Sync from upstream.

Descriptions:
======================================================================
Export Icing logging control to JNI
======================================================================
Prepare Icing logging class for JNI export
======================================================================
Export getDebugInfo to JNI
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Expose the return_deleted_document_info parameter for deleteByQuery JNI
======================================================================
Enable runtime log control for Icing Library
======================================================================
Fix 1 ClangTidyBuild finding:
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Update comments to run benchmarks.
======================================================================
Making icing's own logging class
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Convert the string lexicon debug information to a protocol buffer
======================================================================
Fix issue with printing fingerprinted key in our error logs.
======================================================================
Support dump function for IcingSearchEngine
======================================================================

Bug: 146903474
Bug: 229778472
Bug: 209071710
Bug: 222349894
Bug: 225914361
Change-Id: I9750149d1ed0b59f345b8828ff312a62773667fe

1 files changed, 47 insertions, 0 deletions

diff --git a/icing/util/fingerprint-util.h b/icing/util/fingerprint-util.h
new file mode 100644
index 0000000..9e98617
--- /dev/null
+++ b/icing/util/fingerprint-util.h
@@ -0,0 +1,47 @@
+// Copyright (C) 2022 Google LLC
+//
+// 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 ICING_UTIL_FINGERPRINT_UTIL_H_
+#define ICING_UTIL_FINGERPRINT_UTIL_H_
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+
+namespace icing {
+namespace lib {
+
+namespace fingerprint_util {
+
+// Converts from a fingerprint to a fingerprint string.
+std::string GetFingerprintString(uint64_t fingerprint);
+
+// Converts from a fingerprint string to a fingerprint.
+uint64_t GetFingerprint(std::string_view fingerprint_string);
+
+// A formatter to properly handle a string that is actually just a hash value.
+class FingerprintStringFormatter {
+ public:
+  std::string operator()(std::string_view fingerprint_string) {
+    uint64_t fingerprint = GetFingerprint(fingerprint_string);
+    return std::to_string(fingerprint);
+  }
+};
+
+}  // namespace fingerprint_util
+
+}  // namespace lib
+}  // namespace icing
+
+#endif  // ICING_UTIL_FINGERPRINT_UTIL_H_