initial implementation of resource handling

11 files changed, 532 insertions, 129 deletions

diff --git a/src/core/ext/census/base_resources.c b/src/core/ext/census/base_resources.c
new file mode 100644
index 0000000000..8f0329a72b
--- /dev/null
+++ b/src/core/ext/census/base_resources.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright 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 <stdio.h>
+#include <string.h>
+
+#include <grpc/census.h>
+#include <grpc/support/log.h>
+
+#include "base_resources.h"
+#include "gen/census.pb.h"
+#include "third_party/nanopb/pb_encode.h"
+
+// Add base RPC resource definitions for use by RPC runtime.
+//
+// TODO(aveitch): All of these are currently hardwired definitions encoded in
+// the code in this file. These should be converted to use an external
+// configuration mechanism, in which these resources are defined in a text
+// file, which is compiled to .pb format and read by still-to-be-written
+// configuration functions.
+
+// Structure representing a MeasurementUnit proto.
+typedef struct {
+  int32_t prefix;
+  int n_numerators;
+  const google_census_Resource_BasicUnit *numerators;
+  int n_denominators;
+  const google_census_Resource_BasicUnit *denominators;
+} measurement_unit;
+
+// Encode a nanopb string. Expects the string argument to be passed in as `arg`.
+static bool encode_string(pb_ostream_t *stream, const pb_field_t *field,
+                          void *const *arg) {
+  if (!pb_encode_tag_for_field(stream, field)) {
+    return false;
+  }
+  return pb_encode_string(stream, (uint8_t *)*arg, strlen((const char *)*arg));
+}
+
+// Encode the numerators part of a measurement_unit (passed in as `arg`).
+static bool encode_numerators(pb_ostream_t *stream, const pb_field_t *field,
+                              void *const *arg) {
+  const measurement_unit *mu = (const measurement_unit *)*arg;
+  for (int i = 0; i < mu->n_numerators; i++) {
+    if (!pb_encode_tag_for_field(stream, field)) {
+      return false;
+    }
+    if (!pb_encode_varint(stream, mu->numerators[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Encode the denominators part of a measurement_unit (passed in as `arg`).
+static bool encode_denominators(pb_ostream_t *stream, const pb_field_t *field,
+                                void *const *arg) {
+  const measurement_unit *mu = (const measurement_unit *)*arg;
+  for (int i = 0; i < mu->n_denominators; i++) {
+    if (!pb_encode_tag_for_field(stream, field)) {
+      return false;
+    }
+    if (!pb_encode_varint(stream, mu->numerators[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Define a Resource, given the important details. Encodes a protobuf, which
+// is then passed to census_define_resource.
+static void define_resource(const char *name, const char *description,
+                            const measurement_unit *unit) {
+  // nanopb generated type for Resource. Initialize encoding functions to NULL
+  // since we can't directly initialize them due to embedded union in struct.
+  google_census_Resource resource = {
+      {{NULL}, (void *)name},
+      {{NULL}, (void *)description},
+      true,  // has_unit
+      {true, unit->prefix, {{NULL}, (void *)unit}, {{NULL}, (void *)unit}}};
+  resource.name.funcs.encode = &encode_string;
+  resource.description.funcs.encode = &encode_string;
+  resource.unit.numerator.funcs.encode = &encode_numerators;
+  resource.unit.denominator.funcs.encode = &encode_denominators;
+
+  // Buffer for storing encoded proto.
+  uint8_t buffer[512];
+  pb_ostream_t stream = pb_ostream_from_buffer(buffer, 512);
+  if (!pb_encode(&stream, google_census_Resource_fields, &resource)) {
+    gpr_log(GPR_ERROR, "Error encoding resource %s.", name);
+    return;
+  }
+  int32_t mid = census_define_resource(buffer, stream.bytes_written);
+  if (mid < 0) {
+    gpr_log(GPR_ERROR, "Error defining resource %s.", name);
+  }
+}
+
+// Define a resource for client RPC latency.
