From f46b981d06128642fee7e81f83b4ff09bd5f1be8 Mon Sep 17 00:00:00 2001 From: Akshay Date: Wed, 3 Mar 2021 19:11:42 +0530 Subject: implement simple error handling --- src/decode.rs | 37 +++++++++++++++++++++++++++---------- src/encode.rs | 47 ++++++++++++++++++++++++++++++++++------------- src/error.rs | 45 +++++++++++++++++++++++++++++++++++++++++++++ src/lib.rs | 49 +++++++++++++++++++++++++++++++++---------------- 4 files changed, 139 insertions(+), 39 deletions(-) create mode 100644 src/error.rs diff --git a/src/decode.rs b/src/decode.rs index 59dae97..a9abd37 100644 --- a/src/decode.rs +++ b/src/decode.rs @@ -1,15 +1,22 @@ -use std::io::{self, Cursor, Read}; +use std::io::{Cursor, Read}; use bitvec::prelude::*; use byteorder::{LittleEndian, ReadBytesExt}; +use crate::error::{OBIError, OBIResult}; use crate::{FileHeader, Image, ImageInfoHeader}; -pub fn decode_image(obi_data: &mut Cursor>) -> io::Result { +pub fn decode_image(obi_data: &mut Cursor>) -> OBIResult { // file header - let version = obi_data.read_u16::()?; - let file_size = obi_data.read_u32::()?; - let data_offset = obi_data.read_u32::()?; + let version = obi_data + .read_u16::() + .map_err(|_| OBIError::Decode)?; + let file_size = obi_data + .read_u32::() + .map_err(|_| OBIError::Decode)?; + let data_offset = obi_data + .read_u32::() + .map_err(|_| OBIError::Decode)?; let file_header = FileHeader { version, file_size, @@ -17,10 +24,18 @@ pub fn decode_image(obi_data: &mut Cursor>) -> io::Result { }; // image info header - let width = obi_data.read_u32::()?; - let height = obi_data.read_u32::()?; - let compression_type = obi_data.read_u32::()?; - let post_compression_size = obi_data.read_u32::()?; + let width = obi_data + .read_u32::() + .map_err(|_| OBIError::Decode)?; + let height = obi_data + .read_u32::() + .map_err(|_| OBIError::Decode)?; + let compression_type = obi_data + .read_u32::() + .map_err(|_| OBIError::Decode)?; + let post_compression_size = obi_data + .read_u32::() + .map_err(|_| OBIError::Decode)?; let image_info_header = ImageInfoHeader { width, height, @@ -30,7 +45,9 @@ pub fn decode_image(obi_data: &mut Cursor>) -> io::Result { // pixmap data let mut data_bytes = vec![]; - obi_data.read_to_end(&mut data_bytes)?; + obi_data + .read_to_end(&mut data_bytes) + .map_err(|_| OBIError::Decode)?; let data = data_bytes .iter() .map(|&b| { diff --git a/src/encode.rs b/src/encode.rs index e5760a8..a8c58e0 100644 --- a/src/encode.rs +++ b/src/encode.rs @@ -1,34 +1,55 @@ -use std::io; +use std::borrow::Borrow; use bitvec::{prelude::*, vec::BitVec}; use byteorder::{LittleEndian, WriteBytesExt}; +use crate::error::{OBIError, OBIResult}; use crate::Image; -pub fn encode_image(obi_image: Image) -> io::Result> { +pub fn encode_image(obi_image: I) -> OBIResult> +where + I: Borrow, +{ + let obi_image = obi_image.borrow(); let mut obi_data = Vec::with_capacity(obi_image.file_header.file_size as usize); // file header - let file_header = obi_image.file_header; - obi_data.write_u16::(file_header.version)?; - obi_data.write_u32::(file_header.file_size)?; - obi_data.write_u32::(file_header.data_offset)?; + let file_header = &obi_image.file_header; + obi_data + .write_u16::(file_header.version) + .map_err(|_| OBIError::Encode)?; + obi_data + .write_u32::(file_header.file_size) + .map_err(|_| OBIError::Encode)?; + obi_data + .write_u32::(file_header.data_offset) + .map_err(|_| OBIError::Encode)?; // image info header - let