1 files changed, 215 insertions, 0 deletions
diff --git a/src/ruby/ext/grpc/rb_metadata.c b/src/ruby/ext/grpc/rb_metadata.c
new file mode 100644
index 0000000000..13d515a929
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+++ b/src/ruby/ext/grpc/rb_metadata.c
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+/*
+ *
+ * Copyright 2014, 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 "rb_metadata.h"
+
+#include <ruby.h>
+#include <string.h>
+
+#include <grpc/grpc.h>
+#include "rb_grpc.h"
+
+/* grpc_rb_metadata wraps a grpc_metadata.  It provides a peer ruby object,
+ * 'mark' to minimize copying when a metadata is created from ruby. */
+typedef struct grpc_rb_metadata {
+  /* Holder of ruby objects involved in constructing the metadata */
+  VALUE mark;
+  /* The actual metadata */
+  grpc_metadata *wrapped;
+} grpc_rb_metadata;
+
+
+/* Destroys Metadata instances. */
+static void grpc_rb_metadata_free(void *p) {
+  if (p == NULL) {
+    return;
+  };
+
+  /* Because metadata is only created during a call to grpc_call_add_metadata,
+   * and the call takes ownership of the metadata, this does not free the
+   * wrapped struct, only the wrapper */
+  xfree(p);
+}
+
+/* Protects the mark object from GC */
+static void grpc_rb_metadata_mark(void *p) {
+  grpc_rb_metadata *md = NULL;
+  if (p == NULL) {
+    return;
+  }
+
+  md = (grpc_rb_metadata *)p;
+  /* If it's not already cleaned up, mark the mark object */
+  if (md->mark != Qnil && BUILTIN_TYPE(md->mark) != T_NONE) {
+    rb_gc_mark(md->mark);
+  }
+}
+
+/* Allocates Metadata instances.
+
+   Provides safe default values for the Metadata fields. */
+static VALUE grpc_rb_metadata_alloc(VALUE cls) {
+  grpc_rb_metadata *wrapper = ALLOC(grpc_rb_metadata);
+  wrapper->wrapped = NULL;
+  wrapper->mark = Qnil;
+  return Data_Wrap_Struct(cls, grpc_rb_metadata_mark, grpc_rb_metadata_free,
+                          wrapper);
+}
+
+/* id_key and id_value are the names of the hidden ivars that preserve the
+ * original byte_buffer source string */
+static ID id_key;
+static ID id_value;
+
+/* Initializes Metadata instances. */
+static VALUE grpc_rb_metadata_init(VALUE self, VALUE key, VALUE value) {
+  grpc_rb_metadata *wrapper = NULL;
+  grpc_metadata *md = ALLOC(grpc_metadata);
+
+  /* Use direct pointers to the strings wrapped by the ruby object to avoid
+   * copying */
+  Data_Get_Struct(self, grpc_rb_metadata, wrapper);
+  wrapper->wrapped = md;
+  if (TYPE(key) == T_SYMBOL) {
+    md->key = (char *)rb_id2name(SYM2ID(key));
+  } else {  /* StringValueCStr does all other type exclusions for us */
+    md->key = StringValueCStr(key);
+  }
+  md->value = RSTRING_PTR(value);
+  md->value_length = RSTRING_LEN(value);
+
+  /* Save references to the original values on the mark object so that the
+   * pointers used there are valid for the lifetime of the object. */
+  wrapper->mark = rb_class_new_instance(0, NULL, rb_cObject);
+  rb_ivar_set(wrapper->mark, id_key, key);
+  rb_ivar_set(wrapper->mark, id_value, value);
+
+  return self;
+}
+
+/* Clones Metadata instances.
+
+   Gives Metadata a consistent implementation of Ruby's object copy/dup
+   protocol. */
+static VALUE grpc_rb_metadata_init_copy(VALUE copy, VALUE orig) {
+  grpc_rb_metadata *orig_md = NULL;
+  grpc_rb_metadata *copy_md = NULL;
+
+  if (copy == orig) {
+    return copy;
+  }
+
+  /* Raise an error if orig is not a metadata object or a subclass. */
+  if (TYPE(orig) != T_DATA ||
+      RDATA(orig)->dfree != (RUBY_DATA_FUNC)grpc_rb_metadata_free) {
+    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(rb_cMetadata));
+  }
+
+  Data_Get_Struct(orig, grpc_rb_metadata, orig_md);
+  Data_Get_Struct(copy, grpc_rb_metadata, copy_md);
+
+  /* use ruby's MEMCPY to make a byte-for-byte copy of the metadata wrapper
+   * object. */
+  MEMCPY(copy_md, orig_md, grpc_rb_metadata, 1);
+  return copy;
+}
+
+/* Gets the key from a metadata instance. */
+static VALUE grpc_rb_metadata_key(VALUE self) {
+  VALUE key = Qnil;
+  grpc_rb_metadata *wrapper = NULL;
+  grpc_metadata *md = NULL;
+
+  Data_Get_Struct(self, grpc_rb_metadata, wrapper);
+  if (wrapper->mark != Qnil) {
+    key = rb_ivar_get(wrapper->mark, id_key);
+    if (key != Qnil) {
+      return key;
+    }
+  }
+
+  md = wrapper->wrapped;
+  if (md == NULL || md->key == NULL) {
+    return Qnil;
+  }
+  return rb_str_new2(md->key);
+}
+
+/* Gets the value from a metadata instance. */
+static VALUE grpc_rb_metadata_value(VALUE self) {
+  VALUE val = Qnil;
+  grpc_rb_metadata *wrapper = NULL;
+  grpc_metadata *md = NULL;
+
+  Data_Get_Struct(self, grpc_rb_metadata, wrapper);
+  if (wrapper->mark != Qnil) {
+    val = rb_ivar_get(wrapper->mark, id_value);
+    if (val != Qnil) {
+      return val;
+    }
+  }
+
+  md = wrapper->wrapped;
+  if (md == NULL || md->value == NULL) {
+    return Qnil;
+  }
+  return rb_str_new2(md->value);
+}
+
+/* rb_cMetadata is the Metadata class whose instances proxy grpc_metadata. */
+VALUE rb_cMetadata = Qnil;
+void Init_google_rpc_metadata() {
+  rb_cMetadata = rb_define_class_under(rb_mGoogleRPC, "Metadata", rb_cObject);
+
+  /* Allocates an object managed by the ruby runtime */
+  rb_define_alloc_func(rb_cMetadata, grpc_rb_metadata_alloc);
+
+  /* Provides a ruby constructor and support for dup/clone. */
+  rb_define_method(rb_cMetadata, "initialize", grpc_rb_metadata_init, 2);
+  rb_define_method(rb_cMetadata, "initialize_copy", grpc_rb_metadata_init_copy,
+                   1);
+
+  /* Provides accessors for the code and details. */
+  rb_define_method(rb_cMetadata, "key", grpc_rb_metadata_key, 0);
+  rb_define_method(rb_cMetadata, "value", grpc_rb_metadata_value, 0);
+
+  id_key = rb_intern("__key");
+  id_value = rb_intern("__value");
+}
+
+/* Gets the wrapped metadata from the ruby wrapper */
+grpc_metadata* grpc_rb_get_wrapped_metadata(VALUE v) {
+  grpc_rb_metadata *wrapper = NULL;
+  Data_Get_Struct(v, grpc_rb_metadata, wrapper);
+  return wrapper->wrapped;
+}