+static void define_client_rpc_latency_resource() {
+  google_census_Resource_BasicUnit numerator =
+      google_census_Resource_BasicUnit_SECS;
+  measurement_unit unit = {0, 1, &numerator, 0, NULL};
+  define_resource("client_rpc_latency", "Client RPC latency in seconds", &unit);
+}
+
+// Define a resource for server RPC latency.
+static void define_server_rpc_latency_resource() {
+  google_census_Resource_BasicUnit numerator =
+      google_census_Resource_BasicUnit_SECS;
+  measurement_unit unit = {0, 1, &numerator, 0, NULL};
+  define_resource("server_rpc_latency", "Server RPC latency in seconds", &unit);
+}
+
+// Define all base resources. This should be called by census initialization.
+void define_base_resources() {
+  define_client_rpc_latency_resource();
+  define_server_rpc_latency_resource();
+}
diff --git a/src/core/ext/census/base_resources.h b/src/core/ext/census/base_resources.h
new file mode 100644
index 0000000000..992e5f6ebe
--- /dev/null
+++ b/src/core/ext/census/base_resources.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright 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.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H
+#define GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H
+
+// Define all base resources. This should be called by census initialization.
+void define_base_resources();
+
+#endif  // GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H
diff --git a/src/core/ext/census/initialize.c b/src/core/ext/census/initialize.c
index 896276e44a..118163512a 100644
--- a/src/core/ext/census/initialize.c
+++ b/src/core/ext/census/initialize.c
@@ -32,19 +32,31 @@
  */
 
 #include <grpc/census.h>
+#include "base_resources.h"
+#include "resource.h"
 
 static int features_enabled = CENSUS_FEATURE_NONE;
 
 int census_initialize(int features) {
   if (features_enabled != CENSUS_FEATURE_NONE) {
     // Must have been a previous call to census_initialize; return error
-    return 1;
+    return -1;
   }
-  features_enabled = features;
-  return 0;
+  features_enabled = features & CENSUS_FEATURE_ALL;
+  if (features & CENSUS_FEATURE_STATS) {
+    initialize_resources();
+    define_base_resources();
+  }
+
+  return features_enabled;
 }
 
-void census_shutdown(void) { features_enabled = CENSUS_FEATURE_NONE; }
+void census_shutdown(void) {
+  if (features_enabled & CENSUS_FEATURE_STATS) {
+    shutdown_resources();
+  }
+  features_enabled = CENSUS_FEATURE_NONE;
+}
 
 int census_supported(void) {
   /* TODO(aveitch): improve this as we implement features... */
diff --git a/src/core/ext/census/placeholders.c b/src/core/ext/census/placeholders.c
index fe23d13971..9f99c5bdcf 100644
--- a/src/core/ext/census/placeholders.c
+++ b/src/core/ext/census/placeholders.c
@@ -62,48 +62,3 @@ int census_trace_scan_start(int consume) {
   (void)consume;
   abort();
 }
-
-const census_aggregation *census_view_aggregrations(const census_view *view) {
-  (void)view;
-  abort();
-}
-
-census_view *census_view_create(uint32_t metric_id, const census_context *tags,
-                                const census_aggregation *aggregations,
-                                size_t naggregations) {
-  (void)metric_id;
-  (void)tags;
-  (void)aggregations;
-  (void)naggregations;
-  abort();
-}
-
-const census_context *census_view_tags(const census_view *view) {
-  (void)view;
-  abort();
-}
-
-void census_view_delete(census_view *view) {
-  (void)view;
-  abort();
-}
-
-const census_view_data *census_view_get_data(const census_view *view) {
-  (void)view;
-  abort();
-}
-
-size_t census_view_metric(const census_view *view) {
-  (void)view;
-  abort();
-}
-
-size_t census_view_naggregations(const census_view *view) {
-  (void)view;
-  abort();
-}
-
-void census_view_reset(census_view *view) {
-  (void)view;
-  abort();
-}
diff --git a/src/core/ext/census/resource.c b/src/core/ext/census/resource.c
new file mode 100644
index 0000000000..632b899e41
--- /dev/null
+++ b/src/core/ext/census/resource.c
@@ -0,0 +1,255 @@
+/*
+ *
+ * Copyright 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 "resource.h"
+#include "gen/census.pb.h"
+#include "third_party/nanopb/pb_decode.h"
+
+#include <grpc/census.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+
+#include <stdbool.h>
+#include <string.h>
+
+// Internal representation of a resource.
