Merge pull request #8052 from Vizerai/grpc_tracing

grpc tracing context

BUILD

@@ -319,6 +319,7 @@ cc_library(
     "src/core/ext/census/mlog.h",
     "src/core/ext/census/resource.h",
     "src/core/ext/census/rpc_metric_id.h",
+    "src/core/ext/census/trace_context.h",
     "src/core/lib/surface/init.c",
     "src/core/lib/channel/channel_args.c",
     "src/core/lib/channel/channel_stack.c",
@@ -506,6 +507,7 @@ cc_library(
     "src/core/ext/census/operation.c",
     "src/core/ext/census/placeholders.c",
     "src/core/ext/census/resource.c",
+    "src/core/ext/census/trace_context.c",
     "src/core/ext/census/tracing.c",
     "src/core/plugin_registry/grpc_plugin_registry.c",
   ],
@@ -1042,6 +1044,7 @@ cc_library(
     "src/core/ext/census/mlog.h",
     "src/core/ext/census/resource.h",
     "src/core/ext/census/rpc_metric_id.h",
+    "src/core/ext/census/trace_context.h",
     "src/core/lib/surface/init.c",
     "src/core/lib/surface/init_unsecure.c",
     "src/core/lib/channel/channel_args.c",
@@ -1200,6 +1203,7 @@ cc_library(
     "src/core/ext/census/operation.c",
     "src/core/ext/census/placeholders.c",
     "src/core/ext/census/resource.c",
+    "src/core/ext/census/trace_context.c",
     "src/core/ext/census/tracing.c",
     "src/core/plugin_registry/grpc_unsecure_plugin_registry.c",
   ],
@@ -2348,6 +2352,7 @@ objc_library(
     "src/core/ext/census/operation.c",
     "src/core/ext/census/placeholders.c",
     "src/core/ext/census/resource.c",
+    "src/core/ext/census/trace_context.c",
     "src/core/ext/census/tracing.c",
     "src/core/plugin_registry/grpc_plugin_registry.c",
   ],
@@ -2535,6 +2540,7 @@ objc_library(
     "src/core/ext/census/mlog.h",
     "src/core/ext/census/resource.h",
     "src/core/ext/census/rpc_metric_id.h",
+    "src/core/ext/census/trace_context.h",
   ],
   includes = [
     "include",

CMakeLists.txt

@@ -479,6 +479,7 @@ add_library(grpc
   src/core/ext/census/operation.c
   src/core/ext/census/placeholders.c
   src/core/ext/census/resource.c
+  src/core/ext/census/trace_context.c
   src/core/ext/census/tracing.c
   src/core/plugin_registry/grpc_plugin_registry.c
 )
@@ -934,6 +935,7 @@ add_library(grpc_unsecure
   src/core/ext/census/operation.c
   src/core/ext/census/placeholders.c
   src/core/ext/census/resource.c
+  src/core/ext/census/trace_context.c
   src/core/ext/census/tracing.c
   src/core/plugin_registry/grpc_unsecure_plugin_registry.c
 )

