feat: implement block and fields as Struct implementing From trait
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@ -4,141 +4,178 @@
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// TODO : Est-ce qu'on pourrait/devrait définir un type custom pour représenter les tableaux de bytes ?
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use std::convert::TryFrom;
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#[derive(PartialEq, Debug)]
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pub struct ElementSize {
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struct ElementSize {
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pub size: usize,
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pub pad: usize,
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}
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#[derive(PartialEq, Debug)]
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pub enum MemoryParsingError<'a> {
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MemoryIsEmpty(&'a str),
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MemoryIsNotValid(&'a str),
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}
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impl TryFrom<&[u8]> for ElementSize {
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type Error = &'static str;
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pub fn read_element_size(bytes: &[u8]) -> Result<ElementSize, MemoryParsingError> {
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/* Longueur:
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* - si le bit de poids fort du premier octet est à 0, la longueur est codée sur un octet
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* - si le bit de poids fort du premier octet est à 1, les 7 bits de poids faible codent le nombre d'octets utilisés pour coder la longueur
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*/
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if bytes.len() == 0 {
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return Err(MemoryParsingError::MemoryIsEmpty("Empty bytes input"));
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}
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let mut element_size = ElementSize { size: 0, pad: 1 };
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if bytes[0] & 0b1000_0000 == 0 {
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// Size coded on 1 byte
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element_size.size = bytes[0] as usize;
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} else {
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// Size coded on N bytes
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// N are the 7 lower bits of the first byte
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let size_bytes_len = (bytes[0] & 0b0111_1111) as usize;
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if size_bytes_len > bytes.len() - 1 {
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return Err(MemoryParsingError::MemoryIsNotValid(
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"Invalid memory: not enough bytes to read the size",
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));
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} else if size_bytes_len > 4 {
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return Err(MemoryParsingError::MemoryIsNotValid(
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"Invalid memory: size is too big",
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));
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fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
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/* Longueur:
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* - si le bit de poids fort du premier octet est à 0, la longueur est codée sur un octet
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* - si le bit de poids fort du premier octet est à 1, les 7 bits de poids faible codent le nombre d'octets utilisés pour coder la longueur
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*/
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if bytes.len() == 0 {
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return Err("Empty bytes input");
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}
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let size_bytes = &bytes[1..1 + size_bytes_len];
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// u32::from_be_bytes() requires a 4 bytes array
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let mut padded_bytes = [0u8; 4];
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padded_bytes[size_bytes_len..].copy_from_slice(&size_bytes);
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let mut element_size = ElementSize { size: 0, pad: 1 };
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if bytes[0] & 0b1000_0000 == 0 {
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// Size coded on 1 byte
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element_size.size = bytes[0] as usize;
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} else {
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// Size coded on N bytes
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// N are the 7 lower bits of the first byte
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let size_bytes_len = (bytes[0] & 0b0111_1111) as usize;
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if size_bytes_len > bytes.len() - 1 {
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return Err("Invalid memory: not enough bytes to read the size");
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} else if size_bytes_len > 4 {
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return Err("Invalid memory: size is too big");
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}
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let size_bytes = &bytes[1..1 + size_bytes_len];
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element_size.size = u32::from_be_bytes(padded_bytes) as usize;
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element_size.pad += size_bytes_len;
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// u32::from_be_bytes() requires a 4 bytes array
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let mut padded_bytes = [0u8; 4];
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padded_bytes[size_bytes_len..].copy_from_slice(&size_bytes);
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element_size.size = u32::from_be_bytes(padded_bytes) as usize;
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element_size.pad += size_bytes_len;
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}
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Ok(element_size)
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}
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Ok(element_size)
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}
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pub struct Element {
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pub pad: usize,
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pub contenu: Vec<u8>,
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#[derive(Debug)]
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pub struct Block<'a> {
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pub id: u16,
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pub size: usize,
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pub content: Vec<Field<'a>>,
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}
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pub fn read_element(bytes: &[u8]) -> Element {
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let ElementSize { size, pad } = read_element_size(bytes).unwrap();
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let contenu = bytes[pad..pad+size].to_vec();
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Element {
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pad: pad+size,
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contenu,
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impl<'a> From<&'a [u8]> for Block<'a> {
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fn from(bytes: &'a [u8]) -> Self {
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let mut offset = 0;
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let id = u16::from_be_bytes(bytes[..2].try_into().unwrap());
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offset += 2;
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let ElementSize { size: block_size, pad } = bytes[2..].try_into().unwrap();
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offset += pad;
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let raw_content = &bytes[offset..];
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let mut field_offset = 0;
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// While there is still content to read, parse Fields
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let mut content = Vec::new();
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while field_offset < block_size {
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let field: Field<'a> = raw_content[field_offset..].into();
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field_offset += field.size;
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content.push(field);
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}
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Block {
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id,
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size: offset + block_size,
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content,
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}