+typedef struct {
+  char *name;
+  // Pointer to raw protobuf used in resource definition.
+  uint8_t *raw_pb;
+} resource;
+
+// Protect local resource data structures.
+static gpr_mu resource_lock;
+
+// Deleteing and creating resources are relatively rare events, and should not
+// be done in the critical path of performance sensitive code. We record
+// current resource id's used in a simple array, and just search it each time
+// we need to assign a new id, or look up a resource.
+static resource **resources = NULL;
+
+// Number of entries in *resources
+static size_t n_resources = 0;
+
+// Number of defined resources
+static size_t n_defined_resources = 0;
+
+void initialize_resources() {
+  gpr_mu_init(&resource_lock);
+  gpr_mu_lock(&resource_lock);
+  GPR_ASSERT(resources == NULL && n_resources == 0 && n_defined_resources == 0);
+  // 8 seems like a reasonable size for initial number of resources.
+  n_resources = 8;
+  resources = gpr_malloc(n_resources * sizeof(resource *));
+  memset(resources, 0, n_resources * sizeof(resource *));
+  gpr_mu_unlock(&resource_lock);
+}
+
+// Delete a resource given it's ID. Must be called with resource_lock held.
+static void delete_resource_locked(size_t rid) {
+  GPR_ASSERT(resources[rid] != NULL && resources[rid]->raw_pb != NULL &&
+             resources[rid]->name != NULL && n_defined_resources > 0);
+  gpr_free(resources[rid]->name);
+  gpr_free(resources[rid]->raw_pb);
+  gpr_free(resources[rid]);
+  resources[rid] = NULL;
+  n_defined_resources--;
+}
+
+void shutdown_resources() {
+  gpr_mu_lock(&resource_lock);
+  for (size_t i = 0; i < n_resources; i++) {
+    if (resources[i] != NULL) {
+      delete_resource_locked(i);
+    }
+  }
+  GPR_ASSERT(n_defined_resources == 0);
+  gpr_free(resources);
+  resources = NULL;
+  n_resources = 0;
+  gpr_mu_unlock(&resource_lock);
+}
+
+// Check the contents of string fields in a resource proto.
+static bool validate_string(pb_istream_t *stream, const pb_field_t *field,
+                            void **arg) {
+  resource *vresource = (resource *)*arg;
+  switch (field->tag) {
+    case google_census_Resource_name_tag:
+      // Name must have at least one character
+      if (stream->bytes_left == 0) {
+        gpr_log(GPR_INFO, "Zero-length Resource name.");
+        return false;
+      }
+      vresource->name = gpr_malloc(stream->bytes_left + 1);
+      vresource->name[stream->bytes_left] = '\0';
+      if (!pb_read(stream, (uint8_t *)vresource->name, stream->bytes_left)) {
+        return false;
+      }
+      // Can't have same name as an existing resource.
+      for (size_t i = 0; i < n_resources; i++) {
+        resource *compare = resources[i];
+        if (compare == vresource || compare == NULL) continue;
+        if (strcmp(compare->name, vresource->name) == 0) {
+          gpr_log(GPR_INFO, "Duplicate Resource name %s.", vresource->name);
+          return false;
+        }
+      }
+      break;
+    case google_census_Resource_description_tag:
+      // Description is optional, does not need validating, just skip.
