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authorf0b0s <f0b0s@yandex-team.ru>2022-02-10 16:46:51 +0300
committerDaniil Cherednik <dcherednik@yandex-team.ru>2022-02-10 16:46:51 +0300
commitcdae02d225fb5b3afbb28990e79a7ac6c9125327 (patch)
tree49e222ea1c5804306084bb3ae065bb702625360f /contrib/libs/crcutil/rolling_crc.h
parentdeabc5260ac2e17b8f5152ee060bec1740613540 (diff)
downloadydb-cdae02d225fb5b3afbb28990e79a7ac6c9125327.tar.gz
Restoring authorship annotation for <f0b0s@yandex-team.ru>. Commit 2 of 2.
Diffstat (limited to 'contrib/libs/crcutil/rolling_crc.h')
-rw-r--r--contrib/libs/crcutil/rolling_crc.h212
1 files changed, 106 insertions, 106 deletions
diff --git a/contrib/libs/crcutil/rolling_crc.h b/contrib/libs/crcutil/rolling_crc.h
index 0de69d2bd8..ad4a947e49 100644
--- a/contrib/libs/crcutil/rolling_crc.h
+++ b/contrib/libs/crcutil/rolling_crc.h
@@ -1,106 +1,106 @@
-// Copyright 2010 Google Inc. All rights reserved.
-//
-// 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.
-
-// Implements rolling CRC (e.g. for Rabin fingerprinting).
-
-#ifndef CRCUTIL_ROLLING_CRC_H_
-#define CRCUTIL_ROLLING_CRC_H_
-
-#include "base_types.h" // size_t, uint8
-#include "crc_casts.h" // TO_BYTE
-
-namespace crcutil {
-
-#pragma pack(push, 16)
-
-// CrcImplementation should provide:
-// - typename Crc
-// - typename TableEntry
-// - typename Word
-// - Crc CrcDefault(const void *data, size_t bytes, const Crc &start)
-// - const GfUtil<Crc> &Base() const
-template<typename CrcImplementation> class RollingCrc {
- public:
- typedef typename CrcImplementation::Crc Crc;
- typedef typename CrcImplementation::TableEntry TableEntry;
- typedef typename CrcImplementation::Word Word;
-
- RollingCrc() {}
-
- // Initializes internal data structures.
- // Retains reference to "crc" instance -- it is used by Start().
- RollingCrc(const CrcImplementation &crc,
- size_t roll_window_bytes,
- const Crc &start_value) {
- Init(crc, roll_window_bytes, start_value);
- }
-
- // Computes crc of "roll_window_bytes" using
- // "start_value" of "crc" (see Init()).
- Crc Start(const void *data) const {
- return crc_->CrcDefault(data, roll_window_bytes_, start_value_);
- }
-
- // Computes CRC of "roll_window_bytes" starting in next position.
- Crc Roll(const Crc &old_crc, size_t byte_out, size_t byte_in) const {
- return (old_crc >> 8) ^ in_[TO_BYTE(old_crc) ^ byte_in] ^ out_[byte_out];
- }
-
- // Initializes internal data structures.
- // Retains reference to "crc" instance -- it is used by Start().
- void Init(const CrcImplementation &crc,
- size_t roll_window_bytes,
- const Crc &start_value) {
- crc_ = &crc;
- roll_window_bytes_ = roll_window_bytes;
- start_value_ = start_value;
-
- Crc add = crc.Base().Canonize() ^ start_value;
- add = crc.Base().Multiply(add, crc.Base().Xpow8N(roll_window_bytes));
- add ^= crc.Base().Canonize();
- Crc mul = crc.Base().One() ^ crc.Base().Xpow8N(1);
- add = crc.Base().Multiply(add, mul);
-
- mul = crc.Base().XpowN(8 * roll_window_bytes + crc.Base().Degree());
- for (size_t i = 0; i < 256; ++i) {
- out_[i] = static_cast<TableEntry>(
- crc.Base().MultiplyUnnormalized(
- static_cast<Crc>(i), 8, mul) ^ add);
- }
- for (size_t i = 0; i < 256; ++i) {
- in_[i] = crc.crc_word_[sizeof(Word) - 1][i];
- }
- }
-
- // Returns start value.
