Add filter go

    Signed-off-by:  longhui.li <[email protected]>

CMakeLists.txt

@@ -177,6 +177,7 @@ option(FLB_FILTER_STDOUT      "Enable stdout filter"                Yes)
 option(FLB_FILTER_PARSER      "Enable parser filter"                Yes)
 option(FLB_FILTER_KUBERNETES  "Enable kubernetes filter"            Yes)
 option(FLB_FILTER_REWRITE_TAG "Enable tag rewrite filter"           Yes)
+option(FLB_FILTER_GO          "Enable Go filter"                    Yes)
 option(FLB_FILTER_THROTTLE    "Enable throttle filter"              Yes)
 option(FLB_FILTER_THROTTLE_SIZE "Enable throttle size filter"        No)
 option(FLB_FILTER_NEST        "Enable nest filter"                  Yes)

plugins/CMakeLists.txt

@@ -215,6 +215,7 @@ REGISTER_FILTER_PLUGIN("filter_tensorflow")
 
 if(FLB_REGEX)
   REGISTER_FILTER_PLUGIN("filter_kubernetes")
+  REGISTER_FILTER_PLUGIN("filter_go")
   REGISTER_FILTER_PLUGIN("filter_modify")
   REGISTER_FILTER_PLUGIN("filter_nest")
   REGISTER_FILTER_PLUGIN("filter_parser")

plugins/filter_go/CMakeLists.txt

@@ -0,0 +1,5 @@
+set(src
+        go.c
+  )
+
+FLB_PLUGIN(filter_go "${src}" "")

plugins/filter_go/Readme.md

@@ -0,0 +1,113 @@
+
+
+call golib from c
+
+example go src:
+
+```go
+
+package main
+
+import "C"
+import (
+	"fmt"
+)
+
+const FLB_OK = 0
+
+//export FLBPluginInit
+func FLBPluginInit(name, value []string) int {
+
+	fmt.Printf("get name %#v. ", name)
+	fmt.Printf("get value %#v. ", value)
+
+	return FLB_OK
+}
+
+//export FLBPluginFilter
+func FLBPluginFilter(srcName, srcValue []string) int {
+	// go will return the result in the slice which called in. so can't append item that max slice's cap.
+	// must use cgoAppend instead of append if you want append value.
+	// use cgoSetSlice if you want change value of slice or just append.
+
+	src := loadCallIn(srcName, srcValue)
+
+	src["myadd"] ="teat"
+
+	return unLoadCallIn(src, srcName, srcValue)
+}
+
+//export FLBPluginExit
+func FLBPluginExit() int {
+
+	fmt.Println("go exit")
+
+	return FLB_OK
+}
+
+func loadCallIn(name, value[]string) map[string]string  {
+	res := make(map[string]string)
+	for idx, n := range name {
+		res[n] = value[idx]
+	}
+	return res
+}
+
+func unLoadCallIn(src map[string]string, name, value []string) int  {
+	index := 0
+	for k, v := range src {
+		name = cgoSetSlice(name, index, k)
+		value = cgoSetSlice(value, index, v)
+		index++
+	}
+	fmt.Println("unload ok: ", name, value)
+	return index;
+}
+
+
+// can't append parameters that will over slice's cap.
+// if over slice's cap, then go will malloc new memory, the c can't get the results.
+func cgoAppend(src []string, parameters... string) []string {
+	if cap(src) - len(src) < len(parameters) {
+		fmt.Println(" cann't set parameters. slice cap is full. ", len(src) , cap(src), len(parameters))
+		return src
+	}
+	src = append(src, parameters...)
+	return src
+}
+
+func cgoSetSlice(src []string, index int, value string) []string {
+	if index > cap(src) {
+		fmt.Println(" cann't set parameters. index overflow. ", index, cap(src))
+		return src
+	}
+
+	if index >= len(src) {
+		src = append(src, value)
+	} else {
+		src[index] = value
+	}
+
+	return src
+}
+
+func main()  {}
+
+```
+
+build
+
+```shell
+go build -o cgolib.so -buildmode=c-shared cgolib.go
+```
+
+config
+
+```ini
+[FILTER]
+    Name     go
+    Match    *
+    golib_so /usr/local/libs/cgolib.so
+    url      http://example1.com
+    url2     http://example2.com
+```

plugins/filter_go/cgo.h

@@ -0,0 +1,51 @@
+/* Created by "go tool cgo" - DO NOT EDIT. */
+
+/* package command-line-arguments */
+
+
+#line 1 "cgo-builtin-prolog"
+
+#include <stddef.h> /* for ptrdiff_t below */
+
+#ifndef GO_CGO_EXPORT_PROLOGUE_H
+#define GO_CGO_EXPORT_PROLOGUE_H
+
+typedef struct { const char *p; ptrdiff_t n; } _GoString_;
+
+#endif
+
+/* Start of boilerplate cgo prologue.  */
+#line 1 "cgo-gcc-export-header-prolog"
+
+#ifndef GO_CGO_PROLOGUE_H
+#define GO_CGO_PROLOGUE_H
+
+typedef signed char GoInt8;
+typedef unsigned char GoUint8;
+typedef short GoInt16;
+typedef unsigned short GoUint16;
+typedef int GoInt32;
+typedef unsigned int GoUint32;
+typedef long long GoInt64;
+typedef unsigned long long GoUint64;
+typedef GoInt64 GoInt;
+typedef GoUint64 GoUint;
+//typedef __SIZE_TYPE__ GoUintptr;
+typedef float GoFloat32;
+typedef double GoFloat64;
+//typedef float _Complex GoComplex64;
+//typedef double _Complex GoComplex128;
+
+/*
+  static assertion to make sure the file is being used on architecture
+  at least with matching size of GoInt.
+*/
+//typedef char _check_for_64_bit_pointer_matching_GoInt[sizeof(void*)==64/8 ? 1:-1];
+
+typedef _GoString_ GoString;
+typedef void *GoMap;
+typedef void *GoChan;
+typedef struct { void *t; void *v; } GoInterface;
+typedef struct { void *data; GoInt len; GoInt cap; } GoSlice;
+
+#endif