+      if (!pb_read(stream, NULL, stream->bytes_left)) {
+        return false;
+      }
+      break;
+    default:
+      // No other string fields in Resource. Print warning and skip.
+      gpr_log(GPR_INFO, "Unknown string field type in Resource protobuf.");
+      if (!pb_read(stream, NULL, stream->bytes_left)) {
+        return false;
+      }
+      break;
+  }
+  return true;
+}
+
+// Validate units field of a Resource proto.
+static bool validate_units(pb_istream_t *stream, const pb_field_t *field,
+                           void **arg) {
+  if (field->tag == google_census_Resource_MeasurementUnit_numerator_tag) {
+    *(bool *)*arg = true;  // has_numerator = true.
+  }
+  while (stream->bytes_left) {
+    uint64_t value;
+    if (!pb_decode_varint(stream, &value)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Vlaidate the contents of a Resource proto. `id` is the intended resource id.
+static bool validate_resource_pb(const uint8_t *resource_pb,
+                                 size_t resource_pb_size, size_t id) {
+  GPR_ASSERT(id < n_resources);
+  if (resource_pb == NULL) {
+    return false;
+  }
+  google_census_Resource vresource;
+  vresource.name.funcs.decode = &validate_string;
+  vresource.name.arg = resources[id];
+  vresource.description.funcs.decode = &validate_string;
+  vresource.unit.numerator.funcs.decode = &validate_units;
+  bool has_numerator = false;
+  vresource.unit.numerator.arg = &has_numerator;
+  vresource.unit.denominator.funcs.decode = &validate_units;
+
+  pb_istream_t stream =
+      pb_istream_from_buffer((uint8_t *)resource_pb, resource_pb_size);
+  if (!pb_decode(&stream, google_census_Resource_fields, &vresource)) {
+    return false;
+  }
+  // A Resource must have a name, a unit, with at least one numerator.
+  return (resources[id]->name != NULL && vresource.has_unit && has_numerator);
+}
+
+int32_t census_define_resource(const uint8_t *resource_pb,
+                               size_t resource_pb_size) {
+  // use next_id to optimize expected placement of next new resource.
+  static size_t next_id = 0;
+  if (resource_pb == NULL) {
+    return -1;
+  }
+  gpr_mu_lock(&resource_lock);
+  size_t id = n_resources;  // resource ID - initialize to invalid value.
+  // Expand resources if needed.
+  if (n_resources == n_defined_resources) {
+    resource **new_resources = gpr_malloc(n_resources * 2 * sizeof(resource *));
+    memcpy(new_resources, resources, n_resources * sizeof(resource *));
+    memset(new_resources + n_resources, 0, n_resources * sizeof(resource *));
+    gpr_free(resources);
+    resources = new_resources;
+    n_resources *= 2;
+    id = n_defined_resources;
+  } else {
+    GPR_ASSERT(n_defined_resources < n_resources);
+    // Find a free id.
+    for (size_t base = 0; base < n_resources; base++) {
+      id = (next_id + base) % n_resources;
+      if (resources[id] == NULL) break;
+    }
+  }
+  GPR_ASSERT(id < n_resources && resources[id] == NULL);
+  resources[id] = gpr_malloc(sizeof(resource));
+  resources[id]->name = NULL;
+  // Validate pb, extract name.
+  if (!validate_resource_pb(resource_pb, resource_pb_size, id)) {
+    if (resources[id]->name != NULL) {
+      gpr_free(resources[id]->name);
+    }
+    gpr_free(resources[id]);
+    resources[id] = NULL;
+    gpr_mu_unlock(&resource_lock);
+    return -1;
+  }
+  next_id = (id + 1) % n_resources;
+  // Make copy of raw proto, and return.
