Initial community commit

Src/replicant/nu/ByteReader.h

@@ -0,0 +1,83 @@
+#pragma once
+#include <stdint.h>
+#include "foundation/types.h"
+
+/* A simple byte-oriented reader.
+use this instead of manual parsing as this deals with memory alignment issues
+for you.
+memory alignment can be critical and annoying on some architectures (e.g. PowerPC)
+it also handles little-endian/big-endian issues
+
+Usually you just make one of these things on the stack, passing in your buffer and length
+
+S is signed and U is unsigned
+Show functions will give you data w/o moving the stream position
+Align versions of the functions will assume the stream is properly aligned
+LE versions of the functions treat the byte stream as little-endian oriented
+*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+	typedef struct bytereader_struct_t
+	{
+		size_t byte_length;
+		const uint8_t *data_ptr;
+		const void *data;
+	} bytereader_value_t, bytereader_s, *bytereader_t;
+
+	void bytereader_init(bytereader_t byte_reader, const void *data, size_t byte_length);
+	static size_t bytereader_size(bytereader_t byte_reader) /* returns remaining bytes in stream */
+	{
+		return byte_reader->byte_length;
+	}
+	void bytereader_advance(bytereader_t byte_reader, size_t bytes); /* advances the byte stream */
+	void bytereader_reset(bytereader_t byte_reader); /* reset the data pointer and size back to the original position */
+	static const void *bytereader_pointer(bytereader_t byte_reader) /* returns a pointer to the current bitstream position */
+	{
+		return byte_reader->data_ptr;
+	}
+
+	/* returns the number of bytes to the next 0, or the end of the buffer */
+	size_t bytereader_find_zero(bytereader_t byte_reader);
+
+	/* n byte functions (basically memcpy) */
+	void bytereader_show_n(bytereader_t byte_reader, void *destination, size_t bytes);
+	void bytereader_read_n(bytereader_t byte_reader, void *destination, size_t bytes);
+
+	/* 1 byte functions */
+	uint8_t bytereader_show_u8(bytereader_t byte_reader);
+	uint8_t bytereader_read_u8(bytereader_t byte_reader);
+	int8_t bytereader_show_s8(bytereader_t byte_reader);
+	int8_t bytereader_read_s8(bytereader_t byte_reader);
+
+	/* 2 byte little endian functions */
+	uint16_t bytereader_show_u16_le(bytereader_t byte_reader);
+	uint16_t bytereader_read_u16_le(bytereader_t byte_reader);
+	int16_t bytereader_show_s16_le(bytereader_t byte_reader);
+	int16_t bytereader_read_s16_le(bytereader_t byte_reader);
+
+	/* 2 byte big-endian functions */
+	uint16_t bytereader_show_u16_be(bytereader_t byte_reader);
+	uint16_t bytereader_read_u16_be(bytereader_t byte_reader);
+	int16_t bytereader_show_s16_be(bytereader_t byte_reader);
+	int16_t bytereader_read_s16_be(bytereader_t byte_reader);
+
+	/* 4 byte big-endian functions */
+	uint32_t bytereader_show_u32_be(bytereader_t byte_reader);
+	uint32_t bytereader_read_u32_be(bytereader_t byte_reader);
+
+	/* 4 byte little-endian functions */
+	uint32_t bytereader_show_u32_le(bytereader_t byte_reader);
+	uint32_t bytereader_read_u32_le(bytereader_t byte_reader);
+
+	/* float functions */
+	float bytereader_show_f32_be(bytereader_t byte_reader);
+	float bytereader_read_f32_be(bytereader_t byte_reader);
+
+	GUID bytereader_read_uuid_be(bytereader_t byte_reader);
+	GUID bytereader_read_uuid_le(bytereader_t byte_reader);
+#ifdef __cplusplus
+}
+#endif