1 files changed, 401 insertions, 0 deletions
diff --git a/src/core/lib/channel/channel_args.cc b/src/core/lib/channel/channel_args.cc
new file mode 100644
index 0000000000..101a6fffbc
--- /dev/null
+++ b/src/core/lib/channel/channel_args.cc
@@ -0,0 +1,401 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include <limits.h>
+#include <string.h>
+
+#include <grpc/compression.h>
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/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) {
+  return grpc_channel_args_copy_and_add_and_remove(src, nullptr, 0, to_add,
+                                                   num_to_add);
+}
+
+grpc_channel_args* grpc_channel_args_copy_and_remove(
+    const grpc_channel_args* src, const char** to_remove,
+    size_t num_to_remove) {
+  return grpc_channel_args_copy_and_add_and_remove(src, to_remove,
+                                                   num_to_remove, nullptr, 0);
+}
+
+static bool should_remove_arg(const grpc_arg* arg, const char** to_remove,
+                              size_t num_to_remove) {
+  for (size_t i = 0; i < num_to_remove; ++i) {
+    if (strcmp(arg->key, to_remove[i]) == 0) return true;
+  }
+  return false;
+}
+
+grpc_channel_args* grpc_channel_args_copy_and_add_and_remove(
+    const grpc_channel_args* src, const char** to_remove, size_t num_to_remove,
+    const grpc_arg* to_add, size_t num_to_add) {
+  // Figure out how many args we'll be copying.
+  size_t num_args_to_copy = 0;
+  if (src != nullptr) {
+    for (size_t i = 0; i < src->num_args; ++i) {
+      if (!should_remove_arg(&src->args[i], to_remove, num_to_remove)) {
+        ++num_args_to_copy;
+      }
+    }
+  }
+  // Create result.
+  grpc_channel_args* dst =
+      (grpc_channel_args*)gpr_malloc(sizeof(grpc_channel_args));
+  dst->num_args = num_args_to_copy + num_to_add;
+  if (dst->num_args == 0) {
+    dst->args = nullptr;
+    return dst;
+  }
+  dst->args = (grpc_arg*)gpr_malloc(sizeof(grpc_arg) * dst->num_args);
+  // Copy args from src that are not being removed.
+  size_t dst_idx = 0;
+  if (src != nullptr) {
+    for (size_t i = 0; i < src->num_args; ++i) {
+      if (!should_remove_arg(&src->args[i], to_remove, num_to_remove)) {
+        dst->args[dst_idx++] = copy_arg(&src->args[i]);
+      }
+    }
+  }
+  // Add args from to_add.
+  for (size_t i = 0; i < num_to_add; ++i) {
+    dst->args[dst_idx++] = copy_arg(&to_add[i]);
+  }
+  GPR_ASSERT(dst_idx == dst->num_args);
+  return dst;
+}
+
+grpc_channel_args* grpc_channel_args_copy(const grpc_channel_args* src) {
+  return grpc_channel_args_copy_and_add(src, nullptr, 0);
+}
+
+grpc_channel_args* grpc_channel_args_union(const grpc_channel_args* a,
+                                           const grpc_channel_args* b) {
+  const size_t max_out = (a->num_args + b->num_args);
+  grpc_arg* uniques = (grpc_arg*)gpr_malloc(sizeof(*uniques) * max_out);
+  for (size_t i = 0; i < a->num_args; ++i) uniques[i] = a->args[i];
+
+  size_t uniques_idx = a->num_args;
+  for (size_t i = 0; i < b->num_args; ++i) {
+    const char* b_key = b->args[i].key;
+    if (grpc_channel_args_find(a, b_key) == nullptr) {  // not found
+      uniques[uniques_idx++] = b->args[i];
+    }
+  }
+  grpc_channel_args* result =
+      grpc_channel_args_copy_and_add(nullptr, uniques, uniques_idx);
+  gpr_free(uniques);
+  return result;
+}
+
+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 = (const grpc_arg* const*)ap;
+  const grpc_arg* const* b = (const grpc_arg* const*)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 = (grpc_arg**)gpr_malloc(sizeof(grpc_arg*) * a->num_args);
+  for (size_t i = 0; i < a->num_args; i++) {
+    args[i] = &a->args[i];
+  }
+  if (a->num_args > 1)
+    qsort(args, a->num_args, sizeof(grpc_arg*), cmp_key_stable);
+
+  grpc_channel_args* b =
+      (grpc_channel_args*)gpr_malloc(sizeof(grpc_channel_args));
+  b->num_args = a->num_args;
+  b->args = (grpc_arg*)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;
+  if (!a) return;
+  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);
+}
+
+grpc_compression_algorithm grpc_channel_args_get_compression_algorithm(
+    const grpc_channel_args* a) {
+  size_t i;
+  if (a == nullptr) return GRPC_COMPRESS_NONE;
+  for (i = 0; i < a->num_args; ++i) {
+    if (a->args[i].type == GRPC_ARG_INTEGER &&
+        !strcmp(GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM, 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) {
+  GPR_ASSERT(algorithm < GRPC_COMPRESS_ALGORITHMS_COUNT);
+  grpc_arg tmp;
+  tmp.type = GRPC_ARG_INTEGER;
+  tmp.key = (char*)GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM;
