sadikovi commented on a change in pull request #34611: URL: https://github.com/apache/spark/pull/34611#discussion_r754794034
########## File path: sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedPlainValuesReader.java ########## @@ -53,19 +53,47 @@ public void skip() { throw new UnsupportedOperationException(); } + private void updateCurrentByte() { + try { + currentByte = (byte) in.read(); + } catch (IOException e) { + throw new ParquetDecodingException("Failed to read a byte", e); + } + } + @Override public final void readBooleans(int total, WritableColumnVector c, int rowId) { - // TODO: properly vectorize this - for (int i = 0; i < total; i++) { - c.putBoolean(rowId + i, readBoolean()); + int i = 0; + if (bitOffset > 0) { + i = Math.min(8 - bitOffset, total); + c.putBooleans(rowId, i, currentByte, bitOffset); + bitOffset = (bitOffset + i) & 7; + } + for (; i + 7 < total; i += 8) { + updateCurrentByte(); + c.putBooleans(rowId + i, currentByte); + } + if (i < total) { + updateCurrentByte(); + bitOffset = total - i; + c.putBooleans(rowId + i, bitOffset, currentByte, 0); } } @Override public final void skipBooleans(int total) { - // TODO: properly vectorize this - for (int i = 0; i < total; i++) { - readBoolean(); + // using >>3 instead of /8 below since Java division rounds towards zero i.e. (-1)/8=0 Review comment: I should have clarified my comment - total should be larger than 8-bitOffset to skip at least 1 byte. Thanks for pointing it out. What I meant was that comment does not reflect the actual purpose of bit shift and is confusing. All you are trying to figure out is whether numBytesToSkip is positive or not so both approaches would work just fine. Bit shift tends to be faster than the division operation - I am not sure if JVM is smart enough to realise that these operations are equivalent in this case. By the way, shouldn't ``` if (bitOffset > 0) { updateCurrentByte(); } ``` be outside of the `if (numBytesToSkip >= 0) {`? In other words, what happens when the total is 9 and bitOffset is 0? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org