Begin patching Cython

src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx.pxi

@@ -60,19 +60,23 @@ cdef class Channel:
                   method, host, Timespec deadline not None):
     if queue.is_shutting_down:
       raise ValueError("queue must not be shutting down or shutdown")
-    cdef char *method_c_string = method
-    cdef char *host_c_string = NULL
+    cdef Slice method_slice = Slice.from_bytes(method)
+    cdef Slice host_slice
+    cdef grpc_slice *host_c_slice = NULL
     if host is not None:
-      host_c_string = host
+      host_slice = Slice.from_bytes(host)
+      host_c_slice = &host_slice.c_slice
+    else:
+      host_slice = Slice()
     cdef Call operation_call = Call()
-    operation_call.references = [self, method, host, queue]
+    operation_call.references = [self, method_slice, host_slice, queue]
     cdef grpc_call *parent_call = NULL
     if parent is not None:
       parent_call = parent.c_call
     with nogil:
       operation_call.c_call = grpc_channel_create_call(
           self.c_channel, parent_call, flags,
-          queue.c_completion_queue, method_c_string, host_c_string,
+          queue.c_completion_queue, method_slice.c_slice, host_c_slice,
           deadline.c_time, NULL)
     return operation_call
 

src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi

@@ -51,6 +51,13 @@ cdef extern from "grpc/byte_buffer_reader.h":
     pass
 
 
+cdef extern from "grpc/impl/codegen/exec_ctx_fwd.h":
+
+  struct grpc_exec_ctx:
+    # We don't care about the internals
+    pass
+
+
 cdef extern from "grpc/grpc.h":
 
   ctypedef struct grpc_slice:
@@ -60,6 +67,7 @@ cdef extern from "grpc/grpc.h":
 
   grpc_slice grpc_slice_ref(grpc_slice s) nogil
   void grpc_slice_unref(grpc_slice s) nogil
+  grpc_slice grpc_empty_slice() nogil
   grpc_slice grpc_slice_new(void *p, size_t len, void (*destroy)(void *)) nogil
   grpc_slice grpc_slice_new_with_len(
       void *p, size_t len, void (*destroy)(void *, size_t)) nogil
@@ -175,7 +183,7 @@ cdef extern from "grpc/grpc.h":
 
   ctypedef struct grpc_arg_pointer_vtable:
     void *(*copy)(void *)
-    void (*destroy)(void *)
+    void (*destroy)(grpc_exec_ctx *, void *)
     int (*cmp)(void *, void *)
 
   ctypedef struct grpc_arg_value_pointer:
@@ -217,9 +225,8 @@ cdef extern from "grpc/grpc.h":
     GRPC_CHANNEL_SHUTDOWN
 
   ctypedef struct grpc_metadata:
-    const char *key
-    const char *value
-    size_t value_length
+    grpc_slice key
+    grpc_slice value
     # ignore the 'internal_data.obfuscated' fields.
 
   ctypedef enum grpc_completion_type:
@@ -241,10 +248,8 @@ cdef extern from "grpc/grpc.h":
   void grpc_metadata_array_destroy(grpc_metadata_array *array) nogil
 
   ctypedef struct grpc_call_details:
-    char *method
-    size_t method_capacity
-    char *host
-    size_t host_capacity
+    grpc_slice method
+    grpc_slice host
     gpr_timespec deadline
 
   void grpc_call_details_init(grpc_call_details *details) nogil
@@ -268,13 +273,12 @@ cdef extern from "grpc/grpc.h":
     size_t trailing_metadata_count
     grpc_metadata *trailing_metadata
     grpc_status_code status
-    const char *status_details
+    grpc_slice *status_details
 
   ctypedef struct grpc_op_data_recv_status_on_client:
     grpc_metadata_array *trailing_metadata
     grpc_status_code *status
-    char **status_details
-    size_t *status_details_capacity
+    grpc_slice *status_details
 