+  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 != nullptr) {
+    size_t i;
+    for (i = 0; i < a->num_args; ++i) {
+      if (a->args[i].type == GRPC_ARG_INTEGER &&
+          !strcmp(GRPC_COMPRESSION_CHANNEL_ENABLED_ALGORITHMS_BITSET,
+                  a->args[i].key)) {
+        *states_arg = &a->args[i].value.integer;
+        **states_arg |= 0x1; /* forcefully enable support for no compression */
+        return 1;
+      }
+    }
+  }
+  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 = nullptr;
+  grpc_channel_args* result = *a;
+  const int states_arg_found =
+      find_compression_algorithm_states_bitset(*a, &states_arg);
+
+  if (grpc_channel_args_get_compression_algorithm(*a) == algorithm &&
+      state == 0) {
+    const char* algo_name = nullptr;
+    GPR_ASSERT(grpc_compression_algorithm_name(algorithm, &algo_name) != 0);
+    gpr_log(GPR_ERROR,
+            "Tried to disable default compression algorithm '%s'. The "
+            "operation has been ignored.",
+            algo_name);
+  } else if (states_arg_found) {
+    if (state != 0) {
+      GPR_BITSET((unsigned*)states_arg, algorithm);
+    } else if (algorithm != GRPC_COMPRESS_NONE) {
+      GPR_BITCLEAR((unsigned*)states_arg, algorithm);
+    }
+  } else {
+    /* create a new arg */
+    grpc_arg tmp;
+    tmp.type = GRPC_ARG_INTEGER;
+    tmp.key = (char*)GRPC_COMPRESSION_CHANNEL_ENABLED_ALGORITHMS_BITSET;
+    /* all enabled by default */
+    tmp.value.integer = (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1;
+    if (state != 0) {
+      GPR_BITSET((unsigned*)&tmp.value.integer, algorithm);
+    } else if (algorithm != GRPC_COMPRESS_NONE) {
+      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;
+}
+
+uint32_t 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 (uint32_t)*states_arg;
+  } else {
+    return (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1; /* All algs. enabled */
+  }
+}
+
+grpc_channel_args* grpc_channel_args_set_socket_mutator(
+    grpc_channel_args* a, grpc_socket_mutator* mutator) {
+  grpc_arg tmp = grpc_socket_mutator_to_arg(mutator);
+  return grpc_channel_args_copy_and_add(a, &tmp, 1);
+}
+
+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;
+}
+
+const grpc_arg* grpc_channel_args_find(const grpc_channel_args* args,
+                                       const char* name) {
+  if (args != nullptr) {
+    for (size_t i = 0; i < args->num_args; ++i) {
+      if (strcmp(args->args[i].key, name) == 0) {
+        return &args->args[i];
+      }
+    }
+  }
+  return nullptr;
+}
+
+int grpc_channel_arg_get_integer(const grpc_arg* arg,
+                                 const grpc_integer_options options) {
+  if (arg == nullptr) return options.default_value;
+  if (arg->type != GRPC_ARG_INTEGER) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be an integer", arg->key);
+    return options.default_value;
+  }
+  if (arg->value.integer < options.min_value) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be >= %d", arg->key,
+            options.min_value);
+    return options.default_value;
+  }
+  if (arg->value.integer > options.max_value) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be <= %d", arg->key,
+            options.max_value);
+    return options.default_value;
+  }
+  return arg->value.integer;
+}
+
+bool grpc_channel_arg_get_bool(const grpc_arg* arg, bool default_value) {
+  if (arg == nullptr) return default_value;
+  if (arg->type != GRPC_ARG_INTEGER) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be an integer", arg->key);
+    return default_value;
+  }
+  switch (arg->value.integer) {
+    case 0:
+      return false;
+    case 1:
+      return true;
+    default:
+      gpr_log(GPR_ERROR, "%s treated as bool but set to %d (assuming true)",
+              arg->key, arg->value.integer);
+      return true;
+  }
+}
+
+bool grpc_channel_args_want_minimal_stack(const grpc_channel_args* args) {
+  return grpc_channel_arg_get_bool(
+      grpc_channel_args_find(args, GRPC_ARG_MINIMAL_STACK), false);
+}
+
+grpc_arg grpc_channel_arg_string_create(char* name, char* value) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_STRING;
+  arg.key = name;
+  arg.value.string = value;
+  return arg;
+}
+
+grpc_arg grpc_channel_arg_integer_create(char* name, int value) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_INTEGER;
+  arg.key = name;
+  arg.value.integer = value;
+  return arg;
+}
+
+grpc_arg grpc_channel_arg_pointer_create(
+    char* name, void* value, const grpc_arg_pointer_vtable* vtable) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = name;
+  arg.value.pointer.p = value;
+  arg.value.pointer.vtable = vtable;
+  return arg;
+}