From da0c73b1fa513f59c0c07061a8a515ccd415338a Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@gmail.com>
Date: Fri, 27 Mar 2020 13:50:42 -0700
Subject: [PATCH] add array convert

---
 src/pvxs/data.h        |   2 +-
 src/pvxs/sharedArray.h |  47 ++++++
 src/sharedarray.cpp    | 374 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 422 insertions(+), 1 deletion(-)

diff --git a/src/pvxs/data.h b/src/pvxs/data.h
index d821656..042b14d 100644
--- a/src/pvxs/data.h
+++ b/src/pvxs/data.h
@@ -105,7 +105,7 @@ struct StoreTransform<shared_array<const E>> {
     }
     static inline
     shared_array<const E> out(const shared_array<const void>& v) {
-        return v.template castTo<const E>();
+        return v.template convertTo<const E>();
     }
 };
 
diff --git a/src/pvxs/sharedArray.h b/src/pvxs/sharedArray.h
index cedd561..2fa0fab 100644
--- a/src/pvxs/sharedArray.h
+++ b/src/pvxs/sharedArray.h
@@ -41,6 +41,11 @@ enum class ArrayType : uint8_t {
 PVXS_API
 std::ostream& operator<<(std::ostream& strm, ArrayType code);
 
+//! Return storage size (aka. sizeof() ) for array element type
+//! @throws std::logic_error for invalid types.
+PVXS_API
+size_t elementSize(ArrayType type);
+
 namespace detail {
 template<typename T>
 struct CaptureCode;
@@ -192,6 +197,14 @@ std::ostream& operator<<(std::ostream& strm, const Limiter&);
 PVXS_API
 void _throw_bad_cast(ArrayType from, ArrayType to);
 
+PVXS_API
+void convertArr(ArrayType dtype,       void *dbase,
+                ArrayType stype, const void *sbase,
+                size_t count);
+
+PVXS_API
+shared_array<void> copyAs(ArrayType dtype, ArrayType stype, const void *sbase, size_t count);
+
 } // namespace detail
 
 /** std::vector-like contigious array of items passed by reference.
@@ -438,6 +451,20 @@ public:
         return shared_array<TO>(this->_data, this->_data.get(), this->_count); // implied cast to void*
     }
 
+    template<typename TO, typename std::enable_if<!std::is_void<TO>{} && (std::is_const<E>{} == std::is_const<TO>{}), int>::type =0>
+    shared_array<TO>
+    convertTo() const {
+        if(detail::CaptureBase<TO>::code==detail::CaptureBase<E>::code) {
+            return castTo<TO>();
+        } else {
+            shared_array<TO> ret(this->_count);
+            detail::convertArr(detail::CaptureBase<TO>::code, (void*)ret._data.get(),
+                               detail::CaptureBase<E>::code, this->_data.get(),
+                               this->_count);
+            return ret;
+        }
+    }
+
     //! Provide options when rendering with std::ostream.
     detail::Limiter format() const {
         return detail::Limiter(this->_data.get(),
@@ -586,6 +613,26 @@ public:
         return *this;
     }
 
+    template<typename TO, typename std::enable_if<!std::is_void<TO>{} && (std::is_const<E>{} == std::is_const<TO>{}), int>::type =0>
+    shared_array<TO>
+    convertTo() const {
+        if(detail::CaptureBase<TO>::code==_type) {
+            return castTo<TO>();
+        } else {
+            shared_array<TO> ret(this->_count);
+            detail::convertArr(detail::CaptureBase<TO>::code, (void*)ret._data.get(),
+                               _type, this->_data.get(),
+                               this->_count);
+            return ret;
+        }
+    }
+
+    template<typename TO, typename std::enable_if<std::is_void<TO>{} && (std::is_const<E>{} == std::is_const<TO>{}), int>::type =0>
+    shared_array<TO>
+    convertTo() const {
+        return castTo<TO>();
+    }
+
     //! Provide options when rendering with std::ostream.
     detail::Limiter format() const {
         return detail::Limiter(this->_data.get(),
diff --git a/src/sharedarray.cpp b/src/sharedarray.cpp
index 183bc5f..11f97e1 100644
--- a/src/sharedarray.cpp
+++ b/src/sharedarray.cpp
@@ -4,8 +4,12 @@
  * in file LICENSE that is included with this distribution.
  */
 
+#include <string.h>
+
+#include <epicsStdlib.h>
 
 #include <pvxs/sharedArray.h>
+#include <pvxs/data.h>
 #include "utilpvt.h"
 
 namespace pvxs {
@@ -34,6 +38,30 @@ std::ostream& operator<<(std::ostream& strm, ArrayType code)
     return strm;
 }
 
