feat: allow supporting another vm (#94)

Author: spacewander

.github/workflows/test.yml

@@ -66,4 +66,4 @@ jobs:
           pushd ./t/testdata/rust && cargo build --target=wasm32-wasi && popd
 
           export PATH=$OPENRESTY_PREFIX/nginx/sbin:$PATH
-          prove -I. -Itest-nginx/lib -r t/
+          WASM_VM=wasmtime prove -I. -Itest-nginx/lib -r t/

README.md

@@ -29,9 +29,9 @@ The [Wasm integration of Apache APISIX](https://github.com/apache/apisix/blob/ma
 Remember to add the `wasmtime-c-api/lib` to the library search path when you build Nginx, for instance,
 
 ```
-export wasm_prefix=/path/to/wasm-nginx-module/wasmtime-c-api
+export wasmtime_prefix=/path/to/wasm-nginx-module/wasmtime-c-api
 ./configure ... \
-    --with-ld-opt="-Wl,-rpath,${wasm_prefix}/lib" \
+    --with-ld-opt="-Wl,-rpath,${wasmtime_prefix}/lib" \
 ```
 
 ## Directives
@@ -44,8 +44,8 @@ export wasm_prefix=/path/to/wasm-nginx-module/wasmtime-c-api
 
 **context:** *http*
 
-Select the WASM VM. Currently, only wasmtime is supported. If the directive is
-not set, the WASM VM won't be enabled.
+Select the WASM VM. Currently, only wasmtime is supported.
+If the directive is not set, the WASM VM won't be enabled.
 
 ## Methods
 

config

@@ -25,7 +25,7 @@ ngx_module_srcs=" \
     $ngx_addon_dir/src/vm/vm.c \
 "
 ngx_module_deps=" \
-    $ngx_addon_dir/src/http/ngx_http_wasm_api.h \
+    $ngx_addon_dir/src/http/ngx_http_wasm_api_def.h \
     $ngx_addon_dir/src/vm/vm.h \
 "
 ngx_module_incs=" \

