Parse a header from bytes. Returns None if magic/version is invalid.
(data: &[u8])
| 62 | |
| 63 | /// Parse a header from bytes. Returns None if magic/version is invalid. |
| 64 | pub fn from_bytes(data: &[u8]) -> Result<Self, crate::error::ColumnarError> { |
| 65 | if data.len() < HEADER_SIZE { |
| 66 | return Err(crate::error::ColumnarError::TruncatedSegment { |
| 67 | expected: HEADER_SIZE, |
| 68 | got: data.len(), |
| 69 | }); |
| 70 | } |
| 71 | |
| 72 | let mut magic = [0u8; 4]; |
| 73 | magic.copy_from_slice(&data[0..4]); |
| 74 | if magic != MAGIC { |
| 75 | return Err(crate::error::ColumnarError::InvalidMagic(magic)); |
| 76 | } |
| 77 | |
| 78 | let version_major = data[4]; |
| 79 | let version_minor = data[5]; |
| 80 | |
| 81 | // Reject incompatible major version. |
| 82 | if version_major > VERSION_MAJOR { |
| 83 | return Err(crate::error::ColumnarError::IncompatibleVersion { |
| 84 | reader_major: VERSION_MAJOR, |
| 85 | segment_major: version_major, |
| 86 | segment_minor: version_minor, |
| 87 | }); |
| 88 | } |
| 89 | |
| 90 | Ok(Self { |
| 91 | magic, |
| 92 | version_major, |
| 93 | version_minor, |
| 94 | endianness: data[6], |
| 95 | }) |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | /// On-disk representation of a Bloom filter, bundled with the parameters |