Re: [Tarantool-patches] [PATCH v5 5/8] box, datetime: datetime comparison for indices

[Safin Timur via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

On 17.08.2021 15:16, Serge Petrenko wrote:
> 
> 
> 16.08.2021 02:59, Timur Safin via Tarantool-patches пишет:
>> * storage hints implemented for datetime_t values;
>> * proper comparison for indices of datetime type.
>>
>> Part of #5941
>> Part of #5946
> 
> 
> Please, add a docbot request stating that it's now possible to store
> datetime values in spaces and create indexed datetime fields.

Will use something like that:

@TarantoolBot document

Title: Storage support for datetime values

It's now possible to store datetime values in spaces and create
indexed datetime fields.

Please refer to https://github.com/tarantool/tarantool/discussions/6244
for more detailed description of a storage schema.

> 
> 
>> ---
>>   src/box/field_def.c           | 18 ++++++++
>>   src/box/field_def.h           |  3 ++
>>   src/box/memtx_space.c         |  3 +-
>>   src/box/tuple_compare.cc      | 57 ++++++++++++++++++++++++++
>>   src/box/vinyl.c               |  3 +-
>>   test/engine/datetime.result   | 77 +++++++++++++++++++++++++++++++++++
>>   test/engine/datetime.test.lua | 35 ++++++++++++++++
>>   7 files changed, 192 insertions(+), 4 deletions(-)
>>   create mode 100644 test/engine/datetime.result
>>   create mode 100644 test/engine/datetime.test.lua
>>
>> diff --git a/src/box/field_def.c b/src/box/field_def.c
>> index 2682a42ee..97033d0bb 100644
>> --- a/src/box/field_def.c
>> +++ b/src/box/field_def.c
>> @@ -194,3 +194,21 @@ field_type_by_name(const char *name, size_t len)
>>           return FIELD_TYPE_ANY;
>>       return field_type_MAX;
>>   }
>> +
>> +const bool field_type_index_allowed[] =
>> +    {
>> +    /* [FIELD_TYPE_ANY]      = */ false,
>> +    /* [FIELD_TYPE_UNSIGNED] = */ true,
>> +    /* [FIELD_TYPE_STRING]   = */ true,
>> +    /* [FIELD_TYPE_NUMBER]   = */ true,
>> +    /* [FIELD_TYPE_DOUBLE]   = */ true,
>> +    /* [FIELD_TYPE_INTEGER]  = */ true,
>> +    /* [FIELD_TYPE_BOOLEAN]  = */ true,
>> +    /* [FIELD_TYPE_VARBINARY]= */ true,
>> +    /* [FIELD_TYPE_SCALAR]   = */ true,
>> +    /* [FIELD_TYPE_DECIMAL]  = */ true,
>> +    /* [FIELD_TYPE_UUID]     = */ true,
>> +    /* [FIELD_TYPE_ARRAY]    = */ false,
>> +    /* [FIELD_TYPE_MAP]      = */ false,
>> +    /* [FIELD_TYPE_DATETIME] = */ true,
>> +};
> 
> 
> You wouldn't need that array if you moved
> FIELD_TYPE_DATETIME above FIELD_TYPE_ARRAY
> in the previous commit.
> 
> Please, do so.

Yes, will change order and also move all field support code to this 
patch (as Vova recommends).

> 
> 
>> diff --git a/src/box/field_def.h b/src/box/field_def.h
>> index 120b2a93d..bd02418df 100644
>> --- a/src/box/field_def.h
>> +++ b/src/box/field_def.h
>> @@ -120,6 +120,9 @@ extern const uint32_t field_ext_type[];
>>   extern const struct opt_def field_def_reg[];
>>   extern const struct field_def field_def_default;
>> +/** helper table for checking allowed indices for types */
>> +extern const bool field_type_index_allowed[];
>> +
>>   /**
>>    * @brief Field definition
>>    * Contains information about of one tuple field.
>> diff --git a/src/box/memtx_space.c b/src/box/memtx_space.c
>> index b71318d24..1ab16122e 100644
>> --- a/src/box/memtx_space.c
>> +++ b/src/box/memtx_space.c
>> @@ -748,8 +748,7 @@ memtx_space_check_index_def(struct space *space, 
>> struct index_def *index_def)
>>       /* Check that there are no ANY, ARRAY, MAP parts */
>>       for (uint32_t i = 0; i < key_def->part_count; i++) {
>>           struct key_part *part = &key_def->parts[i];
>> -        if (part->type <= FIELD_TYPE_ANY ||
>> -            part->type >= FIELD_TYPE_ARRAY) {
>> +        if (!field_type_index_allowed[part->type]) {
>>               diag_set(ClientError, ER_MODIFY_INDEX,
>>                    index_def->name, space_name(space),
>>                    tt_sprintf("field type '%s' is not supported",
>> diff --git a/src/box/tuple_compare.cc b/src/box/tuple_compare.cc
>> index 9a69f2a72..110017853 100644
>> --- a/src/box/tuple_compare.cc
>> +++ b/src/box/tuple_compare.cc
>> @@ -538,6 +538,8 @@ tuple_compare_field_with_type(const char *field_a, 
>> enum mp_type a_type,
>>                              field_b, b_type);
>>       case FIELD_TYPE_UUID:
>>           return mp_compare_uuid(field_a, field_b);
>> +    case FIELD_TYPE_DATETIME:
>> +        return mp_compare_datetime(field_a, field_b);
>>       default:
>>           unreachable();
>>           return 0;
>> @@ -1538,6 +1540,21 @@ func_index_compare_with_key(struct tuple 
>> *tuple, hint_t tuple_hint,
>>   #define HINT_VALUE_DOUBLE_MAX    (exp2(HINT_VALUE_BITS - 1) - 1)
>>   #define HINT_VALUE_DOUBLE_MIN    (-exp2(HINT_VALUE_BITS - 1))
>> +/**
>> + * We need to squeeze 64 bits of seconds and 32 bits of nanoseconds
>> + * into 60 bits of hint value. The idea is to represent wide enough
>> + * years range, and leave the rest of bits occupied from nanoseconds 
>> part:
>> + * - 36 bits is enough for time range of [208BC..4147]
>> + * - for nanoseconds there is left 24 bits, which are MSB part of
>> + *   32-bit value
>> + */
>> +#define HINT_VALUE_SECS_BITS    36
>> +#define HINT_VALUE_NSEC_BITS    (HINT_VALUE_BITS - HINT_VALUE_SECS_BITS)
>> +#define HINT_VALUE_SECS_MAX    ((1LL << HINT_VALUE_SECS_BITS) - 1)
> 
> Am I missing something?
> n bits may store values from (-2^(n-1)) to 2^(n-1)-1
> 
> should be (1LL << (HINT_VALUE_SECS_BITS -1))  - 1 ?
> 
> 
>> +#define HINT_VALUE_SECS_MIN    (-(1LL << HINT_VALUE_SECS_BITS))
> 
> 
> 
> 
> should be
> 
> #define HINT_VALUE_SECS_MIN    (-(1LL << (HINT_VALUE_SECS_BITS - 1)))
> 
> ?
> 