Makefile

@@ -909,6 +909,7 @@ bin_decoder_test: $(BINDIR)/$(CONFIG)/bin_decoder_test
 bin_encoder_test: $(BINDIR)/$(CONFIG)/bin_encoder_test
 census_context_test: $(BINDIR)/$(CONFIG)/census_context_test
 census_resource_test: $(BINDIR)/$(CONFIG)/census_resource_test
+census_trace_context_test: $(BINDIR)/$(CONFIG)/census_trace_context_test
 channel_create_test: $(BINDIR)/$(CONFIG)/channel_create_test
 chttp2_hpack_encoder_test: $(BINDIR)/$(CONFIG)/chttp2_hpack_encoder_test
 chttp2_status_conversion_test: $(BINDIR)/$(CONFIG)/chttp2_status_conversion_test
@@ -1237,6 +1238,7 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/bin_encoder_test \
   $(BINDIR)/$(CONFIG)/census_context_test \
   $(BINDIR)/$(CONFIG)/census_resource_test \
+  $(BINDIR)/$(CONFIG)/census_trace_context_test \
   $(BINDIR)/$(CONFIG)/channel_create_test \
   $(BINDIR)/$(CONFIG)/chttp2_hpack_encoder_test \
   $(BINDIR)/$(CONFIG)/chttp2_status_conversion_test \
@@ -1551,6 +1553,8 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/census_context_test || ( echo test census_context_test failed ; exit 1 )
 	$(E) "[RUN]     Testing census_resource_test"
 	$(Q) $(BINDIR)/$(CONFIG)/census_resource_test || ( echo test census_resource_test failed ; exit 1 )
+	$(E) "[RUN]     Testing census_trace_context_test"
+	$(Q) $(BINDIR)/$(CONFIG)/census_trace_context_test || ( echo test census_trace_context_test failed ; exit 1 )
 	$(E) "[RUN]     Testing channel_create_test"
 	$(Q) $(BINDIR)/$(CONFIG)/channel_create_test || ( echo test channel_create_test failed ; exit 1 )
 	$(E) "[RUN]     Testing chttp2_hpack_encoder_test"
@@ -2708,6 +2712,7 @@ LIBGRPC_SRC = \
     src/core/ext/census/operation.c \
     src/core/ext/census/placeholders.c \
     src/core/ext/census/resource.c \
+    src/core/ext/census/trace_context.c \
     src/core/ext/census/tracing.c \
     src/core/plugin_registry/grpc_plugin_registry.c \
 
@@ -3406,6 +3411,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/census/operation.c \
     src/core/ext/census/placeholders.c \
     src/core/ext/census/resource.c \
+    src/core/ext/census/trace_context.c \
     src/core/ext/census/tracing.c \
     src/core/plugin_registry/grpc_unsecure_plugin_registry.c \
 
@@ -7211,6 +7217,38 @@ endif
 endif
 
 
+CENSUS_TRACE_CONTEXT_TEST_SRC = \
+    test/core/census/trace_context_test.c \
+
+CENSUS_TRACE_CONTEXT_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(CENSUS_TRACE_CONTEXT_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/census_trace_context_test: openssl_dep_error
+
+else
+
+
+
+$(BINDIR)/$(CONFIG)/census_trace_context_test: $(CENSUS_TRACE_CONTEXT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LD) $(LDFLAGS) $(CENSUS_TRACE_CONTEXT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/census_trace_context_test
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/census/trace_context_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_census_trace_context_test: $(CENSUS_TRACE_CONTEXT_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(CENSUS_TRACE_CONTEXT_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 CHANNEL_CREATE_TEST_SRC = \
     test/core/surface/channel_create_test.c \
 

binding.gyp

@@ -754,6 +754,7 @@
         'src/core/ext/census/operation.c',
         'src/core/ext/census/placeholders.c',
         'src/core/ext/census/resource.c',
+        'src/core/ext/census/trace_context.c',
         'src/core/ext/census/tracing.c',
         'src/core/plugin_registry/grpc_plugin_registry.c',
       ],

build.yaml

@@ -29,6 +29,7 @@ filegroups:
   - src/core/ext/census/mlog.h
   - src/core/ext/census/resource.h
   - src/core/ext/census/rpc_metric_id.h
+  - src/core/ext/census/trace_context.h
   src:
   - src/core/ext/census/base_resources.c
   - src/core/ext/census/context.c
@@ -42,6 +43,7 @@ filegroups:
   - src/core/ext/census/operation.c
   - src/core/ext/census/placeholders.c
   - src/core/ext/census/resource.c
+  - src/core/ext/census/trace_context.c
   - src/core/ext/census/tracing.c
   plugin: census_grpc_plugin
   uses:
@@ -1347,6 +1349,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: census_trace_context_test
+  build: test
+  language: c
+  src:
+  - test/core/census/trace_context_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: channel_create_test
   build: test
   language: c

