Pipe: support multiple path patterns under tree model

[VGalaxies]

reopen #16435

[Copilot]

Pull Request Overview

Enable Pipe to accept multiple tree path patterns by introducing a union pattern representation and updating parsing, selection, and tests.

• Add UnionTreePattern to represent a union of multiple TreePattern instances and extend parser to build unions from comma-separated inputs (backtick-aware).
• Update parsing semantics to unionize source.path and source.pattern when both are provided; adjust logic to avoid scan parsers for unions.
• Add integration and unit tests covering multiple prefix/IoTDB/hybrid patterns for historical and realtime data; minor test name fixes.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/source/IoTDBNonDataRegionSource.java	Temporarily unwraps UnionTreePattern to first pattern, affecting multi-pattern support.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/datastructure/pattern/UnionTreePattern.java	New union pattern type and utilities (toString, matching, etc.).
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/datastructure/pattern/TreePattern.java	Refactor to parse multiple patterns, introduce helper methods, and move single-pattern state to SingleTreePattern.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/datastructure/pattern/SingleTreePattern.java	New base class encapsulating single-pattern behavior and defaults.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/datastructure/pattern/PrefixTreePattern.java	Switch to extend SingleTreePattern.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/datastructure/pattern/IoTDBTreePattern.java	Switch to extend SingleTreePattern.
iotdb-core/datanode/src/test/java/org/apache/iotdb/db/pipe/source/IoTDBDataRegionSourceTest.java	Add assertions for comma-separated patterns and backtick-escaped commas.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/event/common/tsfile/parser/TsFileInsertionEventParserProvider.java	Avoid scan parser paths when a UnionTreePattern is used.
integration-test/src/test/java/org/apache/iotdb/pipe/it/dual/treemodel/auto/basic/IoTDBTreePatternFormatIT.java	Add integration tests for multiple patterns; fix method names and semantics where both path and pattern are provided.

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[Copilot]

Pull Request Overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 4 comments.

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[Copilot]

This unchecked cast assumes the built TreePattern is always a UnionIoTDBTreePattern. To make this robust, either construct a UnionIoTDBTreePattern directly (e.g., map to List and new UnionIoTDBTreePattern(...)) or guard with an instanceof check and fail fast with a clear error if a non-IoTDB union is received.

Suggested change

	// Even if there are failed statements
	// Even if there are failed statements
	if (!(treePattern instanceof UnionIoTDBTreePattern)) {
	throw new IllegalArgumentException(
	"Expected treePattern to be UnionIoTDBTreePattern, but got: "
	+ treePattern.getClass().getName());
	}

[Caideyipi]

Why "ScanParser" must use single?

[VGalaxies]

I'm not sure whether the implementation of scan parser will conflict with multi patterns?

[Caideyipi]

Surely not. Just check whether the device or measurement fits the pattern one by one.

[Caideyipi]

LGTM