Actually commit the OGG page crate

Signed-off-by: Serial <69764315+Serial-ATA@users.noreply.github.com>

ogg_pager/.gitignore

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+/target
+Cargo.lock

ogg_pager/Cargo.toml

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+[package]
+name = "ogg_pager"
+version = "0.1.0"
+authors = ["Serial <69764315+Serial-ATA@users.noreply.github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+byteorder = "1.4.3"

ogg_pager/src/crc.rs

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+#[rustfmt::skip]
+const CRC_LOOKUP_ARRAY : &[u32] = &[
+    0x0000_0000, 0x04c1_1db7, 0x0982_3b6e, 0x0d43_26d9,
+    0x1304_76dc, 0x17c5_6b6b, 0x1a86_4db2, 0x1e47_5005,
+    0x2608_edb8, 0x22c9_f00f, 0x2f8a_d6d6, 0x2b4b_cb61,
+    0x350c_9b64, 0x31cd_86d3, 0x3c8e_a00a, 0x384f_bdbd,
+    0x4c11_db70, 0x48d0_c6c7, 0x4593_e01e, 0x4152_fda9,
+    0x5f15_adac, 0x5bd4_b01b, 0x5697_96c2, 0x5256_8b75,
+    0x6a19_36c8, 0x6ed8_2b7f, 0x639b_0da6, 0x675a_1011,
+    0x791d_4014, 0x7ddc_5da3, 0x709f_7b7a, 0x745e_66cd,
+    0x9823_b6e0, 0x9ce2_ab57, 0x91a1_8d8e, 0x9560_9039,
+    0x8b27_c03c, 0x8fe6_dd8b, 0x82a5_fb52, 0x8664_e6e5,
+    0xbe2b_5b58, 0xbaea_46ef, 0xb7a9_6036, 0xb368_7d81,
+    0xad2f_2d84, 0xa9ee_3033, 0xa4ad_16ea, 0xa06c_0b5d,
+    0xd432_6d90, 0xd0f3_7027, 0xddb0_56fe, 0xd971_4b49,
+    0xc736_1b4c, 0xc3f7_06fb, 0xceb4_2022, 0xca75_3d95,
+    0xf23a_8028, 0xf6fb_9d9f, 0xfbb8_bb46, 0xff79_a6f1,
+    0xe13e_f6f4, 0xe5ff_eb43, 0xe8bc_cd9a, 0xec7d_d02d,
+    0x3486_7077, 0x3047_6dc0, 0x3d04_4b19, 0x39c5_56ae,
+    0x2782_06ab, 0x2343_1b1c, 0x2e00_3dc5, 0x2ac1_2072,
+    0x128e_9dcf, 0x164f_8078, 0x1b0c_a6a1, 0x1fcd_bb16,
+    0x018a_eb13, 0x054b_f6a4, 0x0808_d07d, 0x0cc9_cdca,
+    0x7897_ab07, 0x7c56_b6b0, 0x7115_9069, 0x75d4_8dde,
+    0x6b93_dddb, 0x6f52_c06c, 0x6211_e6b5, 0x66d0_fb02,
+    0x5e9f_46bf, 0x5a5e_5b08, 0x571d_7dd1, 0x53dc_6066,
+    0x4d9b_3063, 0x495a_2dd4, 0x4419_0b0d, 0x40d8_16ba,
+    0xaca5_c697, 0xa864_db20, 0xa527_fdf9, 0xa1e6_e04e,
+    0xbfa1_b04b, 0xbb60_adfc, 0xb623_8b25, 0xb2e2_9692,
+    0x8aad_2b2f, 0x8e6c_3698, 0x832f_1041, 0x87ee_0df6,
+    0x99a9_5df3, 0x9d68_4044, 0x902b_669d, 0x94ea_7b2a,
+    0xe0b4_1de7, 0xe475_0050, 0xe936_2689, 0xedf7_3b3e,
