GitHub user jianqiao opened a pull request:
https://github.com/apache/incubator-quickstep/pull/18
Fix a potential segfault in CompressedBlockBuilder
This PR fixes a potential bug in `CompressedBlockBuilder`. This fix is
necessary for a subsequent PR on `TextScanOperator` where each work order first
constructs a `ColumnVectorsValueAccessor` and then bulk insert the value
accessor into a `CompressedColumnStoreTupleStorageSubBlock`.
In the typical scenario, `CompressedBlockBuilder` first collects tuples
from a `ValueAccesor` into a `PtrVector<Tuple>` , then calls `buildDictionary`
to process the tuples. However, the collected tuples do not own the underlying
attribute values' **`out_of_line_data`** if the value is of `Char` or `VarChar`
type. This incurs segmentation fault if the `ValueAccessor` (which owns the
`out_of_line_data`) gets released before `buildDictionary` is completed.
The fix is just to ensure that the `PtrVector<Tuple>` owns the underlying
`out_of_line_data`.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/apache/incubator-quickstep
fix-compressed-block-builder-tuple-values-not-owned
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/incubator-quickstep/pull/18.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #18
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commit e95b312d665ea3e6b1353b62f1efca19c303d48e
Author: Jianqiao Zhu <[email protected]>
Date: 2016-06-09T05:43:16Z
Fix a potential segfault with CompressedBlockBuilder
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