Emily Shaffer <[email protected]> writes:
> +Under the covers, Git is mostly a directed graph of objects. Those objects
> come
> +in four flavors; from root to leaf (generally), those flavors are:
Is "acyclic" worth mentioning, I wonder.
> +
> +- Tag
> +- Commit
> +- Tree
> +- Blob
> +
> +We'll take a closer look in the opposite order, though.
> +
> +# Blob
> +
> +Surprise! It's a file. Well, kind of - it can also be a symlink to a file -
> but
> +this is the most atomic type of object. We'll explore these a little more
> later,
> +but really, it's just a file.
It may be easier to understand if we said it is "just a stream of
bytes". And of course the simplest applciation of a stream of bytes
is to store contents of a file, but it also can be used to store the
value of a symbolic file, and also can be used to store the notes.
So, really, it's just a stream of bytes.
> +A tree references zero or more trees or blobs. Said another way, a tree holds
> +one or more trees or files.
That captures only half of a tree. It is a mapping from names to
objects. Of course, being a mapping, it references other objects
(by the way, do not limit the contents to "trees or blobs") on the
value side of the mapping.
A tree gives names to objects within its scope. It maps names
to objects, typically a blob or a tree. Thus, it can be used
(and it indeed is used) to represent a directory full of files
by storing mapping from filenames to blob objects that store
their contents. A subdirectory can be represented by having a
mapping from its name to the tree object that represents the
contents of the subdirectory.
> This sounds familiar - basically, a tree is a
> +directory. (Okay, or a symlink to a directory.) It points to more trees
No, I do not think it is a symlink to a directory. What makes you
think so?
I'd stop here for now. I am certain that I haven't read enough to
say things either negative or positive about the "naming is hard,
naming used in the canonical documentation of Git is unnecessary
hard to read and we propose a better wording" premise given by the
introduction, so I won't comment on it yet.
Thanks.