+    0xf3b0_6b3b, 0xf771_768c, 0xfa32_5055, 0xfef3_4de2,
+    0xc6bc_f05f, 0xc27d_ede8, 0xcf3e_cb31, 0xcbff_d686,
+    0xd5b8_8683, 0xd179_9b34, 0xdc3a_bded, 0xd8fb_a05a,
+    0x690c_e0ee, 0x6dcd_fd59, 0x608e_db80, 0x644f_c637,
+    0x7a08_9632, 0x7ec9_8b85, 0x738a_ad5c, 0x774b_b0eb,
+    0x4f04_0d56, 0x4bc5_10e1, 0x4686_3638, 0x4247_2b8f,
+    0x5c00_7b8a, 0x58c1_663d, 0x5582_40e4, 0x5143_5d53,
+    0x251d_3b9e, 0x21dc_2629, 0x2c9f_00f0, 0x285e_1d47,
+    0x3619_4d42, 0x32d8_50f5, 0x3f9b_762c, 0x3b5a_6b9b,
+    0x0315_d626, 0x07d4_cb91, 0x0a97_ed48, 0x0e56_f0ff,
+    0x1011_a0fa, 0x14d0_bd4d, 0x1993_9b94, 0x1d52_8623,
+    0xf12f_560e, 0xf5ee_4bb9, 0xf8ad_6d60, 0xfc6c_70d7,
+    0xe22b_20d2, 0xe6ea_3d65, 0xeba9_1bbc, 0xef68_060b,
+    0xd727_bbb6, 0xd3e6_a601, 0xdea5_80d8, 0xda64_9d6f,
+    0xc423_cd6a, 0xc0e2_d0dd, 0xcda1_f604, 0xc960_ebb3,
+    0xbd3e_8d7e, 0xb9ff_90c9, 0xb4bc_b610, 0xb07d_aba7,
+    0xae3a_fba2, 0xaafb_e615, 0xa7b8_c0cc, 0xa379_dd7b,
+    0x9b36_60c6, 0x9ff7_7d71, 0x92b4_5ba8, 0x9675_461f,
+    0x8832_161a, 0x8cf3_0bad, 0x81b0_2d74, 0x8571_30c3,
+    0x5d8a_9099, 0x594b_8d2e, 0x5408_abf7, 0x50c9_b640,
+    0x4e8e_e645, 0x4a4f_fbf2, 0x470c_dd2b, 0x43cd_c09c,
+    0x7b82_7d21, 0x7f43_6096, 0x7200_464f, 0x76c1_5bf8,
+    0x6886_0bfd, 0x6c47_164a, 0x6104_3093, 0x65c5_2d24,
+    0x119b_4be9, 0x155a_565e, 0x1819_7087, 0x1cd8_6d30,
+    0x029f_3d35, 0x065e_2082, 0x0b1d_065b, 0x0fdc_1bec,
+    0x3793_a651, 0x3352_bbe6, 0x3e11_9d3f, 0x3ad0_8088,
+    0x2497_d08d, 0x2056_cd3a, 0x2d15_ebe3, 0x29d4_f654,
+    0xc5a9_2679, 0xc168_3bce, 0xcc2b_1d17, 0xc8ea_00a0,
+    0xd6ad_50a5, 0xd26c_4d12, 0xdf2f_6bcb, 0xdbee_767c,
+    0xe3a1_cbc1, 0xe760_d676, 0xea23_f0af, 0xeee2_ed18,
+    0xf0a5_bd1d, 0xf464_a0aa, 0xf927_8673, 0xfde6_9bc4,
+    0x89b8_fd09, 0x8d79_e0be, 0x803a_c667, 0x84fb_dbd0,
+    0x9abc_8bd5, 0x9e7d_9662, 0x933e_b0bb, 0x97ff_ad0c,
+    0xafb0_10b1, 0xab71_0d06, 0xa632_2bdf, 0xa2f3_3668,
+    0xbcb4_666d, 0xb875_7bda, 0xb536_5d03, 0xb1f7_40b4
+];
+
+pub fn crc32(page: &[u8]) -> u32 {
+    let mut crc: u32 = 0;
+
+    for p in page {
+        crc = (crc << 8) ^ CRC_LOOKUP_ARRAY[(u32::from(*p) ^ (crc >> 24)) as usize];
+    }
+
+    crc
+}

