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