Support >16kib frame sizes in core

include/grpc/impl/codegen/grpc_types.h

@@ -142,6 +142,11 @@ typedef struct {
 /** How much memory to use for hpack encoding. Int valued, bytes. */
 #define GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER \
   "grpc.http2.hpack_table_size.encoder"
+/** How big a frame are we willing to receive via HTTP2.
+    Min 16384, max 16777215.
+    Larger values give lower CPU usage for large messages, but more head of line
+    blocking for small messages. */
+#define GRPC_ARG_HTTP2_MAX_FRAME_SIZE "grpc.http2.max_frame_size"
 /** Default authority to pass if none specified on call construction. A string.
  * */
 #define GRPC_ARG_DEFAULT_AUTHORITY "grpc.default_authority"

src/core/ext/transport/chttp2/transport/chttp2_transport.c

@@ -408,6 +408,19 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
           push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
                        (uint32_t)channel_args->args[i].value.integer);
         }
+      } else if (0 == strcmp(channel_args->args[i].key,
+                             GRPC_ARG_HTTP2_MAX_FRAME_SIZE)) {
+        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
+          gpr_log(GPR_ERROR, "%s: must be an integer",
+                  GRPC_ARG_HTTP2_MAX_FRAME_SIZE);
+        } else if (channel_args->args[i].value.integer < 16384 ||
+                   channel_args->args[i].value.integer > 16777215) {
+          gpr_log(GPR_ERROR, "%s: must be between 16384 and 16777215",
+                  GRPC_ARG_HTTP2_MAX_FRAME_SIZE);
+        } else {
+          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE,
+                       (uint32_t)channel_args->args[i].value.integer);
+        }
       }
     }
   }

src/core/ext/transport/chttp2/transport/frame.h

@@ -52,8 +52,6 @@ typedef struct grpc_chttp2_transport_parsing grpc_chttp2_transport_parsing;
 #define GRPC_CHTTP2_FRAME_GOAWAY 7
 #define GRPC_CHTTP2_FRAME_WINDOW_UPDATE 8
 
-#define GRPC_CHTTP2_MAX_PAYLOAD_LENGTH ((1 << 14) - 1)
-
 #define GRPC_CHTTP2_DATA_FLAG_END_STREAM 1
 #define GRPC_CHTTP2_FLAG_ACK 1
 #define GRPC_CHTTP2_DATA_FLAG_END_HEADERS 4

src/core/ext/transport/chttp2/transport/hpack_encoder.c

@@ -78,6 +78,8 @@ typedef struct {
   uint32_t stream_id;
   gpr_slice_buffer *output;
   grpc_transport_one_way_stats *stats;
+  /* maximum size of a frame */
+  size_t max_frame_size;
 } framer_state;
 
 /* fills p (which is expected to be 9 bytes long) with a data frame header */
@@ -123,7 +125,7 @@ static void begin_frame(framer_state *st) {
    needed */
 static void ensure_space(framer_state *st, size_t need_bytes) {
   if (st->output->length - st->output_length_at_start_of_frame + need_bytes <=
-      GRPC_CHTTP2_MAX_PAYLOAD_LENGTH) {
+      st->max_frame_size) {
     return;
   }
   finish_frame(st, 0, 0);
@@ -149,8 +151,8 @@ static void add_header_data(framer_state *st, gpr_slice slice) {
   size_t len = GPR_SLICE_LENGTH(slice);
   size_t remaining;
   if (len == 0) return;
-  remaining = GRPC_CHTTP2_MAX_PAYLOAD_LENGTH +
+  remaining = st->max_frame_size + st->output_length_at_start_of_frame -
-              st->output_length_at_start_of_frame - st->output->length;
+              st->output->length;
   if (len <= remaining) {
     st->stats->header_bytes += len;
     gpr_slice_buffer_add(st->output, slice);
@@ -542,6 +544,7 @@ void grpc_chttp2_hpack_compressor_set_max_table_size(
 void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c,
                                uint32_t stream_id,
                                grpc_metadata_batch *metadata, int is_eof,
+                               size_t max_frame_size,
                                grpc_transport_one_way_stats *stats,
                                gpr_slice_buffer *outbuf) {
   framer_state st;
@@ -555,6 +558,7 @@ void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c,
   st.output = outbuf;
   st.is_first_frame = 1;
   st.stats = stats;
+  st.max_frame_size = max_frame_size;
 
