Implement UUID_TIMESTAMP() function that extracts timestamp from UUIDv1 and UUIDv7 values

Author: varundeepsaini

plugin/type_uuid/item_uuidfunc.cc

@@ -16,6 +16,10 @@
 #define MYSQL_SERVER
 #include "mariadb.h"
 #include "item_uuidfunc.h"
+#include <myisampack.h>
+
+// 100-nanosecond intervals between 1582-10-15 and 1970-01-01
+#define UUID_TIME_OFFSET ((ulonglong) 141427 * 24 * 60 * 60 * 1000 * 1000 * 10)
 
 String *Item_func_sys_guid::val_str(String *str)
 {
@@ -29,3 +33,53 @@ String *Item_func_sys_guid::val_str(String *str)
   my_uuid2str(buf, const_cast<char*>(str->ptr()), 0);
   return str;
 }
+
+
+bool Item_func_uuid_timestamp::fix_length_and_dec(THD *thd)
+{
+  Type_std_attributes::set(
+    Type_temporal_attributes_not_fixed_dec(MAX_DATETIME_WIDTH,
+                                           TIME_SECOND_PART_DIGITS, false),
+    DTCollation_numeric());
+  set_maybe_null();
+  return FALSE;
+}
+
+
+bool Item_func_uuid_timestamp::val_native(THD *thd, Native *to)
+{
+  Type_handler_uuid_new::Fbt_null uuid(args[0]);
+  if (uuid.is_null())
+    return (null_value= true);
+
+  const uchar *buf= (const uchar *) uuid.to_lex_cstring().str;
+  uint version= buf[6] >> 4;
+
+  my_time_t seconds;
+  ulong microseconds;
+
+  if (version == 7)
+  {
+    ulonglong unix_ts_ms= mi_uint6korr(buf);
+    seconds= unix_ts_ms / 1000;
+    microseconds= (unix_ts_ms % 1000) * 1000;
+  }
+  else if (version == 1)
+  {
+    ulonglong uuid_ts= ((ulonglong)(mi_uint2korr(buf + 6) & 0x0FFF) << 48) |
+                       ((ulonglong) mi_uint2korr(buf + 4) << 32) |
+                        (ulonglong) mi_uint4korr(buf);
+
+    if (uuid_ts < UUID_TIME_OFFSET)
+      return (null_value= true);
+
+    ulonglong unix_us= (uuid_ts - UUID_TIME_OFFSET) / 10;
+    seconds= unix_us / 1000000;
+    microseconds= unix_us % 1000000;
+  }
+  else
+    return (null_value= true);
+
+  return null_value= Timestamp(Timeval(seconds, microseconds)).
+                       to_native(to, TIME_SECOND_PART_DIGITS);
+}

plugin/type_uuid/item_uuidfunc.h

@@ -18,6 +18,7 @@
 
 
 #include "item.h"
+#include "item_timefunc.h"
 #include "sql_type_uuid_v1.h"
 #include "sql_type_uuid_v4.h"
 #include "sql_type_uuid_v7.h"
@@ -115,4 +116,29 @@ class Item_func_uuid_v7: public Item_func_uuid_vx<UUIDv7>
   Item *do_get_copy(THD *thd) const override
   { return get_item_copy<Item_func_uuid_v7>(thd, this); }
 };
+
+
+class Item_func_uuid_timestamp: public Item_timestampfunc
+{
+  bool check_arguments() const override
+  {
+    return args[0]->check_type_can_return_str(func_name_cstring());
+  }
+public:
+  Item_func_uuid_timestamp(THD *thd, Item *arg1)
+    : Item_timestampfunc(thd, arg1) {}
+
+  LEX_CSTRING func_name_cstring() const override
+  {
+    static LEX_CSTRING name= {STRING_WITH_LEN("uuid_timestamp") };
+    return name;
+  }
+
+  bool fix_length_and_dec(THD *thd) override;
+  bool val_native(THD *thd, Native *to) override;
+
+  Item *do_get_copy(THD *thd) const override
+  { return get_item_copy<Item_func_uuid_timestamp>(thd, this); }
+};
+
 #endif // ITEM_UUIDFUNC_INCLUDED

