Initial checkin of gRPC to third_party/

third_party/grpc/src/core/channel/channel_args.c

+/*
+ *
+ * Copyright 2015-2016, 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/grpc.h>
+#include "src/core/channel/channel_args.h"
+#include "src/core/support/string.h"
+
+#include <grpc/census.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
+
+#include <string.h>
+
+static grpc_arg copy_arg(const grpc_arg *src) {
+  grpc_arg dst;
+  dst.type = src->type;
+  dst.key = gpr_strdup(src->key);
+  switch (dst.type) {
+    case GRPC_ARG_STRING:
+      dst.value.string = gpr_strdup(src->value.string);
+      break;
+    case GRPC_ARG_INTEGER:
+      dst.value.integer = src->value.integer;
+      break;
+    case GRPC_ARG_POINTER:
+      dst.value.pointer = src->value.pointer;
+      dst.value.pointer.p =
+          src->value.pointer.vtable->copy(src->value.pointer.p);
+      break;
+  }
+  return dst;
+}
+
+grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
+                                                  const grpc_arg *to_add,
+                                                  size_t num_to_add) {
+  grpc_channel_args *dst = gpr_malloc(sizeof(grpc_channel_args));
+  size_t i;
+  size_t src_num_args = (src == NULL) ? 0 : src->num_args;
+  if (!src && !to_add) {
+    dst->num_args = 0;
+    dst->args = NULL;
+    return dst;
+  }
+  dst->num_args = src_num_args + num_to_add;
+  dst->args = gpr_malloc(sizeof(grpc_arg) * dst->num_args);
+  for (i = 0; i < src_num_args; i++) {
+    dst->args[i] = copy_arg(&src->args[i]);
+  }
+  for (i = 0; i < num_to_add; i++) {
+    dst->args[i + src_num_args] = copy_arg(&to_add[i]);
+  }
+  return dst;
+}
+
+grpc_channel_args *grpc_channel_args_copy(const grpc_channel_args *src) {
+  return grpc_channel_args_copy_and_add(src, NULL, 0);
+}
+
+grpc_channel_args *grpc_channel_args_merge(const grpc_channel_args *a,
+                                           const grpc_channel_args *b) {
+  return grpc_channel_args_copy_and_add(a, b->args, b->num_args);
+}
+
+static int cmp_arg(const grpc_arg *a, const grpc_arg *b) {
+  int c = GPR_ICMP(a->type, b->type);
+  if (c != 0) return c;
+  c = strcmp(a->key, b->key);
+  if (c != 0) return c;
+  switch (a->type) {
+    case GRPC_ARG_STRING:
+      return strcmp(a->value.string, b->value.string);
+    case GRPC_ARG_INTEGER:
+      return GPR_ICMP(a->value.integer, b->value.integer);
+    case GRPC_ARG_POINTER:
+      c = GPR_ICMP(a->value.pointer.p, b->value.pointer.p);
+      if (c != 0) {
+        c = GPR_ICMP(a->value.pointer.vtable, b->value.pointer.vtable);
+        if (c == 0) {
+          c = a->value.pointer.vtable->cmp(a->value.pointer.p,
+                                           b->value.pointer.p);
+        }
+      }
+      return c;
+  }
+  GPR_UNREACHABLE_CODE(return 0);
+}
+
+/* stabilizing comparison function: since channel_args ordering matters for
+ * keys with the same name, we need to preserve that ordering */
+static int cmp_key_stable(const void *ap, const void *bp) {
+  const grpc_arg *const *a = ap;
+  const grpc_arg *const *b = bp;
+  int c = strcmp((*a)->key, (*b)->key);
+  if (c == 0) c = GPR_ICMP(*a, *b);
+  return c;
+}
+
+grpc_channel_args *grpc_channel_args_normalize(const grpc_channel_args *a) {
+  grpc_arg **args = gpr_malloc(sizeof(grpc_arg *) * a->num_args);
+  for (size_t i = 0; i < a->num_args; i++) {
+    args[i] = &a->args[i];
+  }
+  qsort(args, a->num_args, sizeof(grpc_arg *), cmp_key_stable);
+
+  grpc_channel_args *b = gpr_malloc(sizeof(grpc_channel_args));
+  b->num_args = a->num_args;
+  b->args = gpr_malloc(sizeof(grpc_arg) * b->num_args);
+  for (size_t i = 0; i < a->num_args; i++) {
+    b->args[i] = copy_arg(args[i]);
+  }
+
+  gpr_free(args);
+  return b;
+}
+
+void grpc_channel_args_destroy(grpc_channel_args *a) {
+  size_t i;
+  for (i = 0; i < a->num_args; i++) {