config.m4

@@ -273,6 +273,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/census/operation.c \
     src/core/ext/census/placeholders.c \
     src/core/ext/census/resource.c \
+    src/core/ext/census/trace_context.c \
     src/core/ext/census/tracing.c \
     src/core/plugin_registry/grpc_plugin_registry.c \
     src/boringssl/err_data.c \

gRPC-Core.podspec

@@ -410,6 +410,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/census/mlog.h',
                       'src/core/ext/census/resource.h',
                       'src/core/ext/census/rpc_metric_id.h',
+                      'src/core/ext/census/trace_context.h',
                       'src/core/lib/surface/init.c',
                       'src/core/lib/channel/channel_args.c',
                       'src/core/lib/channel/channel_stack.c',
@@ -600,6 +601,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/census/operation.c',
                       'src/core/ext/census/placeholders.c',
                       'src/core/ext/census/resource.c',
+                      'src/core/ext/census/trace_context.c',
                       'src/core/ext/census/tracing.c',
                       'src/core/plugin_registry/grpc_plugin_registry.c'
 
@@ -776,7 +778,8 @@ Pod::Spec.new do |s|
                               'src/core/ext/census/grpc_filter.h',
                               'src/core/ext/census/mlog.h',
                               'src/core/ext/census/resource.h',
-                              'src/core/ext/census/rpc_metric_id.h'
+                              'src/core/ext/census/rpc_metric_id.h',
+                              'src/core/ext/census/trace_context.h'
   end
 
   s.subspec 'Cronet-Interface' do |ss|

grpc.gemspec

@@ -330,6 +330,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/census/mlog.h )
   s.files += %w( src/core/ext/census/resource.h )
   s.files += %w( src/core/ext/census/rpc_metric_id.h )
+  s.files += %w( src/core/ext/census/trace_context.h )
   s.files += %w( src/core/lib/surface/init.c )
   s.files += %w( src/core/lib/channel/channel_args.c )
   s.files += %w( src/core/lib/channel/channel_stack.c )
@@ -520,6 +521,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/census/operation.c )
   s.files += %w( src/core/ext/census/placeholders.c )
   s.files += %w( src/core/ext/census/resource.c )
+  s.files += %w( src/core/ext/census/trace_context.c )
   s.files += %w( src/core/ext/census/tracing.c )
   s.files += %w( src/core/plugin_registry/grpc_plugin_registry.c )
   s.files += %w( third_party/boringssl/crypto/aes/internal.h )

package.xml

@@ -337,6 +337,7 @@
     <file baseinstalldir="/" name="src/core/ext/census/mlog.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/census/resource.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/census/rpc_metric_id.h" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/census/trace_context.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/surface/init.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_args.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/channel/channel_stack.c" role="src" />
@@ -527,6 +528,7 @@
     <file baseinstalldir="/" name="src/core/ext/census/operation.c" role="src" />
     <file baseinstalldir="/" name="src/core/ext/census/placeholders.c" role="src" />
     <file baseinstalldir="/" name="src/core/ext/census/resource.c" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/census/trace_context.c" role="src" />
     <file baseinstalldir="/" name="src/core/ext/census/tracing.c" role="src" />
     <file baseinstalldir="/" name="src/core/plugin_registry/grpc_plugin_registry.c" role="src" />
     <file baseinstalldir="/" name="third_party/boringssl/crypto/aes/internal.h" role="src" />