+size_t elementSize(ArrayType type)
+{
+    switch(type) {
+#define CASE(CODE, Type) case ArrayType::CODE: return sizeof(Type)
+    CASE(Bool, bool);
+    CASE(UInt8, uint8_t);
+    CASE(UInt16, uint16_t);
+    CASE(UInt32, uint32_t);
+    CASE(UInt64, uint64_t);
+    CASE(Int8, int8_t);
+    CASE(Int16, int16_t);
+    CASE(Int32, int32_t);
+    CASE(Int64, int64_t);
+    CASE(Float32, float);
+    CASE(Float64, double);
+    CASE(String, std::string);
+    CASE(Value, Value);
+#undef CASE
+    case ArrayType::Null:
+        break;
+    }
+    throw std::logic_error("Invalid ArrayType");
+}
+
 namespace detail {
 
 namespace {
@@ -90,6 +118,352 @@ void _throw_bad_cast(ArrayType from, ArrayType to)
     throw std::logic_error(SB()<<"Unable to cast array from "<<from<<" to "<<to);
 }
 
+namespace {
+
+template<typename Src, typename Dest>
+void convertCast(const void *sbase, void *dbase, size_t count)
+{
+    auto S = static_cast<const Src*>(sbase);
+    auto D = static_cast<Dest*>(dbase);
+    for(auto i : range(count))
+        D[i] = S[i];
+}
+
+void printValue(std::string& dest, const bool& src)
+{
+    dest = src ? "true" : "false";
+}
+
+template<typename Src>
+typename std::enable_if<!std::is_same<Src, bool>{}>::type
+printValue(std::string& dest, const Src& src)
+{
+    std::ostringstream strm;
+    strm<<src;
+    // no error check, we only print POD scalar types which are unambigious
+    dest = strm.str();
+}
+
+template<typename Src>
+void convertToStr(const void *sbase, void *dbase, size_t count)
+{
+    auto S = static_cast<const Src*>(sbase);
+    auto D = static_cast<std::string*>(dbase);
+    for(auto i : range(count))
+        printValue(D[i], S[i]);
+}
+
+void parseValue(bool& dest, const std::string& src)
+{
+    if(src=="true")
+        dest = true;
+    else if(src=="false")
+        dest = false;
+    else
+        throw std::runtime_error(SB()<<"Expected \"true\" or \"false\", not \""<<escape(src)<<"\"");
+}
+
+#define CASE(ETYPE, TYPE) \
+void parseValue(TYPE& dest, const std::string& src) { \
+    epics ## ETYPE temp; \
+    if(epicsParse ## ETYPE(src.c_str(), &temp, 0, nullptr)) \
+        throw std::runtime_error(SB()<<"Expected " #TYPE ", not \""<<escape(src)<<"\""); \
+    dest = temp; \
+}
+
+CASE(Int8, int8_t)
+CASE(Int16, int16_t)
+CASE(Int32, int32_t)
+CASE(Int64, int64_t)
+CASE(UInt8, uint8_t)
+CASE(UInt16, uint16_t)
+CASE(UInt32, uint32_t)
+CASE(UInt64, uint64_t)
+
+#undef CASE
+
+#define CASE(ETYPE, TYPE) \
+void parseValue(TYPE& dest, const std::string& src) { \
+    epics ## ETYPE temp; \
+    if(epicsParse ## ETYPE(src.c_str(), &temp, nullptr)) \
+        throw std::runtime_error(SB()<<"Expected " #TYPE ", not \""<<escape(src)<<"\""); \
+    dest = temp; \
+}
+
+CASE(Float32, float)
+CASE(Float64, double)
+
+#undef CASE
+
+template<typename Dest>
+void convertFromStr(const void *sbase, void *dbase, size_t count)
+{
+    auto S = static_cast<const std::string*>(sbase);
+    auto D = static_cast<Dest*>(dbase);
+    for(auto i : range(count))
+        parseValue(D[i], S[i]);
+}
+
+} // namespace
+
+void convertArr(ArrayType dtype,       void *dbase,
+                ArrayType stype, const void *sbase,
+                size_t count)
+{
+    switch (stype) {
+    case ArrayType::Bool:
+        switch(dtype) {
+        case ArrayType::Bool:   memcpy(dbase, sbase, count*sizeof(bool)); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<bool, uint8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<bool, uint16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<bool, uint32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<bool, uint64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<bool, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<bool, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<bool>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Int8:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<int8_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  memcpy(dbase, sbase, count*sizeof(int8_t)); return;
+            // cast sint -> *int always sign extends
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<int8_t, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<int8_t, int32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<int8_t, int64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<int8_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<int8_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<int8_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Int16:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<int16_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<int16_t, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: memcpy(dbase, sbase, count*sizeof(int16_t)); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<int16_t, int32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<int16_t, int64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<int16_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<int16_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<int16_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Int32:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<int32_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<int32_t, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<int32_t, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: memcpy(dbase, sbase, count*sizeof(int32_t)); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<int32_t, int64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<int32_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<int32_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<int32_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Int64:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<int64_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<int64_t, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<int64_t, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<int64_t, int32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: memcpy(dbase, sbase, count*sizeof(int64_t)); return;