+  resources[id]->raw_pb = gpr_malloc(resource_pb_size);
+  memcpy(resources[id]->raw_pb, resource_pb, resource_pb_size);
+  n_defined_resources++;
+  gpr_mu_unlock(&resource_lock);
+  return (int32_t)id;
+}
+
+void census_delete_resource(int32_t rid) {
+  gpr_mu_lock(&resource_lock);
+  if (rid >= 0 && (size_t)rid < n_resources && resources[rid] != NULL) {
+    delete_resource_locked((size_t)rid);
+  }
+  gpr_mu_unlock(&resource_lock);
+}
+
+int32_t census_resource_id(const char *name) {
+  gpr_mu_lock(&resource_lock);
+  for (int32_t id = 0; (size_t)id < n_resources; id++) {
+    if (resources[id] != NULL) {
+      if (strcmp(resources[id]->name, name) == 0) {
+        gpr_mu_unlock(&resource_lock);
+        return id;
+      }
+    }
+  }
+  gpr_mu_unlock(&resource_lock);
+  return -1;
+}
diff --git a/src/core/ext/census/resource.h b/src/core/ext/census/resource.h
new file mode 100644
index 0000000000..5ad5a0f7a0
--- /dev/null
+++ b/src/core/ext/census/resource.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 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.
+ *
+ */
+
+// Census-internal resource definition and manipluation functions.
+#ifndef GRPC_CORE_EXT_CENSUS_RESOURCE_H
+#define GRPC_CORE_EXT_CENSUS_RESOURCE_H
+
+// Initialize and shutdown the resources subsystem.
+void initialize_resources();
+void shutdown_resources();
+
+#endif /* GRPC_CORE_EXT_CENSUS_RESOURCE_H */
diff --git a/src/python/grpcio/grpc/_cython/imports.generated.c b/src/python/grpcio/grpc/_cython/imports.generated.c
index f71cf12844..29ada16afd 100644
--- a/src/python/grpcio/grpc/_cython/imports.generated.c
+++ b/src/python/grpcio/grpc/_cython/imports.generated.c
@@ -61,15 +61,10 @@ census_trace_print_type census_trace_print_import;
 census_trace_scan_start_type census_trace_scan_start_import;
 census_get_trace_record_type census_get_trace_record_import;
 census_trace_scan_end_type census_trace_scan_end_import;
+census_define_resource_type census_define_resource_import;
+census_delete_resource_type census_delete_resource_import;
+census_resource_id_type census_resource_id_import;
 census_record_values_type census_record_values_import;
-census_view_create_type census_view_create_import;
-census_view_delete_type census_view_delete_import;
-census_view_metric_type census_view_metric_import;
-census_view_naggregations_type census_view_naggregations_import;
-census_view_tags_type census_view_tags_import;
-census_view_aggregrations_type census_view_aggregrations_import;
-census_view_get_data_type census_view_get_data_import;
-census_view_reset_type census_view_reset_import;
 grpc_compression_algorithm_parse_type grpc_compression_algorithm_parse_import;
 grpc_compression_algorithm_name_type grpc_compression_algorithm_name_import;
 grpc_compression_algorithm_for_level_type grpc_compression_algorithm_for_level_import;
@@ -333,15 +328,10 @@ void pygrpc_load_imports(HMODULE library) {
   census_trace_scan_start_import = (census_trace_scan_start_type) GetProcAddress(library, "census_trace_scan_start");
   census_get_trace_record_import = (census_get_trace_record_type) GetProcAddress(library, "census_get_trace_record");
   census_trace_scan_end_import = (census_trace_scan_end_type) GetProcAddress(library, "census_trace_scan_end");
+  census_define_resource_import = (census_define_resource_type) GetProcAddress(library, "census_define_resource");
+  census_delete_resource_import = (census_delete_resource_type) GetProcAddress(library, "census_delete_resource");
+  census_resource_id_import = (census_resource_id_type) GetProcAddress(library, "census_resource_id");
   census_record_values_import = (census_record_values_type) GetProcAddress(library, "census_record_values");
-  census_view_create_import = (census_view_create_type) GetProcAddress(library, "census_view_create");
-  census_view_delete_import = (census_view_delete_type) GetProcAddress(library, "census_view_delete");
-  census_view_metric_import = (census_view_metric_type) GetProcAddress(library, "census_view_metric");
