ggershinsky commented on a change in pull request #925:
URL: https://github.com/apache/parquet-mr/pull/925#discussion_r699207678
##########
File path:
parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
##########
@@ -1226,12 +1226,25 @@ public ParquetMetadata readParquetMetadata(InputStream
from) throws IOException
static FileMetaData filterFileMetaDataByMidpoint(FileMetaData metaData,
RangeMetadataFilter filter) {
List<RowGroup> rowGroups = metaData.getRow_groups();
List<RowGroup> newRowGroups = new ArrayList<RowGroup>();
+ long preStartIndex = 0;
+ long preCompressedSize = 0;
for (RowGroup rowGroup : rowGroups) {
long totalSize = 0;
long startIndex;
-
if (rowGroup.isSetFile_offset()) {
- startIndex = rowGroup.getFile_offset();
+ assert rowGroup.isSetTotal_compressed_size();
+
+ if (preStartIndex == 0) {
+ //the first block always holds the truth
+ startIndex = rowGroup.getFile_offset();
+ } else {
+ //calculate offset for other blocks
Review comment:
Could you expand the comment a bit, to briefly explain the problem?
(maybe with mentioning the jira number). To help ensure future changes don't
revert this to the more intuitive getFile_offset().
##########
File path:
parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
##########
@@ -201,9 +201,23 @@ public FileMetaData toParquetMetadata(int currentVersion,
ParquetMetadata parque
List<BlockMetaData> blocks = parquetMetadata.getBlocks();
List<RowGroup> rowGroups = new ArrayList<RowGroup>();
long numRows = 0;
+ long preBlockStartPos = 0;
+ long preBlockCompressedSize = 0;
for (BlockMetaData block : blocks) {
numRows += block.getRowCount();
+ long blockStartPos = block.getStartingPos();
+ // first block
+ if (blockStartPos == 4) {
Review comment:
why this check is necessary, doesn't the first block always start at 4?
Or this addresses a file merging usecase?
##########
File path:
parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
##########
@@ -1254,14 +1276,41 @@ static FileMetaData
filterFileMetaDataByMidpoint(FileMetaData metaData, RangeMet
return metaData;
}
+ private static long tryUseFileOffset(RowGroup rowGroup, long preStartIndex,
long preCompressedSize) {
+ long startIndex = 0;
+ startIndex = rowGroup.getFile_offset();
+ // skip checking the first rowGroup
+ // (in case of summary file, there are multiple first groups from
different footers)
+ if (preStartIndex != 0 && preStartIndex <= startIndex) {
+
+ //calculate start index for other blocks
+ long minStartIndex = preStartIndex + preCompressedSize;
+ if (startIndex < minStartIndex) {
+ // a bad offset detected, try first column's offset
+ // can not use minStartIndex in case of padding
+ startIndex = getOffset(rowGroup.getColumns().get(0));
Review comment:
this will throw an exception in encrypted files.
##########
File path:
parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
##########
@@ -201,9 +201,23 @@ public FileMetaData toParquetMetadata(int currentVersion,
ParquetMetadata parque
List<BlockMetaData> blocks = parquetMetadata.getBlocks();
List<RowGroup> rowGroups = new ArrayList<RowGroup>();
long numRows = 0;
+ long preBlockStartPos = 0;
+ long preBlockCompressedSize = 0;
for (BlockMetaData block : blocks) {
numRows += block.getRowCount();
+ long blockStartPos = block.getStartingPos();
+ // first block
+ if (blockStartPos == 4) {
+ preBlockStartPos = 0;
+ preBlockCompressedSize = 0;
+ }
+ if (preBlockStartPos != 0) {
+ assert blockStartPos >= preBlockStartPos + preBlockCompressedSize;
Review comment:
why >= instead of == ?
##########
File path:
parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
##########
@@ -1254,14 +1276,41 @@ static FileMetaData
filterFileMetaDataByMidpoint(FileMetaData metaData, RangeMet
return metaData;
}
+ private static long tryUseFileOffset(RowGroup rowGroup, long preStartIndex,
long preCompressedSize) {
+ long startIndex = 0;
+ startIndex = rowGroup.getFile_offset();
+ // skip checking the first rowGroup
+ // (in case of summary file, there are multiple first groups from
different footers)
+ if (preStartIndex != 0 && preStartIndex <= startIndex) {
+
+ //calculate start index for other blocks
+ long minStartIndex = preStartIndex + preCompressedSize;
+ if (startIndex < minStartIndex) {
+ // a bad offset detected, try first column's offset
+ // can not use minStartIndex in case of padding
+ startIndex = getOffset(rowGroup.getColumns().get(0));
Review comment:
got it, will check a few things
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