Initial checkin of gRPC to third_party/

third_party/grpc/src/core/channel/http_client_filter.c

Index: third_party/grpc/src/core/channel/http_client_filter.c
diff --git a/third_party/grpc/src/core/channel/http_client_filter.c b/third_party/grpc/src/core/channel/http_client_filter.c
new file mode 100644
index 0000000000000000000000000000000000000000..1aa27208c2e9725aebfad8b2ddfc18a29a9671c1
--- /dev/null
+++ b/third_party/grpc/src/core/channel/http_client_filter.c
@@ -0,0 +1,248 @@
+/*
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/channel/http_client_filter.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <string.h>
+#include "src/core/profiling/timers.h"
+#include "src/core/support/string.h"
+#include "src/core/transport/static_metadata.h"
+
+typedef struct call_data {
+  grpc_linked_mdelem method;
+  grpc_linked_mdelem scheme;
+  grpc_linked_mdelem authority;
+  grpc_linked_mdelem te_trailers;
+  grpc_linked_mdelem content_type;
+  grpc_linked_mdelem user_agent;
+
+  grpc_metadata_batch *recv_initial_metadata;
+
+  /** Closure to call when finished with the hc_on_recv hook */
+  grpc_closure *on_done_recv;
+  /** Receive closures are chained: we inject this closure as the on_done_recv
+      up-call on transport_op, and remember to call our on_done_recv member
+      after handling it. */
+  grpc_closure hc_on_recv;
+} call_data;
+
+typedef struct channel_data {
+  grpc_mdelem *static_scheme;
+  grpc_mdelem *user_agent;
+} channel_data;
+
+typedef struct {
+  grpc_call_element *elem;
+  grpc_exec_ctx *exec_ctx;
+} client_recv_filter_args;
+
+static grpc_mdelem *client_recv_filter(void *user_data, grpc_mdelem *md) {
+  client_recv_filter_args *a = user_data;
+  if (md == GRPC_MDELEM_STATUS_200) {
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_STATUS) {
+    grpc_call_element_send_cancel(a->exec_ctx, a->elem);
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_CONTENT_TYPE) {
+    return NULL;
+  }
+  return md;
+}
+
+static void hc_on_recv(grpc_exec_ctx *exec_ctx, void *user_data, bool success) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  client_recv_filter_args a;
+  a.elem = elem;
+  a.exec_ctx = exec_ctx;
+  grpc_metadata_batch_filter(calld->recv_initial_metadata, client_recv_filter,
+                             &a);
+  calld->on_done_recv->cb(exec_ctx, calld->on_done_recv->cb_arg, success);
+}
+
+static grpc_mdelem *client_strip_filter(void *user_data, grpc_mdelem *md) {
+  /* eat the things we'd like to set ourselves */
+  if (md->key == GRPC_MDSTR_METHOD) return NULL;
+  if (md->key == GRPC_MDSTR_SCHEME) return NULL;
+  if (md->key == GRPC_MDSTR_TE) return NULL;
+  if (md->key == GRPC_MDSTR_CONTENT_TYPE) return NULL;
+  if (md->key == GRPC_MDSTR_USER_AGENT) return NULL;
+  return md;
+}
+
+static void hc_mutate_op(grpc_call_element *elem,
+                         grpc_transport_stream_op *op) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+  channel_data *channeld = elem->channel_data;
+  if (op->send_initial_metadata != NULL) {
+    grpc_metadata_batch_filter(op->send_initial_metadata, client_strip_filter,
+                               elem);
+    /* Send : prefixed headers, which have to be before any application
+       layer headers. */
+    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->method,
+                                 GRPC_MDELEM_METHOD_POST);
+    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->scheme,
+                                 channeld->static_scheme);
+    grpc_metadata_batch_add_tail(op->send_initial_metadata, &calld->te_trailers,
+                                 GRPC_MDELEM_TE_TRAILERS);
+    grpc_metadata_batch_add_tail(
+        op->send_initial_metadata, &calld->content_type,
+        GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC);
+    grpc_metadata_batch_add_tail(op->send_initial_metadata, &calld->user_agent,
+                                 GRPC_MDELEM_REF(channeld->user_agent));
+  }
+