src/core/ext/census/trace_context.c

@@ -0,0 +1,86 @@
+/*
+ *
+ * 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 "src/core/ext/census/trace_context.h"
+
+#include <grpc/census.h>
+#include <grpc/support/log.h>
+#include <stdbool.h>
+
+#include "third_party/nanopb/pb_decode.h"
+#include "third_party/nanopb/pb_encode.h"
+
+// This function assumes the TraceContext is valid.
+size_t encode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                            const size_t buf_size) {
+  // Create a stream that will write to our buffer.
+  pb_ostream_t stream = pb_ostream_from_buffer(buffer, buf_size);
+
+  // encode message
+  bool status = pb_encode(&stream, google_trace_TraceContext_fields, ctxt);
+
+  if (!status) {
+    gpr_log(GPR_DEBUG, "TraceContext encoding failed: %s",
+            PB_GET_ERROR(&stream));
+    return 0;
+  }
+
+  return stream.bytes_written;
+}
+
+bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                          const size_t nbytes) {
+  // Create a stream that reads nbytes from the buffer.
+  pb_istream_t stream = pb_istream_from_buffer(buffer, nbytes);
+
+  // decode message
+  bool status = pb_decode(&stream, google_trace_TraceContext_fields, ctxt);
+
+  if (!status) {
+    gpr_log(GPR_DEBUG, "TraceContext decoding failed: %s",
+            PB_GET_ERROR(&stream));
+    return false;
+  }
+
+  // check fields
+  if (!ctxt->has_trace_id) {
+    gpr_log(GPR_DEBUG, "Invalid TraceContext: missing trace_id");
+    return false;
+  }
+  if (!ctxt->has_span_id) {
+    gpr_log(GPR_DEBUG, "Invalid TraceContext: missing span_id");
+    return false;
+  }
+
+  return true;
+}

src/core/ext/census/trace_context.h

@@ -0,0 +1,68 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+/* Functions for manipulating trace contexts as defined in
+   src/proto/census/trace.proto */
+#ifndef GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H
+#define GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H
+
+#include "src/core/ext/census/gen/trace_context.pb.h"
+
+/* Maximum number of bytes required to encode a TraceContext (31)
+1 byte for trace_id field
+1 byte for trace_id length
+1 byte for trace_id.hi field
+8 bytes for trace_id.hi (uint64_t)
+1 byte for trace_id.lo field
+8 bytes for trace_id.lo (uint64_t)
+1 byte for span_id field
+8 bytes for span_id (uint64_t)
+1 byte for is_sampled field
+1 byte for is_sampled (bool) */
+#define TRACE_MAX_CONTEXT_SIZE 31
+
+/* Encode a trace context (ctxt) into proto format to the buffer provided.  The
+size of buffer must be at least TRACE_MAX_CONTEXT_SIZE.  On success, returns the
+number of bytes successfully encoded into buffer.  On failure, returns 0. */
+size_t encode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                            const size_t buf_size);
+
+/* Decode a proto-encoded TraceContext from the provided buffer into the
+TraceContext structure (ctxt).  The function expects to be supplied the number
+of bytes to be read from buffer (nbytes).  This function will also validate that
+the TraceContext has a span_id and a trace_id, and will return false if either
+of these do not exist. On success, returns true and false otherwise. */
+bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                          const size_t nbytes);
+
+#endif

src/core/ext/census/tracing.c

@@ -31,15 +31,21 @@
  *
  */
 
+//#include "src/core/ext/census/tracing.h"
+
 #include <grpc/census.h>
 
+
+
 /* TODO(aveitch): These are all placeholder implementations. */
 
-int census_trace_mask(const census_context *context) {
-  return CENSUS_TRACE_MASK_NONE;
-}
+// int census_trace_mask(const census_context *context) {
+//   return CENSUS_TRACE_MASK_NONE;
+// }
+
+// void census_set_trace_mask(int trace_mask) {}
 
-void census_set_trace_mask(int trace_mask) {}
+// void census_trace_print(census_context *context, uint32_t type,
+//                         const char *buffer, size_t n) {}
 
-void census_trace_print(census_context *context, uint32_t type,
-                        const char *buffer, size_t n) {}
+// void SetTracerParams(const Params& params);

src/python/grpcio/grpc_core_dependencies.py

@@ -267,6 +267,7 @@ CORE_SOURCE_FILES = [
   'src/core/ext/census/operation.c',
   'src/core/ext/census/placeholders.c',
   'src/core/ext/census/resource.c',
+  'src/core/ext/census/trace_context.c',
   'src/core/ext/census/tracing.c',
   'src/core/plugin_registry/grpc_plugin_registry.c',
   'src/boringssl/err_data.c',