   /* Encode a metadata batch; store the returned values, representing
      a metadata element that needs to be unreffed back into the metadata

src/core/ext/transport/chttp2/transport/hpack_encoder.h

@@ -91,6 +91,7 @@ void grpc_chttp2_hpack_compressor_set_max_usable_size(
 
 void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c, uint32_t id,
                                grpc_metadata_batch *metadata, int is_eof,
+                               size_t max_frame_size,
                                grpc_transport_one_way_stats *stats,
                                gpr_slice_buffer *outbuf);
 

src/core/ext/transport/chttp2/transport/internal.h

@@ -223,6 +223,8 @@ typedef struct {
   uint8_t is_client;
   /** callback for when writing is done */
   grpc_closure done_cb;
+  /** maximum frame size */
+  uint32_t max_frame_size;
 } grpc_chttp2_transport_writing;
 
 struct grpc_chttp2_transport_parsing {

src/core/ext/transport/chttp2/transport/writing.c

@@ -51,6 +51,10 @@ int grpc_chttp2_unlocking_check_writes(
 
   GPR_TIMER_BEGIN("grpc_chttp2_unlocking_check_writes", 0);
 
+  transport_writing->max_frame_size =
+      transport_global
+          ->settings[GRPC_ACKED_SETTINGS][GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE];
+
   /* simple writes are queued to qbuf, and flushed here */
   gpr_slice_buffer_swap(&transport_global->qbuf, &transport_writing->outbuf);
   GPR_ASSERT(transport_global->qbuf.count == 0);
@@ -206,14 +210,15 @@ static void finalize_outbuf(grpc_exec_ctx *exec_ctx,
   while (
       grpc_chttp2_list_pop_writing_stream(transport_writing, &stream_writing)) {
     uint32_t max_outgoing =
-        (uint32_t)GPR_MIN(GRPC_CHTTP2_MAX_PAYLOAD_LENGTH,
+        (uint32_t)GPR_MIN(transport_writing->max_frame_size,
                           GPR_MIN(stream_writing->outgoing_window,
                                   transport_writing->outgoing_window));
     /* send initial metadata if it's available */
     if (stream_writing->send_initial_metadata != NULL) {
       grpc_chttp2_encode_header(
           &transport_writing->hpack_compressor, stream_writing->id,
-          stream_writing->send_initial_metadata, 0, &stream_writing->stats,
+          stream_writing->send_initial_metadata, 0,
+          transport_writing->max_frame_size, &stream_writing->stats,
           &transport_writing->outbuf);
       stream_writing->send_initial_metadata = NULL;
       stream_writing->sent_initial_metadata = 1;
@@ -303,7 +308,8 @@ static void finalize_outbuf(grpc_exec_ctx *exec_ctx,
       } else {
         grpc_chttp2_encode_header(
             &transport_writing->hpack_compressor, stream_writing->id,
-            stream_writing->send_trailing_metadata, 1, &stream_writing->stats,
+            stream_writing->send_trailing_metadata, 1,
+            transport_writing->max_frame_size, &stream_writing->stats,
             &transport_writing->outbuf);
       }
       if (!transport_writing->is_client && !stream_writing->read_closed) {

test/core/end2end/tests/invoke_large_request.c

@@ -39,6 +39,7 @@
 #include <grpc/byte_buffer.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
@@ -101,9 +102,25 @@ static gpr_slice large_slice(void) {
   return slice;
 }
 
