mercurial/revlog.py

47392:8089d0fa8400

    `concurrencychecker` is an optional function that receives 3 arguments: a
    file handle, a filename, and an expected position. It should check whether
    the current position in the file handle is valid, and log/warn/fail (by
    raising).


    Internal details
    ----------------

    A large part of the revlog logic deals with revisions' "index entries", tuple
    objects that contains the same "items" whatever the revlog version.
    Different versions will have different ways of storing these items (sometimes
    not having them at all), but the tuple will always be the same. New fields
    are usually added at the end to avoid breaking existing code that relies
    on the existing order. The field are defined as follows:

    [0] offset:
            The byte index of the start of revision data chunk.
            That value is shifted up by 16 bits. use "offset = field >> 16" to
            retrieve it.

        flags:
            A flag field that carries special information or changes the behavior
            of the revision. (see `REVIDX_*` constants for details)
            The flag field only occupies the first 16 bits of this field,
            use "flags = field & 0xFFFF" to retrieve the value.

    [1] compressed length:
            The size, in bytes, of the chunk on disk

    [2] uncompressed length:
            The size, in bytes, of the full revision once reconstructed.

    [3] base rev:
            Either the base of the revision delta chain (without general
            delta), or the base of the delta (stored in the data chunk)
            with general delta.

    [4] link rev:
            Changelog revision number of the changeset introducing this
            revision.

    [5] parent 1 rev:
            Revision number of the first parent

    [6] parent 2 rev:
            Revision number of the second parent

    [7] node id:
            The node id of the current revision

    [8] sidedata offset:
            The byte index of the start of the revision's side-data chunk.

    [9] sidedata chunk length:
            The size, in bytes, of the revision's side-data chunk.

    [10] data compression mode:
            two bits that detail the way the data chunk is compressed on disk.
            (see "COMP_MODE_*" constants for details). For revlog version 0 and
            1 this will always be COMP_MODE_INLINE.

    [11] side-data compression mode:
            two bits that detail the way the sidedata chunk is compressed on disk.
            (see "COMP_MODE_*" constants for details)
    """

    _flagserrorclass = error.RevlogError

    def __init__(

47393:7a0ec25d5836

    `concurrencychecker` is an optional function that receives 3 arguments: a
    file handle, a filename, and an expected position. It should check whether
    the current position in the file handle is valid, and log/warn/fail (by
    raising).

    See mercurial/revlogutils/contants.py for details about the content of an
    index entry.
    """

    _flagserrorclass = error.RevlogError

    def __init__(