Revert "Revert "Implemented series period detect method using pocketfft lib""

This reverts commit d7d83c99e5.

.gitmodules

@@ -354,3 +354,6 @@
 [submodule "contrib/aklomp-base64"]
 	path = contrib/aklomp-base64
 	url = https://github.com/aklomp/base64.git
+[submodule "contrib/pocketfft"]
+	path = contrib/pocketfft
+	url = https://github.com/mreineck/pocketfft.git

contrib/CMakeLists.txt

@@ -44,6 +44,7 @@ else ()
 endif ()
 add_contrib (miniselect-cmake miniselect)
 add_contrib (pdqsort-cmake pdqsort)
+add_contrib (pocketfft-cmake pocketfft)
 add_contrib (crc32-vpmsum-cmake crc32-vpmsum)
 add_contrib (sparsehash-c11-cmake sparsehash-c11)
 add_contrib (abseil-cpp-cmake abseil-cpp)

contrib/pocketfft

@@ -0,0 +1 @@
+Subproject commit 9efd4da52cf8d28d14531d14e43ad9d913807546

contrib/pocketfft-cmake/CMakeLists.txt

@@ -0,0 +1,10 @@
+option (ENABLE_POCKETFFT "Enable pocketfft" ${ENABLE_LIBRARIES})
+
+if (NOT ENABLE_POCKETFFT)
+    message(STATUS "Not using pocketfft")
+    return()
+endif()
+
+add_library(_pocketfft INTERFACE)
+target_include_directories(_pocketfft INTERFACE ${ClickHouse_SOURCE_DIR}/contrib/pocketfft)
+add_library(ch_contrib::pocketfft ALIAS _pocketfft)

docs/en/sql-reference/functions/time-series-functions.md

@@ -0,0 +1,47 @@
+---
+slug: /en/sql-reference/functions/time-series-functions
+sidebar_position: 172
+sidebar_label: Time Series
+---
+
+# Time Series Functions
+
+Below functions are used for time series analysis.
+
+## seriesPeriodDetectFFT
+
+Finds the period of the given time series data using FFT
+Detect Period in time series data using FFT.
+FFT - Fast Fourier transform (https://en.wikipedia.org/wiki/Fast_Fourier_transform)
+
+**Syntax**
+
+``` sql
+seriesPeriodDetectFFT(series);
+```
+
+**Arguments**
+
+- `series` - An array of numeric values
+
+**Returned value**
+
+- A real value equal to the period of time series
+
+Type: [Float64](../../sql-reference/data-types/float.md).
+
+**Examples**
+
+Query:
+
+``` sql
+SELECT seriesPeriodDetectFFT([1, 4, 6, 1, 4, 6, 1, 4, 6, 1, 4, 6, 1, 4, 6, 1, 4, 6, 1, 4, 6]) AS print_0;
+```
+
+Result:
+
+``` text
+┌───────────print_0──────┐
+│                      3 │
+└────────────────────────┘
+```

src/CMakeLists.txt

@@ -436,6 +436,10 @@ dbms_target_link_libraries(PRIVATE ch_contrib::zstd)
 target_link_libraries (clickhouse_common_io PUBLIC ch_contrib::zstd)
 target_link_libraries (clickhouse_common_io PUBLIC ch_contrib::xz)
 
+if (TARGET ch_contrib::pocketfft)
+    target_link_libraries(clickhouse_common_io PUBLIC ch_contrib::pocketfft)
+endif ()
+
 if (TARGET ch_contrib::icu)
     dbms_target_link_libraries (PRIVATE ch_contrib::icu)
 endif ()

src/Common/config.h.in

@@ -61,6 +61,7 @@
 #cmakedefine01 FIU_ENABLE
 #cmakedefine01 USE_BCRYPT
 #cmakedefine01 USE_LIBARCHIVE
+#cmakedefine01 USE_POCKETFFT
 
 /// This is needed for .incbin in assembly. For some reason, include paths don't work there in presence of LTO.
 /// That's why we use absolute paths.

src/Functions/CMakeLists.txt

@@ -95,6 +95,10 @@ if (TARGET ch_contrib::rapidjson)
     list (APPEND PRIVATE_LIBS ch_contrib::rapidjson)
 endif()
 