+  if (op->recv_initial_metadata != NULL) {
+    /* substitute our callback for the higher callback */
+    calld->recv_initial_metadata = op->recv_initial_metadata;
+    calld->on_done_recv = op->recv_initial_metadata_ready;
+    op->recv_initial_metadata_ready = &calld->hc_on_recv;
+  }
+}
+
+static void hc_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem,
+                                  grpc_transport_stream_op *op) {
+  GPR_TIMER_BEGIN("hc_start_transport_op", 0);
+  GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
+  hc_mutate_op(elem, op);
+  GPR_TIMER_END("hc_start_transport_op", 0);
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+/* Constructor for call_data */
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {
+  call_data *calld = elem->call_data;
+  calld->on_done_recv = NULL;
+  grpc_closure_init(&calld->hc_on_recv, hc_on_recv, elem);
+}
+
+/* Destructor for call_data */
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_call_element *elem) {}
+
+static grpc_mdelem *scheme_from_args(const grpc_channel_args *args) {
+  unsigned i;
+  size_t j;
+  grpc_mdelem *valid_schemes[] = {GRPC_MDELEM_SCHEME_HTTP,
+                                  GRPC_MDELEM_SCHEME_HTTPS};
+  if (args != NULL) {
+    for (i = 0; i < args->num_args; ++i) {
+      if (args->args[i].type == GRPC_ARG_STRING &&
+          strcmp(args->args[i].key, GRPC_ARG_HTTP2_SCHEME) == 0) {
+        for (j = 0; j < GPR_ARRAY_SIZE(valid_schemes); j++) {
+          if (0 == strcmp(grpc_mdstr_as_c_string(valid_schemes[j]->value),
+                          args->args[i].value.string)) {
+            return valid_schemes[j];
+          }
+        }
+      }
+    }
+  }
+  return GRPC_MDELEM_SCHEME_HTTP;
+}
+
+static grpc_mdstr *user_agent_from_args(const grpc_channel_args *args) {
+  gpr_strvec v;
+  size_t i;
+  int is_first = 1;
+  char *tmp;
+  grpc_mdstr *result;
+
+  gpr_strvec_init(&v);
+
+  for (i = 0; args && i < args->num_args; i++) {
+    if (0 == strcmp(args->args[i].key, GRPC_ARG_PRIMARY_USER_AGENT_STRING)) {
+      if (args->args[i].type != GRPC_ARG_STRING) {
+        gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
+                GRPC_ARG_PRIMARY_USER_AGENT_STRING);
+      } else {
+        if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
+        is_first = 0;
+        gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string));
+      }
+    }
+  }
+
+  gpr_asprintf(&tmp, "%sgrpc-c/%s (%s)", is_first ? "" : " ",
+               grpc_version_string(), GPR_PLATFORM_STRING);
+  is_first = 0;
+  gpr_strvec_add(&v, tmp);
+
+  for (i = 0; args && i < args->num_args; i++) {
+    if (0 == strcmp(args->args[i].key, GRPC_ARG_SECONDARY_USER_AGENT_STRING)) {
+      if (args->args[i].type != GRPC_ARG_STRING) {
+        gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
+                GRPC_ARG_SECONDARY_USER_AGENT_STRING);
+      } else {
+        if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
+        is_first = 0;
+        gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string));
+      }
+    }
+  }
+
+  tmp = gpr_strvec_flatten(&v, NULL);
+  gpr_strvec_destroy(&v);
+  result = grpc_mdstr_from_string(tmp);
+  gpr_free(tmp);
+
+  return result;
+}
+
+/* Constructor for channel_data */
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  channel_data *chand = elem->channel_data;
+  GPR_ASSERT(!args->is_last);
+  chand->static_scheme = scheme_from_args(args->channel_args);
+  chand->user_agent = grpc_mdelem_from_metadata_strings(
+      GRPC_MDSTR_USER_AGENT, user_agent_from_args(args->channel_args));
+}
+
+/* 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_MDELEM_UNREF(chand->user_agent);
+}
+
+const grpc_channel_filter grpc_http_client_filter = {
+    hc_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem, grpc_call_stack_ignore_set_pollset, destroy_call_elem,
+    sizeof(channel_data), init_channel_elem, destroy_channel_elem,
+    grpc_call_next_get_peer, "http-client"};