Move sources into firebase::firestore and internal namespaces (#494)

* Move sources into firebase::firestore and internal namespaces

Combine support and core/util packages; this distinction wasn't really
paying its freight.

10 files changed, 336 insertions, 0 deletions

diff --git a/Firestore/core/.clang-format b/Firestore/core/.clang-format
new file mode 100644
index 0000000..7a0e321
--- /dev/null
+++ b/Firestore/core/.clang-format
@@ -0,0 +1,8 @@
+BasedOnStyle: Google
+Standard: Cpp11
+ColumnLimit: 80
+BinPackParameters: false
+AllowAllParametersOfDeclarationOnNextLine: true
+SpacesInContainerLiterals: true
+PointerAlignment: Left
+AllowShortFunctionsOnASingleLine: None
diff --git a/Firestore/core/src/firebase/firestore/base/port.h b/Firestore/core/src/firebase/firestore/base/port.h
new file mode 100644
index 0000000..37d1041
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/base/port.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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.
+ */
+
+#ifndef FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_
+#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_
+
+#if defined(__APPLE__)
+// On Apple platforms we support building via Cocoapods without CMake. When
+// building this way we can't test the presence of features so predefine all
+// the platform-support feature macros to their expected values.
+
+// All supported Apple platforms have arc4random(3).
+#define HAVE_ARC4RANDOM 1
+
+#else
+
+#error "Unknown platform."
+#endif  // defined(__APPLE__)
+
+#endif  // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_
diff --git a/Firestore/core/src/firebase/firestore/util/CMakeLists.txt b/Firestore/core/src/firebase/firestore/util/CMakeLists.txt
new file mode 100644
index 0000000..ce81363
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/util/CMakeLists.txt
@@ -0,0 +1,19 @@
+# Copyright 2017 Google
+#
+# 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.
+
+add_library(
+  firebase_firestore_util
+  autoid.cc
+  secure_random_arc4random.cc
+)
diff --git a/Firestore/core/src/firebase/firestore/util/autoid.cc b/Firestore/core/src/firebase/firestore/util/autoid.cc
new file mode 100644
index 0000000..10a2cde
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/util/autoid.cc
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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 "Firestore/core/src/firebase/firestore/util/autoid.h"
+
+#include <random>
+#include <string>
+
+#include "Firestore/core/src/firebase/firestore/util/secure_random.h"
+
+namespace firebase {
+namespace firestore {
+namespace util {
+
+namespace {
+
+const int kAutoIdLength = 20;
+const char kAutoIdAlphabet[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+
+SecureRandom shared_random;
+
+}  // namespace
+
+std::string CreateAutoId() {
+  std::string auto_id;
+  auto_id.reserve(kAutoIdLength);
+
+  // -2 here because:
+  //   * sizeof(kAutoIdAlphabet) includes the trailing null terminator
+  //   * uniform_int_distribution is inclusive on both sizes
+  std::uniform_int_distribution<int> letters(0, sizeof(kAutoIdAlphabet) - 2);
+
+  for (int i = 0; i < kAutoIdLength; i++) {
+    int rand_index = letters(shared_random);
+    auto_id.append(1, kAutoIdAlphabet[rand_index]);
+  }
+  return auto_id;
+}
+
+}  // namespace util
+}  // namespace firestore
+}  // namespace firebase
diff --git a/Firestore/core/src/firebase/firestore/util/autoid.h b/Firestore/core/src/firebase/firestore/util/autoid.h
new file mode 100644
index 0000000..22d7d7d
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/util/autoid.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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.
+ */
+
+#ifndef FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_AUTOID_H_
+#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_AUTOID_H_
+
+#include <string>
+
+namespace firebase {
+namespace firestore {
+namespace util {
+
+// Generates a random ID suitable for use as a document ID.
+std::string CreateAutoId();
+
+}  // namespace util
+}  // namespace firestore
+}  // namespace firebase
+
+#endif  // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_AUTOID_H_
diff --git a/Firestore/core/src/firebase/firestore/util/secure_random.h b/Firestore/core/src/firebase/firestore/util/secure_random.h
new file mode 100644
index 0000000..72be1bd
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/util/secure_random.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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.
