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Posted to issues@drill.apache.org by "ASF GitHub Bot (JIRA)" <ji...@apache.org> on 2017/12/13 16:25:00 UTC
[jira] [Commented] (DRILL-6028) Allow splitting generated code in
ChainedHashTable into blocks to avoid "code too large" error
[ https://issues.apache.org/jira/browse/DRILL-6028?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16289472#comment-16289472 ]
ASF GitHub Bot commented on DRILL-6028:
---------------------------------------
GitHub user arina-ielchiieva opened a pull request:
https://github.com/apache/drill/pull/1071
DRILL-6028: Allow splitting generated code in ChainedHashTable into b…
…locks to avoid "code too large" error
1. Added new parameter seedValue to getHashBuild and getHashProbe methods in HashTableTemplate.
2. Generate logical expression for each key so its can be split into blocks if number of expressions in method exceeds upper limit.
3. ParameterExpression was added to generate reference to method parameter during code generation.
Details in [DRILL-6028](https://issues.apache.org/jira/browse/DRILL-6028)
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/arina-ielchiieva/drill DRILL-6028
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/drill/pull/1071.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 #1071
----
commit 90dbd2db96bed8fa3cd3dab7575aadab240a621c
Author: Arina Ielchiieva <ar...@gmail.com>
Date: 2017-12-12T16:45:57Z
DRILL-6028: Allow splitting generated code in ChainedHashTable into blocks to avoid "code too large" error
1. Added new parameter seedValue to getHashBuild and getHashProbe methods in HashTableTemplate.
2. Generate logical expression for each key so its can be split into blocks if number of expressions in method exceeds upper limit.
3. ParameterExpression was added to generate reference to method parameter during code generation.
----
> Allow splitting generated code in ChainedHashTable into blocks to avoid "code too large" error
> ----------------------------------------------------------------------------------------------
>
> Key: DRILL-6028
> URL: https://issues.apache.org/jira/browse/DRILL-6028
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.10.0
> Reporter: Arina Ielchiieva
> Assignee: Arina Ielchiieva
> Fix For: 1.13.0
>
>
> Allow splitting generated code in ChainedHashTable into blocks to avoid "code too large" error.
> *REPRODUCE*
> File {{1200_columns.csv}}
> {noformat}
> 0,1,2,3...1200
> 0,1,2,3...1200
> {noformat}
> Query
> {noformat}
> select columns[0], column[1]...columns[1200] from dfs.`1200_columns.csv`
> union
> select columns[0], column[1]...columns[1200] from dfs.`1200_columns.csv`
> {noformat}
> Error
> {noformat}
> Error: SYSTEM ERROR: CompileException: File 'org.apache.drill.exec.compile.DrillJavaFileObject[HashTableGen10.java]', Line -7886, Column 24: HashTableGen10.java:57650: error: code too large
> public boolean isKeyMatchInternalBuild(int incomingRowIdx, int htRowIdx)
> ^ (compiler.err.limit.code)
> {noformat}
> *ROOT CAUSE*
> DRILL-4715 added ability to ensure that methods size won't go beyond the 64k limit imposed by JVM. {{BlkCreateMode.TRUE_IF_BOUND}} was added to create new block only if # of expressions added hit upper-bound defined by {{exec.java.compiler.exp_in_method_size}}. Once number of expressions in methods hits upper bound we create from call inner method.
> Example:
> {noformat}
> public void doSetup(RecordBatch incomingBuild, RecordBatch incomingProbe) throws SchemaChangeException {
> // some logic
> return doSetup0(incomingBuild, incomingProbe);
> }
> {noformat}
> During code generation {{ChainedHashTable}} added all code in its methods in one block (using {{BlkCreateMode.FALSE}}) since {{getHashBuild}} and {{getHashProbe}} methods contained state and thus could not be split. In these methods hash was generated for each key expression. For the first key seed was 0, subsequent keys hash was generated based on seed from previous key.
> To allow splitting for there methods the following was done:
> 1. Method signatures was changed: added new parameter {{seedValue}}. Initially starting seed value was hard-coded during code generation (set to 0), now it is passed as method parameter.
> 2. Initially hash function call for all keys was transformed into one logical expression which did not allow splitting. Now we create logical expression for each key and thus splitting is possible. New {{seedValue}} parameter is used as seed holder to pass seed value for the next key.
> 3. {{ParameterExpression}} was added to generate reference to method parameter during code generation.
> Code example:
> {noformat}
> public int getHashBuild(int incomingRowIdx, int seedValue)
> throws SchemaChangeException
> {
> {
> NullableVarCharHolder out3 = new NullableVarCharHolder();
> {
> out3 .isSet = vv0 .getAccessor().isSet((incomingRowIdx));
> if (out3 .isSet == 1) {
> out3 .buffer = vv0 .getBuffer();
> long startEnd = vv0 .getAccessor().getStartEnd((incomingRowIdx));
> out3 .start = ((int) startEnd);
> out3 .end = ((int)(startEnd >> 32));
> }
> }
> IntHolder seedValue4 = new IntHolder();
> seedValue4 .value = seedValue;
> //---- start of eval portion of hash32 function. ----//
> IntHolder out5 = new IntHolder();
> {
> final IntHolder out = new IntHolder();
> NullableVarCharHolder in = out3;
> IntHolder seed = seedValue4;
>
> Hash32FunctionsWithSeed$NullableVarCharHash_eval: {
> if (in.isSet == 0) {
> out.value = seed.value;
> } else
> {
> out.value = org.apache.drill.exec.expr.fn.impl.HashHelper.hash32(in.start, in.end, in.buffer, seed.value);
> }
> }
>
> out5 = out;
> }
> //---- end of eval portion of hash32 function. ----//
> seedValue = out5 .value;
> return getHashBuild0((incomingRowIdx), (seedValue));
> }
> {noformat}
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