Yes, my definition made sense only when used as a mask (in prior version 
of a code). Thus did not take into consideration a sign bit. You 
absolutely correct that if seconds are signed then we have lesser number 
of bits, and your definitions of HINT_VALUE_SECS_MAX/HINT_VALUE_SECS_MIN 
should be used.

> 
>> +#define HINT_VALUE_NSEC_SHIFT    (sizeof(int) * CHAR_BIT - 
>> HINT_VALUE_NSEC_BITS)
>> +#define HINT_VALUE_NSEC_MAX    ((1ULL << HINT_VALUE_NSEC_BITS) - 1)
>> +
>>   /*
>>    * HINT_CLASS_BITS should be big enough to store any mp_class value.
>>    * Note, ((1 << HINT_CLASS_BITS) - 1) is reserved for HINT_NONE.
>> @@ -1630,6 +1647,25 @@ hint_uuid_raw(const char *data)
>>       return hint_create(MP_CLASS_UUID, val);
>>   }
>> +static inline hint_t
>> +hint_datetime(struct datetime *date)
>> +{
>> +    /*
>> +     * Use at most HINT_VALUE_SECS_BITS from datetime
>> +     * seconds field as a hint value, and at MSB part
>> +     * of HINT_VALUE_NSEC_BITS from nanoseconds.
>> +     */
>> +    int64_t secs = date->secs;
>> +    int32_t nsec = date->nsec;
>> +    uint64_t val = secs <= HINT_VALUE_SECS_MIN ? 0 :
>> +            secs - HINT_VALUE_SECS_MIN;
>> +    if (val >= HINT_VALUE_SECS_MAX)
>> +        val = HINT_VALUE_SECS_MAX;
>> +    val <<= HINT_VALUE_NSEC_BITS;
>> +    val |= (nsec >> HINT_VALUE_NSEC_SHIFT) & HINT_VALUE_NSEC_MAX;
>> +    return hint_create(MP_CLASS_DATETIME, val);
>> +}
>> +
> 
> <stripped>
> 

Patch increment here small (so far)
------------------------------------
diff --git a/src/box/tuple_compare.cc b/src/box/tuple_compare.cc
index 110017853..2478498ba 100644
--- a/src/box/tuple_compare.cc
+++ b/src/box/tuple_compare.cc
@@ -1550,8 +1550,8 @@ func_index_compare_with_key(struct tuple *tuple, 
hint_t tuple_hint,
   */
  #define HINT_VALUE_SECS_BITS	36
  #define HINT_VALUE_NSEC_BITS	(HINT_VALUE_BITS - HINT_VALUE_SECS_BITS)
-#define HINT_VALUE_SECS_MAX	((1LL << HINT_VALUE_SECS_BITS) - 1)
-#define HINT_VALUE_SECS_MIN	(-(1LL << HINT_VALUE_SECS_BITS))
+#define HINT_VALUE_SECS_MAX	((1LL << (HINT_VALUE_SECS_BITS - 1)) - 1)
+#define HINT_VALUE_SECS_MIN	(-(1LL << (HINT_VALUE_SECS_BITS - 1)))
  #define HINT_VALUE_NSEC_SHIFT	(sizeof(int) * CHAR_BIT - 
HINT_VALUE_NSEC_BITS)
  #define HINT_VALUE_NSEC_MAX	((1ULL << HINT_VALUE_NSEC_BITS) - 1)

------------------------------------

But please see code moves which will be done in the next version of a 
patchset, so all field and indices changes will become part of a single 
patch.

Regards,
Timur