-  census_view_naggregations_import = (census_view_naggregations_type) GetProcAddress(library, "census_view_naggregations");
-  census_view_tags_import = (census_view_tags_type) GetProcAddress(library, "census_view_tags");
-  census_view_aggregrations_import = (census_view_aggregrations_type) GetProcAddress(library, "census_view_aggregrations");
-  census_view_get_data_import = (census_view_get_data_type) GetProcAddress(library, "census_view_get_data");
-  census_view_reset_import = (census_view_reset_type) GetProcAddress(library, "census_view_reset");
   grpc_compression_algorithm_parse_import = (grpc_compression_algorithm_parse_type) GetProcAddress(library, "grpc_compression_algorithm_parse");
   grpc_compression_algorithm_name_import = (grpc_compression_algorithm_name_type) GetProcAddress(library, "grpc_compression_algorithm_name");
   grpc_compression_algorithm_for_level_import = (grpc_compression_algorithm_for_level_type) GetProcAddress(library, "grpc_compression_algorithm_for_level");
diff --git a/src/python/grpcio/grpc/_cython/imports.generated.h b/src/python/grpcio/grpc/_cython/imports.generated.h
index a364075e9e..f6dd79cadc 100644
--- a/src/python/grpcio/grpc/_cython/imports.generated.h
+++ b/src/python/grpcio/grpc/_cython/imports.generated.h
@@ -134,33 +134,18 @@ extern census_get_trace_record_type census_get_trace_record_import;
 typedef void(*census_trace_scan_end_type)();
 extern census_trace_scan_end_type census_trace_scan_end_import;
 #define census_trace_scan_end census_trace_scan_end_import
+typedef int32_t(*census_define_resource_type)(const uint8_t *resource_pb, size_t resource_pb_size);
+extern census_define_resource_type census_define_resource_import;
+#define census_define_resource census_define_resource_import
+typedef void(*census_delete_resource_type)(int32_t resource_id);
+extern census_delete_resource_type census_delete_resource_import;
+#define census_delete_resource census_delete_resource_import
+typedef int32_t(*census_resource_id_type)(const char *name);
+extern census_resource_id_type census_resource_id_import;
+#define census_resource_id census_resource_id_import
 typedef void(*census_record_values_type)(census_context *context, census_value *values, size_t nvalues);
 extern census_record_values_type census_record_values_import;
 #define census_record_values census_record_values_import
-typedef census_view *(*census_view_create_type)(uint32_t metric_id, const census_context *tags, const census_aggregation *aggregations, size_t naggregations);
-extern census_view_create_type census_view_create_import;
-#define census_view_create census_view_create_import
-typedef void(*census_view_delete_type)(census_view *view);
-extern census_view_delete_type census_view_delete_import;
-#define census_view_delete census_view_delete_import
-typedef size_t(*census_view_metric_type)(const census_view *view);
-extern census_view_metric_type census_view_metric_import;
-#define census_view_metric census_view_metric_import
-typedef size_t(*census_view_naggregations_type)(const census_view *view);
-extern census_view_naggregations_type census_view_naggregations_import;
-#define census_view_naggregations census_view_naggregations_import
-typedef const census_context *(*census_view_tags_type)(const census_view *view);
-extern census_view_tags_type census_view_tags_import;
-#define census_view_tags census_view_tags_import
-typedef const census_aggregation *(*census_view_aggregrations_type)(const census_view *view);
-extern census_view_aggregrations_type census_view_aggregrations_import;
-#define census_view_aggregrations census_view_aggregrations_import
-typedef const census_view_data *(*census_view_get_data_type)(const census_view *view);
-extern census_view_get_data_type census_view_get_data_import;
-#define census_view_get_data census_view_get_data_import
-typedef void(*census_view_reset_type)(census_view *view);
-extern census_view_reset_type census_view_reset_import;