+        case ArrayType::Float32:convertCast<int64_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<int64_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<int64_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::UInt8:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<uint8_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  memcpy(dbase, sbase, count*sizeof(uint8_t)); return;
+            //case uint -> *int never sign extends
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<uint8_t, uint16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<uint8_t, uint32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<uint8_t, uint64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<uint8_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<uint8_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<uint8_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::UInt16:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<uint16_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<uint16_t, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: memcpy(dbase, sbase, count*sizeof(uint16_t)); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<uint16_t, uint32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<uint16_t, uint64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<uint16_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<uint16_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<uint16_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::UInt32:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<uint32_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<uint32_t, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<uint32_t, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: memcpy(dbase, sbase, count*sizeof(uint32_t)); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<uint32_t, int64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertCast<uint32_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<uint32_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<uint32_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::UInt64:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<uint64_t, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<uint64_t, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<uint64_t, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<uint64_t, int32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: memcpy(dbase, sbase, count*sizeof(uint64_t)); return;
+        case ArrayType::Float32:convertCast<uint64_t, float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertCast<uint64_t, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<uint64_t>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Float32:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<float, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<float, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<float, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<float, int32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<float, int64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:memcpy(dbase, sbase, count*sizeof(float)); return;
+        case ArrayType::Float64:convertCast<float, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<float>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Float64:
+        switch(dtype) {
+        case ArrayType::Bool:   convertCast<double, bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:
+        case ArrayType::UInt8:  convertCast<double, int8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:
+        case ArrayType::UInt16: convertCast<double, int16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:
+        case ArrayType::UInt32: convertCast<double, int32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:
+        case ArrayType::UInt64: convertCast<double, int64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:memcpy(dbase, sbase, count*sizeof(double)); return;
+        case ArrayType::Float64:convertCast<double, double>(sbase, dbase, count); return;
+        case ArrayType::String: convertToStr<double>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::String:
+        switch(dtype) {
+        case ArrayType::Bool:   convertFromStr<bool>(sbase, dbase, count); return;
+        case ArrayType::Int8:   convertFromStr<int8_t>(sbase, dbase, count); return;
+        case ArrayType::UInt8:  convertFromStr<uint8_t>(sbase, dbase, count); return;
+        case ArrayType::Int16:  convertFromStr<int16_t>(sbase, dbase, count); return;
+        case ArrayType::UInt16: convertFromStr<uint16_t>(sbase, dbase, count); return;
+        case ArrayType::Int32:  convertFromStr<int32_t>(sbase, dbase, count); return;
+        case ArrayType::UInt32: convertFromStr<uint32_t>(sbase, dbase, count); return;
+        case ArrayType::Int64:  convertFromStr<int64_t>(sbase, dbase, count); return;
+        case ArrayType::UInt64: convertFromStr<uint64_t>(sbase, dbase, count); return;
+        case ArrayType::Float32:convertFromStr<float>(sbase, dbase, count); return;
+        case ArrayType::Float64:convertFromStr<double>(sbase, dbase, count); return;
+            break;
+        case ArrayType::String: convertCast<std::string, std::string>(sbase, dbase, count); return;
+        case ArrayType::Value:
+        case ArrayType::Null: break; // no convert
+        }
+        break;
+    case ArrayType::Value:
+    case ArrayType::Null:
+        break;
+    }
+    throw NoConvert();
+}
+
+shared_array<void> copyAs(ArrayType dtype, ArrayType stype, const void *sbase, size_t count)
+{
+    shared_array<void> ret;
+    switch(dtype) {
+#define CASE(CODE, Type) case ArrayType::CODE: ret = shared_array<Type>(count).castTo<void>(); break
+    CASE(Bool, bool);
+    CASE(UInt8, uint8_t);
+    CASE(UInt16, uint16_t);
+    CASE(UInt32, uint32_t);
+    CASE(UInt64, uint64_t);
+    CASE(Int8, int8_t);
+    CASE(Int16, int16_t);
+    CASE(Int32, int32_t);
+    CASE(Int64, int64_t);
+    CASE(Float32, float);
+    CASE(Float64, double);
+    CASE(String, std::string);
+    CASE(Value, Value);
+#undef CASE
+    case ArrayType::Null:
+        break;
+    }
+    if(stype!=ArrayType::Null)
+        convertArr(dtype, ret.data(), stype, sbase, count);
+    return ret;
+}
+
 } // namespace detail
 
 } // namespace pvxs