/*
* 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.
*/
package com.facebook.presto.orc.stream;
import java.io.IOException;
import java.io.InputStream;
public final class TestingBitPackingUtils
{
private TestingBitPackingUtils() {}
// Old implementation of bit unpacking code from Hive ORC reader
public static void unpackGeneric(long[] buffer, int offset, int len, int bitSize, InputStream input)
throws IOException
{
int bitsLeft = 0;
int current = 0;
for (int i = offset; i < (offset + len); i++) {
long result = 0;
int bitsLeftToRead = bitSize;
while (bitsLeftToRead > bitsLeft) {
result <<= bitsLeft;
result |= current & ((1 << bitsLeft) - 1);
bitsLeftToRead -= bitsLeft;
current = input.read();
bitsLeft = 8;
}
// handle the left over bits
if (bitsLeftToRead > 0) {
result <<= bitsLeftToRead;
bitsLeft -= bitsLeftToRead;
result |= (current >> bitsLeft) & ((1 << bitsLeftToRead) - 1);
}
buffer[i] = result;
}
}
}