+if (TARGET ch_contrib::pocketfft)
+    list (APPEND PRIVATE_LIBS ch_contrib::pocketfft)
+endif()
+
 if (TARGET ch_contrib::crc32-vpmsum)
     list (APPEND PUBLIC_LIBS ch_contrib::crc32-vpmsum)
 endif()

src/Functions/seriesPeriodDetectFFT.cpp

@@ -0,0 +1,164 @@
+#include "config.h"
+
+#if USE_POCKETFFT
+#    ifdef __clang__
+#        pragma clang diagnostic push
+#        pragma clang diagnostic ignored "-Wshadow"
+#        pragma clang diagnostic ignored "-Wextra-semi-stmt"
+#        pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
+#    endif
+
+#    include <pocketfft_hdronly.h>
+
+#    ifdef __clang__
+#        pragma clang diagnostic pop
+#    endif
+
+#    include <cmath>
+#    include <Columns/ColumnArray.h>
+#    include <Columns/ColumnsNumber.h>
+#    include <DataTypes/DataTypeArray.h>
+#    include <DataTypes/DataTypesNumber.h>
+#    include <Functions/FunctionFactory.h>
+#    include <Functions/FunctionHelpers.h>
+#    include <Functions/IFunction.h>
+
+
+namespace DB
+{
+namespace ErrorCodes
+{
+extern const int BAD_ARGUMENTS;
+extern const int ILLEGAL_COLUMN;
+}
+
+/*Detect Period in time series data using FFT.
+ * FFT - Fast Fourier transform (https://en.wikipedia.org/wiki/Fast_Fourier_transform)
+ * 1. Convert time series data to frequency domain using FFT.
+ * 2. Remove the 0th(the Dc component) and n/2th the Nyquist frequency
+ * 3. Find the peak value (highest) for dominant frequency component.
+ * 4. Inverse of the dominant frequency component is the period.
+*/
+
+class FunctionSeriesPeriodDetectFFT : public IFunction
+{
+public:
+    static constexpr auto name = "seriesPeriodDetectFFT";
+
+    static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionSeriesPeriodDetectFFT>(); }
+
+    std::string getName() const override { return name; }
+
+    size_t getNumberOfArguments() const override { return 1; }
+
+    bool useDefaultImplementationForConstants() const override { return true; }
+
+    bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
+
+    DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
+    {
+        FunctionArgumentDescriptors args{{"time_series", &isArray<IDataType>, nullptr, "Array"}};
+        validateFunctionArgumentTypes(*this, arguments, args);
+
+        return std::make_shared<DataTypeFloat64>();
+    }
+
+    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t) const override
+    {
+        ColumnPtr array_ptr = arguments[0].column;
+        const ColumnArray * array = checkAndGetColumn<ColumnArray>(array_ptr.get());
+
+        const IColumn & src_data = array->getData();
+
+        auto res = ColumnFloat64::create(1);
+        auto & res_data = res->getData();
+
+        Float64 period;
+
+        if (executeNumber<UInt8>(src_data, period) || executeNumber<UInt16>(src_data, period) || executeNumber<UInt32>(src_data, period)
+            || executeNumber<UInt64>(src_data, period) || executeNumber<Int8>(src_data, period) || executeNumber<Int16>(src_data, period)
+            || executeNumber<Int32>(src_data, period) || executeNumber<Int64>(src_data, period) || executeNumber<Float32>(src_data, period)
+            || executeNumber<Float64>(src_data, period))
+        {
+            res_data[0] = period;
+            return res;
+        }
+        else
+            throw Exception(
+                ErrorCodes::ILLEGAL_COLUMN,
+                "Illegal column {} of first argument of function {}",
+                arguments[0].column->getName(),
+                getName());
+    }
+
+    template <typename T>
+    bool executeNumber(const IColumn & src_data, Float64 & period) const
+    {
+        const ColumnVector<T> * src_data_concrete = checkAndGetColumn<ColumnVector<T>>(&src_data);
+        if (!src_data_concrete)
+            return false;
+
+        const PaddedPODArray<T> & src_vec = src_data_concrete->getData();
+
+        size_t len = src_vec.size();
+        if (len < 4)
+            throw Exception(ErrorCodes::BAD_ARGUMENTS, "At least four data points are needed for function {}", getName());
+
+        std::vector<Float64> src(src_vec.begin(), src_vec.end());
+        std::vector<std::complex<double>> out((len / 2) + 1);
+
+        pocketfft::shape_t shape{len};
+
+        pocketfft::shape_t axes;
+        axes.reserve(shape.size());
+        for (size_t i = 0; i < shape.size(); ++i)
+            axes.push_back(i);
+
+        pocketfft::stride_t stride_src{sizeof(double)};
+        pocketfft::stride_t stride_out{sizeof(std::complex<double>)};
+
+        pocketfft::r2c(shape, stride_src, stride_out, axes, pocketfft::FORWARD, src.data(), out.data(), static_cast<double>(1));
+
+        size_t spec_len = (len - 1) / 2; //removing the nyquist element when len is even
+
+        double max_mag = 0;
+        size_t idx = 1;
+        for (size_t i = 1; i < spec_len; ++i)
+        {
+            double magnitude = sqrt(out[i].real() * out[i].real() + out[i].imag() * out[i].imag());
+            if (magnitude > max_mag)
+            {
+                max_mag = magnitude;
+                idx = i;
+            }
+        }
+
+        // In case all FFT values are zero, it means the input signal is flat.
+        // It implies the period of the series should be 0.
+        if (max_mag == 0)
+        {
+            period = 0;
+            return true;
+        }
+
+        std::vector<double> xfreq(spec_len);
+        double step = 0.5 / (spec_len - 1);
+        for (size_t i = 0; i < spec_len; ++i)
+            xfreq[i] = i * step;
+
+        auto freq = xfreq[idx];
+
+        period = std::round(1 / freq);
+        return true;
+    }
+};
+
+REGISTER_FUNCTION(SeriesPeriodDetectFFT)
+{
+    factory.registerFunction<FunctionSeriesPeriodDetectFFT>(FunctionDocumentation{
+        .description = R"(
+Detects period in time series data using FFT.)",
+        .categories{"Time series analysis"}});
+}
+}
+#endif

