SERVER-22374 initial implementation of collation classes

Includes:
 - CollationSpec
 - CollationSpecSerializer
 - CollatorInterface
 - CollatorInterfaceICU
 - CollatorFactoryInterface
 - CollatorFactoryICU

1 files changed, 100 insertions, 0 deletions

diff --git a/src/mongo/db/query/collation/collator_factory_icu.cpp b/src/mongo/db/query/collation/collator_factory_icu.cpp
new file mode 100644
index 00000000000..190960f6515
--- /dev/null
+++ b/src/mongo/db/query/collation/collator_factory_icu.cpp
@@ -0,0 +1,100 @@
+/**
+ *    Copyright (C) 2016 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/query/collation/collator_factory_icu.h"
+
+#include <unicode/errorcode.h>
+
+#include "mongo/bson/bsonobj.h"
+#include "mongo/db/query/collation/collator_interface_icu.h"
+#include "mongo/stdx/memory.h"
+#include "mongo/util/mongoutils/str.h"
+
+namespace mongo {
+
+namespace {
+
+// Extracts the collation options from 'spec' and performs basic validation.
+//
+// Validation or normalization requiring the ICU library is done later.
+StatusWith<CollationSpec> parseToCollationSpec(const BSONObj& spec) {
+    CollationSpec parsedSpec;
+
+    for (auto elem : spec) {
+        if (str::equals(CollationSpec::kLocaleField, elem.fieldName())) {
+            if (elem.type() != BSONType::String) {
+                return {ErrorCodes::FailedToParse,
+                        str::stream() << "Field '" << CollationSpec::kLocaleField
+                                      << "' must be of type string in: " << spec};
+            }
+
+            parsedSpec.localeID = elem.String();
+        } else {
+            return {ErrorCodes::FailedToParse,
+                    str::stream() << "Unknown collation spec field: " << elem.fieldName()};
+        }
+    }
+
+    if (parsedSpec.localeID.empty()) {
+        return {ErrorCodes::FailedToParse, str::stream() << "Missing locale string"};
+    }
+
+    return parsedSpec;
+}
+
+}  // namespace
+
+StatusWith<std::unique_ptr<CollatorInterface>> CollatorFactoryICU::makeFromBSON(
+    const BSONObj& spec) {
+    auto parsedSpec = parseToCollationSpec(spec);
+    if (!parsedSpec.isOK()) {
+        return parsedSpec.getStatus();
+    }
+
+    // TODO SERVER-22373: use ICU to validate and normalize locale string. As part of this work, we
+    // should add unit test coverage for both locale string validation and normalization.
+    auto locale = icu::Locale::createFromName(parsedSpec.getValue().localeID.c_str());
+
+    UErrorCode status = U_ZERO_ERROR;
+    std::unique_ptr<icu::Collator> icuCollator(icu::Collator::createInstance(locale, status));
+    if (U_FAILURE(status)) {
+        icu::ErrorCode icuError;
+        icuError.set(status);
+        return {ErrorCodes::OperationFailed,
+                str::stream() << "Failed to create collator: " << icuError.errorName()
+                              << ". Collation spec: " << spec};
+    }
+
+    auto mongoCollator = stdx::make_unique<CollatorInterfaceICU>(std::move(parsedSpec.getValue()),
+                                                                 std::move(icuCollator));
+    return {std::move(mongoCollator)};
+}
+
+}  // namespace mongo