+    switch (a->args[i].type) {
+      case GRPC_ARG_STRING:
+        gpr_free(a->args[i].value.string);
+        break;
+      case GRPC_ARG_INTEGER:
+        break;
+      case GRPC_ARG_POINTER:
+        a->args[i].value.pointer.vtable->destroy(a->args[i].value.pointer.p);
+        break;
+    }
+    gpr_free(a->args[i].key);
+  }
+  gpr_free(a->args);
+  gpr_free(a);
+}
+
+int grpc_channel_args_is_census_enabled(const grpc_channel_args *a) {
+  size_t i;
+  if (a == NULL) return 0;
+  for (i = 0; i < a->num_args; i++) {
+    if (0 == strcmp(a->args[i].key, GRPC_ARG_ENABLE_CENSUS)) {
+      return a->args[i].value.integer != 0 && census_enabled();
+    }
+  }
+  return census_enabled();
+}
+
+grpc_compression_algorithm grpc_channel_args_get_compression_algorithm(
+    const grpc_channel_args *a) {
+  size_t i;
+  if (a == NULL) return 0;
+  for (i = 0; i < a->num_args; ++i) {
+    if (a->args[i].type == GRPC_ARG_INTEGER &&
+        !strcmp(GRPC_COMPRESSION_ALGORITHM_ARG, a->args[i].key)) {
+      return (grpc_compression_algorithm)a->args[i].value.integer;
+      break;
+    }
+  }
+  return GRPC_COMPRESS_NONE;
+}
+
+grpc_channel_args *grpc_channel_args_set_compression_algorithm(
+    grpc_channel_args *a, grpc_compression_algorithm algorithm) {
+  grpc_arg tmp;
+  tmp.type = GRPC_ARG_INTEGER;
+  tmp.key = GRPC_COMPRESSION_ALGORITHM_ARG;
+  tmp.value.integer = algorithm;
+  return grpc_channel_args_copy_and_add(a, &tmp, 1);
+}
+
+/** Returns 1 if the argument for compression algorithm's enabled states bitset
+ * was found in \a a, returning the arg's value in \a states. Otherwise, returns
+ * 0. */
+static int find_compression_algorithm_states_bitset(const grpc_channel_args *a,
+                                                    int **states_arg) {
+  if (a != NULL) {
+    size_t i;
+    for (i = 0; i < a->num_args; ++i) {
+      if (a->args[i].type == GRPC_ARG_INTEGER &&
+          !strcmp(GRPC_COMPRESSION_ALGORITHM_STATE_ARG, a->args[i].key)) {
+        *states_arg = &a->args[i].value.integer;
+        return 1; /* GPR_TRUE */
+      }
+    }
+  }
+  return 0; /* GPR_FALSE */
+}
+
+grpc_channel_args *grpc_channel_args_compression_algorithm_set_state(
+    grpc_channel_args **a, grpc_compression_algorithm algorithm, int state) {
+  int *states_arg;
+  grpc_channel_args *result = *a;
+  const int states_arg_found =
+      find_compression_algorithm_states_bitset(*a, &states_arg);
+
+  if (states_arg_found) {
+    if (state != 0) {
+      GPR_BITSET((unsigned *)states_arg, algorithm);
+    } else {
+      GPR_BITCLEAR((unsigned *)states_arg, algorithm);
+    }
+  } else {
+    /* create a new arg */
+    grpc_arg tmp;
+    tmp.type = GRPC_ARG_INTEGER;
+    tmp.key = GRPC_COMPRESSION_ALGORITHM_STATE_ARG;
+    /* all enabled by default */
+    tmp.value.integer = (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1;
+    if (state != 0) {
+      GPR_BITSET((unsigned *)&tmp.value.integer, algorithm);
+    } else {
+      GPR_BITCLEAR((unsigned *)&tmp.value.integer, algorithm);
+    }
+    result = grpc_channel_args_copy_and_add(*a, &tmp, 1);
+    grpc_channel_args_destroy(*a);
+    *a = result;
+  }
+  return result;
+}
+
+int grpc_channel_args_compression_algorithm_get_states(
+    const grpc_channel_args *a) {
+  int *states_arg;
+  if (find_compression_algorithm_states_bitset(a, &states_arg)) {
+    return *states_arg;
+  } else {
+    return (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1; /* All algs. enabled */
+  }
+}
+
+int grpc_channel_args_compare(const grpc_channel_args *a,
+                              const grpc_channel_args *b) {
+  int c = GPR_ICMP(a->num_args, b->num_args);
+  if (c != 0) return c;
+  for (size_t i = 0; i < a->num_args; i++) {
+    c = cmp_arg(&a->args[i], &b->args[i]);
+    if (c != 0) return c;
+  }
+  return 0;
+}