src/configure_config.cmake

@@ -166,5 +166,8 @@ endif()
 if (TARGET ch_contrib::libarchive)
     set(USE_LIBARCHIVE 1)
 endif()
+if (TARGET ch_contrib::pocketfft)
+    set(USE_POCKETFFT 1)
+endif()
 
 set(SOURCE_DIR ${PROJECT_SOURCE_DIR})

tests/queries/0_stateless/02813_series_period_detect.reference

@@ -0,0 +1,5 @@
+14
+3
+3
+3
+0

tests/queries/0_stateless/02813_series_period_detect.sql

@@ -0,0 +1,12 @@
+-- Tags: no-fasttest
+
+SELECT seriesPeriodDetectFFT([139, 87, 110, 68, 54, 50, 51, 53, 133, 86, 141, 97, 156, 94, 149, 95, 140, 77, 61, 50, 54, 47, 133, 72, 152, 94, 148, 105, 162, 101, 160, 87, 63, 53, 55, 54, 151, 103, 189, 108, 183, 113, 175, 113, 178, 90, 71, 62, 62, 65, 165, 109, 181, 115, 182, 121, 178, 114, 170]);
+SELECT seriesPeriodDetectFFT([10,20,30,10,20,30,10,20,30, 10,20,30,10,20,30,10,20,30,10,20,30]);
+SELECT seriesPeriodDetectFFT([10.1, 20.45, 40.34, 10.1, 20.45, 40.34,10.1, 20.45, 40.34,10.1, 20.45, 40.34,10.1, 20.45, 40.34,10.1, 20.45, 40.34,10.1, 20.45, 40.34, 10.1, 20.45, 40.34]);
+SELECT seriesPeriodDetectFFT([10.1, 10, 400, 10.1, 10, 400, 10.1, 10, 400,10.1, 10, 400,10.1, 10, 400,10.1, 10, 400,10.1, 10, 400,10.1, 10, 400]);
+SELECT seriesPeriodDetectFFT([2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2]);
+SELECT seriesPeriodDetectFFT([1,2,3]);  -- { serverError BAD_ARGUMENTS}
+SELECT seriesPeriodDetectFFT(); --{ serverError NUMBER_OF_ARGUMENTS_DOESNT_MATCH}
+SELECT seriesPeriodDetectFFT([]); -- { serverError ILLEGAL_COLUMN}
+SELECT seriesPeriodDetectFFT([NULL, NULL, NULL]); -- { serverError ILLEGAL_COLUMN}
+SELECT seriesPeriodDetectFFT([10,20,30,10,202,30,NULL]); -- { serverError ILLEGAL_COLUMN }

utils/check-style/aspell-ignore/en/aspell-dict.txt

@@ -2231,6 +2231,7 @@ seektable
 sequenceCount
 sequenceMatch
 sequenceNextNode
+seriesPeriodDetectFFT
 serverTimeZone
 serverTimezone
 serverUUID