-static void test_invoke_large_request(grpc_end2end_test_config config) {
+static void test_invoke_large_request(grpc_end2end_test_config config,
+                                      int max_frame_size, int lookahead_bytes) {
+  char *name;
+  gpr_asprintf(&name,
+               "test_invoke_large_request:max_frame_size=%d:lookahead_bytes=%d",
+               max_frame_size, lookahead_bytes);
+
+  grpc_arg args[2];
+  args[0].type = GRPC_ARG_INTEGER;
+  args[0].key = GRPC_ARG_HTTP2_MAX_FRAME_SIZE;
+  args[0].value.integer = max_frame_size;
+  args[1].type = GRPC_ARG_INTEGER;
+  args[1].key = GRPC_ARG_HTTP2_STREAM_LOOKAHEAD_BYTES;
+  args[1].value.integer = lookahead_bytes;
+  grpc_channel_args channel_args = {GPR_ARRAY_SIZE(args), args};
+
   grpc_end2end_test_fixture f =
-      begin_test(config, "test_invoke_large_request", NULL, NULL);
+      begin_test(config, name, &channel_args, &channel_args);
+  gpr_free(name);
 
   gpr_slice request_payload_slice = large_slice();
   gpr_slice response_payload_slice = large_slice();
@@ -255,7 +272,26 @@ static void test_invoke_large_request(grpc_end2end_test_config config) {
 }
 
 void invoke_large_request(grpc_end2end_test_config config) {
-  test_invoke_large_request(config);
+  test_invoke_large_request(config, 16384, 65536);
+  test_invoke_large_request(config, 32768, 65536);
+
+  test_invoke_large_request(config, 1000000 - 1, 65536);
+  test_invoke_large_request(config, 1000000, 65536);
+  test_invoke_large_request(config, 1000000 + 1, 65536);
+  test_invoke_large_request(config, 1000000 + 2, 65536);
+  test_invoke_large_request(config, 1000000 + 3, 65536);
+  test_invoke_large_request(config, 1000000 + 4, 65536);
+  test_invoke_large_request(config, 1000000 + 5, 65536);
+  test_invoke_large_request(config, 1000000 + 6, 65536);
+
+  test_invoke_large_request(config, 1000000 - 1, 2000000);
+  test_invoke_large_request(config, 1000000, 2000000);
+  test_invoke_large_request(config, 1000000 + 1, 2000000);
+  test_invoke_large_request(config, 1000000 + 2, 2000000);
+  test_invoke_large_request(config, 1000000 + 3, 2000000);
+  test_invoke_large_request(config, 1000000 + 4, 2000000);
+  test_invoke_large_request(config, 1000000 + 5, 2000000);
+  test_invoke_large_request(config, 1000000 + 6, 2000000);
 }
 
 void invoke_large_request_pre_init(void) {}

test/core/transport/chttp2/hpack_encoder_test.c

@@ -97,7 +97,7 @@ static void verify(size_t window_available, int eof, size_t expect_window_used,
 
   grpc_transport_one_way_stats stats;
   memset(&stats, 0, sizeof(stats));
-  grpc_chttp2_encode_header(&g_compressor, 0xdeadbeef, &b, eof, &stats,
+  grpc_chttp2_encode_header(&g_compressor, 0xdeadbeef, &b, eof, 16384, &stats,
                             &output);
   merged = grpc_slice_merge(output.slices, output.count);
   gpr_slice_buffer_destroy(&output);
@@ -202,7 +202,8 @@ static void verify_table_size_change_match_elem_size(const char *key,
 
   grpc_transport_one_way_stats stats;
   memset(&stats, 0, sizeof(stats));
-  grpc_chttp2_encode_header(&g_compressor, 0xdeadbeef, &b, 0, &stats, &output);
+  grpc_chttp2_encode_header(&g_compressor, 0xdeadbeef, &b, 0, 16384, &stats,
+                            &output);
   gpr_slice_buffer_destroy(&output);
   grpc_metadata_batch_destroy(&b);