Github user rip-nsk commented on a diff in the pull request:
https://github.com/apache/orc/pull/273#discussion_r190921533
--- Diff: c++/src/RLEV2Util.hh ---
@@ -0,0 +1,145 @@
+/**
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements. See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership. The ASF licenses this file
+* to you 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 ORC_RLEV2UTIL_HH
+#define ORC_RLEV2UTIL_HH
+
+#include "RLEv2.hh"
+
+namespace orc {
+ inline uint32_t decodeBitWidth(uint32_t n) {
+ if (n <= FixedBitSizes::TWENTYFOUR) {
+ return n + 1;
+ } else if (n == FixedBitSizes::TWENTYSIX) {
+ return 26;
+ } else if (n == FixedBitSizes::TWENTYEIGHT) {
+ return 28;
+ } else if (n == FixedBitSizes::THIRTY) {
+ return 30;
+ } else if (n == FixedBitSizes::THIRTYTWO) {
+ return 32;
+ } else if (n == FixedBitSizes::FORTY) {
+ return 40;
+ } else if (n == FixedBitSizes::FORTYEIGHT) {
+ return 48;
+ } else if (n == FixedBitSizes::FIFTYSIX) {
+ return 56;
+ } else {
+ return 64;
+ }
+ }
+
+ inline uint32_t getClosestFixedBits(uint32_t n) {
+ if (n == 0) {
+ return 1;
+ }
+
+ if (n >= 1 && n <= 24) {
+ return n;
+ } else if (n <= 26) {
+ return 26;
+ } else if (n <= 28) {
+ return 28;
+ } else if (n <= 30) {
+ return 30;
+ } else if (n <= 32) {
+ return 32;
+ } else if (n <= 40) {
+ return 40;
+ } else if (n <= 48) {
+ return 48;
+ } else if (n <= 56) {
+ return 56;
+ } else {
+ return 64;
+ }
+ }
+
+ inline uint32_t getClosestAlignedFixedBits(uint32_t n) {
+ if (n == 0 || n == 1) {
+ return 1;
+ } else if (n <= 2) {
+ return 2;
+ } else if (n <= 4) {
+ return 4;
+ } else if (n <= 8) {
+ return 8;
+ } else if (n <= 16) {
+ return 16;
+ } else if (n <= 24) {
+ return 24;
+ } else if (n <= 32) {
+ return 32;
+ } else if (n <= 40) {
+ return 40;
+ } else if (n <= 48) {
+ return 48;
+ } else if (n <= 56) {
+ return 56;
+ } else {
+ return 64;
+ }
+ }
+
+ inline uint32_t encodeBitWidth(uint32_t n) {
+ n = getClosestFixedBits(n);
+
+ if (n >= 1 && n <= 24) {
+ return n - 1;
+ } else if (n <= 26) {
+ return FixedBitSizes::TWENTYSIX;
+ } else if (n <= 28) {
+ return FixedBitSizes::TWENTYEIGHT;
+ } else if (n <= 30) {
+ return FixedBitSizes::THIRTY;
+ } else if (n <= 32) {
+ return FixedBitSizes::THIRTYTWO;
+ } else if (n <= 40) {
+ return FixedBitSizes::FORTY;
+ } else if (n <= 48) {
+ return FixedBitSizes::FORTYEIGHT;
+ } else if (n <= 56) {
+ return FixedBitSizes::FIFTYSIX;
+ } else {
+ return FixedBitSizes::SIXTYFOUR;
+ }
+ }
+
+ inline uint32_t findClosestNumBits(int64_t value) {
+ if (value < 0) {
+ return getClosestFixedBits(64);
+ }
+
+ uint32_t count = 0;
+ while (value != 0) {
+ count++;
+ value = value >> 1;
+ }
+ return getClosestFixedBits(count);
+ }
+
+ inline bool isSafeSubtract(long left, long right) {
--- End diff --
s/long/int64_t
---