test/core/census/data/context_full.txt

@@ -0,0 +1,3 @@
+trace_id { hi : 5; lo : 1 }
+span_id : 7
+is_sampled : true

test/core/census/data/context_no_sample.txt

@@ -0,0 +1,2 @@
+trace_id { hi : 5; lo : 1 }
+span_id : 7

test/core/census/data/context_span_only.txt

@@ -0,0 +1,2 @@
+span_id : 7
+is_sampled : true

test/core/census/data/context_trace_only.txt

@@ -0,0 +1,2 @@
+trace_id { hi : 5; lo : 1 }
+is_sampled : true

test/core/census/trace_context_test.c

@@ -0,0 +1,231 @@
+/*
+ *
+ * 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 <grpc/census.h>
+#include <grpc/support/log.h>
+#include <grpc/support/port_platform.h>
+#include <grpc/support/useful.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "src/core/ext/census/base_resources.h"
+#include "src/core/ext/census/resource.h"
+#include "test/core/util/test_config.h"
+
+#include "src/core/ext/census/gen/trace_context.pb.h"
+#include "src/core/ext/census/trace_context.h"
+#include "third_party/nanopb/pb_decode.h"
+#include "third_party/nanopb/pb_encode.h"
+
+#define BUF_SIZE 256
+
+/* Encodes a TraceContext structure (ctxt1) to a buffer, and then decodes it
+to a second TraceContext (ctxt2).  Validates that the resulting TraceContext
+has a span_id, trace_id, and that the values are equal to those in initial
+TraceContext. On success, returns true.  If encode_trace_context returns 0,
+decode_trace_context fails, or the resulting TraceContext is missing a trace_id
+or span_id, it will return false. */
+bool validate_encode_decode_context(google_trace_TraceContext *ctxt1,
+                                    uint8_t *buffer, size_t buf_size) {
+  google_trace_TraceContext ctxt2 = google_trace_TraceContext_init_zero;
+  size_t msg_length;
+  GPR_ASSERT(ctxt1->has_trace_id && ctxt1->has_span_id);
+
+  msg_length = encode_trace_context(ctxt1, buffer, buf_size);
+  if (msg_length == 0) {
+    return false;
+  }
+
+  if (!decode_trace_context(&ctxt2, buffer, msg_length)) {
+    return false;
+  }
+
+  if (!ctxt2.has_trace_id || !ctxt2.has_span_id) {
+    return false;
+  }
+
+  GPR_ASSERT(
+      ctxt1->trace_id.hi == ctxt2.trace_id.hi &&
+      ctxt1->trace_id.lo == ctxt2.trace_id.lo &&
+      ctxt1->span_id == ctxt2.span_id &&
+      ctxt1->has_is_sampled == ctxt2.has_is_sampled &&
+      (ctxt1->has_is_sampled ? ctxt1->is_sampled == ctxt2.is_sampled : true));
+
+  return true;
+}
+
+/* Decodes a proto-encoded TraceContext from a buffer.  If decode_trace_context
+fails or the resulting TraceContext is missing a trace_id or span_id it will
+return false, otherwise returns true. */
+bool validate_decode_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                             size_t msg_length) {
+  // Validate the decoding of a context written to buffer.
+  if (!decode_trace_context(ctxt, buffer, msg_length)) {
+    return false;
+  }
+
+  if (!ctxt->has_trace_id || !ctxt->has_span_id) {
+    return false;
+  }
+
+  return true;
+}
+
+/* Read an encoded trace context from a file.  Validates that the decoding
+gives the expected result (succeed). */
+static void read_and_validate_context_from_file(google_trace_TraceContext *ctxt,
+                                                const char *file,
+                                                const bool succeed) {
+  uint8_t buffer[BUF_SIZE];
+  FILE *input = fopen(file, "rb");
+  GPR_ASSERT(input != NULL);
+  size_t nbytes = fread(buffer, 1, BUF_SIZE, input);
+  GPR_ASSERT(nbytes <= BUF_SIZE && feof(input) && !ferror(input));
