Merge branch 'master' into 2phase_thd

1 files changed, 178 insertions, 0 deletions

diff --git a/src/core/ext/filters/client_channel/method_params.cc b/src/core/ext/filters/client_channel/method_params.cc
new file mode 100644
index 0000000000..374b87e170
--- /dev/null
+++ b/src/core/ext/filters/client_channel/method_params.cc
@@ -0,0 +1,178 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/filters/client_channel/method_params.h"
+#include "src/core/ext/filters/client_channel/status_util.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gprpp/memory.h"
+
+// As per the retry design, we do not allow more than 5 retry attempts.
+#define MAX_MAX_RETRY_ATTEMPTS 5
+
+namespace grpc_core {
+namespace internal {
+
+namespace {
+
+bool ParseWaitForReady(
+    grpc_json* field, ClientChannelMethodParams::WaitForReady* wait_for_ready) {
+  if (field->type != GRPC_JSON_TRUE && field->type != GRPC_JSON_FALSE) {
+    return false;
+  }
+  *wait_for_ready = field->type == GRPC_JSON_TRUE
+                        ? ClientChannelMethodParams::WAIT_FOR_READY_TRUE
+                        : ClientChannelMethodParams::WAIT_FOR_READY_FALSE;
+  return true;
+}
+
+// Parses a JSON field of the form generated for a google.proto.Duration
+// proto message, as per:
+//   https://developers.google.com/protocol-buffers/docs/proto3#json
+bool ParseDuration(grpc_json* field, grpc_millis* duration) {
+  if (field->type != GRPC_JSON_STRING) return false;
+  size_t len = strlen(field->value);
+  if (field->value[len - 1] != 's') return false;
+  UniquePtr<char> buf(gpr_strdup(field->value));
+  *(buf.get() + len - 1) = '\0';  // Remove trailing 's'.
+  char* decimal_point = strchr(buf.get(), '.');
+  int nanos = 0;
+  if (decimal_point != nullptr) {
+    *decimal_point = '\0';
+    nanos = gpr_parse_nonnegative_int(decimal_point + 1);
+    if (nanos == -1) {
+      return false;
+    }
+    int num_digits = static_cast<int>(strlen(decimal_point + 1));
+    if (num_digits > 9) {  // We don't accept greater precision than nanos.
+      return false;
+    }
+    for (int i = 0; i < (9 - num_digits); ++i) {
+      nanos *= 10;
+    }
+  }
+  int seconds =
+      decimal_point == buf.get() ? 0 : gpr_parse_nonnegative_int(buf.get());
+  if (seconds == -1) return false;
+  *duration = seconds * GPR_MS_PER_SEC + nanos / GPR_NS_PER_MS;
+  return true;
+}
+
+UniquePtr<ClientChannelMethodParams::RetryPolicy> ParseRetryPolicy(
+    grpc_json* field) {
+  auto retry_policy = MakeUnique<ClientChannelMethodParams::RetryPolicy>();
+  if (field->type != GRPC_JSON_OBJECT) return nullptr;
+  for (grpc_json* sub_field = field->child; sub_field != nullptr;
+       sub_field = sub_field->next) {
+    if (sub_field->key == nullptr) return nullptr;
+    if (strcmp(sub_field->key, "maxAttempts") == 0) {
+      if (retry_policy->max_attempts != 0) return nullptr;  // Duplicate.
+      if (sub_field->type != GRPC_JSON_NUMBER) return nullptr;
+      retry_policy->max_attempts = gpr_parse_nonnegative_int(sub_field->value);
+      if (retry_policy->max_attempts <= 1) return nullptr;
+      if (retry_policy->max_attempts > MAX_MAX_RETRY_ATTEMPTS) {
+        gpr_log(GPR_ERROR,
+                "service config: clamped retryPolicy.maxAttempts at %d",
+                MAX_MAX_RETRY_ATTEMPTS);
+        retry_policy->max_attempts = MAX_MAX_RETRY_ATTEMPTS;
+      }
+    } else if (strcmp(sub_field->key, "initialBackoff") == 0) {
+      if (retry_policy->initial_backoff > 0) return nullptr;  // Duplicate.
+      if (!ParseDuration(sub_field, &retry_policy->initial_backoff)) {
+        return nullptr;
+      }
+      if (retry_policy->initial_backoff == 0) return nullptr;
+    } else if (strcmp(sub_field->key, "maxBackoff") == 0) {
+      if (retry_policy->max_backoff > 0) return nullptr;  // Duplicate.
+      if (!ParseDuration(sub_field, &retry_policy->max_backoff)) {
+        return nullptr;
+      }
+      if (retry_policy->max_backoff == 0) return nullptr;
+    } else if (strcmp(sub_field->key, "backoffMultiplier") == 0) {
+      if (retry_policy->backoff_multiplier != 0) return nullptr;  // Duplicate.
+      if (sub_field->type != GRPC_JSON_NUMBER) return nullptr;
+      if (sscanf(sub_field->value, "%f", &retry_policy->backoff_multiplier) !=
+          1) {
+        return nullptr;
+      }
+      if (retry_policy->backoff_multiplier <= 0) return nullptr;
+    } else if (strcmp(sub_field->key, "retryableStatusCodes") == 0) {
+      if (!retry_policy->retryable_status_codes.Empty()) {
+        return nullptr;  // Duplicate.
+      }
+      if (sub_field->type != GRPC_JSON_ARRAY) return nullptr;
+      for (grpc_json* element = sub_field->child; element != nullptr;
+           element = element->next) {
+        if (element->type != GRPC_JSON_STRING) return nullptr;
+        grpc_status_code status;
+        if (!grpc_status_code_from_string(element->value, &status)) {
+          return nullptr;
+        }
+        retry_policy->retryable_status_codes.Add(status);
+      }
+      if (retry_policy->retryable_status_codes.Empty()) return nullptr;
+    }
+  }
+  // Make sure required fields are set.
+  if (retry_policy->max_attempts == 0 || retry_policy->initial_backoff == 0 ||
+      retry_policy->max_backoff == 0 || retry_policy->backoff_multiplier == 0 ||
+      retry_policy->retryable_status_codes.Empty()) {
+    return nullptr;
+  }
+  return retry_policy;
+}
+
+}  // namespace
+
+RefCountedPtr<ClientChannelMethodParams>
+ClientChannelMethodParams::CreateFromJson(const grpc_json* json) {
+  RefCountedPtr<ClientChannelMethodParams> method_params =
+      MakeRefCounted<ClientChannelMethodParams>();
+  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
+    if (field->key == nullptr) continue;
+    if (strcmp(field->key, "waitForReady") == 0) {
+      if (method_params->wait_for_ready_ != WAIT_FOR_READY_UNSET) {
+        return nullptr;  // Duplicate.
+      }
+      if (!ParseWaitForReady(field, &method_params->wait_for_ready_)) {
+        return nullptr;
+      }
+    } else if (strcmp(field->key, "timeout") == 0) {
+      if (method_params->timeout_ > 0) return nullptr;  // Duplicate.
+      if (!ParseDuration(field, &method_params->timeout_)) return nullptr;
+    } else if (strcmp(field->key, "retryPolicy") == 0) {
+      if (method_params->retry_policy_ != nullptr) {
+        return nullptr;  // Duplicate.
+      }
+      method_params->retry_policy_ = ParseRetryPolicy(field);
+      if (method_params->retry_policy_ == nullptr) return nullptr;
+    }
+  }
+  return method_params;
+}
+
+}  // namespace internal
+}  // namespace grpc_core