image_info_header = obi_image.image_info_header; - obi_data.write_u32::(image_info_header.width)?; - obi_data.write_u32::(image_info_header.height)?; - obi_data.write_u32::(image_info_header.compression_type)?; - obi_data.write_u32::(image_info_header.post_compression_size)?; + let image_info_header = &obi_image.image_info_header; + obi_data + .write_u32::(image_info_header.width) + .map_err(|_| OBIError::Encode)?; + obi_data + .write_u32::(image_info_header.height) + .map_err(|_| OBIError::Encode)?; + obi_data + .write_u32::(image_info_header.compression_type) + .map_err(|_| OBIError::Encode)?; + obi_data + .write_u32::(image_info_header.post_compression_size) + .map_err(|_| OBIError::Encode)?; // pixmap data - let pixmap = obi_image.data; + let pixmap = &obi_image.data; for byte in pixmap.chunks(8) { let mut bv = BitVec::::new(); for &b in byte { bv.push(b); } - obi_data.write_u8(bv.load::())?; + obi_data + .write_u8(bv.load::()) + .map_err(|_| OBIError::Encode)?; } return Ok(obi_data); diff --git a/src/error.rs b/src/error.rs new file mode 100644 index 0000000..8c2f096 --- /dev/null +++ b/src/error.rs @@ -0,0 +1,45 @@ +use std::{error, fmt}; + +pub type OBIResult = Result; + +#[derive(Debug)] +pub enum OBIError { + Encode, + Decode, + Image, +} + +impl fmt::Display for OBIError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + OBIError::Encode => writeln!(f, "Encoding error"), + OBIError::Decode => writeln!(f, "Decoding error"), + OBIError::Image => writeln!(f, "Image manipulation error"), + } + } +} + +impl error::Error for OBIError {} + +#[derive(Debug)] +enum Encode { + Metadata(MetadataError), + ChunkError(u32), +} + +#[derive(Debug)] +enum Decode { + Metadata(MetadataError), + ChunkError(u32), +} + +#[derive(Debug)] +enum MetadataError { + VersionError, + FileSizeError, + DataOffsetError, + WidthError, + HeightError, + CompressionTypeError, + PostCompressionSizeError, +} diff --git a/src/lib.rs b/src/lib.rs index cd7923c..7429101 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,8 +1,13 @@ #![allow(unreachable_patterns)] #![allow(non_snake_case)] -pub mod decode; -pub mod encode; +use std::io; + +mod decode; +mod encode; +pub mod error; + +use crate::error::{OBIError, OBIResult}; #[non_exhaustive] #[derive(Copy, Clone, Debug, PartialEq)] @@ -59,6 +64,7 @@ impl ImageInfoHeader { } #[non_exhaustive] +#[derive(Copy, Clone, Debug, PartialEq)] pub enum CompressionType { RLE, Kosinki, @@ -96,23 +102,34 @@ impl Image { data, } } -} -#[cfg(test)] -mod tests { - use super::*; - use std::mem::size_of; + pub fn width(&self) -> u32 { + self.image_info_header.width + } + + pub fn height(&self) -> u32 { + self.image_info_header.height + } + + fn to_index(&self, x: u32, y: u32) -> usize { + (y * self.width() + x) as usize + } + + pub fn set_pixel(&mut self, x: u32, y: u32, val: bool) -> OBIResult<()> { + if x >= self.width() || y > self.height() { + Err(OBIError::Image) + } else { + let index = self.to_index(x, y); + self.data[index] = val; + Ok(()) + } + } - #[test] - fn size_of_image_info_header() { - let file_header_size = size_of::(); - assert_eq!(16, file_header_size); + pub fn encode(&self) -> OBIResult> { + encode::encode_image(self) } - #[test] - fn encode_decode() { - let img = Image::new(100, 80); - let encoded = encode::encode_image(img).unwrap(); - assert_eq!(encoded.len(), 1026); + pub fn decode(data: &mut io::Cursor>) -> OBIResult { + decode::decode_image(data) } } -- cgit v1.2.3