feat: support scan metrics of FileStoreScan to align with ScanMetrics

[SteNicholas]

Purpose

Linked issue: close #88

Support scan metrics of FileStoreScan to align with ScanMetrics including:

• lastScanDuration
• lastScannedSnapshotId
• lastScannedManifests
• lastScanSkippedTableFiles
• lastScanResultedTableFiles

Tests

KeyValueFileStoreScanTest, TestMaxSequenceNumber.

API and Format

No.

Documentation

No.

[SteNicholas]

Ping @lucasfang, @lxy-9602.

[Copilot]

Pull request overview

This pull request adds scan metrics support to FileStoreScan to align with Java Paimon's ScanMetrics API. The implementation tracks key scanning operations metrics including scan duration, scanned snapshot ID, number of manifests scanned, and counts of skipped and resulted table files.

Changes:

• Added ScanMetrics class defining metric name constants for scan operations
• Integrated metrics collection into FileStoreScan with a new metrics member and getter method
• Modified ReadManifests to track both all manifests and filtered manifests for metrics calculation
• Added test coverage for the scan metrics functionality
• Changed commit duration metric from nanoseconds to milliseconds for consistency

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/paimon/core/operation/metrics/scan_metrics.h	Defines constants for scan metric names (duration, snapshot ID, manifests count, file counts)
src/paimon/core/operation/file_store_scan.h	Adds metrics member variable, getter method, and updates ReadManifests signature
src/paimon/core/operation/file_store_scan.cpp	Implements metrics collection logic during scan plan creation and updates ReadManifests implementation
src/paimon/core/operation/key_value_file_store_scan_test.cpp	Adds basic test validation for scan metrics (snapshot ID metric)
src/paimon/core/operation/file_store_commit_impl.cpp	Changes commit duration metric unit from nanoseconds to milliseconds for consistency

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[lxy-9602]

+1