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}
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}
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#[derive(Debug)]
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pub struct Field<'a> {
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pub size: usize,
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pub content: &'a [u8],
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}
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impl<'a> From<&'a [u8]> for Field<'a> {
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fn from(bytes: &'a [u8]) -> Self {
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let ElementSize { size, pad } = bytes.try_into().unwrap();
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let contenu = &bytes[pad..pad+size];
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Field {
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size: pad+size,
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content: contenu,
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}
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}
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}
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pub fn decode_ssv_memory(bytes: &[u8], size: usize) -> Vec<Block> {
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let mut blocks: Vec<Block> = Vec::new();
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let mut offset = 0;
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while offset < size {
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let block: Block = bytes[offset..].into();
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offset += block.size;
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blocks.push(block);
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}
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blocks
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}
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#[cfg(test)]
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mod test_read_element_size {
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mod test_element_size {
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use super::*;
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#[test]
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fn short_size() {
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let bytes = [0b_0000_0001_u8];
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let element_size = read_element_size(&bytes).unwrap();
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let bytes: &[u8] = &[0b_0000_0001_u8];
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let element_size: ElementSize = bytes.try_into().unwrap();
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assert_eq!(element_size.size, 1);
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assert_eq!(element_size.pad, 1);
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let bytes = [0b_0100_0000_u8];
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let element_size = read_element_size(&bytes).unwrap();
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let bytes: &[u8] = &[0b_0100_0000_u8];
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let element_size: ElementSize = bytes.try_into().unwrap();
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assert_eq!(element_size.size, 64);
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assert_eq!(element_size.pad, 1);
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}
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#[test]
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fn long_size() {
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let bytes = [0b_1000_0010_u8, 0b_0000_0001_u8, 0b_0100_0000_u8];
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let element_size = read_element_size(&bytes).unwrap();
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let bytes: &[u8] = &[0b_1000_0010_u8, 0b_0000_0001_u8, 0b_0100_0000_u8];
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let element_size: ElementSize = bytes.try_into().unwrap();
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assert_eq!(element_size.size, 320);
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assert_eq!(element_size.pad, 3);
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}
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#[test]
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fn null_size() {
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let bytes = [];
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let toto = "toto";
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// Expect an error
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let bytes: &[u8] = &[];
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let result: Result<ElementSize, &str> = bytes.try_into();
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assert_eq!(
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read_element_size(&bytes),
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Err(MemoryParsingError::MemoryIsEmpty("Empty bytes input")),
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result,
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Err("Empty bytes input"),
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);
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}
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#[test]
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fn invalid_memory() {
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let bytes = [0b_1000_0001_u8];
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let bytes: &[u8] = &[0b_1000_0001_u8];
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let result: Result<ElementSize, &str> = bytes.try_into();
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assert_eq!(
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read_element_size(&bytes),
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Err(MemoryParsingError::MemoryIsNotValid(
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"Invalid memory: not enough bytes to read the size"
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)),
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result,
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Err("Invalid memory: not enough bytes to read the size"),
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);
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let bytes = [0b_1000_0010_u8, 1];
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let bytes: &[u8] = &[0b_1000_0010_u8, 1];
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let result: Result<ElementSize, &str> = bytes.try_into();
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assert_eq!(
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read_element_size(&bytes),
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Err(MemoryParsingError::MemoryIsNotValid(
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"Invalid memory: not enough bytes to read the size"
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)),
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result,
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Err("Invalid memory: not enough bytes to read the size"),
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);
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let bytes = [0b_1000_0101_u8, 1, 1, 1, 1, 1];
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let bytes: &[u8] = &[0b_1000_0101_u8, 1, 1, 1, 1, 1];
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let result: Result<ElementSize, &str> = bytes.try_into();
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assert_eq!(
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read_element_size(&bytes),
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Err(MemoryParsingError::MemoryIsNotValid(
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"Invalid memory: size is too big"
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)),
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result,
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Err("Invalid memory: size is too big"),
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);
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}
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}
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#[cfg(test)]
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mod test_read_element {
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mod test_field {
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use super::*;
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#[test]
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fn short_size() {
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let bytes = [51,
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let bytes: &[u8] = &[51,
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1, 48, 1, 56, 11, 57, 57, 55, 48, 48,
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53, 50, 52, 49, 57, 52, 1, 52, 2, 50,
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50, 17, 80, 72, 65, 82, 77, 65, 67, 73,
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@ -146,20 +183,142 @@ mod test_read_element {
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70, 82, 65, 78, 67, 79, 73, 83, 69, 1,
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84,
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];
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let element = read_element(&bytes);
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assert_eq!(element.pad, 52);
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assert_eq!(element.contenu[..5], [1, 48, 1, 56, 11]);
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let element: Field = bytes.try_into().unwrap();