plugin/type_uuid/mysql-test/type_uuid/func_uuid_timestamp.result

@@ -0,0 +1,60 @@
+SELECT UUID_TIMESTAMP('018d17f3-e9a3-7000-8000-000000000000');
+UUID_TIMESTAMP('018d17f3-e9a3-7000-8000-000000000000')
+2024-01-17 20:34:37.539000
+SELECT UUID_TIMESTAMP('0188b5b8-8000-7000-8000-000000000000');
+UUID_TIMESTAMP('0188b5b8-8000-7000-8000-000000000000')
+2023-06-13 22:35:47.520000
+SELECT UUID_TIMESTAMP('1ee81f00-a8a8-11ee-8000-000000000000') IS NOT NULL AS has_timestamp;
+has_timestamp
+1
+SET @uuid1 = UUID();
+SELECT UUID_TIMESTAMP(@uuid1) IS NOT NULL AS has_timestamp;
+has_timestamp
+1
+SELECT TIMESTAMPDIFF(SECOND, UUID_TIMESTAMP(UUID()), NOW()) BETWEEN -5 AND 5 AS timestamp_is_recent;
+timestamp_is_recent
+1
+SET @uuid7 = UUID_V7();
+SELECT UUID_TIMESTAMP(@uuid7) IS NOT NULL AS has_timestamp;
+has_timestamp
+1
+SELECT TIMESTAMPDIFF(SECOND, UUID_TIMESTAMP(UUID_V7()), NOW()) BETWEEN -5 AND 5 AS timestamp_is_recent;
+timestamp_is_recent
+1
+SELECT UUID_TIMESTAMP(UUID_V4()) IS NULL AS no_timestamp_for_v4;
+no_timestamp_for_v4
+1
+SELECT UUID_TIMESTAMP('a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11') IS NULL AS no_timestamp_for_v4;
+no_timestamp_for_v4
+1
+SELECT UUID_TIMESTAMP(NULL);
+UUID_TIMESTAMP(NULL)
+NULL
+SELECT UUID_TIMESTAMP('not-a-valid-uuid');
+UUID_TIMESTAMP('not-a-valid-uuid')
+NULL
+Warnings:
+Warning	1292	Incorrect uuid value: 'not-a-valid-uuid'
+SELECT UUID_TIMESTAMP(CAST('018d17f3-e9a3-7000-8000-000000000000' AS UUID));
+UUID_TIMESTAMP(CAST('018d17f3-e9a3-7000-8000-000000000000' AS UUID))
+2024-01-17 20:34:37.539000
+CREATE TABLE t1 AS SELECT UUID_TIMESTAMP(UUID()) AS ts;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `ts` timestamp(6) NULL DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT UUID_TIMESTAMP(UUID_V7()) AS ts;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `ts` timestamp(6) NULL DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
+DROP TABLE t1;
+SELECT UUID_TIMESTAMP('018d17f3-e9a3-7000-8000-000000000000');
+UUID_TIMESTAMP('018d17f3-e9a3-7000-8000-000000000000')
+2024-01-17 20:34:37.539000
+SELECT UUID_TIMESTAMP('00000000-0000-1000-8000-000000000000') IS NULL AS before_unix_epoch;
+before_unix_epoch
+1