-#define census_view_reset census_view_reset_import
 typedef int(*grpc_compression_algorithm_parse_type)(const char *name, size_t name_length, grpc_compression_algorithm *algorithm);
 extern grpc_compression_algorithm_parse_type grpc_compression_algorithm_parse_import;
 #define grpc_compression_algorithm_parse grpc_compression_algorithm_parse_import
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index d0f23f42cc..c7d042d565 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -243,6 +243,7 @@ CORE_SOURCE_FILES = [
   'src/core/ext/lb_policy/round_robin/round_robin.c',
   'src/core/ext/resolver/dns/native/dns_resolver.c',
   'src/core/ext/resolver/sockaddr/sockaddr_resolver.c',
+  'src/core/ext/census/base_resources.c',
   'src/core/ext/census/context.c',
   'src/core/ext/census/gen/census.pb.c',
   'src/core/ext/census/grpc_context.c',
@@ -252,6 +253,7 @@ CORE_SOURCE_FILES = [
   'src/core/ext/census/mlog.c',
   'src/core/ext/census/operation.c',
   'src/core/ext/census/placeholders.c',
+  'src/core/ext/census/resource.c',
   'src/core/ext/census/tracing.c',
   'src/core/plugin_registry/grpc_plugin_registry.c',
   'src/boringssl/err_data.c',
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.c b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
index 3b62984def..5d0f565ea8 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.c
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
@@ -61,15 +61,10 @@ census_trace_print_type census_trace_print_import;
 census_trace_scan_start_type census_trace_scan_start_import;
 census_get_trace_record_type census_get_trace_record_import;
 census_trace_scan_end_type census_trace_scan_end_import;
+census_define_resource_type census_define_resource_import;
+census_delete_resource_type census_delete_resource_import;
+census_resource_id_type census_resource_id_import;
 census_record_values_type census_record_values_import;
-census_view_create_type census_view_create_import;
-census_view_delete_type census_view_delete_import;
-census_view_metric_type census_view_metric_import;
-census_view_naggregations_type census_view_naggregations_import;
-census_view_tags_type census_view_tags_import;
-census_view_aggregrations_type census_view_aggregrations_import;
-census_view_get_data_type census_view_get_data_import;
-census_view_reset_type census_view_reset_import;
 grpc_compression_algorithm_parse_type grpc_compression_algorithm_parse_import;
 grpc_compression_algorithm_name_type grpc_compression_algorithm_name_import;
 grpc_compression_algorithm_for_level_type grpc_compression_algorithm_for_level_import;
@@ -329,15 +324,10 @@ void grpc_rb_load_imports(HMODULE library) {
   census_trace_scan_start_import = (census_trace_scan_start_type) GetProcAddress(library, "census_trace_scan_start");
   census_get_trace_record_import = (census_get_trace_record_type) GetProcAddress(library, "census_get_trace_record");
   census_trace_scan_end_import = (census_trace_scan_end_type) GetProcAddress(library, "census_trace_scan_end");
+  census_define_resource_import = (census_define_resource_type) GetProcAddress(library, "census_define_resource");
+  census_delete_resource_import = (census_delete_resource_type) GetProcAddress(library, "census_delete_resource");
+  census_resource_id_import = (census_resource_id_type) GetProcAddress(library, "census_resource_id");
   census_record_values_import = (census_record_values_type) GetProcAddress(library, "census_record_values");
-  census_view_create_import = (census_view_create_type) GetProcAddress(library, "census_view_create");
-  census_view_delete_import = (census_view_delete_type) GetProcAddress(library, "census_view_delete");
-  census_view_metric_import = (census_view_metric_type) GetProcAddress(library, "census_view_metric");
-  census_view_naggregations_import = (census_view_naggregations_type) GetProcAddress(library, "census_view_naggregations");
-  census_view_tags_import = (census_view_tags_type) GetProcAddress(library, "census_view_tags");
