buffer.c File Reference

Functions to read/write raw big endian data. More...

#include <stdlib.h>
#include <string.h>
#include "buffer.h"
#include "debug.h"

Functions
MOBIBuffer *	mobi_buffer_init (const size_t len)
	Initializer for MOBIBuffer structure. More...
MOBIBuffer *	mobi_buffer_init_null (unsigned char *data, const size_t len)
	Initializer for MOBIBuffer structure. More...
void	mobi_buffer_resize (MOBIBuffer *buf, const size_t newlen)
	Resize buffer. More...
void	mobi_buffer_add8 (MOBIBuffer *buf, const uint8_t data)
	Adds 8-bit value to MOBIBuffer. More...
void	mobi_buffer_add16 (MOBIBuffer *buf, const uint16_t data)
	Adds 16-bit value to MOBIBuffer. More...
void	mobi_buffer_add32 (MOBIBuffer *buf, const uint32_t data)
	Adds 32-bit value to MOBIBuffer. More...
void	mobi_buffer_addraw (MOBIBuffer *buf, const unsigned char *data, const size_t len)
	Adds raw data to MOBIBuffer. More...
void	mobi_buffer_addstring (MOBIBuffer *buf, const char *str)
	Adds string to MOBIBuffer without null terminator. More...
void	mobi_buffer_addzeros (MOBIBuffer *buf, const size_t count)
	Adds count of zeroes to MOBIBuffer. More...
uint8_t	mobi_buffer_get8 (MOBIBuffer *buf)
	Reads 8-bit value from MOBIBuffer. More...
uint16_t	mobi_buffer_get16 (MOBIBuffer *buf)
	Reads 16-bit value from MOBIBuffer. More...
uint32_t	mobi_buffer_get32 (MOBIBuffer *buf)
	Reads 32-bit value from MOBIBuffer. More...
uint32_t	mobi_buffer_get_varlen (MOBIBuffer *buf, size_t *len)
	Reads variable length value from MOBIBuffer. More...
uint32_t	mobi_buffer_get_varlen_dec (MOBIBuffer *buf, size_t *len)
	Reads variable length value from MOBIBuffer going backwards. More...
void	mobi_buffer_getstring (char *str, MOBIBuffer *buf, const size_t len)
	Reads raw data from MOBIBuffer and pads it with zero character. More...
void	mobi_buffer_appendstring (char *str, MOBIBuffer *buf, const size_t len)
	Reads raw data from MOBIBuffer, appends it to a string and pads it with zero character. More...
void	mobi_buffer_getraw (void *data, MOBIBuffer *buf, const size_t len)
	Reads raw data from MOBIBuffer. More...
unsigned char *	mobi_buffer_getpointer (MOBIBuffer *buf, const size_t len)
	Get pointer to MOBIBuffer data at offset. More...
void	mobi_buffer_dup8 (uint8_t **val, MOBIBuffer *buf)
	Read 8-bit value from MOBIBuffer into allocated memory. More...
void	mobi_buffer_dup16 (uint16_t **val, MOBIBuffer *buf)
	Read 16-bit value from MOBIBuffer into allocated memory. More...
void	mobi_buffer_dup32 (uint32_t **val, MOBIBuffer *buf)
	Read 32-bit value from MOBIBuffer into allocated memory. More...
void	mobi_buffer_copy8 (MOBIBuffer *dest, MOBIBuffer *source)
	Copy 8-bit value from one MOBIBuffer into another. More...
void	mobi_buffer_copy (MOBIBuffer *dest, MOBIBuffer *source, const size_t len)
	Copy raw value from one MOBIBuffer into another. More...
void	mobi_buffer_move (MOBIBuffer *buf, const int offset, const size_t len)
	Copy raw value within one MOBIBuffer. More...
bool	mobi_buffer_match_magic (MOBIBuffer *buf, const char *magic)
	Check if buffer data header contains magic signature. More...
bool	mobi_buffer_match_magic_offset (MOBIBuffer *buf, const char *magic, const size_t offset)
	Check if buffer contains magic signature at given offset. More...
void	mobi_buffer_seek (MOBIBuffer *buf, const int diff)
	Move current buffer offset by diff bytes. More...
void	mobi_buffer_setpos (MOBIBuffer *buf, const size_t pos)
	Set buffer offset to pos position. More...
void	mobi_buffer_free (MOBIBuffer *buf)
	Free pointer to MOBIBuffer structure and pointer to data. More...
void	mobi_buffer_free_null (MOBIBuffer *buf)
	Free pointer to MOBIBuffer structure. More...

Detailed Description

Functions to read/write raw big endian data.

