From 5d6d60e5c4cbc4f133602733ab1dc3886a976b66 Mon Sep 17 00:00:00 2001
From: Avril <flanchan@cumallover.me>
Date: Thu, 26 Nov 2020 20:30:05 +0000
Subject: [PATCH] in-place un/shuffling works

---
 lean/Makefile            |  2 +-
 lean/include/map.h       |  4 +++
 lean/include/shuffle.hpp | 36 +++++++++++++++++++
 lean/src/main.c          |  8 +++--
 lean/src/map.c           |  4 +--
 lean/src/work.cpp        | 75 +++++++++++++++++++++++++++++++++++++++-
 6 files changed, 123 insertions(+), 6 deletions(-)
 create mode 100644 lean/include/shuffle.hpp

diff --git a/lean/Makefile b/lean/Makefile
index 1c81948..11b9bdc 100644
--- a/lean/Makefile
+++ b/lean/Makefile
@@ -16,7 +16,7 @@ CXX_OPT_FLAGS?= $(OPT_FLAGS) -felide-constructors
 
 CFLAGS   += $(COMMON_FLAGS) --std=gnu11
 CXXFLAGS += $(COMMON_FLAGS) --std=gnu++20 -fno-exceptions
-LDFLAGS  += 
+LDFLAGS  += -lfmt 
 
 RELEASE_CFLAGS?=   -O3 -flto $(OPT_FLAGS)
 RELEASE_CXXFLAGS?= -O3 -flto $(CXX_OPT_FLAGS)
diff --git a/lean/include/map.h b/lean/include/map.h
index 244be43..307481a 100644
--- a/lean/include/map.h
+++ b/lean/include/map.h
@@ -24,6 +24,7 @@ void* map_and_then(const char* file, map_cb callback, void* user);
 #ifdef __cplusplus
 }
 #include <panic.h>
+#include "reinterpret.h"
 #include <cstdint>
 namespace mm {
 	struct mmap {
@@ -52,6 +53,9 @@ namespace mm {
 			}
 		}
 
+		inline const span<const unsigned char> as_span() const { return span(as_ptr(), size()); }
+		inline span<unsigned char> as_span() { return span(as_ptr(), size()); }
+
 		inline const std::uint8_t* as_ptr() const { return (const std::uint8_t*)inner.ptr; }
 		inline std::uint8_t* as_ptr() { return (std::uint8_t*)inner.ptr; }
 
diff --git a/lean/include/shuffle.hpp b/lean/include/shuffle.hpp
new file mode 100644
index 0000000..f56724f
--- /dev/null
+++ b/lean/include/shuffle.hpp
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <rng.h>
+#include <reinterpret.h>
+#include <algorithm>
+#include <fmt/format.h>
+
+namespace rng {
+	template<typename T, typename R>
+	inline void shuffle(R& rng, span<T> span)
+	{
+		fmt::print(" -> shuffling {} objects...", span.size());
+		for(std::size_t i=span.size()-1;i>0;i--)
+		{
+			auto j = rng.next_long(i);
+			std::swap(span[i], span[j]);
+		}
+		fmt::print(" OK\n");
+	}
+
+	template<typename T, typename R>
+	inline void unshuffle(R& rng, span<T> span)
+	{
+		std::vector<std::size_t> rng_values;
+
+		fmt::print(" -> unshuffling {} objects...", span.size());
+		for(std::size_t i=span.size()-1;i>0;i--)
+			rng_values.push_back(rng.next_long(i));
+
+		for(std::size_t i=1;i<span.size();i++) {
+			std::swap(span[i], span[rng_values.back()]);
+			rng_values.pop_back();
+		}
+		fmt::print(" OK\n");
+	}
+}
diff --git a/lean/src/main.c b/lean/src/main.c
index 94b8681..ae7e57f 100644
--- a/lean/src/main.c
+++ b/lean/src/main.c
@@ -45,14 +45,18 @@ int main(int argc, char** argv)
 {
 	struct prog_args args = {.argc = argc, .argv = argv};
 	
-	rng_test();
+	//rng_test();
 	
 	rng_t r = rng_new(RNG_INIT(RNG_KIND_FRNG, frng = { { 1.0, 2.0 } }));
 	rng_test_spec(r);
 	rng_free(r);
 
 	if( argv[1] ) {
-		map_and_then(argv[1], &map_callback, &args);
+		//map_and_then(argv[1], &map_callback, &args);
+		return do_work((work_args_t) {
+				.op = OP_SHUFFLE_IP,
+				.data.op_shuffle_ip.file = argv[1],
+				});
 	}
 
 	return 0;
diff --git a/lean/src/map.c b/lean/src/map.c
index 4020937..2a245af 100644
--- a/lean/src/map.c
+++ b/lean/src/map.c
@@ -16,7 +16,7 @@ int open_and_map(const char* file, mmap_t* restrict ptr)
 {
 	int fd;
 	struct stat st;
-	if ((fd = open(file, O_RDONLY, FILEMODE)) < 0) {
+	if ((fd = open(file, O_RDWR, FILEMODE)) < 0) {
 		perror("Failed to open file");
 		return 0;
 	}
@@ -29,7 +29,7 @@ int open_and_map(const char* file, mmap_t* restrict ptr)
 
 	register struct mmap map = { .fd = fd, .ptr = NULL, .len = st.st_size };
 
