feat: implement extism_http_request (#7)

* chore: bring extism pdk header up to date

* feat: partial working http_request

* ci: add test for http example which should eventually pass

* feat: use memory in HTTPResponse

* chore: update method name, add comments to example

* ci: try to download modules before compiling

* ci: download mods from example directory

* fix: add fastjson dep to go.mod

Co-authored-by: zach <zachshipko@gmail.com>

Author: nilslice

.github/workflows/ci.yml

@@ -56,6 +56,10 @@ jobs:
 
       - name: Compile example
         run: |
+          pushd example
+          go mod download
+          popd 
+        
           make -B example
 
       - name: Test example
@@ -66,3 +70,5 @@ jobs:
           echo $TEST | grep '"count": 4'
           echo $TEST | grep '"config": "1"'
           echo $TEST | grep '"a": "this is var a"'
+        
+          extism call example/http.wasm --wasi http_get | grep '"userId": 1'

Makefile

@@ -1,6 +1,9 @@
 .PHONY: example
 example:
 	tinygo build -o example/example.wasm -target wasi example/main.go
+	tinygo build -o example/http.wasm -target wasi example/http.go
 
 test:
-	extism call example/example.wasm count_vowels --wasi --input "this is a test" --set-config '{"thing": "1234"}'
+	extism call example/example.wasm count_vowels --wasi --input "this is a test" --set-config '{"thing": "1234"}'	
+	@echo ""
+	extism call example/http.wasm http_get --wasi --log-level info

example/example.wasm

@@ -3,3 +3,7 @@ module github.com/extism/go-pdk/example
 go 1.19
 
 require github.com/extism/go-pdk v0.0.0-20220910220145-f385a5f19d1d
+
+require github.com/valyala/fastjson v1.6.3 // indirect
+
+replace github.com/extism/go-pdk => ../

example/go.mod

@@ -1,2 +1,2 @@
-github.com/extism/go-pdk v0.0.0-20220910220145-f385a5f19d1d h1:nwr+atxLObICflh2BGTC7SKqln218aa+zKg9Yn9JMSM=
-github.com/extism/go-pdk v0.0.0-20220910220145-f385a5f19d1d/go.mod h1:rfOf4Z9uXtA4W3SYoPN34poctHYSo6ScSqcKoAswHjM=
+github.com/valyala/fastjson v1.6.3 h1:tAKFnnwmeMGPbwJ7IwxcTPCNr3uIzoIj3/Fh90ra4xc=
+github.com/valyala/fastjson v1.6.3/go.mod h1:CLCAqky6SMuOcxStkYQvblddUtoRxhYMGLrsQns1aXY=

example/go.sum

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"github.com/extism/go-pdk"
+)
+
+//export http_get
+func http_get() int32 {
+	// create an HTTP Request (withuot relying on WASI), set headers as needed
+	req := pdk.NewHTTPRequest("GET", "https://jsonplaceholder.typicode.com/todos/1")
+	req.SetHeader("some-name", "some-value")
+	req.SetHeader("another", "again")
+	// send the request, get response back (can check status on response via res.Status())
+	res := req.Send()
+
+	// zero-copy output to host
+	pdk.OutputMemory(res.Memory())
+
+	return 0
+}
+
+func main() {}

example/http.go

@@ -4,57 +4,62 @@
 
 #define IMPORT(a, b) __attribute__((import_module(a), import_name(b)))
 
+typedef uint64_t ExtismPointer;
+
 IMPORT("env", "extism_input_length") extern uint64_t extism_input_length();
-IMPORT("env", "extism_length") extern uint64_t extism_length(uint64_t);
-IMPORT("env", "extism_alloc") extern uint64_t extism_alloc(uint64_t);
-IMPORT("env", "extism_free") extern void extism_free(uint64_t);
+IMPORT("env", "extism_length") extern uint64_t extism_length(ExtismPointer);
+IMPORT("env", "extism_alloc") extern ExtismPointer extism_alloc(uint64_t);
+IMPORT("env", "extism_free") extern void extism_free(ExtismPointer);
 
 IMPORT("env", "extism_input_load_u8")
-extern uint8_t extism_input_load_u8(uint64_t);
+extern uint8_t extism_input_load_u8(ExtismPointer);
 
 IMPORT("env", "extism_input_load_u64")
-extern uint64_t extism_input_load_u64(uint64_t);
+extern uint64_t extism_input_load_u64(ExtismPointer);
 
 IMPORT("env", "extism_output_set")
-extern void extism_output_set(uint64_t, uint64_t);
+extern void extism_output_set(ExtismPointer, uint64_t);
 
 IMPORT("env", "extism_error_set")
-extern void extism_error_set(uint64_t);
+extern void extism_error_set(ExtismPointer);
 
 IMPORT("env", "extism_config_get")
-extern uint64_t extism_config_get(uint64_t);
+extern ExtismPointer extism_config_get(ExtismPointer);
 
 IMPORT("env", "extism_var_get")
-extern uint64_t extism_var_get(uint64_t);
+extern ExtismPointer extism_var_get(ExtismPointer);
 
 IMPORT("env", "extism_var_set")
-extern void extism_var_set(uint64_t, uint64_t);
+extern void extism_var_set(ExtismPointer, ExtismPointer);
 
 IMPORT("env", "extism_store_u8")
-extern void extism_store_u8(uint64_t, uint8_t);
+extern void extism_store_u8(ExtismPointer, uint8_t);
 