ogg_pager/src/error.rs

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+use std::error::Error;
+use std::fmt;
+
+pub type Result<T> = std::result::Result<T, PageError>;
+
+#[derive(Debug)]
+pub enum PageError {
+    InvalidVersion,
+    BadSegmentCount,
+    MissingMagic,
+    Io(std::io::Error),
+}
+
+impl fmt::Display for PageError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            PageError::InvalidVersion => {
+                write!(f, "Invalid stream structure version (Should always be 0)")
+            }
+            PageError::BadSegmentCount => write!(f, "Page has a segment count < 1"),
+            PageError::MissingMagic => write!(f, "Page is missing a magic signature"),
+            PageError::Io(..) => write!(f, "Encountered an std::io::Error"),
+        }
+    }
+}
+
+impl Error for PageError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match *self {
+            PageError::Io(ref e) => Some(e),
+            _ => None,
+        }
+    }
+}
+
+impl From<std::io::Error> for PageError {
+    fn from(err: std::io::Error) -> PageError {
+        PageError::Io(err)
+    }
+}

ogg_pager/src/lib.rs

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+mod error;
+mod crc;
+
+use std::io::{Read, Seek, SeekFrom};
+
+use byteorder::{LittleEndian, ReadBytesExt};
+
+pub use error::{PageError, Result};
+
+#[derive(Clone)]
+pub struct Page {
+    pub content: Vec<u8>,
+    pub header_type: u8,
+    pub abgp: u64,
+    pub serial: u32,
+    pub seq_num: u32,
+    pub checksum: u32,
+    pub start: usize,
+    pub end: usize,
+}
+
+impl Page {
+    pub fn as_bytes(&self) -> Vec<u8> {
+        let mut bytes = Vec::new();
+        let segments = self.segments();
+        let segment_count = [segments.len() as u8];
+
+        bytes.extend(b"OggS".iter());
+        bytes.extend([0_u8].iter());
+        bytes.extend(self.header_type.to_le_bytes().iter());
+        bytes.extend(self.abgp.to_le_bytes().iter());
+        bytes.extend(self.serial.to_le_bytes().iter());
+        bytes.extend(self.seq_num.to_le_bytes().iter());
+        bytes.extend(self.checksum.to_le_bytes().iter());
+        bytes.extend(segment_count.iter());
+        bytes.extend(segments.iter());
+        bytes.extend(self.content.iter());
+
+        bytes
+    }
+
+    pub fn segments(&self) -> Vec<u8> {
+        let len = self.content.len();
+
+        let mut last_len = (len % 255) as u8;
+        if last_len == 0 {
+            last_len = 255
+        }
+
+        let mut needed = len / 255;
+        if needed != 255 {
+            needed += 1
+        }
+
+        let mut segments = Vec::new();
+
+        for i in 0..needed {
+            if i + 1 < needed {
+                segments.push(255)
+            } else {
+                segments.push(last_len)
+            }
+        }
+
+        segments
+    }
+
+    pub fn read<V>(mut data: V) -> Result<Self>
+    where
+        V: Read + Seek,
+    {
+        let start = data.seek(SeekFrom::Current(0))? as usize;
+
+        let mut sig = [0; 4];
+        data.read_exact(&mut sig)?;
+
+        if &sig != b"OggS" {
+            return Err(PageError::MissingMagic);
+        }
+
+        // Version, always 0
+        let version = data.read_u8()?;
+
+        if version != 0 {
+            return Err(PageError::InvalidVersion);
+        }
+
+        let header_type = data.read_u8()?;
+
+        let abgp = data.read_u64::<LittleEndian>()?;
+        let serial = data.read_u32::<LittleEndian>()?;
+        let seq_num = data.read_u32::<LittleEndian>()?;
+        let checksum = data.read_u32::<LittleEndian>()?;
+
+        let segments = data.read_u8()?;
+
+        if segments < 1 {
+            return Err(PageError::BadSegmentCount);
+        }
+
+        let mut segment_table = vec![0; segments as usize];
+        data.read_exact(&mut segment_table)?;
+
+        let mut content = vec![0; segment_table.iter().map(|&b| b as usize).sum()];
+        data.read_exact(&mut content)?;
+
+        let end = data.seek(SeekFrom::Current(0))? as usize;
+
+        Ok(Page {
+            content,
+            header_type,
+            abgp,
+            serial,
+            seq_num,
+            checksum,
+            start,
+            end,
+        })
+    }
+
+    pub fn gen_crc(&mut self) {
+        self.checksum = crc::crc32(&*self.as_bytes());
+    }
+}