comparison rust/hg-core/src/revlog/index.rs @ 48458:96ea4db4741b

rhg: fix a crash on non-generaldelta revlogs

Differential Revision: https://phab.mercurial-scm.org/D11882

48457:1fb3615dfce2

pub struct Index {
    bytes: Box<dyn Deref<Target = [u8]> + Send>,
    /// Offsets of starts of index blocks.
    /// Only needed when the index is interleaved with data.
    offsets: Option<Vec<usize>>,
}

impl Index {
    /// Create an index from bytes.
    /// Calculate the start of each entry when is_inline is true.

            // A proper new version should have had a repo/store
            // requirement.
            return Err(HgError::corrupted("unsupported revlog version"));
        }

        if header.format_flags().is_inline() {
            let mut offset: usize = 0;
            let mut offsets = Vec::new();

            while offset + INDEX_ENTRY_SIZE <= bytes.len() {

            if offset == bytes.len() {
                Ok(Self {
                    bytes,
                    offsets: Some(offsets),
                })
            } else {
                Err(HgError::corrupted("unexpected inline revlog length")
                    .into())
            }
        } else {
            Ok(Self {
                bytes,
                offsets: None,
            })
        }
    }

    /// Value of the inline flag.
    pub fn is_inline(&self) -> bool {
        self.offsets.is_some()

    pub fn uncompressed_len(&self) -> usize {
        BigEndian::read_u32(&self.bytes[12..=15]) as usize
    }

    /// Return the revision upon which the data has been derived.
    pub fn base_revision(&self) -> Revision {
        // TODO Maybe return an Option when base_revision == rev?
        //      Requires to add rev to IndexEntry

        BigEndian::read_i32(&self.bytes[16..])
    }

        is_general_delta: bool,
        version: u16,
        offset: usize,
        compressed_len: usize,
        uncompressed_len: usize,
        base_revision: Revision,
    }

    #[cfg(test)]
    impl IndexEntryBuilder {
        pub fn new() -> Self {

                is_general_delta: true,
                version: 2,
                offset: 0,
                compressed_len: 0,
                uncompressed_len: 0,
                base_revision: 0,
            }
        }

        pub fn is_first(&mut self, value: bool) -> &mut Self {
            self.is_first = value;

        pub fn with_uncompressed_len(&mut self, value: usize) -> &mut Self {
            self.uncompressed_len = value;
            self
        }

        pub fn with_base_revision(&mut self, value: Revision) -> &mut Self {
            self.base_revision = value;
            self
        }

        pub fn build(&self) -> Vec<u8> {
            let mut bytes = Vec::with_capacity(INDEX_ENTRY_SIZE);

                bytes.extend(&(self.offset as u64).to_be_bytes()[2..]);
            }
            bytes.extend(&[0u8; 2]); // Revision flags.
            bytes.extend(&(self.compressed_len as u32).to_be_bytes());
            bytes.extend(&(self.uncompressed_len as u32).to_be_bytes());
            bytes.extend(&self.base_revision.to_be_bytes());
            bytes
        }
    }

    pub fn is_inline(index_bytes: &[u8]) -> bool {

        assert_eq!(entry.uncompressed_len(), 1)
    }

    #[test]
    fn test_base_revision() {
        let bytes = IndexEntryBuilder::new().with_base_revision(1).build();
        let entry = IndexEntry {
            bytes: &bytes,
            offset_override: None,
        };

        assert_eq!(entry.base_revision(), 1)
    }

    #[test]
    fn version_test() {
        let bytes = IndexEntryBuilder::new()

48458:96ea4db4741b

pub struct Index {
    bytes: Box<dyn Deref<Target = [u8]> + Send>,
    /// Offsets of starts of index blocks.
    /// Only needed when the index is interleaved with data.
    offsets: Option<Vec<usize>>,
    uses_generaldelta: bool,
}

impl Index {
    /// Create an index from bytes.
    /// Calculate the start of each entry when is_inline is true.

            // A proper new version should have had a repo/store
            // requirement.
            return Err(HgError::corrupted("unsupported revlog version"));
        }

        // This is only correct because we know version is REVLOGV1.
        // In v2 we always use generaldelta, while in v0 we never use
        // generaldelta. Similar for [is_inline] (it's only used in v1).
        let uses_generaldelta = header.format_flags().uses_generaldelta();

        if header.format_flags().is_inline() {
            let mut offset: usize = 0;
            let mut offsets = Vec::new();

            while offset + INDEX_ENTRY_SIZE <= bytes.len() {

            if offset == bytes.len() {
                Ok(Self {
                    bytes,
                    offsets: Some(offsets),
                    uses_generaldelta,
                })
            } else {
                Err(HgError::corrupted("unexpected inline revlog length")
                    .into())
            }
        } else {
            Ok(Self {
                bytes,
                offsets: None,
                uses_generaldelta,
            })
        }
    }

    pub fn uses_generaldelta(&self) -> bool {
        self.uses_generaldelta
    }

    /// Value of the inline flag.
    pub fn is_inline(&self) -> bool {
        self.offsets.is_some()

    pub fn uncompressed_len(&self) -> usize {
        BigEndian::read_u32(&self.bytes[12..=15]) as usize
    }

    /// Return the revision upon which the data has been derived.
    pub fn base_revision_or_base_of_delta_chain(&self) -> Revision {
        // TODO Maybe return an Option when base_revision == rev?
        //      Requires to add rev to IndexEntry

        BigEndian::read_i32(&self.bytes[16..])
    }

        is_general_delta: bool,
        version: u16,
        offset: usize,
        compressed_len: usize,
        uncompressed_len: usize,
        base_revision_or_base_of_delta_chain: Revision,
    }

    #[cfg(test)]
    impl IndexEntryBuilder {
        pub fn new() -> Self {

                is_general_delta: true,
                version: 2,
                offset: 0,
                compressed_len: 0,
                uncompressed_len: 0,
                base_revision_or_base_of_delta_chain: 0,
            }
        }

        pub fn is_first(&mut self, value: bool) -> &mut Self {
            self.is_first = value;

        pub fn with_uncompressed_len(&mut self, value: usize) -> &mut Self {
            self.uncompressed_len = value;
            self
        }

        pub fn with_base_revision_or_base_of_delta_chain(
            &mut self,
            value: Revision,
        ) -> &mut Self {
            self.base_revision_or_base_of_delta_chain = value;
            self
        }

        pub fn build(&self) -> Vec<u8> {
            let mut bytes = Vec::with_capacity(INDEX_ENTRY_SIZE);

                bytes.extend(&(self.offset as u64).to_be_bytes()[2..]);
            }
            bytes.extend(&[0u8; 2]); // Revision flags.
            bytes.extend(&(self.compressed_len as u32).to_be_bytes());
            bytes.extend(&(self.uncompressed_len as u32).to_be_bytes());
            bytes.extend(
                &self.base_revision_or_base_of_delta_chain.to_be_bytes(),
            );
            bytes
        }
    }

    pub fn is_inline(index_bytes: &[u8]) -> bool {

        assert_eq!(entry.uncompressed_len(), 1)
    }

    #[test]
    fn test_base_revision_or_base_of_delta_chain() {
        let bytes = IndexEntryBuilder::new()
            .with_base_revision_or_base_of_delta_chain(1)
            .build();
        let entry = IndexEntry {
            bytes: &bytes,
            offset_override: None,
        };

        assert_eq!(entry.base_revision_or_base_of_delta_chain(), 1)
    }

    #[test]
    fn version_test() {
        let bytes = IndexEntryBuilder::new()