+ */
+
+#ifndef FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_SECURE_RANDOM_H_
+#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_SECURE_RANDOM_H_
+
+#include <stdint.h>
+
+#include <limits>
+
+namespace firebase {
+namespace firestore {
+namespace util {
+
+// A "secure" pseudorandom number generator, suitable for generating
+// unguessable identifiers. This exists because
+//
+//   * std::mt19937 is blazing fast but its outputs can be guessed once enough
+//     previous outputs have been observed.
+//   * std::random_device isn't guaranteed to come from a secure PRNG or be
+//     fast.
+//
+// The implementation satisfies the C++11 UniformRandomBitGenerator concept and
+// delegates to an implementation that generates high quality random values
+// quickly with periodic reseeding.
+class SecureRandom {
+ public:
+  // C++11 UniformRandomBitGenerator interface
+  using result_type = uint32_t;
+
+  static constexpr result_type min() {
+    return std::numeric_limits<result_type>::min();
+  }
+
+  static constexpr result_type max() {
+    return std::numeric_limits<result_type>::max();
+  }
+
+  result_type operator()();
+};
+
+}  // namespace util
+}  // namespace firestore
+}  // namespace firebase
+
+#endif  // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_SECURE_RANDOM_H_
diff --git a/Firestore/core/src/firebase/firestore/util/secure_random_arc4random.cc b/Firestore/core/src/firebase/firestore/util/secure_random_arc4random.cc
new file mode 100644
index 0000000..a76ade3
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/util/secure_random_arc4random.cc
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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 "Firestore/core/src/firebase/firestore/util/secure_random.h"
+
+#include "Firestore/core/src/firebase/firestore/base/port.h"
+
+#if HAVE_ARC4RANDOM
+
+#include <stdlib.h>
+
+namespace firebase {
+namespace firestore {
+namespace util {
+
+SecureRandom::result_type SecureRandom::operator()() {
+  return arc4random();
+}
+
+}  // namespace util
+}  // namespace firestore
+}  // namespace firebase
+
+#endif  // HAVE_ARC4RANDOM
diff --git a/Firestore/core/test/firebase/firestore/util/CMakeLists.txt b/Firestore/core/test/firebase/firestore/util/CMakeLists.txt
new file mode 100644
index 0000000..223fa41
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/util/CMakeLists.txt
@@ -0,0 +1,23 @@
+# Copyright 2017 Google
+#
+# 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.
+
+cc_test(
+  firebase_firestore_util_test
+  autoid_test.cc
+  secure_random_test.cc
+)
+target_link_libraries(
+  firebase_firestore_util_test
+  firebase_firestore_util
+)
diff --git a/Firestore/core/test/firebase/firestore/util/autoid_test.cc b/Firestore/core/test/firebase/firestore/util/autoid_test.cc
new file mode 100644
index 0000000..730c683
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/util/autoid_test.cc
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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 "Firestore/core/src/firebase/firestore/util/autoid.h"
+
+#include <ctype.h>
+
+#include "gtest/gtest.h"
+
+using firebase::firestore::util::CreateAutoId;
+
+TEST(AutoId, IsSane) {
+  for (int i = 0; i < 50; i++) {
+    std::string auto_id = CreateAutoId();
+    EXPECT_EQ(20, auto_id.length());
+    for (int pos = 0; pos < 20; pos++) {
+      char c = auto_id[pos];
+      EXPECT_TRUE(isalpha(c) || isdigit(c))
+          << "Should be printable ascii character: '" << c << "' in \""
+          << auto_id << "\"";
+    }
+  }
+}
diff --git a/Firestore/core/test/firebase/firestore/util/secure_random_test.cc b/Firestore/core/test/firebase/firestore/util/secure_random_test.cc
new file mode 100644
index 0000000..f96f3de
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/util/secure_random_test.cc
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2017 Google
+ *
+ * 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 "Firestore/core/src/firebase/firestore/util/secure_random.h"
+
+#include "gtest/gtest.h"
+
+using firebase::firestore::util::SecureRandom;
+
+TEST(SecureRandomTest, ResultsAreBounded) {
+  SecureRandom rng;
+
+  // Verify that values are on the min/max closed interval.
+  for (int i = 0; i < 1000; i++) {
+    SecureRandom::result_type value = rng();
+    EXPECT_GE(value, rng.min());
+    EXPECT_LE(value, rng.max());
+  }
+}