Add binary interval parsing (#237)

* Add binary interval parsing

* Fix argument types in functions

Co-authored-by: Eric Davies <[email protected]>

* Add function explanation

* Bump version

* Fix variable name

Co-authored-by: Eric Davies <[email protected]>

Author: Sam Morrison

Project.toml

@@ -1,7 +1,7 @@
 name = "LibPQ"
 uuid = "194296ae-ab2e-5f79-8cd4-7183a0a5a0d1"
 license = "MIT"
-version = "1.8.1"
+version = "1.9.0"
 
 [deps]
 BinaryProvider = "b99e7846-7c00-51b0-8f62-c81ae34c0232"

src/parsing.jl

@@ -434,6 +434,47 @@ function _interval_regex()
     return Regex(String(take!(io)))
 end
 
+function _split_period(period::T, ::Type{P}) where {T<:Period,P<:Period}
+    q, r = divrem(period, convert(T, P(1)))
+    return P(q), r
+end
+
+# Splits internal interval types into the expected period types from
+# https://www.postgresql.org/docs/10/datatype-datetime.html#DATATYPE-INTERVAL-INPUT
+function _split_periods(months, days, microseconds)
+    periods = Period[]
+
+    push!(periods, _split_period(months, Year)...)
+    push!(periods, _split_period(days, Week)...)
+
+    seconds, ms = _split_period(microseconds, Second)
+    minutes, seconds = _split_period(seconds, Minute)
+    hours, minutes = _split_period(minutes, Hour)
+
+    push!(periods, hours, minutes, seconds, ms)
+    filter!(!iszero, periods)
+
+    return Dates.CompoundPeriod(periods)
+end
+
+# Parse binary into postgres interval
+function Base.parse(
+    ::Type{Dates.CompoundPeriod}, pqv::PQBinaryValue{PQ_SYSTEM_TYPES[:interval]}
+)
+    current_pointer = data_pointer(pqv)
+
+    microsecond = Microsecond(ntoh(unsafe_load(Ptr{Int64}(current_pointer))))
+    current_pointer += sizeof(Int64)
+
+    day = Day(ntoh(unsafe_load(Ptr{Int32}(current_pointer))))
+    current_pointer += sizeof(Int32)
+
+    month = Month(ntoh(unsafe_load(Ptr{Int32}(current_pointer))))
+
+    # Split combined periods to match the output from text queries
+    return _split_periods(Month(month), Day(day), Microsecond(microsecond))
+end
+
 # parse the iso_8601 interval output format
 # https://www.postgresql.org/docs/10/datatype-datetime.html#DATATYPE-INTERVAL-OUTPUT
 function pqparse(::Type{Dates.CompoundPeriod}, str::AbstractString)

test/runtests.jl

@@ -1153,7 +1153,6 @@ end
                 binary_not_implemented_types = [
                     Decimal,
                     Time,
-                    Dates.CompoundPeriod,
                     Array,
                     OffsetArray,
                 ]
@@ -1235,6 +1234,11 @@ end
                             ("INTERVAL '1000 years 7 weeks'", Dates.CompoundPeriod(Period[Year(1000), Day(7 * 7)])),
                             ("INTERVAL '1 day -1 hour'", Dates.CompoundPeriod(Period[Day(1), Hour(-1)])),
                             ("INTERVAL '-1 month 1 day'", Dates.CompoundPeriod(Period[Month(-1), Day(1)])),
+                            # With fields specification
+                            ("INTERVAL '1 day 2:03:04' HOUR TO MINUTE", Dates.CompoundPeriod(Period[Day(1), Hour(2), Minute(3)])),
+                            # With precision
+                            ("INTERVAL '6.1001 seconds' SECOND(0)", Dates.CompoundPeriod(Period[Second(6)])),
+                            ("INTERVAL '6.1001 seconds' SECOND(2)", Dates.CompoundPeriod(Period[Second(6), Millisecond(100)])),
                             ("'{{{1,2,3},{4,5,6}}}'::int2[]", Array{Union{Int16, Missing}}(reshape(Int16[1 2 3; 4 5 6], 1, 2, 3))),
                             ("'{}'::int2[]", Union{Missing, Int16}[]),
                             ("'{{{1,2,3},{4,5,6}}}'::int4[]", Array{Union{Int32, Missing}}(reshape(Int32[1 2 3; 4 5 6], 1, 2, 3))),