x64

sn_utils.cpp

@@ -0,0 +1,72 @@
+#include "stdafx.h"
+#include "sn_utils.h"
+
+// sanity checks
+static_assert(std::numeric_limits<double>::is_iec559, "IEEE754 required");
+static_assert(sizeof(float) == 4, "Float must be 4 bytes");
+static_assert(sizeof(double) == 8, "Double must be 8 bytes");
+static_assert(-1 == ~0, "Two's complement required");
+
+// deserialize little endian uint16
+uint16_t sn_utils::ld_uint16(std::istream &s)
+{
+	uint8_t buf[2];
+	s.read((char*)buf, 2);
+	uint16_t v = (buf[1] << 8) | buf[0];
+	return reinterpret_cast<uint16_t&>(v);
+}
+
+// deserialize little endian uint32
+uint32_t sn_utils::ld_uint32(std::istream &s)
+{
+	uint8_t buf[4];
+	s.read((char*)buf, 4);
+	uint32_t v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+	return reinterpret_cast<uint32_t&>(v);
+}
+
+// deserialize little endian int32
+int32_t sn_utils::ld_int32(std::istream &s)
+{
+	uint8_t buf[4];
+	s.read((char*)buf, 4);
+	uint32_t v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+	return reinterpret_cast<int32_t&>(v);
+}
+
+// deserialize little endian ieee754 float32
+float sn_utils::ld_float32(std::istream &s)
+{
+	uint8_t buf[4];
+	s.read((char*)buf, 4);
+	uint32_t v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+	return reinterpret_cast<float&>(v);
+}
+
+// deserialize little endian ieee754 float64
+double sn_utils::ld_float64(std::istream &s)
+{
+	uint8_t buf[8];
+	s.read((char*)buf, 8);
+	uint64_t v = ((uint64_t)buf[7] << 56) | ((uint64_t)buf[6] << 48) |
+		         ((uint64_t)buf[5] << 40) | ((uint64_t)buf[4] << 32) |
+	             ((uint64_t)buf[3] << 24) | ((uint64_t)buf[2] << 16) |
+		         ((uint64_t)buf[1] << 8) | (uint64_t)buf[0];
+	return reinterpret_cast<double&>(v);
+}
+
+// deserialize null-terminated string
+std::string sn_utils::d_str(std::istream &s)
+{
+	std::string r;
+	r.reserve(32);
+	char buf[1];
+	while (true)
+	{
+		s.read(buf, 1);
+		if (buf[0] == 0)
+			break;
+		r.push_back(buf[0]);
+	}
+	return r;
+}