stiga-huang commented on a change in pull request #1056:
URL: https://github.com/apache/orc/pull/1056#discussion_r822592473
##
File path: c++/src/RleDecoderV2.cc
##
@@ -703,80 +680,61 @@ uint64_t RleDecoderV2::nextDelta(int64_t* const data,
runLength = static_cast(firstByte & 0x01) << 8;
runLength |= readByte();
++runLength; // account for first value
-runRead = deltaBase = 0;
+runRead = 0;
+int64_t prevValue;
// read the first value stored as vint
if (isSigned) {
- firstValue = static_cast(readVslong());
+ prevValue = readVslong();
} else {
- firstValue = static_cast(readVulong());
+ prevValue = static_cast(readVulong());
}
-prevValue = firstValue;
+literals[0] = prevValue;
// read the fixed delta value stored as vint (deltas can be negative even
// if all number are positive)
-deltaBase = static_cast(readVslong());
- }
-
- uint64_t nRead = std::min(runLength - runRead, numValues);
-
- uint64_t pos = offset;
- for ( ; pos < offset + nRead; ++pos) {
-// skip null positions
-if (!notNull || notNull[pos]) break;
- }
- if (runRead == 0 && pos < offset + nRead) {
-data[pos++] = firstValue;
-++runRead;
- }
-
- if (bitSize == 0) {
-// add fixed deltas to adjacent values
-for ( ; pos < offset + nRead; ++pos) {
- // skip null positions
- if (notNull && !notNull[pos]) {
-continue;
- }
- prevValue = data[pos] = prevValue + deltaBase;
- ++runRead;
-}
- } else {
-for ( ; pos < offset + nRead; ++pos) {
- // skip null positions
- if (!notNull || notNull[pos]) break;
-}
-if (runRead < 2 && pos < offset + nRead) {
- // add delta base and first value
- prevValue = data[pos++] = firstValue + deltaBase;
- ++runRead;
-}
+int64_t deltaBase = readVslong();
-// write the unpacked values, add it to previous value and store final
-// value to result buffer. if the delta base value is negative then it
-// is a decreasing sequence else an increasing sequence
-uint64_t remaining = (offset + nRead) - pos;
-runRead += readLongs(data, pos, remaining, bitSize, notNull);
-
-if (deltaBase < 0) {
- for ( ; pos < offset + nRead; ++pos) {
-// skip null positions
-if (notNull && !notNull[pos]) {
- continue;
-}
-prevValue = data[pos] = prevValue - data[pos];
+if (bitSize == 0) {
+ // add fixed deltas to adjacent values
+ for (uint64_t i = 1; i < runLength; ++i) {
+prevValue = literals[i] = prevValue + deltaBase;
}
} else {
- for ( ; pos < offset + nRead; ++pos) {
-// skip null positions
-if (notNull && !notNull[pos]) {
- continue;
+ prevValue = literals[1] = prevValue + deltaBase;
+ // write the unpacked values, add it to previous value and store final
+ // value to result buffer. if the delta base value is negative then it
+ // is a decreasing sequence else an increasing sequence
+ readLongs(literals.data(), 2, runLength - 2, bitSize);
+ if (deltaBase < 0) {
+for (uint64_t i = 2; i < runLength; ++i) {
+ prevValue = literals[i] = prevValue - literals[i];
+}
+ } else {
+for (uint64_t i = 2; i < runLength; ++i) {
+ prevValue = literals[i] = prevValue + literals[i];
}
-prevValue = data[pos] = prevValue + data[pos];
}
}
}
- return nRead;
+
+ return copyDataFromBuffer(data, offset, numValues, notNull);
}
+uint64_t RleDecoderV2::copyDataFromBuffer(int64_t* data, uint64_t offset,
+ uint64_t numValues, const char*
notNull) {
+ uint64_t nRead = std::min(runLength - runRead, numValues);
+ if (notNull) {
+for (uint64_t i = offset; i < (offset + nRead); ++i) {
+ if (notNull[i]) {
+data[i] = literals[runRead++];
+ }
+}
+ } else {
+memcpy(data + offset, literals.data() + runRead, nRead * sizeof(int64_t));
+runRead += nRead;
+ }
+ return nRead;
+}
Review comment:
Done.
##
File path: c++/src/RleDecoderV2.cc
##
@@ -703,80 +680,61 @@ uint64_t RleDecoderV2::nextDelta(int64_t* const data,
runLength = static_cast(firstByte & 0x01) << 8;
runLength |= readByte();
++runLength; // account for first value
-runRead = deltaBase = 0;
+runRead = 0;
+int64_t prevValue;
// read the first value stored as vint
if (isSigned) {
- firstValue = static_cast(readVslong());
+ prevValue = readVslong();
} else {
- firstValue = static_cast(readVulong());
+ prevValue = static_cast(readVulong());
}
-prevValue = firstValue;
+literals[0] = prevValue;
// read the fixed delta value stored as vint (deltas can be negative even
// if all number are positive)
-deltaBase = static_cast(readVslong());
- }
-
- uint64_t nRead = std
