[td-11818] add unit test.

source/util/test/pageBufferTest.cpp

+#include <gtest/gtest.h>
+#include <cassert>
+#include <iostream>
+
+#include "taos.h"
+#include "tpagedbuf.h"
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#pragma GCC diagnostic ignored "-Wunused-variable"
+
+namespace {
+// simple test
+void simpleTest() {
+  SDiskbasedBuf* pResultBuf = NULL;
+  int32_t ret = createDiskbasedBuffer(&pResultBuf, 1024, 4096, 1, "/tmp/");
+  
+  int32_t pageId = 0;
+  int32_t groupId = 0;
+  
+  SFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  ASSERT_TRUE(pBufPage != NULL);
+  
+  ASSERT_EQ(getTotalBufSize(pResultBuf), 1024);
+  
+  SIDList list = getDataBufPagesIdList(pResultBuf, groupId);
+  ASSERT_EQ(taosArrayGetSize(list), 1);
+  ASSERT_EQ(getNumOfResultBufGroupId(pResultBuf), 1);
+
+  releaseBufPage(pResultBuf, pBufPage);
+
+  SFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+
+  SFilePage* t = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t == pBufPage1);
+
+  SFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t1 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t1 == pBufPage2);
+
+  SFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t2 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t2 == pBufPage3);
+
+  SFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t3 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t3 == pBufPage4);
+
+  SFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t4 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t4 == pBufPage5);
+
+  destroyResultBuf(pResultBuf);
+}
+
+void writeDownTest() {
+  SDiskbasedBuf* pResultBuf = NULL;
+  int32_t ret = createDiskbasedBuffer(&pResultBuf, 1024, 4*1024, 1, "/tmp/");
+
+  int32_t pageId = 0;
+  int32_t writePageId = 0;
+  int32_t groupId = 0;
+  int32_t nx = 12345;
+
+  SFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  ASSERT_TRUE(pBufPage != NULL);
+
+  *(int32_t*)(pBufPage->data) = nx;
+  writePageId = pageId;
+  releaseBufPage(pResultBuf, pBufPage);
+
+  SFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t1 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t1 == pBufPage1);
+  ASSERT_TRUE(pageId == 1);
+
+  SFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t2 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t2 == pBufPage2);
+  ASSERT_TRUE(pageId == 2);
+
+  SFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t3 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t3 == pBufPage3);
+  ASSERT_TRUE(pageId == 3);
+
+  SFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t4 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t4 == pBufPage4);
+  ASSERT_TRUE(pageId == 4);
+  releaseBufPage(pResultBuf, t4);
+
+  // flush the written page to disk, and read it out again
+  SFilePage* pBufPagex = getBufPage(pResultBuf, writePageId);
+  ASSERT_EQ(*(int32_t*)pBufPagex->data, nx);
+
+  SArray* pa = getDataBufPagesIdList(pResultBuf, groupId);
+  ASSERT_EQ(taosArrayGetSize(pa), 5);
+
+  destroyResultBuf(pResultBuf);
+}
+
+void recyclePageTest() {
+  SDiskbasedBuf* pResultBuf = NULL;
+  int32_t ret = createDiskbasedBuffer(&pResultBuf, 1024, 4*1024, 1, "/tmp/");
+
+  int32_t pageId = 0;
+  int32_t writePageId = 0;
+  int32_t groupId = 0;
+  int32_t nx = 12345;
+
+  SFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  ASSERT_TRUE(pBufPage != NULL);
+  releaseBufPage(pResultBuf, pBufPage);
+
+  SFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t1 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t1 == pBufPage1);
+  ASSERT_TRUE(pageId == 1);
+
+  SFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t2 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t2 == pBufPage2);
+  ASSERT_TRUE(pageId == 2);
+
+  SFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t3 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t3 == pBufPage3);
+  ASSERT_TRUE(pageId == 3);
+
+  SFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t4 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t4 == pBufPage4);
+  ASSERT_TRUE(pageId == 4);
+  releaseBufPage(pResultBuf, t4);
+
+  SFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* t5 = getBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t5 == pBufPage5);
+  ASSERT_TRUE(pageId == 5);
+
+  // flush the written page to disk, and read it out again
+  SFilePage* pBufPagex = getBufPage(pResultBuf, writePageId);
+  *(int32_t*)(pBufPagex->data) = nx;
+  writePageId = pageId;   // update the data
+  releaseBufPage(pResultBuf, pBufPagex);
+
+  SFilePage* pBufPagex1 = getBufPage(pResultBuf, 1);
+
+  SArray* pa = getDataBufPagesIdList(pResultBuf, groupId);
+  ASSERT_EQ(taosArrayGetSize(pa), 6);
+
+  destroyResultBuf(pResultBuf);
+}
+} // namespace
+
+
+TEST(testCase, resultBufferTest) {
+  srand(time(NULL));
+  simpleTest();
+  writeDownTest();
+  recyclePageTest();
+}
+
+#pragma GCC diagnostic pop
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