Copyright (c) 2014 Bartek Fabiszewski http://www.fabiszewski.net

This file is part of libmobi. Licensed under LGPL, either version 3, or any later. See http://www.gnu.org/licenses/

Function Documentation

mobi_buffer_add16()

void mobi_buffer_add16	(	MOBIBuffer *	buf,
		const uint16_t	data
	)

Adds 16-bit value to MOBIBuffer.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	data	Integer to be put into the buffer

mobi_buffer_add32()

void mobi_buffer_add32	(	MOBIBuffer *	buf,
		const uint32_t	data
	)

Adds 32-bit value to MOBIBuffer.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	data	Integer to be put into the buffer

mobi_buffer_add8()

void mobi_buffer_add8	(	MOBIBuffer *	buf,
		const uint8_t	data
	)

Adds 8-bit value to MOBIBuffer.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	data	Integer to be put into the buffer

mobi_buffer_addraw()

void mobi_buffer_addraw	(	MOBIBuffer *	buf,
		const unsigned char *	data,
		const size_t	len
	)

Adds raw data to MOBIBuffer.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	data	Pointer to read data
[in]	len	Size of the read data

mobi_buffer_addstring()

void mobi_buffer_addstring	(	MOBIBuffer *	buf,
		const char *	str
	)

Adds string to MOBIBuffer without null terminator.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	str	Pointer to string

mobi_buffer_addzeros()

void mobi_buffer_addzeros	(	MOBIBuffer *	buf,
		const size_t	count
	)

Adds count of zeroes to MOBIBuffer.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	count	Number of zeroes to be put into the buffer

mobi_buffer_appendstring()

void mobi_buffer_appendstring	(	char *	str,
		MOBIBuffer *	buf,
		const size_t	len
	)

Reads raw data from MOBIBuffer, appends it to a string and pads it with zero character.

Parameters

[in,out]	str	A string to which data will be appended
[in]	buf	MOBIBuffer structure containing data
[in]	len	Length of the data to be read from buffer

mobi_buffer_copy()

void mobi_buffer_copy	(	MOBIBuffer *	dest,
		MOBIBuffer *	source,
		const size_t	len
	)

Copy raw value from one MOBIBuffer into another.

Parameters

[out]	dest	Destination buffer
[in]	source	Source buffer
[in]	len	Number of bytes to copy

mobi_buffer_copy8()

void mobi_buffer_copy8	(	MOBIBuffer *	dest,
		MOBIBuffer *	source
	)

Copy 8-bit value from one MOBIBuffer into another.

Parameters

[out]	dest	Destination buffer
[in]	source	Source buffer

mobi_buffer_dup16()

void mobi_buffer_dup16	(	uint16_t **	val,
		MOBIBuffer *	buf
	)

Read 16-bit value from MOBIBuffer into allocated memory.

Read 16-bit value from buffer into allocated memory. Returns pointer to the value, which must be freed later. If the data is not accessible function will return null pointer.

Parameters

[out]	val	Pointer to value or null pointer on failure
[in]	buf	MOBIBuffer structure containing data

mobi_buffer_dup32()

void mobi_buffer_dup32	(	uint32_t **	val,
		MOBIBuffer *	buf
	)

Read 32-bit value from MOBIBuffer into allocated memory.

Read 32-bit value from buffer into allocated memory. Returns pointer to the value, which must be freed later. If the data is not accessible function will return null pointer.

Parameters

[out]	val	Pointer to value
[in]	buf	MOBIBuffer structure containing data

mobi_buffer_dup8()

void mobi_buffer_dup8	(	uint8_t **	val,
		MOBIBuffer *	buf
	)

Read 8-bit value from MOBIBuffer into allocated memory.

Read 8-bit value from buffer into memory allocated by the function. Returns pointer to the value, which must be freed later. If the data is not accessible function will return null pointer.

Parameters

[out]	val	Pointer to value or null pointer on failure
[in]	buf	MOBIBuffer structure containing data

mobi_buffer_free()

void mobi_buffer_free

(

MOBIBuffer *

buf

)

Free pointer to MOBIBuffer structure and pointer to data.

Free data initialized with mobi_buffer_init();

Parameters

[in]

buf

MOBIBuffer structure

mobi_buffer_free_null()

void mobi_buffer_free_null

(

MOBIBuffer *

buf

)

Free pointer to MOBIBuffer structure.

Free data initialized with mobi_buffer_init_null(); Unlike mobi_buffer_free() it will not free pointer to buf->data

Parameters

[in]

buf

MOBIBuffer structure

mobi_buffer_get16()

uint16_t mobi_buffer_get16

(

MOBIBuffer *

buf

)

Reads 16-bit value from MOBIBuffer.

Parameters

[in]

buf

MOBIBuffer structure containing data

Returns

Read value, 0 if end of buffer is encountered

mobi_buffer_get32()

uint32_t mobi_buffer_get32

(

MOBIBuffer *

buf

)

Reads 32-bit value from MOBIBuffer.

Parameters

[in]

buf

MOBIBuffer structure containing data

Returns

Read value, 0 if end of buffer is encountered

mobi_buffer_get8()

uint8_t mobi_buffer_get8

(

MOBIBuffer *

buf

)

Reads 8-bit value from MOBIBuffer.

Parameters

[in]

buf

MOBIBuffer structure containing data

Returns

Read value, 0 if end of buffer is encountered

mobi_buffer_get_varlen()

uint32_t mobi_buffer_get_varlen	(	MOBIBuffer *	buf,
		size_t *	len
	)

Reads variable length value from MOBIBuffer.

