From e37acd8c1a42782df86045128a376878d2b0dac6 Mon Sep 17 00:00:00 2001
From: Ryan Armstrong <ryan@cavaliercoder.com>
Date: Tue, 8 Mar 2016 13:55:02 +0800
Subject: [PATCH] Fixed Go pointer return in zbx_module_item_list. Fixes #7

---
 Dockerfile |  2 +-
 Makefile   | 12 +++++++++---
 module.go  | 27 +++++++++++++++++++++------
 3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index bf33798..0c7cde8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -15,7 +15,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
-FROM golang:1.5
+FROM golang:1.6
 
 # install Zabbix agent
 RUN \
diff --git a/Makefile b/Makefile
index d67aad9..a27c5bc 100644
--- a/Makefile
+++ b/Makefile
@@ -27,11 +27,17 @@ clean:
 	go clean -i -x
 	rm -vf g2z.h
 
-clean-all: clean
+clean-dummy:
 	cd dummy && $(MAKE) clean
 
+clean-all: clean clean-dummy
+	
 docker-build:
-	docker build -t cavaliercoder/g2z .
+	docker build \
+		--build-arg "http_proxy=$(http_proxy)" \
+		--build-arg "https_proxy=$(https_proxy)" \
+		--build-arg "no_proxy=$(no_proxy)" \
+		-t cavaliercoder/g2z .
 
 docker-run: docker-build
 	docker run --rm -it \
@@ -40,4 +46,4 @@ docker-run: docker-build
 		--privileged \
 		cavaliercoder/g2z
 
-.PHONY: all g2z dummy clean clean-all docker-build docker-run
+.PHONY: all g2z dummy clean clean-dummy clean-all docker-build docker-run
diff --git a/module.go b/module.go
index 5190eb5..31c5793 100644
--- a/module.go
+++ b/module.go
@@ -21,6 +21,7 @@ package g2z
 
 /*
 // zabbix agent headers
+#include <stdlib.h>
 #include <stdint.h>
 #include "module.h"
 
@@ -29,6 +30,20 @@ typedef int (*agent_item_handler)(AGENT_REQUEST*, AGENT_RESULT*);
 
 // item callback router function defined in router.go
 int route_item(AGENT_REQUEST *request, AGENT_RESULT *result);
+
+// create new metric list
+static ZBX_METRIC *new_metric_list(const size_t n) {
+	return (ZBX_METRIC*)calloc(sizeof(ZBX_METRIC), n + 1);
+}
+
+// append a metric to a metric list
+static void append_metric(ZBX_METRIC *list, const ZBX_METRIC *n) {
+	while(NULL != list->key)
+		list++;
+
+	memcpy(list, n, sizeof(ZBX_METRIC));
+}
+
 */
 import "C"
 
@@ -101,17 +116,17 @@ func zbx_module_item_list() *C.ZBX_METRIC {
 	router := C.agent_item_handler(unsafe.Pointer(C.route_item))
 
 	// create null-terminated array of C.ZBX_METRICS
-	i := 0
-	metrics := make([]C.ZBX_METRIC, len(itemHandlers)+1)
+	metrics := C.new_metric_list(C.size_t(len(itemHandlers))) // never freed
 	for _, item := range itemHandlers {
-		metrics[i] = C.ZBX_METRIC{
+		m := C.ZBX_METRIC{
 			key:        C.CString(item.Key), // freed by Zabbix
 			flags:      C.CF_HAVEPARAMS,
 			function:   router,
 			test_param: C.CString(item.TestParams), // freed by Zabbix
-		}
-		i++
+		} // freed by Go GC
+
+		C.append_metric(metrics, &m)
 	}
 
-	return &metrics[0]
+	return metrics
 }