fix(stream): handle const boundary in external window range

[JinqingKuang]

Description

fix(stream): handle const boundary in external window range

Issue(s)

• Fix: https://project.feishu.cn/taosdata_td/defect/detail/6766024000

Checklist

Please check the items in the checklist if applicable.

• Is the user manual updated?
• Are the test cases passed and automated?
• Is there no significant decrease in test coverage?

[gemini-code-assist]

Code Review

This pull request aims to fix an issue in stream processing by correctly handling constant boundaries in external window ranges, specifically within sclCalcStreamExtWinsTimeRange. However, the implementation introduces a vulnerability to signed integer overflows when processing boundary values near INT64_MAX. These overflows can lead to incorrect window ranges, potentially causing logic bypasses or incorrect data processing in streams. It is recommended to use overflow-safe arithmetic or add explicit checks for boundary conditions. Additionally, there are opportunities to refactor parts of the new logic to reduce code duplication and improve maintainability.

[Copilot]

Pull request overview

This PR fixes a stream execution bug triggered by external window time-range calculation when a filter uses a constant timestamp boundary together with stream window placeholders (e.g., _twstart), and adds CI coverage to prevent regressions.

Changes:

• Update external window range calculation to correctly handle constant (VALUE node) timestamp boundaries and broadcast single-row timestamp results across all external windows.
• Add a new stream regression test covering ts >= <const> combined with ts < _twstart.
• Register the new test in the CI task list.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
test/ci/cases.task	Adds the new trigger-mode stream regression test to CI execution.
test/cases/18-StreamProcessing/03-TriggerMode/test_interval_const_filter_twstart.py	New regression test reproducing the const-boundary + _twstart filter scenario and asserting stream tasks don’t fail.
source/libs/scalar/src/scalar.c	Fixes external window time range calculation to support constant timestamp boundaries and align row counts with external window count.

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

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[JinqingKuang]

Code review

Found 3 issues:

1. winOutIdx 语义的潜在混淆 - 条件从 pWin->tw.skey == pExtW->lastSKey 改为 pWin->winOutIdx >= 0，但 winOutIdx 有三种状态（-1: 起始边界已修改, -2: 结束边界已修改, >= 0: 已分配输出缓冲区）。新条件只检查是否已分配缓冲区，不能正确处理 winOutIdx == -1 或 -2 的情况，可能导致空窗口处理逻辑被错误跳过。

TDengine/source/libs/executor/src/externalwindowoperator.c

Lines 1788 to 1790 in eaa9453

	if (NULL == pExtW->pEmptyInputBlock || (pWin && pWin->winOutIdx >= 0)) {
	goto _exit;

2. 数组越界风险 - 在 sclCalcStreamExtWinsTimeRange() 中，循环使用 res->numOfRows 访问 ctx->stream.pWins[i]，但没有验证 pWins 数组大小是否至少为 res->numOfRows。res->numOfRows 来自表达式计算结果，与原始分配的数组大小没有保证相等，可能导致缓冲区溢出。

TDengine/source/libs/scalar/src/scalar.c

Lines 1333 to 1363 in eaa9453

	ctx->stream.pWins[i].winOutIdx = -1;
	}
	} else if (node->opType == OP_TYPE_GREATER_EQUAL) {
	for (int32_t i = 0; i < winNum; ++i) {
	int64_t tsVal = pTsValList[(tsValRows == 1) ? 0 : i];
	ctx->stream.pWins[i].tw.skey = (-1 == ctx->stream.pWins[i].winOutIdx) ? TMAX(tsVal, ctx->stream.pWins[i].tw.skey) : tsVal;
	ctx->stream.pWins[i].winOutIdx = -1;
	}
	} else {
	qError("invalid op type:%d in ext win range start expr", node->opType);
	return TSDB_CODE_STREAM_INTERNAL_ERROR;
	}
	}
	if (2 == ctx->stream.extWinType) {
	//if (ctx->stream.pStreamRuntimeFuncInfo->triggerType != STREAM_TRIGGER_SLIDING) {
	// consider triggerType and keep the ekey exclude
	if (node->opType == OP_TYPE_LOWER_THAN) {
	for (int32_t i = 0; i < winNum; ++i) {
	int64_t tsVal = pTsValList[(tsValRows == 1) ? 0 : i];
	ctx->stream.pWins[i].tw.ekey = (-2 == ctx->stream.pWins[i].winOutIdx) ? TMIN(tsVal, ctx->stream.pWins[i].tw.ekey) : tsVal;
	ctx->stream.pWins[i].winOutIdx = -2;
	}
	} else if (node->opType == OP_TYPE_LOWER_EQUAL) {
	for (int32_t i = 0; i < winNum; ++i) {
	int64_t tsVal = pTsValList[(tsValRows == 1) ? 0 : i];
	ctx->stream.pWins[i].tw.ekey = (-2 == ctx->stream.pWins[i].winOutIdx) ? TMIN(tsVal + 1, ctx->stream.pWins[i].tw.ekey) : (tsVal + 1);
	ctx->stream.pWins[i].winOutIdx = -2;
	}
	} else {
	qError("invalid op type:%d in ext win range end expr", node->opType);

3. 空窗口处理逻辑的条件变更缺少说明 - 在 extWinAggHandleEmptyWins 中，条件从基于时间的 lastSKey 比较改为基于 winOutIdx 的检查，这是重大的语义变更。原逻辑用于避免重复处理相同起始时间的窗口，新逻辑检查窗口输出索引状态。如果 winOutIdx 在某些场景下未正确更新，可能导致空窗口处理逻辑被错误跳过或执行。

TDengine/source/libs/executor/src/externalwindowoperator.c

Lines 1788 to 1790 in eaa9453

	if (NULL == pExtW->pEmptyInputBlock || (pWin && pWin->winOutIdx >= 0)) {
	goto _exit;

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[JinqingKuang]

1. 问题 1、3 已修复；
2. 问题 2 不是问题，前面有对行数的校验，校验不通过会报错并提前返回。

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

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