+  bool res = validate_decode_context(ctxt, buffer, nbytes);
+  GPR_ASSERT(res == succeed);
+  GPR_ASSERT(fclose(input) == 0);
+}
+
+// Test full proto-buffer.
+static void test_full() {
+  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
+  read_and_validate_context_from_file(
+      &ctxt, "test/core/census/data/context_full.pb", true);
+}
+
+// Test empty proto-buffer.
+static void test_empty() {
+  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
+  read_and_validate_context_from_file(
+      &ctxt, "test/core/census/data/context_empty.pb", false);
+}
+
+// Test proto-buffer with only trace_id.
+static void test_trace_only() {
+  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
+  read_and_validate_context_from_file(
+      &ctxt, "test/core/census/data/context_trace_only.pb", false);
+}
+
+// Test proto-buffer with only span_id.
+static void test_span_only() {
+  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
+  read_and_validate_context_from_file(
+      &ctxt, "test/core/census/data/context_span_only.pb", false);
+}
+
+// Test proto-buffer without is_sampled value.
+static void test_no_sample() {
+  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
+  read_and_validate_context_from_file(
+      &ctxt, "test/core/census/data/context_no_sample.pb", true);
+  GPR_ASSERT(ctxt.has_is_sampled == false && ctxt.is_sampled == false);
+}
+
+static void test_encode_decode() {
+  uint8_t buffer[BUF_SIZE] = {0};
+
+  google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
+  ctxt1.has_trace_id = true;
+  ctxt1.trace_id.has_hi = true;
+  ctxt1.trace_id.has_lo = true;
+  ctxt1.trace_id.lo = 1;
+  ctxt1.trace_id.hi = 2;
+  ctxt1.has_span_id = true;
+  ctxt1.span_id = 3;
+  validate_encode_decode_context(&ctxt1, buffer, sizeof(buffer));
+
+  google_trace_TraceContext ctxt2 = google_trace_TraceContext_init_zero;
+  ctxt2.has_trace_id = true;
+  ctxt2.trace_id.has_hi = false;
+  ctxt2.trace_id.has_lo = false;
+  ctxt2.has_span_id = true;
+  validate_encode_decode_context(&ctxt2, buffer, sizeof(buffer));
+}
+
+// Test a corrupted proto-buffer.
+static void test_corrupt() {
+  uint8_t buffer[BUF_SIZE] = {0};
+  google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
+  size_t msg_length;
+
+  ctxt1.has_trace_id = true;
+  ctxt1.trace_id.has_hi = true;
+  ctxt1.trace_id.has_lo = true;
+  ctxt1.trace_id.lo = 1;
+  ctxt1.trace_id.hi = 2;
+  ctxt1.has_span_id = true;
+  ctxt1.span_id = 3;
+  ctxt1.is_sampled = true;
+  msg_length = encode_trace_context(&ctxt1, buffer, sizeof(buffer));
+
+  /* Corrupt some bytes.  255 (0xFF) should be illegal for the first byte of the
+  proto encoded object. */
+  buffer[0] = 255;
+
+  bool res = validate_decode_context(&ctxt1, buffer, msg_length);
+  GPR_ASSERT(res == false);
+}
+
+static void test_buffer_size() {
+  // This buffer is too small, so the encode should fail.
+  uint8_t buffer[16] = {0};
+  google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
+  size_t msg_length;
+
+  ctxt1.has_trace_id = true;
+  ctxt1.trace_id.has_hi = true;
+  ctxt1.trace_id.has_lo = true;
+  ctxt1.trace_id.lo = 1;
+  ctxt1.trace_id.hi = 2;
+  ctxt1.has_span_id = true;
+  ctxt1.span_id = 3;
+  ctxt1.is_sampled = true;
+  msg_length = encode_trace_context(&ctxt1, buffer, sizeof(buffer));
+
+  GPR_ASSERT(msg_length == 0);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  test_full();
+  test_empty();
+  test_trace_only();
+  test_span_only();
+  test_encode_decode();
+  test_corrupt();
+  test_no_sample();
+  test_buffer_size();
+
+  return 0;
+}