   ctypedef struct grpc_op_data_recv_close_on_server:
     int *cancelled
@@ -321,9 +325,9 @@ cdef extern from "grpc/grpc.h":
                                              const grpc_channel_args *args,
                                              void *reserved) nogil
   grpc_call *grpc_channel_create_call(
-      grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
-      grpc_completion_queue *completion_queue, const char *method,
-      const char *host, gpr_timespec deadline, void *reserved) nogil
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_completion_queue *completion_queue, grpc_slice method,
+    const grpc_slice *host, gpr_timespec deadline, void *reserved) nogil
   grpc_connectivity_state grpc_channel_check_connectivity_state(
       grpc_channel *channel, int try_to_connect) nogil
   void grpc_channel_watch_connectivity_state(
@@ -473,8 +477,7 @@ cdef extern from "grpc/compression.h":
     grpc_compression_algorithm default_compression_algorithm
 
   int grpc_compression_algorithm_parse(
-      const char *name, size_t name_length,
-      grpc_compression_algorithm *algorithm) nogil
+      grpc_slice value, grpc_compression_algorithm *algorithm) nogil
   int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
                                       char **name) nogil
   grpc_compression_algorithm grpc_compression_algorithm_for_level(

src/python/grpcio/grpc/_cython/_cygrpc/records.pxd.pxi

@@ -70,6 +70,15 @@ cdef class Event:
   cdef readonly Operations batch_operations
 
 
+cdef class Slice:
+
+  cdef grpc_slice c_slice
+
+  cdef void _assign_slice(self, grpc_slice new_slice) nogil
+  @staticmethod
+  cdef Slice from_slice(grpc_slice slice)
+
+
 cdef class ByteBuffer:
 
   cdef grpc_byte_buffer *c_byte_buffer
@@ -97,7 +106,8 @@ cdef class ChannelArgs:
 cdef class Metadatum:
 
   cdef grpc_metadata c_metadata
-  cdef object _key, _value
+  cdef Slice _key,
+  cdef Slice _value
 
 
 cdef class Metadata:
@@ -112,8 +122,7 @@ cdef class Operation:
   cdef ByteBuffer _received_message
   cdef Metadata _received_metadata
   cdef grpc_status_code _received_status_code
-  cdef char *_received_status_details
-  cdef size_t _received_status_details_capacity
+  cdef Slice _received_status_details
   cdef int _received_cancelled
   cdef readonly bint is_valid
   cdef object references

src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi

@@ -189,17 +189,11 @@ cdef class CallDetails:
 
   @property
   def method(self):
-    if self.c_details.method != NULL:
-      return <bytes>self.c_details.method
-    else:
-      return None
+    return Slice.from_slice(self.c_details.method).bytes()
 
   @property
   def host(self):
-    if self.c_details.host != NULL:
-      return <bytes>self.c_details.host
-    else:
-      return None
+    return Slice.from_slice(self.c_details.host).bytes()
 
   @property
   def deadline(self):
@@ -233,6 +227,42 @@ cdef class Event:
     self.is_new_request = is_new_request
 
 
+cdef class Slice:
+
+  def __cinit__(self):
+    with nogil:
+      grpc_init()
+      self.c_slice = grpc_empty_slice()
+
+  cdef void _assign_slice(self, grpc_slice new_slice) nogil:
+    grpc_slice_unref(self.c_slice)
+    self.c_slice = new_slice
+
+  @staticmethod
+  def from_bytes(bytes data):
+    cdef Slice self = Slice()
+    self._assign_slice(grpc_slice_from_copied_buffer(data, len(data)))
+    return self
+
+  @staticmethod
+  cdef Slice from_slice(grpc_slice slice):
+    cdef Slice self = Slice()
+    grpc_slice_ref(slice)
+    self._assign_slice(slice)
+    return self
+
+  def bytes(self):
+    with nogil:
+      pointer = grpc_slice_start_ptr(self.c_slice)
+      length = grpc_slice_length(self.c_slice)
+    return (<char *>pointer)[:length]
+
+  def __dealloc__(self):
+    with nogil:
+      grpc_slice_unref(self.c_slice)
+      grpc_shutdown()
+
+
 cdef class ByteBuffer:
 
   def __cinit__(self, bytes data):
@@ -310,7 +340,7 @@ cdef void* copy_ptr(void* ptr):
   return ptr
 