Reads maximum 4 bytes from the buffer. Stops when byte has bit 7 set.

Parameters

[in]	buf	MOBIBuffer structure containing data
[out]	len	Value will be increased by number of bytes read

Returns

Read value, 0 if end of buffer is encountered

mobi_buffer_get_varlen_dec()

uint32_t mobi_buffer_get_varlen_dec	(	MOBIBuffer *	buf,
		size_t *	len
	)

Reads variable length value from MOBIBuffer going backwards.

Reads maximum 4 bytes from the buffer. Stops when byte has bit 7 set.

This function has a limitation. It will not read first byte in a buffer, as it would cause buffer offset to underflow. That means that it cannot read variable length values that are placed at the beginning of a buffer. This will result in an error.

Parameters

[in]	buf	MOBIBuffer structure containing data
[out]	len	Value will be increased by number of bytes read

Returns

Read value, 0 if end of buffer is encountered

mobi_buffer_getpointer()

unsigned char* mobi_buffer_getpointer	(	MOBIBuffer *	buf,
		const size_t	len
	)

Get pointer to MOBIBuffer data at offset.

Parameters

[in]	buf	MOBIBuffer structure containing data
[in]	len	Check if requested length is available in buffer

Returns

Pointer to offset, or NULL on failure

mobi_buffer_getraw()

void mobi_buffer_getraw	(	void *	data,
		MOBIBuffer *	buf,
		const size_t	len
	)

Reads raw data from MOBIBuffer.

Parameters

[out]	data	Destination to which data will be appended
[in]	buf	MOBIBuffer structure containing data
[in]	len	Length of the data to be read from buffer

mobi_buffer_getstring()

void mobi_buffer_getstring	(	char *	str,
		MOBIBuffer *	buf,
		const size_t	len
	)

Reads raw data from MOBIBuffer and pads it with zero character.

Parameters

[out]	str	Destination for string read from buffer. Length must be (len + 1)
[in]	buf	MOBIBuffer structure containing data
[in]	len	Length of the data to be read from buffer

mobi_buffer_init()

MOBIBuffer* mobi_buffer_init

(

const size_t

len

)

Initializer for MOBIBuffer structure.

It allocates memory for structure and for data. Memory should be freed with mobi_buffer_free().

Parameters

[in]

len

Size of data to be allocated for the buffer

Returns

MOBIBuffer on success, NULL otherwise

mobi_buffer_init_null()

MOBIBuffer* mobi_buffer_init_null	(	unsigned char *	data,
		const size_t	len
	)

Initializer for MOBIBuffer structure.

It allocates memory for structure but, unlike mobi_buffer_init(), it does not allocate memory for data. Instead it works on external data. Memory should be freed with mobi_buffer_free_null() (buf->data will not be deallocated).

Parameters

[in,out]	data	Set data as buffer data
[in]	len	Size of data held by the buffer

Returns

MOBIBuffer on success, NULL otherwise

mobi_buffer_match_magic()

bool mobi_buffer_match_magic	(	MOBIBuffer *	buf,
		const char *	magic
	)

Check if buffer data header contains magic signature.

Parameters

[in]	buf	MOBIBuffer buffer containing data
[in]	magic	Magic signature

Returns

boolean true on match, false otherwise

mobi_buffer_match_magic_offset()

bool mobi_buffer_match_magic_offset	(	MOBIBuffer *	buf,
		const char *	magic,
		const size_t	offset
	)

Check if buffer contains magic signature at given offset.

Parameters

[in]	buf	MOBIBuffer buffer containing data
[in]	magic	Magic signature
[in]	offset	Offset

Returns

boolean true on match, false otherwise

mobi_buffer_move()

void mobi_buffer_move	(	MOBIBuffer *	buf,
		const int	offset,
		const size_t	len
	)

Copy raw value within one MOBIBuffer.

Memmove len bytes from offset (relative to current position) to current position in buffer and advance buffer position. Data may overlap.

Parameters

[out]	buf	Buffer
[in]	offset	Offset to read from
[in]	len	Number of bytes to copy

mobi_buffer_resize()

void mobi_buffer_resize	(	MOBIBuffer *	buf,
		const size_t	newlen
	)

Resize buffer.

Smaller size than offset will cause data truncation.

Parameters

[in,out]	buf	MOBIBuffer structure to be filled with data
[in]	newlen	New buffer size

mobi_buffer_seek()

void mobi_buffer_seek	(	MOBIBuffer *	buf,
		const int	diff
	)

Move current buffer offset by diff bytes.

Parameters

[in,out]	buf	MOBIBuffer buffer containing data
[in]	diff	Number of bytes by which the offset is adjusted

mobi_buffer_setpos()

void mobi_buffer_setpos	(	MOBIBuffer *	buf,
		const size_t	pos
	)

Set buffer offset to pos position.

Parameters

[in,out]	buf	MOBIBuffer buffer containing data
[in]	pos	New position