- Crc StartValue() const { return start_value_; }
-
- // Returns length of roll window.
- size_t WindowBytes() const { return roll_window_bytes_; }
-
- protected:
- TableEntry in_[256];
- TableEntry out_[256];
-
- // Used only by Start().
- Crc start_value_;
- const CrcImplementation *crc_;
- size_t roll_window_bytes_;
-} GCC_ALIGN_ATTRIBUTE(16);
-
-#pragma pack(pop)
-
-} // namespace crcutil
-
-#endif // CRCUTIL_ROLLING_CRC_H_
+// Copyright 2010 Google Inc. All rights reserved.
+//
+// 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.
+
+// Implements rolling CRC (e.g. for Rabin fingerprinting).
+
+#ifndef CRCUTIL_ROLLING_CRC_H_
+#define CRCUTIL_ROLLING_CRC_H_
+
+#include "base_types.h" // size_t, uint8
+#include "crc_casts.h" // TO_BYTE
+
+namespace crcutil {
+
+#pragma pack(push, 16)
+
+// CrcImplementation should provide:
+// - typename Crc
+// - typename TableEntry
+// - typename Word
+// - Crc CrcDefault(const void *data, size_t bytes, const Crc &start)
+// - const GfUtil<Crc> &Base() const
+template<typename CrcImplementation> class RollingCrc {
+ public:
+ typedef typename CrcImplementation::Crc Crc;
+ typedef typename CrcImplementation::TableEntry TableEntry;
+ typedef typename CrcImplementation::Word Word;
+
+ RollingCrc() {}
+
+ // Initializes internal data structures.
+ // Retains reference to "crc" instance -- it is used by Start().
+ RollingCrc(const CrcImplementation &crc,
+ size_t roll_window_bytes,
+ const Crc &start_value) {
+ Init(crc, roll_window_bytes, start_value);
+ }
+
+ // Computes crc of "roll_window_bytes" using
+ // "start_value" of "crc" (see Init()).
+ Crc Start(const void *data) const {
+ return crc_->CrcDefault(data, roll_window_bytes_, start_value_);
+ }
+
+ // Computes CRC of "roll_window_bytes" starting in next position.
+ Crc Roll(const Crc &old_crc, size_t byte_out, size_t byte_in) const {
+ return (old_crc >> 8) ^ in_[TO_BYTE(old_crc) ^ byte_in] ^ out_[byte_out];
+ }
+
+ // Initializes internal data structures.
+ // Retains reference to "crc" instance -- it is used by Start().
+ void Init(const CrcImplementation &crc,
+ size_t roll_window_bytes,
+ const Crc &start_value) {
+ crc_ = &crc;
+ roll_window_bytes_ = roll_window_bytes;
+ start_value_ = start_value;
+
+ Crc add = crc.Base().Canonize() ^ start_value;
+ add = crc.Base().Multiply(add, crc.Base().Xpow8N(roll_window_bytes));
+ add ^= crc.Base().Canonize();
+ Crc mul = crc.Base().One() ^ crc.Base().Xpow8N(1);
+ add = crc.Base().Multiply(add, mul);
+
+ mul = crc.Base().XpowN(8 * roll_window_bytes + crc.Base().Degree());
+ for (size_t i = 0; i < 256; ++i) {
+ out_[i] = static_cast<TableEntry>(
+ crc.Base().MultiplyUnnormalized(
+ static_cast<Crc>(i), 8, mul) ^ add);
+ }
+ for (size_t i = 0; i < 256; ++i) {
+ in_[i] = crc.crc_word_[sizeof(Word) - 1][i];
+ }
+ }
+
+ // Returns start value.
+ Crc StartValue() const { return start_value_; }
+
+ // Returns length of roll window.
+ size_t WindowBytes() const { return roll_window_bytes_; }
+
+ protected:
+ TableEntry in_[256];
+ TableEntry out_[256];
+
+ // Used only by Start().
+ Crc start_value_;
+ const CrcImplementation *crc_;
+ size_t roll_window_bytes_;
+} GCC_ALIGN_ATTRIBUTE(16);
+
+#pragma pack(pop)
+
+} // namespace crcutil
+
+#endif // CRCUTIL_ROLLING_CRC_H_