[td-10564] refactor and add test cases.

source/libs/qcom/src/queryUtil.c

+#include "os.h"
+#include "taosmsg.h"
+
+#define VALIDNUMOFCOLS(x)  ((x) >= TSDB_MIN_COLUMNS && (x) <= TSDB_MAX_COLUMNS)
+#define VALIDNUMOFTAGS(x)  ((x) >= 0 && (x) <= TSDB_MAX_TAGS)
+
+static struct SSchema _s = {
+    .colId = TSDB_TBNAME_COLUMN_INDEX,
+    .type  = TSDB_DATA_TYPE_BINARY,
+    .bytes = TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE,
+    .name = "tbname",
+};
+
+SSchema* tGetTbnameColumnSchema() {
+  return &_s;
+}
+
+static bool doValidateSchema(SSchema* pSchema, int32_t numOfCols, int32_t maxLen) {
+  int32_t rowLen = 0;
+
+  for (int32_t i = 0; i < numOfCols; ++i) {
+    // 1. valid types
+    if (!isValidDataType(pSchema[i].type)) {
+      return false;
+    }
+
+    // 2. valid length for each type
+    if (pSchema[i].type == TSDB_DATA_TYPE_BINARY) {
+      if (pSchema[i].bytes > TSDB_MAX_BINARY_LEN) {
+        return false;
+      }
+    } else if (pSchema[i].type == TSDB_DATA_TYPE_NCHAR) {
+      if (pSchema[i].bytes > TSDB_MAX_NCHAR_LEN) {
+        return false;
+      }
+    } else {
+      if (pSchema[i].bytes != tDataTypes[pSchema[i].type].bytes) {
+        return false;
+      }
+    }
+
+    // 3. valid column names
+    for (int32_t j = i + 1; j < numOfCols; ++j) {
+      if (strncasecmp(pSchema[i].name, pSchema[j].name, sizeof(pSchema[i].name) - 1) == 0) {
+        return false;
+      }
+    }
+
+    rowLen += pSchema[i].bytes;
+  }
+
+  return rowLen <= maxLen;
+}
+
+bool tIsValidSchema(struct SSchema* pSchema, int32_t numOfCols, int32_t numOfTags) {
+  if (!VALIDNUMOFCOLS(numOfCols)) {
+    return false;
+  }
+
+  if (!VALIDNUMOFTAGS(numOfTags)) {
+    return false;
+  }
+
+  /* first column must be the timestamp, which is a primary key */
+  if (pSchema[0].type != TSDB_DATA_TYPE_TIMESTAMP) {
+    return false;
+  }
+
+  if (!doValidateSchema(pSchema, numOfCols, TSDB_MAX_BYTES_PER_ROW)) {
+    return false;
+  }
+
+  if (!doValidateSchema(&pSchema[numOfCols], numOfTags, TSDB_MAX_TAGS_LEN)) {
+    return false;
+  }
+
+  return true;
+}
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