Turned load reporting into a plugin

3 files changed, 76 insertions, 40 deletions

diff --git a/src/core/ext/load_reporting/load_reporting.c b/src/core/ext/load_reporting/load_reporting.c
index 9081ffce15..fb32685dc9 100644
--- a/src/core/ext/load_reporting/load_reporting.c
+++ b/src/core/ext/load_reporting/load_reporting.c
@@ -42,27 +42,33 @@
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/channel_init.h"
 
-struct grpc_load_reporting_data {
+struct grpc_load_reporting_config {
   grpc_load_reporting_fn fn;
   void *data;
 };
 
-grpc_load_reporting_data *grpc_load_reporting_create(grpc_load_reporting_fn fn,
-                                                     void *data) {
-  grpc_load_reporting_data *lrd = gpr_malloc(sizeof(grpc_load_reporting_data));
-  lrd->fn = fn;
-  lrd->data = data;
-  return lrd;
+grpc_load_reporting_config *grpc_load_reporting_config_create(
+    grpc_load_reporting_fn fn, void *data) {
+  grpc_load_reporting_config *lrc =
+      gpr_malloc(sizeof(grpc_load_reporting_config));
+  lrc->fn = fn;
+  lrc->data = data;
+  return lrc;
 }
 
-void grpc_load_reporting_destroy(grpc_load_reporting_data *lrd) {
-  gpr_free(lrd);
+grpc_load_reporting_config *grpc_load_reporting_config_copy(
+    grpc_load_reporting_config *src) {
+  return grpc_load_reporting_config_create(src->fn, src->data);
 }
 
-void grpc_load_reporting_call(grpc_load_reporting_data *lrd,
-    const grpc_call_stats *stats) {
-  if (lrd->fn != NULL) {
-    lrd->fn(lrd->data, stats);
+void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc) {
+  gpr_free(lrc);
+}
+
+void grpc_load_reporting_config_call(grpc_load_reporting_config *lrc,
+                                     const grpc_call_stats *stats) {
+  if (lrc->fn != NULL) {
+    lrc->fn(stats, lrc->data);
   }
 }
 
@@ -87,6 +93,31 @@ static bool maybe_add_load_reporting_filter(grpc_channel_stack_builder *builder,
   return true;
 }
 
+static void lrd_arg_destroy(void *p) { grpc_load_reporting_config_destroy(p); }
+
+static void *lrd_arg_copy(void *p) {
+  return grpc_load_reporting_config_copy(p);
+}
+
+static int lrd_arg_cmp(void *a, void *b) {
+  grpc_load_reporting_config *lhs = a;
+  grpc_load_reporting_config *rhs = b;
+  return !(lhs->fn == rhs->fn && lhs->data == rhs->data);
+}
+
+static const grpc_arg_pointer_vtable lrd_ptr_vtable = {
+    lrd_arg_copy, lrd_arg_destroy, lrd_arg_cmp};
+
+grpc_arg grpc_load_reporting_config_create_arg(
+    grpc_load_reporting_config *lrc) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = GRPC_ARG_ENABLE_LOAD_REPORTING;
+  arg.value.pointer.p = lrc;
+  arg.value.pointer.vtable = &lrd_ptr_vtable;
+  return arg;
+}
+
 /* Plugin registration */
 
 void grpc_load_reporting_plugin_init(void) {
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/load_reporting/load_reporting.h
index fcf555da85..806af2bda7 100644
--- a/src/core/ext/load_reporting/load_reporting.h
+++ b/src/core/ext/load_reporting/load_reporting.h
@@ -37,28 +37,28 @@
 #include "src/core/lib/iomgr/closure.h"
 #include "src/core/lib/surface/call.h"
 
-typedef struct grpc_load_reporting_data grpc_load_reporting_data;
+typedef struct grpc_load_reporting_config grpc_load_reporting_config;
 
-/** Custom function to be called by the load reporting filter.
- *
- * The \a data pointer is the same as the one passed to \a
- * grpc_load_reporting_init. \a stats are the final per-call statistics gathered
- * by the gRPC runtime. */
-typedef void (*grpc_load_reporting_fn)(void *data,
-                                       const grpc_call_stats *stats);
+/** Custom function to be called by the load reporting filter. */
+typedef void (*grpc_load_reporting_fn)(const grpc_call_stats *stats,
+                                       void *data);
 