-  census_view_aggregrations_import = (census_view_aggregrations_type) GetProcAddress(library, "census_view_aggregrations");
-  census_view_get_data_import = (census_view_get_data_type) GetProcAddress(library, "census_view_get_data");
-  census_view_reset_import = (census_view_reset_type) GetProcAddress(library, "census_view_reset");
   grpc_compression_algorithm_parse_import = (grpc_compression_algorithm_parse_type) GetProcAddress(library, "grpc_compression_algorithm_parse");
   grpc_compression_algorithm_name_import = (grpc_compression_algorithm_name_type) GetProcAddress(library, "grpc_compression_algorithm_name");
   grpc_compression_algorithm_for_level_import = (grpc_compression_algorithm_for_level_type) GetProcAddress(library, "grpc_compression_algorithm_for_level");
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index 1428e6d71c..4033e5e626 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -134,33 +134,18 @@ extern census_get_trace_record_type census_get_trace_record_import;
 typedef void(*census_trace_scan_end_type)();
 extern census_trace_scan_end_type census_trace_scan_end_import;
 #define census_trace_scan_end census_trace_scan_end_import
+typedef int32_t(*census_define_resource_type)(const uint8_t *resource_pb, size_t resource_pb_size);
+extern census_define_resource_type census_define_resource_import;
+#define census_define_resource census_define_resource_import
+typedef void(*census_delete_resource_type)(int32_t resource_id);
+extern census_delete_resource_type census_delete_resource_import;
+#define census_delete_resource census_delete_resource_import
+typedef int32_t(*census_resource_id_type)(const char *name);
+extern census_resource_id_type census_resource_id_import;
+#define census_resource_id census_resource_id_import
 typedef void(*census_record_values_type)(census_context *context, census_value *values, size_t nvalues);
 extern census_record_values_type census_record_values_import;
 #define census_record_values census_record_values_import
-typedef census_view *(*census_view_create_type)(uint32_t metric_id, const census_context *tags, const census_aggregation *aggregations, size_t naggregations);
-extern census_view_create_type census_view_create_import;
-#define census_view_create census_view_create_import
-typedef void(*census_view_delete_type)(census_view *view);
-extern census_view_delete_type census_view_delete_import;
-#define census_view_delete census_view_delete_import
-typedef size_t(*census_view_metric_type)(const census_view *view);
-extern census_view_metric_type census_view_metric_import;
-#define census_view_metric census_view_metric_import
-typedef size_t(*census_view_naggregations_type)(const census_view *view);
-extern census_view_naggregations_type census_view_naggregations_import;
-#define census_view_naggregations census_view_naggregations_import
-typedef const census_context *(*census_view_tags_type)(const census_view *view);
-extern census_view_tags_type census_view_tags_import;
-#define census_view_tags census_view_tags_import
-typedef const census_aggregation *(*census_view_aggregrations_type)(const census_view *view);
-extern census_view_aggregrations_type census_view_aggregrations_import;
-#define census_view_aggregrations census_view_aggregrations_import
-typedef const census_view_data *(*census_view_get_data_type)(const census_view *view);
-extern census_view_get_data_type census_view_get_data_import;
-#define census_view_get_data census_view_get_data_import
-typedef void(*census_view_reset_type)(census_view *view);
-extern census_view_reset_type census_view_reset_import;
-#define census_view_reset census_view_reset_import
 typedef int(*grpc_compression_algorithm_parse_type)(const char *name, size_t name_length, grpc_compression_algorithm *algorithm);
 extern grpc_compression_algorithm_parse_type grpc_compression_algorithm_parse_import;
 #define grpc_compression_algorithm_parse grpc_compression_algorithm_parse_import