 
-cdef void destroy_ptr(void* ptr):
+cdef void destroy_ptr(grpc_exec_ctx* ctx, void* ptr):
   pass
 
 
@@ -382,20 +412,20 @@ cdef class ChannelArgs:
 
 cdef class Metadatum:
 
+  # TODO(atash) this should just accept Slice objects.
   def __cinit__(self, bytes key, bytes value):
-    self._key = key
-    self._value = value
-    self.c_metadata.key = self._key
-    self.c_metadata.value = self._value
-    self.c_metadata.value_length = len(self._value)
+    self._key = Slice.from_bytes(key)
+    self._value = Slice.from_bytes(value)
+    self.c_metadata.key = self._key.c_slice
+    self.c_metadata.value = self._value.c_slice
 
   @property
   def key(self):
-    return <bytes>self.c_metadata.key
+    return self._key.bytes()
 
   @property
   def value(self):
-    return <bytes>self.c_metadata.value[:self.c_metadata.value_length]
+    return self._value.bytes()
 
   def __len__(self):
     return 2
@@ -465,9 +495,8 @@ cdef class Metadata:
 
   def __getitem__(self, size_t i):
     return Metadatum(
-        key=<bytes>self.c_metadata_array.metadata[i].key,
-        value=<bytes>self.c_metadata_array.metadata[i].value[
-            :self.c_metadata_array.metadata[i].value_length])
+        key=Slice.from_slice(self.c_metadata_array.metadata[i].key).bytes(),
+        value=Slice.from_slice(self.c_metadata_array.metadata[i].value).bytes())
 
   def __iter__(self):
     return _MetadataIterator(self)
@@ -478,8 +507,7 @@ cdef class Operation:
   def __cinit__(self):
     grpc_init()
     self.references = []
-    self._received_status_details = NULL
-    self._received_status_details_capacity = 0
+    self._received_status_details = Slice()
     self.is_valid = False
 
   @property
@@ -536,19 +564,13 @@ cdef class Operation:
   def received_status_details(self):
     if self.c_op.type != GRPC_OP_RECV_STATUS_ON_CLIENT:
       raise TypeError("self must be an operation receiving status details")
-    if self._received_status_details:
-      return self._received_status_details
-    else:
-      return None
+    return self._received_status_details.bytes()
 
   @property
   def received_status_details_or_none(self):
     if self.c_op.type != GRPC_OP_RECV_STATUS_ON_CLIENT:
       return None
-    if self._received_status_details:
-      return self._received_status_details
-    else:
-      return None
+    return self._received_status_details.bytes()
 
   @property
   def received_cancelled(self):
@@ -564,11 +586,6 @@ cdef class Operation:
     return False if self._received_cancelled == 0 else True
 
   def __dealloc__(self):
-    # We *almost* don't need to do anything; most of the objects are handled by
-    # Python. The remaining one(s) are primitive fields filled in by GRPC core.
-    # This means that we need to clean up after receive_status_on_client.
-    if self.c_op.type == GRPC_OP_RECV_STATUS_ON_CLIENT:
-      gpr_free(self._received_status_details)
     grpc_shutdown()
 
 def operation_send_initial_metadata(Metadata metadata, int flags):
@@ -609,9 +626,10 @@ def operation_send_status_from_server(
   op.c_op.data.send_status_from_server.trailing_metadata = (
       metadata.c_metadata_array.metadata)
   op.c_op.data.send_status_from_server.status = code
-  op.c_op.data.send_status_from_server.status_details = details
+  cdef Slice details_slice = Slice.from_bytes(details)
+  op.c_op.data.send_status_from_server.status_details = &details_slice.c_slice
   op.references.append(metadata)
-  op.references.append(details)
+  op.references.append(details_slice)
   op.is_valid = True
   return op
 
@@ -647,9 +665,7 @@ def operation_receive_status_on_client(int flags):
   op.c_op.data.receive_status_on_client.status = (
       &op._received_status_code)
   op.c_op.data.receive_status_on_client.status_details = (
-      &op._received_status_details)
-  op.c_op.data.receive_status_on_client.status_details_capacity = (
-      &op._received_status_details_capacity)
+      &op._received_status_details.c_slice)
   op.is_valid = True
   return op