Package org.apache.sysds.hops.rewrite

## Class RewriteSplitDagUnknownCSVRead

- java.lang.Object
- - org.apache.sysds.hops.rewrite.StatementBlockRewriteRule
  - - org.apache.sysds.hops.rewrite.RewriteSplitDagUnknownCSVRead

-     public class RewriteSplitDagUnknownCSVRead
      extends StatementBlockRewriteRule

  Rule: Split Hop DAG after CSV reads with unknown size. This is important to create recompile hooks if format is read from mtd (we are not able to split it on statementblock creation) and mtd has unknown size (which can only happen for CSV).

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `RewriteSplitDagUnknownCSVRead()` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `boolean` | `createsSplitDag()` | Indicates if the rewrite potentially splits dags, which is used for phase ordering of rewrites.
    `List<StatementBlock>` | `rewriteStatementBlock​(StatementBlock sb, ProgramRewriteStatus state)` | Handle an arbitrary statement block.
    `List<StatementBlock>` | `rewriteStatementBlocks​(List<StatementBlock> sbs, ProgramRewriteStatus sate)` | Handle a list of statement blocks.

    - ### Methods inherited from class org.apache.sysds.hops.rewrite.StatementBlockRewriteRule

      `createCutVarName`

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### RewriteSplitDagUnknownCSVRead

          public RewriteSplitDagUnknownCSVRead()

  - ### Method Detail

    - #### createsSplitDag

          public boolean createsSplitDag()

      Description copied from class: `StatementBlockRewriteRule`
      Indicates if the rewrite potentially splits dags, which is used for phase ordering of rewrites.
      Specified by:
        `createsSplitDag` in class `StatementBlockRewriteRule`
      Returns:
        true if dag splits are possible.

    - #### rewriteStatementBlock

          public List<StatementBlock> rewriteStatementBlock​(StatementBlock sb,
                                                            ProgramRewriteStatus state)

      Description copied from class: `StatementBlockRewriteRule`
      Handle an arbitrary statement block. Specific type constraints have to be ensured within the individual rewrites. If a rewrite does not apply to individual blocks, it should simply return the input block.
      Specified by:
        `rewriteStatementBlock` in class `StatementBlockRewriteRule`
      Parameters:
        `sb` - statement block
        `state` - program rewrite status
      Returns:
        list of statement blocks

    - #### rewriteStatementBlocks

          public List<StatementBlock> rewriteStatementBlocks​(List<StatementBlock> sbs,
                                                             ProgramRewriteStatus sate)

      Description copied from class: `StatementBlockRewriteRule`
      Handle a list of statement blocks. Specific type constraints have to be ensured within the individual rewrites. If a rewrite does not require sequence access, it should simply return the input list of statement blocks.
      Specified by:
        `rewriteStatementBlocks` in class `StatementBlockRewriteRule`
      Parameters:
        `sbs` - list of statement blocks
        `sate` - program rewrite status
      Returns:
        list of statement blocks