tools/doxygen/Doxyfile.core.internal

@@ -947,6 +947,7 @@ src/core/ext/census/grpc_filter.h \
 src/core/ext/census/mlog.h \
 src/core/ext/census/resource.h \
 src/core/ext/census/rpc_metric_id.h \
+src/core/ext/census/trace_context.h \
 src/core/lib/surface/init.c \
 src/core/lib/channel/channel_args.c \
 src/core/lib/channel/channel_stack.c \
@@ -1137,6 +1138,7 @@ 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/trace_context.c \
 src/core/ext/census/tracing.c \
 src/core/plugin_registry/grpc_plugin_registry.c \
 include/grpc/support/alloc.h \

tools/run_tests/sources_and_headers.json

@@ -156,6 +156,22 @@
     "third_party": false, 
     "type": "target"
   }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util", 
+      "grpc", 
+      "grpc_test_util"
+    ], 
+    "headers": [], 
+    "language": "c", 
+    "name": "census_trace_context_test", 
+    "src": [
+      "test/core/census/trace_context_test.c"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
   {
     "deps": [
       "gpr", 
@@ -5695,7 +5711,8 @@
       "src/core/ext/census/grpc_filter.h", 
       "src/core/ext/census/mlog.h", 
       "src/core/ext/census/resource.h", 
-      "src/core/ext/census/rpc_metric_id.h"
+      "src/core/ext/census/rpc_metric_id.h", 
+      "src/core/ext/census/trace_context.h"
     ], 
     "language": "c", 
     "name": "census", 
@@ -5723,6 +5740,8 @@
       "src/core/ext/census/resource.c", 
       "src/core/ext/census/resource.h", 
       "src/core/ext/census/rpc_metric_id.h", 
+      "src/core/ext/census/trace_context.c", 
+      "src/core/ext/census/trace_context.h", 
       "src/core/ext/census/tracing.c"
     ], 
     "third_party": false, 

tools/run_tests/tests.json

@@ -190,6 +190,27 @@
       "windows"
     ]
   }, 
+  {
+    "args": [], 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c", 
+    "name": "census_trace_context_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ]
+  }, 
   {
     "args": [], 
     "ci_platforms": [

vsprojects/buildtests_c.sln

@@ -120,6 +120,17 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "census_resource_test", "vcx
 		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "census_trace_context_test", "vcxproj\test\census_trace_context_test\census_trace_context_test.vcxproj", "{14511310-FAE4-C287-31DC-D6F456D10AF3}"
+	ProjectSection(myProperties) = preProject
+        	lib = "False"
+	EndProjectSection
+	ProjectSection(ProjectDependencies) = postProject
+		{17BCAFC0-5FDC-4C94-AEB9-95F3E220614B} = {17BCAFC0-5FDC-4C94-AEB9-95F3E220614B}
+		{29D16885-7228-4C31-81ED-5F9187C7F2A9} = {29D16885-7228-4C31-81ED-5F9187C7F2A9}
+		{EAB0A629-17A9-44DB-B5FF-E91A721FE037} = {EAB0A629-17A9-44DB-B5FF-E91A721FE037}
+		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
+	EndProjectSection
+EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "channel_create_test", "vcxproj\test\channel_create_test\channel_create_test.vcxproj", "{AFC88484-3A2E-32BC-25B2-23DF741D4F3D}"
 	ProjectSection(myProperties) = preProject
         	lib = "False"
@@ -1660,6 +1671,22 @@ Global
 		{18CF99B5-3C61-EC3D-9509-3C95334C3B88}.Release-DLL|Win32.Build.0 = Release|Win32
 		{18CF99B5-3C61-EC3D-9509-3C95334C3B88}.Release-DLL|x64.ActiveCfg = Release|x64
 		{18CF99B5-3C61-EC3D-9509-3C95334C3B88}.Release-DLL|x64.Build.0 = Release|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug|Win32.ActiveCfg = Debug|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug|x64.ActiveCfg = Debug|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release|Win32.ActiveCfg = Release|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release|x64.ActiveCfg = Release|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug|Win32.Build.0 = Debug|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug|x64.Build.0 = Debug|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release|Win32.Build.0 = Release|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release|x64.Build.0 = Release|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug-DLL|Win32.ActiveCfg = Debug|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug-DLL|Win32.Build.0 = Debug|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug-DLL|x64.ActiveCfg = Debug|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Debug-DLL|x64.Build.0 = Debug|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release-DLL|Win32.ActiveCfg = Release|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release-DLL|Win32.Build.0 = Release|Win32
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release-DLL|x64.ActiveCfg = Release|x64
+		{14511310-FAE4-C287-31DC-D6F456D10AF3}.Release-DLL|x64.Build.0 = Release|x64
 		{AFC88484-3A2E-32BC-25B2-23DF741D4F3D}.Debug|Win32.ActiveCfg = Debug|Win32
 		{AFC88484-3A2E-32BC-25B2-23DF741D4F3D}.Debug|x64.ActiveCfg = Debug|x64
 		{AFC88484-3A2E-32BC-25B2-23DF741D4F3D}.Release|Win32.ActiveCfg = Release|Win32