 /** Register \a fn as the function to be invoked by the load reporting filter,
- * passing \a data as its namesake argument. To be called only from a plugin
- * init function. */
-grpc_load_reporting_data *grpc_load_reporting_create(grpc_load_reporting_fn fn,
-                                                     void *data);
+ * passing \a data alongisde the call stats */
+grpc_load_reporting_config *grpc_load_reporting_config_create(
+    grpc_load_reporting_fn fn, void *data);
+
+grpc_load_reporting_config *grpc_load_reporting_config_copy(
+    grpc_load_reporting_config *src);
 
-// XXX
-void grpc_load_reporting_destroy(grpc_load_reporting_data *lrd);
+void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc);
 
 /** Invoke the function registered by \a grpc_load_reporting_init, passing it \a
  * stats as one of the arguments (see \a load_reporting_fn). */
-void grpc_load_reporting_call(grpc_load_reporting_data *lrd,
-                              const grpc_call_stats *stats);
+void grpc_load_reporting_config_call(grpc_load_reporting_config *lrc,
+                                     const grpc_call_stats *stats);
+
+/** Return a \a grpc_arg enabling load reporting */
+grpc_arg grpc_load_reporting_config_create_arg(grpc_load_reporting_config *lrc);
 
 #endif /* GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H */
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index 81f4a0277c..6970f064b8 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -31,8 +31,8 @@
  *
  */
 
-#include <string.h>
 #include <grpc/support/log.h>
+#include <string.h>
 
 #include "src/core/ext/load_reporting/load_reporting.h"
 #include "src/core/ext/load_reporting/load_reporting_filter.h"
@@ -40,7 +40,7 @@
 #include "src/core/lib/profiling/timers.h"
 
 typedef struct call_data { void *dummy; } call_data;
-typedef struct channel_data { grpc_load_reporting_data *lrd; } channel_data;
+typedef struct channel_data { grpc_load_reporting_config *lrc; } channel_data;
 
 /* Constructor for call_data */
 static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
@@ -50,9 +50,11 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               const grpc_call_stats *stats, void *ignored) {
   channel_data *chand = elem->channel_data;
-  GPR_TIMER_BEGIN("load_reporting_filter", 0);
-  grpc_load_reporting_call(chand->lrd, stats);
-  GPR_TIMER_END("load_reporting_filter", 0);
+  if (chand->lrc != NULL) {
+    GPR_TIMER_BEGIN("load_reporting_filter", 0);
+    grpc_load_reporting_config_call(chand->lrc, stats);
+    GPR_TIMER_END("load_reporting_filter", 0);
+  }
 }
 
 /* Constructor for channel_data */
@@ -65,20 +67,23 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
   memset(chand, 0, sizeof(channel_data));
 
   for (size_t i = 0; i < args->channel_args->num_args; i++) {
-    if (0 == strcmp(args->channel_args->args[i].key, GRPC_ARG_ENABLE_LOAD_REPORTING)) {
-      chand->lrd = args->channel_args->args[i].value.pointer.p;
-      GPR_ASSERT(chand->lrd != NULL);
+    if (0 == strcmp(args->channel_args->args[i].key,
+                    GRPC_ARG_ENABLE_LOAD_REPORTING)) {
+      grpc_load_reporting_config *arg_lrc =
+          args->channel_args->args[i].value.pointer.p;
+      chand->lrc = grpc_load_reporting_config_copy(arg_lrc);
+      GPR_ASSERT(chand->lrc != NULL);
+      break;
     }
   }
-  GPR_ASSERT(chand->lrd != NULL); /* arg actually found */
-
+  GPR_ASSERT(chand->lrc != NULL); /* arg actually found */
 }
 
 /* Destructor for channel data */
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {
   channel_data *chand = elem->channel_data;
-  grpc_load_reporting_destroy(chand->lrd);
+  grpc_load_reporting_config_destroy(chand->lrc);
 }
 
 const grpc_channel_filter grpc_load_reporting_filter = {