gen_wasm_host_api.py

@@ -0,0 +1,224 @@
+#!/usr/bin/env python
+# Copyright 2022 Shenzhen ZhiLiu Technology Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import os
+import re
+import sys
+from string import Template
+
+
+max_wasm_api_arg = 12
+header = """/*
+ * Copyright 2022 Shenzhen ZhiLiu Technology Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+/* Code generated by `./gen_wasm_host_api.py src/http`. DO NOT EDIT. */"""
+
+api_def_tpl = """
+$header
+#ifndef NGX_HTTP_WASM_API_DEF_H
+#define NGX_HTTP_WASM_API_DEF_H
+
+
+#include <ngx_core.h>
+
+
+$host_api_def
+
+
+#endif
+"""
+
+tpl = """
+$header
+#ifndef $vm_api_header_name
+#define $vm_api_header_name
+
+
+#include <wasm.h>
+$vm_header
+#include <ngx_core.h>
+#include "proxy_wasm/proxy_wasm_types.h"
+#include "http/ngx_http_wasm_api_def.h"
+
+
+#define MAX_WASM_API_ARG  $max_wasm_api_arg
+
+$wasm_api_def
+
+
+#endif
+"""
+
+
+def predefined_macro(vm):
+    if vm == "wasmtime":
+        vm_def = """
+#define DEFINE_WASM_API(NAME, ARG_CHECK) \\
+    static wasm_trap_t* wasmtime_##NAME( \\
+        void *env, \\
+        wasmtime_caller_t *caller, \\
+        const wasmtime_val_t *args, \\
+        size_t nargs, \\
+        wasmtime_val_t *results, \\
+        size_t nresults \\
+    ) { \\
+        ARG_CHECK \\
+        results[0].kind = WASMTIME_I32; \\
+        results[0].of.i32 = res; \\
+        return NULL; \\
+    }
+#define DEFINE_WASM_NAME(NAME, ARG) \\
+    {ngx_string(#NAME), wasmtime_##NAME, ARG},
+
+
+typedef struct {
+    ngx_str_t                name;
+    wasmtime_func_callback_t cb;
+    int8_t                   param_num;
+    wasm_valkind_t           param_type[MAX_WASM_API_ARG];
+} ngx_wasm_wasmtime_host_api_t;
+
+"""
+
+    for i in range(max_wasm_api_arg + 1):
+        if i == 0:
+            void_def = """
+#define DEFINE_WASM_NAME_ARG_VOID \\
+    0, {}
+#define DEFINE_WASM_API_ARG_CHECK_VOID(NAME) \\
+    int32_t res = NAME();
+"""
+            vm_def += void_def
+        else:
+            param_s = ""
+            if vm == "wasmtime":
+                kind = "WASM_I32"
+            for j in range(1, i + 1):
+                if j % 5 == 1:
+                    param_s += "    "
+                param_s += kind + ", "
+                if j % 5 == 0:
+                    param_s += " \\\n"
+            vm_def += """
+#define DEFINE_WASM_NAME_ARG_I32_%d \\
+    %d, { \\
+%s}""" % (i, i, param_s)
+            vm_def += """
+#define DEFINE_WASM_API_ARG_CHECK_I32_%d(NAME) \\\n""" % (i)
+            for j in range(i):
+                if vm == "wasmtime":
+                    vm_def += "    int32_t p%d = args[%d].of.i32; \\\n" % (j, j)
+            param_s = ", ".join('p' + str(j) for j in range(i))
+            vm_def += "    int32_t res = NAME(%s);\n" % (param_s)
+    return vm_def
+
+
+def get_host_apis(src_dir):
+    apis = []
+    with open(os.path.join(src_dir, "ngx_http_wasm_api.c")) as f:
+        matching = False
+        api = ""
+        name = ""
+        for line in f:
+            m = re.match(r"^(proxy_\w+)\(", line)
+            if m is not None:
+                matching = True
+                name = m.group(1)
+            elif line[0] == '{' and matching:
+                matching = False
+                n_param = len(api.split(','))
+                if "(void)" in api:
+                    n_param -= 1
+                apis.append({
+                    "name": name,
+                    "n_param": n_param
+                })
+                api = ""
+            if matching:
+                api += line.rstrip()
+    return apis
+
+
+if __name__ == '__main__':
+    host_api_def = ""
+    api_def = ""
+    name_def = ""
+    for i in range(max_wasm_api_arg + 1):
+        if i == 0:
+            host_api_def += "#define DEFINE_WASM_API_ARG_VOID void\n"
+        else:
+            param_suffix = "I32_%d" % i
+            param_s = ""
+            for j in range(1, i + 1):
+                if j % 8 == 1:
+                    if j != 1:
+                        param_s += ","
+                    param_s += " \\\n    "
+                else:
+                    param_s += ", "
+                param_s += "int32_t"
+            host_api_def += "#define DEFINE_WASM_API_ARG_%s%s\n" % (param_suffix, param_s)
+    host_api_def += "\n\n"
+
+    src_dir = sys.argv[1]
+    apis = get_host_apis(src_dir)
+
+    for api in apis:
+        name = api["name"]
+        n_param = api["n_param"]
+        if n_param == 0:
+            param_suffix = "VOID"
+        else:
+            param_suffix = "I32_%d" % n_param
+
+        host_api_def += """int32_t %s(DEFINE_WASM_API_ARG_%s);\n""" % (name, param_suffix)
+        api_def += """
+DEFINE_WASM_API(%s,
+                DEFINE_WASM_API_ARG_CHECK_%s(%s))""" % (name, param_suffix, name)
+
+        name_def += "    DEFINE_WASM_NAME(%s, DEFINE_WASM_NAME_ARG_%s)\n" % (name, param_suffix)
+
+    name_def += "    { ngx_null_string, NULL, 0, {} }\n};"
+
+    s = Template(api_def_tpl)
+    with open(os.path.join(src_dir, "ngx_http_wasm_api_def.h"), 'w') as f:
+        f.write(s.substitute(header=header, host_api_def=host_api_def))
+
+    s = Template(tpl)
+
+    wasmtime_def = predefined_macro("wasmtime")
+    wasmtime_def += api_def + "\n\nstatic ngx_wasm_wasmtime_host_api_t host_apis[] = {\n"
+    wasmtime_def += name_def
+    with open(os.path.join(src_dir, "ngx_http_wasm_api_wasmtime.h"), 'w') as f:
+        f.write(s.substitute(
+            header=header,
+            vm_header="#include <wasmtime.h>",
+            vm_api_header_name="NGX_HTTP_WASM_API_WASMTIME_H",
+            wasm_api_def=wasmtime_def,
+            max_wasm_api_arg=max_wasm_api_arg,
+        ))