vsprojects/vcxproj/grpc/grpc.vcxproj

@@ -456,6 +456,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\mlog.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\resource.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\rpc_metric_id.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\trace_context.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\surface\init.c">
@@ -838,6 +839,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\resource.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\trace_context.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\tracing.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\plugin_registry\grpc_plugin_registry.c">

vsprojects/vcxproj/grpc/grpc.vcxproj.filters

@@ -571,6 +571,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\resource.c">
       <Filter>src\core\ext\census</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\trace_context.c">
+      <Filter>src\core\ext\census</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\tracing.c">
       <Filter>src\core\ext\census</Filter>
     </ClCompile>
@@ -1142,6 +1145,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\rpc_metric_id.h">
       <Filter>src\core\ext\census</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\trace_context.h">
+      <Filter>src\core\ext\census</Filter>
+    </ClInclude>
   </ItemGroup>
 
   <ItemGroup>

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj

@@ -422,6 +422,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\mlog.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\resource.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\rpc_metric_id.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\trace_context.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\surface\init.c">
@@ -746,6 +747,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\resource.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\trace_context.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\tracing.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\plugin_registry\grpc_unsecure_plugin_registry.c">

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters

@@ -484,6 +484,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\resource.c">
       <Filter>src\core\ext\census</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\trace_context.c">
+      <Filter>src\core\ext\census</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\ext\census\tracing.c">
       <Filter>src\core\ext\census</Filter>
     </ClCompile>
@@ -980,6 +983,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\rpc_metric_id.h">
       <Filter>src\core\ext\census</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\ext\census\trace_context.h">
+      <Filter>src\core\ext\census</Filter>
+    </ClInclude>
   </ItemGroup>
 
   <ItemGroup>

vsprojects/vcxproj/test/census_trace_context_test/census_trace_context_test.vcxproj

@@ -0,0 +1,199 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\1.0.204.1.props')" />
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{14511310-FAE4-C287-31DC-D6F456D10AF3}</ProjectGuid>
+    <IgnoreWarnIntDirInTempDetected>true</IgnoreWarnIntDirInTempDetected>
+    <IntDir>$(SolutionDir)IntDir\$(MSBuildProjectName)\</IntDir>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '10.0'" Label="Configuration">
+    <PlatformToolset>v100</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '11.0'" Label="Configuration">
+    <PlatformToolset>v110</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '12.0'" Label="Configuration">
+    <PlatformToolset>v120</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '14.0'" Label="Configuration">
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="$(SolutionDir)\..\vsprojects\global.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\openssl.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\winsock.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\zlib.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'">
+    <TargetName>census_trace_context_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Debug</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Debug</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'">
+    <TargetName>census_trace_context_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Release</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Release</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
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