plugin/type_uuid/mysql-test/type_uuid/func_uuid_timestamp.test

@@ -0,0 +1,40 @@
+# UUID_TIMESTAMP() function to extract timestamp from UUIDv1 and UUIDv7
+
+SELECT UUID_TIMESTAMP('018d17f3-e9a3-7000-8000-000000000000');
+
+SELECT UUID_TIMESTAMP('0188b5b8-8000-7000-8000-000000000000');
+
+SELECT UUID_TIMESTAMP('1ee81f00-a8a8-11ee-8000-000000000000') IS NOT NULL AS has_timestamp;
+
+SET @uuid1 = UUID();
+SELECT UUID_TIMESTAMP(@uuid1) IS NOT NULL AS has_timestamp;
+
+SELECT TIMESTAMPDIFF(SECOND, UUID_TIMESTAMP(UUID()), NOW()) BETWEEN -5 AND 5 AS timestamp_is_recent;
+
+SET @uuid7 = UUID_V7();
+SELECT UUID_TIMESTAMP(@uuid7) IS NOT NULL AS has_timestamp;
+
+SELECT TIMESTAMPDIFF(SECOND, UUID_TIMESTAMP(UUID_V7()), NOW()) BETWEEN -5 AND 5 AS timestamp_is_recent;
+
+SELECT UUID_TIMESTAMP(UUID_V4()) IS NULL AS no_timestamp_for_v4;
+
+SELECT UUID_TIMESTAMP('a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11') IS NULL AS no_timestamp_for_v4;
+
+SELECT UUID_TIMESTAMP(NULL);
+
+SELECT UUID_TIMESTAMP('not-a-valid-uuid');
+
+SELECT UUID_TIMESTAMP(CAST('018d17f3-e9a3-7000-8000-000000000000' AS UUID));
+
+CREATE TABLE t1 AS SELECT UUID_TIMESTAMP(UUID()) AS ts;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 AS SELECT UUID_TIMESTAMP(UUID_V7()) AS ts;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+
+SELECT UUID_TIMESTAMP('018d17f3-e9a3-7000-8000-000000000000');
+
+SELECT UUID_TIMESTAMP('00000000-0000-1000-8000-000000000000') IS NULL AS before_unix_epoch;
+

plugin/type_uuid/plugin.cc

@@ -180,16 +180,33 @@ class Create_func_uuid_v7 : public Create_func_arg0
   virtual ~Create_func_uuid_v7() {}
 };
 
+class Create_func_uuid_timestamp : public Create_func_arg1
+{
+public:
+  Item *create_1_arg(THD *thd, Item *arg1) override
+  {
+    DBUG_ENTER("Create_func_uuid_timestamp::create_1_arg");
+    DBUG_RETURN(new (thd->mem_root) Item_func_uuid_timestamp(thd, arg1));
+  }
+  static Create_func_uuid_timestamp s_singleton;
+
+protected:
+  Create_func_uuid_timestamp() {}
+  virtual ~Create_func_uuid_timestamp() {}
+};
+
 Create_func_uuid Create_func_uuid::s_singleton;
 Create_func_sys_guid Create_func_sys_guid::s_singleton;
 Create_func_uuid_v4 Create_func_uuid_v4::s_singleton;
 Create_func_uuid_v7 Create_func_uuid_v7::s_singleton;
+Create_func_uuid_timestamp Create_func_uuid_timestamp::s_singleton;
 
 static Plugin_function
   plugin_descriptor_function_uuid(&Create_func_uuid::s_singleton),
   plugin_descriptor_function_sys_guid(&Create_func_sys_guid::s_singleton),
   plugin_descriptor_function_uuid_v4(&Create_func_uuid_v4::s_singleton),
-  plugin_descriptor_function_uuid_v7(&Create_func_uuid_v7::s_singleton);
+  plugin_descriptor_function_uuid_v7(&Create_func_uuid_v7::s_singleton),
+  plugin_descriptor_function_uuid_timestamp(&Create_func_uuid_timestamp::s_singleton);
 
 static constexpr Name type_name={STRING_WITH_LEN("uuid")};
 
@@ -301,5 +318,20 @@ maria_declare_plugin(type_uuid)
   NULL,                         // System variables
   "1.0.1",                      // String version representation
   MariaDB_PLUGIN_MATURITY_STABLE// Maturity(see include/mysql/plugin.h)*/
+},
+{
+  MariaDB_FUNCTION_PLUGIN,      // the plugin type (see include/mysql/plugin.h)
+  &plugin_descriptor_function_uuid_timestamp, // pointer to type-specific plugin descriptor
+  "uuid_timestamp",             // plugin name
+  "Varun Deep Saini",           // plugin author
+  "Function UUID_TIMESTAMP()",  // the plugin description
+  PLUGIN_LICENSE_GPL,           // the plugin license (see include/mysql/plugin.h)
+  0,                            // Pointer to plugin initialization function
+  0,                            // Pointer to plugin deinitialization function
+  0x0100,                       // Numeric version 0xAABB means AA.BB version
+  NULL,                         // Status variables
+  NULL,                         // System variables
+  "1.0",                        // String version representation
+  MariaDB_PLUGIN_MATURITY_STABLE// Maturity(see include/mysql/plugin.h)*/
 }
 maria_declare_plugin_end;