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assert_eq!(element.size, 52);
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assert_eq!(element.content[..5], [1, 48, 1, 56, 11]);
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}
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#[test]
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fn long_size() {
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let mut bytes = vec![0b_1000_0010_u8,
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let mut bytes_vec = vec![0b_1000_0010_u8,
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0b_0000_0001_u8, 0b_0000_0000_u8, // size = 256
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];
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// Add 256 bytes to the content
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bytes.append(&mut vec![1; 256]);
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let element = read_element(&bytes);
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assert_eq!(element.pad, 259);
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assert_eq!(element.contenu.len(), 256);
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bytes_vec.append(&mut vec![1; 256]);
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let bytes: &[u8] = &bytes_vec;
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let element: Field = bytes.try_into().unwrap();
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assert_eq!(element.size, 259);
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assert_eq!(element.content.len(), 256);
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}
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}
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#[cfg(test)]
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mod test_block {
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use super::*;
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#[test]
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fn test_francoise_pharmacien0052419_partial_block_1() {
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let bytes: &[u8] = &[
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1, 48,
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1, 56,
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11, 57, 57, 55, 48, 48, 53, 50, 52, 49, 57, 52,
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];
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let field1: Field = bytes.into();
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assert_eq!(field1.size, 2);
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assert_eq!(field1.content, &[48]);
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let field2: Field = bytes[field1.size..].into();
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assert_eq!(field2.size, 2);
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assert_eq!(field2.content, &[56]);
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let field3: Field = bytes[field1.size + field2.size..].into();
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assert_eq!(field3.size, 12);
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assert_eq!(field3.content, &[57, 57, 55, 48, 48, 53, 50, 52, 49, 57, 52]);
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}
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#[test]
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fn test_francoise_pharmacien0052419() {
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let bytes: &[u8] = &[
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0, 1, 51, // 3
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1, 48, // 2
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1, 56, // 2
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11, 57, 57, 55, 48, 48, 53, 50, 52, 49, 57, 52, // 12
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1, 52, // 2
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2, 50, 50, // 3
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17, 80, 72, 65, 82, 77, 65, 67, 73, 69, 78, 48, 48, 53, 50, 52, 49, 57, // 18
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9, 70, 82, 65, 78, 67, 79, 73, 83, 69, // 10
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1, 84, // 2
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// total: 54
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0, 2, 83,
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1, 1,
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1, 48,
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1, 49,
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2, 56, 54,
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1, 49,
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9, 48, 66, 48, 50, 50, 49, 57, 53, 56,
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1, 56,
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24, 80, 72, 65, 82, 77, 65, 67, 73, 69, 32, 68, 85, 32, 67, 69, 78, 84, 82, 69, 50, 50, 49, 57, 53,
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8, 48, 48, 50, 48, 50, 52, 49, 57,
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1, 56,
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0,
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1, 48,
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1, 49,
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2, 53, 48,
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2, 49, 48,
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2, 48, 48,
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1, 48,
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1, 48,
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1, 48,
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1, 49,
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1, 49,
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];
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let first_block: Block = bytes.into();
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assert_eq!(first_block.id, 1);
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assert_eq!(first_block.size, 54);
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assert_eq!(first_block.content.len(), 8);
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let second_block: Block = bytes[first_block.size..].into();
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assert_eq!(second_block.id, 2);
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assert_eq!(second_block.size, 86);
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assert_eq!(second_block.content.len(), 21);
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}
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}
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#[cfg(test)]
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mod test_decode_ssv_memory {
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use super::*;
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#[test]
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fn test_francoise_pharmacien0052419() {
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let bytes: &[u8] = &[
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0, 1, 51, // 3
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1, 48, // 2
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1, 56, // 2
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11, 57, 57, 55, 48, 48, 53, 50, 52, 49, 57, 52, // 12
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1, 52, // 2
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2, 50, 50, // 3
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17, 80, 72, 65, 82, 77, 65, 67, 73, 69, 78, 48, 48, 53, 50, 52, 49, 57, // 18
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9, 70, 82, 65, 78, 67, 79, 73, 83, 69, // 10
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1, 84, // 2
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// total: 54
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0, 2, 83,
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1, 1,
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1, 48,
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1, 49,
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2, 56, 54,
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1, 49,
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9, 48, 66, 48, 50, 50, 49, 57, 53, 56,
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1, 56,
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24, 80, 72, 65, 82, 77, 65, 67, 73, 69, 32, 68, 85, 32, 67, 69, 78, 84, 82, 69, 50, 50, 49, 57, 53,
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8, 48, 48, 50, 48, 50, 52, 49, 57,
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1, 56,
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0,
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1, 48,
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1, 49,
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2, 53, 48,
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2, 49, 48,
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2, 48, 48,
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1, 48,
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1, 48,
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1, 48,
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1, 49,
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1, 49,
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];
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let blocks = decode_ssv_memory(&bytes, bytes.len());
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assert_eq!(blocks.len(), 2);
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}
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}
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