 IMPORT("env", "extism_load_u8")
-extern uint8_t extism_load_u8(uint64_t);
+extern uint8_t extism_load_u8(ExtismPointer);
 
 IMPORT("env", "extism_store_u64")
-extern void extism_store_u64(uint64_t, uint64_t);
+extern void extism_store_u64(ExtismPointer, uint64_t);
 
 IMPORT("env", "extism_load_u64")
-extern uint64_t extism_load_u64(uint64_t);
+extern uint64_t extism_load_u64(ExtismPointer);
 
 IMPORT("env", "extism_http_request")
-extern uint64_t extism_http_request(uint64_t, uint64_t);
+extern ExtismPointer extism_http_request(ExtismPointer, ExtismPointer);
+
+IMPORT("env", "extism_http_status_code")
+extern int32_t extism_http_status_code();
 
 IMPORT("env", "extism_log_info")
-extern void extism_log_info(uint64_t);
+extern void extism_log_info(ExtismPointer);
 IMPORT("env", "extism_log_debug")
-extern void extism_log_debug(uint64_t);
+extern void extism_log_debug(ExtismPointer);
 IMPORT("env", "extism_log_warn")
-extern void extism_log_warn(uint64_t);
+extern void extism_log_warn(ExtismPointer);
 IMPORT("env", "extism_log_error")
-extern void extism_log_error(uint64_t);
+extern void extism_log_error(ExtismPointer);
 
-static void extism_load(uint64_t offs, uint8_t *buffer, uint64_t length) {
+static void extism_load(ExtismPointer offs, uint8_t *buffer, uint64_t length) {
   uint64_t n;
   uint64_t left = 0;
 
@@ -88,7 +93,7 @@ static void extism_load_input(uint8_t *buffer, uint64_t length) {
   }
 }
 
-static void extism_store(uint64_t offs, const uint8_t *buffer,
+static void extism_store(ExtismPointer offs, const uint8_t *buffer,
                          uint64_t length) {
   uint64_t n;
   uint64_t left = 0;

example/http.wasm

@@ -2,6 +2,9 @@ package pdk
 
 import (
 	"encoding/binary"
+	"strings"
+
+	"github.com/valyala/fastjson"
 )
 
 /*
@@ -116,6 +119,10 @@ func Output(data []byte) {
 	C.extism_output_set(offset, clength)
 }
 
+func OutputString(s string) {
+	Output([]byte(s))
+}
+
 func GetConfig(key string) (string, bool) {
 	mem := AllocateBytes([]byte(key))
 
@@ -182,6 +189,84 @@ func RemoveVar(key string) {
 	)
 }
 
+type HTTPRequest struct {
+	url    string
+	header map[string]string
+	method string
+	body   []byte
+}
+
+type HTTPResponse struct {
+	memory Memory
+	status uint16
+}
+
+func (r HTTPResponse) Memory() Memory {
+	return r.memory
+}
+
+func (r HTTPResponse) Body() []byte {
+	buf := make([]byte, r.memory.length)
+	r.memory.Load(buf)
+	return buf
+}
+
+func (r HTTPResponse) Status() uint16 {
+	return r.status
+}
+
+func NewHTTPRequest(method string, url string) *HTTPRequest {
+	return &HTTPRequest{url: url, header: nil, method: strings.ToUpper(method), body: nil}
+}
+
+func (r *HTTPRequest) SetHeader(key string, value string) *HTTPRequest {
+	if r.header == nil {
+		r.header = map[string]string{}
+	}
+	r.header[key] = value
+	return r
+}
+
+func (r *HTTPRequest) SetBody(body []byte) *HTTPRequest {
+	r.body = body
+	return r
+}
+
+func (r *HTTPRequest) Send() HTTPResponse {
+	arena := &fastjson.Arena{}
+	json := arena.NewObject()
+	headers := arena.NewObject()
+	if r.header != nil {
+		for k, v := range r.header {
+			headers.Set(k, arena.NewString(v))
+		}
+
+		json.Set("header", headers)
+	}
+	json.Set("url", arena.NewString(r.url))
+	json.Set("method", arena.NewString(r.method))
+
+	var buf []byte
+	enc := json.MarshalTo(buf)
+
+	req := AllocateBytes(enc)
+	defer req.Free()
+	data := AllocateBytes(r.body)
+	defer data.Free()
+
+	offset := C.extism_http_request(C.uint64_t(req.offset), data.offset)
+	length := uint64(C.extism_length(offset))
+	status := uint16(C.extism_http_status_code())
+
+	memory := Memory{offset, length}
+	defer memory.Free()
+
+	return HTTPResponse{
+		memory,
+		status,
+	}
+}
+
 func (m *Memory) Load(buffer []byte) {
 	load(m.offset, buffer)
 }

extism-pdk.h

@@ -1,3 +1,5 @@
 module github.com/extism/go-pdk
 
 go 1.19
+
+require github.com/valyala/fastjson v1.6.3

extism_pdk.go

@@ -0,0 +1,2 @@
+github.com/valyala/fastjson v1.6.3 h1:tAKFnnwmeMGPbwJ7IwxcTPCNr3uIzoIj3/Fh90ra4xc=
+github.com/valyala/fastjson v1.6.3/go.mod h1:CLCAqky6SMuOcxStkYQvblddUtoRxhYMGLrsQns1aXY=