": {
-                "uri": "/hello-world*"
+                "uri": "/rust-large-upload*"
+            },
+            "action": {
+                "pass": "applications/rust-large-upload"
+            }
+        },
+        {
+            "match": {
+                "uri": "/rust-hello-world*"
             },
             "action": {
                 "pass": "applications/rust-hello-world"
@@ -342,6 +358,21 @@ Create the following Unit config
             "request_end_handler": "luw_request_end_handler",
             "response_end_handler": "luw_response_end_handler"
         },
+        "large-upload": {
+            "type": "wasm",
+            "module": "/path/to/unit-wasm/examples/c/large-upload.wasm",
+            "request_handler": "luw_request_handler",
+            "malloc_handler": "luw_malloc_handler",
+            "free_handler": "luw_free_handler",
+            "module_init_handler": "luw_module_init_handler",
+            "module_end_handler": "luw_module_end_handler",
+            "response_end_handler": "luw_response_end_handler",
+            "access": {
+                "filesystem": [
+                    "/var/tmp"
+                ]
+            }
+        },
         "rust-echo-request": {
             "type": "wasm",
             "module": "/path/to/unit-wasm/examples/rust/echo-request/target/wasm32-wasi/debug/rust_echo_request.wasm",
@@ -360,6 +391,21 @@ Create the following Unit config
             "request_end_handler": "uwr_request_end_handler",
             "response_end_handler": "uwr_response_end_handler"
         },
+        "rust-large-upload": {
+            "type": "wasm",
+            "module": "/path/to/src/unit-wasm/examples/rust/large-upload/target/wasm32-wasi/debug/rust_large_upload.wasm",
+            "request_handler": "uwr_request_handler",
+            "malloc_handler": "luw_malloc_handler",
+            "free_handler": "luw_free_handler",
+            "module_init_handler": "uwr_module_init_handler",
+            "module_end_handler": "uwr_module_end_handler",
+            "response_end_handler": "uwr_response_end_handler",
+            "access": {
+                "filesystem": [
+                    "/var/tmp"
+                ]
+            }
+        },
         "rust-hello-world": {
             "type": "wasm",
             "module": "/path/to/unit-wasm/examples/rust/hello-world/target/wasm32-wasi/debug/rust_hello_world.wasm",