Exposed compression level in channel arguments (C and C++)

include/grpc++/channel_arguments.h

@@ -38,6 +38,7 @@
 #include <list>
 
 #include <grpc++/config.h>
+#include <grpc/compression.h>
 #include <grpc/grpc.h>
 
 namespace grpc {
@@ -58,6 +59,9 @@ class ChannelArguments {
   void SetSslTargetNameOverride(const grpc::string& name);
   // TODO(yangg) add flow control options
 
+  // Set the compression level for the channel.
+  void SetCompressionLevel(grpc_compression_level level);
+
   // Generic channel argument setters. Only for advanced use cases.
   void SetInt(const grpc::string& key, int value);
   void SetString(const grpc::string& key, const grpc::string& value);

src/core/channel/channel_args.c

@@ -115,3 +115,27 @@ int grpc_channel_args_is_census_enabled(const grpc_channel_args *a) {
   }
   return 0;
 }
+
+grpc_compression_level grpc_channel_args_get_compression_level(
+    const grpc_channel_args *a) {
+  size_t i;
+  if (a) {
+    for (i = 0; a && i < a->num_args; ++i) {
+      if (a->args[i].type == GRPC_ARG_INTEGER &&
+          !strcmp(GRPC_COMPRESSION_LEVEL_ARG, a->args[i].key)) {
+        return a->args[i].value.integer;
+        break;
+      }
+    }
+  }
+  return GRPC_COMPRESS_LEVEL_NONE;
+}
+
+void grpc_channel_args_set_compression_level(
+    grpc_channel_args **a, grpc_compression_level level) {
+  grpc_arg tmp;
+  tmp.type = GRPC_ARG_INTEGER;
+  tmp.key = GRPC_COMPRESSION_LEVEL_ARG;
+  tmp.value.integer = level;
+  *a = grpc_channel_args_copy_and_add(*a, &tmp);
+}

src/core/channel/channel_args.h

@@ -34,21 +34,31 @@
 #ifndef GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H
 #define GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H
 
+#include <grpc/compression.h>
 #include <grpc/grpc.h>
 
 /* Copy some arguments */
 grpc_channel_args *grpc_channel_args_copy(const grpc_channel_args *src);
 
-/* Copy some arguments and add the to_add parameter in the end.
+/** Copy some arguments and add the to_add parameter in the end.
    If to_add is NULL, it is equivalent to call grpc_channel_args_copy. */
 grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
                                                   const grpc_arg *to_add);
 
-/* Destroy arguments created by grpc_channel_args_copy */
+/** Destroy arguments created by grpc_channel_args_copy */
 void grpc_channel_args_destroy(grpc_channel_args *a);
 
-/* Reads census_enabled settings from channel args. Returns 1 if census_enabled
-   is specified in channel args, otherwise returns 0. */
+/** Reads census_enabled settings from channel args. Returns 1 if census_enabled
+ * is specified in channel args, otherwise returns 0. */
 int grpc_channel_args_is_census_enabled(const grpc_channel_args *a);
 
+/** Returns the compression level set in \a a. */
+grpc_compression_level grpc_channel_args_get_compression_level(
+    const grpc_channel_args *a);
+
+/** Sets the compression level in \a a to \a level. Setting it to
+ * GRPC_COMPRESS_LEVEL_NONE disables compression for the channel. */
+void grpc_channel_args_set_compression_level(
+    grpc_channel_args **a, grpc_compression_level level);
+
 #endif  /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H */

src/cpp/client/channel_arguments.cc

@@ -34,6 +34,7 @@
 #include <grpc++/channel_arguments.h>
 
 #include <grpc/grpc_security.h>
+#include "src/core/channel/channel_args.h"
 
 namespace grpc {
 
@@ -41,6 +42,10 @@ void ChannelArguments::SetSslTargetNameOverride(const grpc::string& name) {
   SetString(GRPC_SSL_TARGET_NAME_OVERRIDE_ARG, name);
 }
 
+void ChannelArguments::SetCompressionLevel(grpc_compression_level level) {
+  SetInt(GRPC_COMPRESSION_LEVEL_ARG, level);
+}
+
 grpc::string ChannelArguments::GetSslTargetNameOverride() const {
   for (unsigned int i = 0; i < args_.size(); i++) {
     if (grpc::string(GRPC_SSL_TARGET_NAME_OVERRIDE_ARG) == args_[i].key) {