-	if ((map.ptr = mmap(NULL, map.len, PROT_READ, MAP_SHARED,fd, 0)) == MAP_FAILED) {
+	if ((map.ptr = mmap(NULL, map.len, PROT_READ | PROT_WRITE, MAP_SHARED,fd, 0)) == MAP_FAILED) {
 		perror("mmap() failed");
 		close(fd);
 		return 0;
diff --git a/lean/src/work.cpp b/lean/src/work.cpp
index e50a670..4e7a440 100644
--- a/lean/src/work.cpp
+++ b/lean/src/work.cpp
@@ -1,6 +1,42 @@
+#include <tuple>
+#include <functional>
+#include <cfloat>
+
+#include <fmt/format.h>
+
 #include <shuffle3.h>
-#include <work.h>
 #include <panic.h>
+#include <map.h>
+#include <reinterpret.h>
+#include <shuffle.hpp>
+
+#include <work.h>
+
+template<typename T, typename Fn>
+std::tuple<T, T> minmax_t(const span<T>& array, Fn keep)
+{
+	T lowest;
+	T highest;
+	for(std::size_t i=0;i<array.size();i++)
+	{
+		if(!keep(array[i])) continue;
+
+		if(!i) lowest = highest = array[i];
+		else {
+			auto item = array[i];
+			if(item < lowest) lowest = item;
+			if(item > highest) highest = item;
+		}
+	}
+	fmt::print("MMX {}, {}\n", lowest, highest);
+	return {lowest, highest};
+}
+
+template<typename T>
+inline std::tuple<T, T> minmax_t(const span<T>& array)
+{
+	return minmax_t(array, [](T _val) { return true; });
+}
 
 namespace work
 {
@@ -8,6 +44,35 @@ namespace work
 	template<bool unshuffle>
 	int xshuffle_ip(const char* file)
 	{
+		mm::mmap map(file);
+
+		if constexpr(unshuffle)
+		{
+			auto [byte_l, byte_h] = minmax_t(map.as_span().reinterpret<std::int8_t>());
+			rng::drng		drng((std::int32_t) ((0xfffa << 16) | (byte_l<<7) | byte_h ));
+			rng::unshuffle(drng,  map.as_span());
+
+			auto [float_l, float_h] = minmax_t(map.as_span().reinterpret<float>(), [](float f) -> bool { return !( (f!=f) || f < -FLT_MAX || f > FLT_MAX); });
+			rng::frng		frng(float_l, float_h);
+			rng::unshuffle(frng,  map.as_span().reinterpret<float>());
+
+			auto [long_l, long_h] = minmax_t(map.as_span().reinterpret<std::int64_t>());
+			rng::xoroshiro128plus	xorng(*(const std::uint64_t*)&long_l, *(const std::uint64_t*)&long_h);
+			rng::unshuffle(xorng, map.as_span().reinterpret<std::int64_t>());
+		} else {
+			auto [long_l, long_h] = minmax_t(map.as_span().reinterpret<std::int64_t>());
+			rng::xoroshiro128plus	xorng(*(const std::uint64_t*)&long_l, *(const std::uint64_t*)&long_h);
+			rng::shuffle(xorng, map.as_span().reinterpret<std::int64_t>());
+
+			auto [float_l, float_h] = minmax_t(map.as_span().reinterpret<float>(), [](float f) -> bool { return !( (f!=f) || f < -FLT_MAX || f > FLT_MAX); });
+			rng::frng		frng(float_l, float_h);
+			rng::shuffle(frng,  map.as_span().reinterpret<float>());
+			
+			auto [byte_l, byte_h] = minmax_t(map.as_span().reinterpret<std::int8_t>());
+			rng::drng		drng((std::int32_t) ((0xfffa << 16) | (byte_l<<7) | byte_h ));
+			rng::shuffle(drng,  map.as_span());
+		}
+
 		return 0;
 	}
 
@@ -15,6 +80,14 @@ namespace work
 	template<bool unshuffle>
 	int xshuffle_op(const char* ifile, const char* ofile, bool is_buffered)
 	{
+
+		if constexpr(unshuffle)
+		{
+
+		} else {
+
+		}
+		panic("Unimplemented");
 		return 0;
 	}