From 3606a1af3a88cf3a2317873ab84f6763af4e6569 Mon Sep 17 00:00:00 2001
From: Bomin Zhang <localvar@hotmail.com>
Date: Mon, 17 Mar 2025 10:39:47 +0800
Subject: [PATCH] enh: improve performance of buildChildTableName (#30159)

---
 source/common/src/tname.c | 40 +++++++++++++++++----------------------
 source/util/src/tutil.c   | 14 ++++++--------
 2 files changed, 23 insertions(+), 31 deletions(-)

diff --git a/source/common/src/tname.c b/source/common/src/tname.c
index 6bd64fb5e6..c06a990704 100644
--- a/source/common/src/tname.c
+++ b/source/common/src/tname.c
@@ -16,7 +16,6 @@
 #define _DEFAULT_SOURCE
 #include "tname.h"
 #include "tcommon.h"
-#include "tstrbuild.h"
 
 #define VALID_NAME_TYPE(x) ((x) == TSDB_DB_NAME_T || (x) == TSDB_TABLE_NAME_T)
 
@@ -234,43 +233,38 @@ static int compareKv(const void* p1, const void* p2) {
  * use stable name and tags to grearate child table name
  */
 int32_t buildChildTableName(RandTableName* rName) {
-  SStringBuilder sb = {0};
-  taosStringBuilderAppendStringLen(&sb, rName->stbFullName, rName->stbFullNameLen);
-  if (sb.buf == NULL) {
-    return TSDB_CODE_OUT_OF_MEMORY;
-  }
-
   taosArraySort(rName->tags, compareKv);
+
+  T_MD5_CTX context;
+  tMD5Init(&context);
+
+  // add stable name
+  tMD5Update(&context, (uint8_t*)rName->stbFullName, rName->stbFullNameLen);
+
+  // add tags
   for (int j = 0; j < taosArrayGetSize(rName->tags); ++j) {
-    taosStringBuilderAppendChar(&sb, ',');
     SSmlKv* tagKv = taosArrayGet(rName->tags, j);
     if (tagKv == NULL) {
       return TSDB_CODE_SML_INVALID_DATA;
     }
 
-    taosStringBuilderAppendStringLen(&sb, tagKv->key, tagKv->keyLen);
-    taosStringBuilderAppendChar(&sb, '=');
+    tMD5Update(&context, (uint8_t*)",", 1);
+    tMD5Update(&context, (uint8_t*)tagKv->key, tagKv->keyLen);
+    tMD5Update(&context, (uint8_t*)"=", 1);
+
     if (IS_VAR_DATA_TYPE(tagKv->type)) {
-      taosStringBuilderAppendStringLen(&sb, tagKv->value, tagKv->length);
+      tMD5Update(&context, (uint8_t*)tagKv->value, tagKv->length);
     } else {
-      taosStringBuilderAppendStringLen(&sb, (char*)(&(tagKv->value)), tagKv->length);
+      tMD5Update(&context, (uint8_t*)(&(tagKv->value)), tagKv->length);
     }
   }
 
-  size_t    len = 0;
-  char*     keyJoined = taosStringBuilderGetResult(&sb, &len);
-  T_MD5_CTX context;
-  tMD5Init(&context);
-  tMD5Update(&context, (uint8_t*)keyJoined, (uint32_t)len);
   tMD5Final(&context);
 
-  char temp[8] = {0};
   rName->ctbShortName[0] = 't';
   rName->ctbShortName[1] = '_';
-  for (int i = 0; i < 16; i++) {
-    (void)sprintf(temp, "%02x", context.digest[i]);
-    (void)strcat(rName->ctbShortName, temp);
-  }
-  taosStringBuilderDestroy(&sb);
+  taosByteArrayToHexStr(context.digest, 16, rName->ctbShortName + 2);
+  rName->ctbShortName[34] = 0;
+
   return TSDB_CODE_SUCCESS;
 }
diff --git a/source/util/src/tutil.c b/source/util/src/tutil.c
index cdcef4b807..e8f1dd61fd 100644
--- a/source/util/src/tutil.c
+++ b/source/util/src/tutil.c
@@ -329,9 +329,9 @@ char *strbetween(char *string, char *begin, char *end) {
   return result;
 }
 
-int32_t tintToHex(uint64_t val, char hex[]) {
-  const char hexstr[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+static const char hexstr[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
 
+int32_t tintToHex(uint64_t val, char hex[]) {
   int32_t j = 0, k = 0;
   if (val == 0) {
     hex[j++] = hexstr[0];
@@ -355,13 +355,12 @@ int32_t titoa(uint64_t val, size_t radix, char str[]) {
     return 0;
   }
 
-  const char *s = "0123456789abcdef";
   char        buf[65] = {0};
 
   int32_t  i = 0;
   uint64_t v = val;
   do {
-    buf[i++] = s[v % radix];
+    buf[i++] = hexstr[v % radix];
     v /= radix;
   } while (v > 0);
 
@@ -373,13 +372,12 @@ int32_t titoa(uint64_t val, size_t radix, char str[]) {
   return i;
 }
 
-int32_t taosByteArrayToHexStr(char bytes[], int32_t len, char hexstr[]) {
+int32_t taosByteArrayToHexStr(char bytes[], int32_t len, char str[]) {
   int32_t i;
-  char    hexval[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
 
   for (i = 0; i < len; i++) {
-    hexstr[i * 2] = hexval[((bytes[i] >> 4u) & 0xF)];
-    hexstr[(i * 2) + 1] = hexval[(bytes[i]) & 0x0F];
+    str[i * 2] = hexstr[((bytes[i] >> 4u) & 0xF)];
+    str[(i * 2) + 1] = hexstr[(bytes[i]) & 0x0F];
   }
 
   return 0;